摘要:

166 PYMAN META-SUBSTITUTED X1X.-Metu-substituted Aromatic Compounds. By FRANK LEE PYMAN. AT the suggestion of Dr. Charles Walker of Sd eizium Glasg ow at tempts were made in 1913 to form the selenium analogue of arsanilic acid, namely p-aminophenylselenic acid NH,*C,H,*Se03H in order to determine its physiological action. Whilst? aniline sulphate and arsenate readily yield sulphanilic acid and arsanilic acid, respectively a t an elevated temperature no similar compound could be obtained from aniline selenate. It was found however, that phenylselenious acid gave on nitration a nitrophenylseleniouj acid which is shown to be the meta-compound in the manner described below. On reducing this compound with sodium hydrogen sulphite di-maitrophenyl diselelzltde resulted and gave di-m-aminophenyl diselenide on further reduction with sodium sulphide.Di-m-aminophenyl diselenide gave on acetylation di-m-acetylaminophemyl cFiselenide from which m-acetylminophenyl-selenious acid was obtained by oxidation with nitric acid. From this the salts of m-acet ylaminophenylselenic acid were obtained on oxidation with potassium permanganate whilst on attempting to liberate the free acid hydrolysis h k place with the formation of m-amino pheny ls e 1 e lzlic acid : NO,*C,H,*SeO,H + (NO,*C,H,-Se) + (NH,*C,H,*Se) -+ (NHAc*C,H,*Se) -+ NHAc*C,H,*SeO,H -+ NHAc*C,H,*SeO,K + NH,*C,H,*SeO,H. When these results were first communicated to the Society (P., 1914 30 302) the orientation of the nitro-group in nitrophenyl-selenious acid had not been determined and in the discussion on the paper Dr.Tuck suggested that the constitution of this acid might be settled by preparing the three isomerides by the acttio AROMATIC SELENIUM COMPOUNDS. 16’7 of the nitrobenzenediazoniu chlorides on potassium selenocyanate and suitable after-treatment. This method had already been applied by Bauer (Ber. 1913 46 92) to the preparation of o-nittro-phenyl selenocyanate and by Morgan and Elliot (P. 1914 30, 248) to the preparation of p-chloi-ophenyl selenmyanate and their derivatives. At the author’s request Mr. H. King has now kindly prepared 712-nitrophenyl selenocyanate from which he has obtained on r e duction with tin and hydrochloric acid di-m-aminophanyl diselenide identical with the product resulting from the reduction of nitrophenylselenious acid thereby proving the constitutdon of the compounds described above.EXPEILIMENTAL. Pheitylseleniws Acid PhSe0,H. The preparation of this acid and its nitrate have been described by Stoecker and Krafft (Bey. 1906 39 2197). Diphenyl diselenide (1 part by weight) was dissolved in concentrated nitric acid (40 parts by weight) and heated. On cooling the well-crystallised nitrate of phenylselenious acid separated. In order to liberab the free acid the nitrate was dissolved in ammonia and mixed with silver nitrate when silver phenylselenite was precipitabed and gave the free acid when decomposed with the equivalent quantity of hydrochloric acid. Doughty (Amer. Chem. J. 1909 41 326) subsequently obtained this acid by the action of hydrochloric acid on phenylselenic acid resulting from the interaction of selenic acid and benzene.He was unable to confirm the previous author’s statement that the acid crystallised with 2H20 finding it t a be anhydrous. For t’he purpose of the present investigation considerable quanti-ties of this acid wete required gnd a modification of Stoecker and Kraff t’s process was adopted. Instead of employing pure diphenyl diselenide the mixture of this substance with selenophenol, obtained by the action of selenium on magnesium phenyl bromide (Taboury Bull. Soc. chinz. 1903 [iii] 29 761) was used. On treating this with 4 c.c.-instead of 30 c.c.-of nitric acid for each gram phenylselenious acid nitrate was readily prepared in quantity. When mixed with sufficient ammonia to neutralise the nitric acid it gave free phenylselenious acid which was found to be practically anhydrous in agreement with Doughty’s observation.To a solution of magnesium phenyl bromide in dry ether pre-pared from 24 grams of magnesium and 157 grams of bromo-1 168 PYMAX META-SUBSTITUTED benzene 79 grams of selenium were added gradually and the mix-ture was boiled for half an hour. The product was decomposed with ice and dilute hydrochloric acid well shaken and the ethereal layer removed the aqueoys layer being extracted with ether twice again The ethereal extracts were colmbined dried with calcium chloride and the solvent was removed on the water-bath. The resulting oil (about 130 grams) was then allowed to flow drop by drop into concentrated nitric acid (D 1.4) of which 4 C.C.were employed for each gram of the oil. The nitric acid solution was then digested for an hour on the water-bath and kept when crude phenylselenious acid nitrate separated in hard crystals. This was collected on asbestos dissolved in water and the solution filtered from insoluble mattes. The solution was then extracted with ether to remove further impurities and evaporated to a syrup. On cooling this set to a chalky mass of the nearly pure nitrate which, after t'horough drying in the air amounted to about 110 grams. The yield is thus 44 per cent of the theoretical. For the preparation of the free acid 10 grams of the nitrate were dissolved i n 20 C.C. of water and 6 C.C. of 10 per cent. aqueous ammonium hydroxide added.On stirring phenylselenious acid separated in sandy yellow grains which were purified by crystallisation from water. 6.5 Grams of the pure acid were isolated without carrying out the separation t o an end whilst 7.6 grams are required theoretically. Phenylselenious acid pre-pared in this way melted a t 124-125O (corr.) after drying a t looo. The air-dried acid was practically anhydrous. (Found loss at 100°=0.4; C=37*6; H=3*3. C,H,-SeO,H requires C=38*0; H=3*2 per cent.) Sodium phenylselenite crystallises from water in colourless plates containing 2H,O. It is readily soluble in water. Found loss a t looo 14.6. Found in anhydrous salt Se= 37.9 37.5." C6H,-Se0,Na,2H,0 (247.2) requires H,O = 14.6 per cent. C,H,*bO,Na requires Se = 37.5 per cent. Salts of Phenylselenic Acid.Stoecker and Krafft (loc. cit.) prepared phenylselenic acid by the oxidation of diphenyl diselenide with moist chlorine Doughty by the method given above (Zoc. cit.). The potassium salt can be obtained conveniently by oxidising phenylselenious acid with * For uls estimation of selenium in the compounds described in this paper Fmrichs'a method (Arch. Pharm. 1902 M 666) was employed AROMATIC SELBNiWM COMPOl?lKDS. 169 potassium permanganate removing -manganese dioxide and evaporating t o low bulk when it ci-ystallises from the solution. Potassium phenylselenaate forms colourless prismatic needles which after being dried in the air sinter from about 50" and melt from 65O to 90° in the water of crystallisation. It is readily soluble in cold and very readily so in hot water.Found loss in a vacuum over H,SO and then a t looo 12.7. C,H,-Se03K,2H,0 (279.4) requires E,O = 12.9 per cent. Found in anhydrous salt Se = 32 * 2. C,H,*SeO,K requires Se = 32-6 per cent. Sodiunz phenylselenat e was prepared from the barium salt which has been described by Doughty (Zoc. cit.) by double decomposition with sodium sulphate. It crystallises from water in long clear, oblong plates which contain 3H20 and is readily soluble in cold, very readily so in hot water. Found in air-dried salt loss at 120°=24.2; Se=26*5. C,H,-Se03Na,4H,0 (299.2) requires H,O = 24.1 ; Se= 26.5 per cent. Jn-Nitl.ophenylselertioiis Acid NO,*Cf,H,*SeO,H. Phenylselenious acid did not yield a nitra-derivative when treated with a mixture of sulphuric and nitric acids a t looo.When subjected to the action of a large excess of fuming nitric acid a t 150° for one hour it gave a 20 per cent. yield of m-nitrophenyl-selenious acid. The best method for the preparation of this acid, hawever was found in the action of nascent nitric acid generated from potassium nitrate. Thirty grams of phenylselenious acid nitrate were dissolved in 30 C.C. of sulphuric acid and the solution was cooled with running water. Twelve grams of finely powdered potassium nitrate were then stirred into the solution which was similarly cooled. The mixture was heated for two hours in the steam-bath and poured into 600 C.C. of water. After keeping for several hours the separated crystals were collected. They amounted tc 17.4 to 18.7 grams of an almost pure product melting a t 155O or slightly lower.~-~itrophenylseZenicrus acid crystallises from wahr in . yellow, prismatic needles which melt a t 156-157O (corr.) after drying a t looo. It is fairly readily soluble in boiling water sparingly so in cold. Found loss a t l0Oo=0*4 ; in dried substance C= 30.8 ; H = 2.2. CGH,O,NSe (234.2) requires C = 30.8 ; H = 2.2 per cent f 70 FYMAN META-SUBSTITUTED m-Nit r o p k en y lselenic A cid NO,* C,H,* Se0,IT. Thirty-five grams of m-nitrophenylselenious acid were dissolved in 600 C.C. of boiling water t o which 20 C.C. of 10 per cent. aqueous potassium hydroxide had been added and mixed with a solution of 16 grams of potassium permanganate in 200 C.C. of hot water. Further small quantities of permanganate were then added until the red colour no longer' quickly vanished.The manganese dioxide was removed by filtration and the solution evaporated to low bulk and cooled when potassium m-nitrophenylselenate crystallised out. After purification by recrystallisation from water 34 grams were obtained. Pofnssium m-nitroph enylselennt e forms hard yellow rosettes of flat needles. It is anhydrous and is readily soluble in hot. but somewhat sparingly so in cold water. It explodes violently a t about 330° (corr.). Found Se - 27.1. C,H,O,NESe (288.3) requires Sc = 27.5 per cent. Bnrizrm m-nitrophenylseltwnte was prepared from the potassium salt by double decomposition with the calculated quantity of barium chloride. It forms colourless leaflets which are fairly readily soluble in hot but sparingly so in cold water.It contains 2H20 which are lost a t 120° but not a t 1 1 0 O . Found in air-dried salt loss a t 120O = 5.6. Ba = 20.2. C,,H80,,N,BaSe,,2H,0 (671.9) requires H,O =5*4 ; Ba = 20.5 per cent. m-Nitrophen?/7se2e?2ic acid was prepared from the barium salt' by the addition of the calculated quantity of sulphuric acid, removal of barium sulphate and evaporation t o a syrup when it cryshllised on keeping in colourless plates containing 2H20. The air-dried acid melts below looo but after drying first in a vacuum over sulphuric acid then att looo it is rendered anhydrous and then melts a t 1 4 6 O (corr.). Found Ioss a t 100°=12*8. 0-2379 dried a t looo required 18.95 C.C. of NI20-NaOH for neutralisation whence equivalent = 251.C,H,0,NSe,2H20 (286.3) requires H,O = 12.7 per cent. C6H,05NS0 requires M.W. = 250.3. Di-rn-nit rophenyl Diselenide (NO,*C,H,*Se),. Twenty-f our grams of m-nitrophenylselenious acid were dissolved in 250 C.C. of boiling water and a saturated solution of sodiu AROMATIC SELENIUM COMPOUNDS. 171 hydrogen sulphite was added so long as a turbidity was produced. After cooling and stirring the oil which had separated became crystalline and was collected and washed with water. The theoretical yield-20.5 grams-was obtained and the product melted a t 79O. After crystallisation from ether this compound formed yellow spears which melted a t 83O (corr.). Found C=35*6; H=2.2. Cl,H80,N,Se2 (402.5) requires C = 35.8 ; H = 2.0 per cent. It is insoluble in water moderately readily soluble in cold alcohol or ether fairly readily so in hot alcohol and easily so in hot ether.I)i-m-aminophen(yI Diselenide (NH2*C,H,-Se),. Fifty grams of di-m-nitrophenyl diselenide were added to a solu-tion of 300 grams of commercial hydrated sodium sulphide in 500 C.C. of 10 per cent!. aqueous sodium hydroxide previously heated to about 60° and the mixture was boiled for one hour under a reflux condenser. One litre of boiling water was then added and an excess of concentrated hydrochloric acid. After digestion for two hours on the steam-bath the separated sulphur was removed by filtration. The filtrate was cooled basified with sodium carbonate and extracted with ether. The ethereal solu-tion was dried with anhydrous potassium carbonate and distilled.The residue was mixed with an excess of 10 per cent. hydrochloric acid when 39.7 grams of di-m-aminophenyl diselenide dihydro-chloride separated in sandy crystals. Di-m-amin o ph enyl disetenide dih y droc hl oride cry st?llises from dilute hydrochloric acid in yellow grains formed of small needles. It melts and decomposes a t 291-292O (corr.). It is readily soluble in hot but sparingly so in cold dilute hydrochloric acid. Found loss a t P O O o = l . l ; in dried salt C=35*3; €€=3*5; Se =37-5 ; C1= 16.8. CI2Hl2N2Se2,2HC1 (415.4) requires C = 34.7 ; H = 3.4 ; Se = 38.1 ; C1=17.1 per cent. Di-m-acet?/laminoyhen?/l Diselenide (CH,*CO*NH*C,H,*Se),. 25.2 Grams of di-m-aminophenyl diselenide dihydrochloride were converted into the base and this was treated with 25 O.C.of acetic anhydride. The clear liquid quickly began to crystallise and soon set to a yellow chalky-mass which was washed well with ether and dried in the air. 19-6 Grams of di-m-acetylaminophenyl diselenid melting a t 180° were thus obtained the yield amounting to 76 p r ce& of the theoretical. For the preparation of this substitnce the previous iaolation of di-m-aminophenyl diselenide as the dihydrochlmide is unnecessary ; thus 91 grams of dim-nitrophenyl diselenide were reduced by the method given previously and the ethereal residue of crude di-m-aminolphenyl diselenide was mixed with 50 C.C. of acetio anhydride and treated as above. The resultJng di-m-acetylaminophenyl diselenide melted a t 179* and amounted t o 76 grams that is 79 per cent.of khe theoretical. Di-mace tylaminophenyl diselenide crystallises from glacial acetic acid in rwettes of short yellow needles which melt a t 185-186O (corr.). It is anhydrous and is insoluble in hot or cold water, almost insoluble in hot or cold ether readily soiluble in hotl alcohol or glacial acetic acid but sparingly so in these solvents when cold. Cl,R,,0,N2Se (426.6) requires C= 45.0 ; H == 3-8 per cent. Found C=45*0; H=4.0. Formcctiom of Di-m-aminopheizyl niselenide b y the Rechiction of rn-Nitrophen y l Sele nocyana t e . m-Nitroaniline (6.9 grams) was diazotised in dilute hydrochloric acid solution a t Oo and after filtering from 1 gram of diazoamino-compound the acidity of the solution to Congo paper was removed by the addition of 10 grams of sodium acetate crystals.Potassium selenocyanate (7.2 grams) dissolved in a little water was added slowly with stirring. There was a brisk evolution of nitrogen accompanied by the separation of a red oil. On washing with water the latter gradually solidified and was dissolved in ether to free it from selenium powder (0.6 gram). The ethereal solution was conmntrated again filt'ered from a small quantity of a viscous red air and finally evaporated t o a syrup which crystallised on stirring. The product consisted of transparent crystals embedded in a small quantity of a deep red gum. The yield of crude m-nitrophenyl selenocyanate was 7.2 grams or 73 per cent. of theory. The crude product (3.4 grams) was dissolved in hot alcohol (50 c.c.) and reduced by boiling for one hour with tin (3.5 grams) and hydrochloric acid (45 c.c.; 32 per cent.).On conmntration under diminished pressure the hot solution deposited an orange yellow granular crystalline stannichloride (5.8 grams). One gram of the stannichloride was dissolved in water and the tin removed as sulphide. The solution on concentration gave tw AROMATIC SELENIUM COMPOUNDS. 173 successive separations of crystalline di-m-aminophenyl diselenide dihydrochloride 0.2 gram and 0.25 gram each melting a t 278-280° (uncorr.). (Found C1= 17.0. Calc. C1= 17.1 per cent .) Di-m-aminophenyl diselenide dihydrochloride obtained by the reduction of di-m-nitrophenyl diselenide melted a t the same temperature as did a mixture of the two. Moreover both form a sparingly soluble primrose-yellow stannochloride crystallising in microscopic needles and a stannichloride which tends to separate as an oil from cold solutions but in granular crystals from hot Solutions.Acetylation of the di-m-aminophenyl diselenide prepared from m-nitrophenyl selenocyanate gave di-nz-acetylaminophenyl di-selenide in short needles which melted a t 183-185O (uncorr.) the acetyl derivative of the reduction productl of di-m-nitrophenyl diselenide melting a t the same temperature whilst a mixture of the two showed no depression of the melting point. m- A ce tyZamimoph.ertyZseE e nious A cid CH,*CO*NH*C,H,* Se0,H. Ten grams of di-m-acetylaminophenyl diselenide were added with stirring in quantities of about 1 gram to 40 C.C. of nitric acid (D 1.4) kept a t - 6 O to -3O.A t first the diselenide dissolved, giving a clear solution but the separation of white crystals soon commenced and increased on the further addition of this substance. The crystals were collected on asbestos washed with concentrated nitric acid and drained on porous porcelain. This substance melted a t 146O and was the nitrate of m-acetylaminophenylselenious acid. After grinding it1 with water filtering and washing with water crude m-acetylaminophenylselenious acid melting a t 201°, remained undissolved. The product a t this stage still contained nitric acid and a portion on boiling with water with the view of recrystallising it readily oixidised. The whole was therefore dis-solved in an excess of hot dilute ammonia (200 c.~.) treated with animal charcoal filtered and acidified with glacial acetic acid.On keeping m-acetylaminophenylselenious acid crystiallised in fine, colourless needles which were collected washed well with water, and dried in the air. The yield amounted to 8.5 grams of the pure acid. in-A ce tytamiizophen ylselert ious acid crystallises from boiling water in short slender colourless needles which begin to turn brown at about ZOOo and melt and decompose a t 209O (corr.). It is sparingly soluble in hot very sparingly so in cold water. Found C=39.5 39.5; H=3.7 3.8. C8H,0,NSe (246.3) requires C = 39.0 ; H = 3.7 per cent. I 174 META-SUBSTITUTED AROMATIC SELENIUM COMPOUKDS. Sodium m-acet ylaminophen ylselenit e crystallises from water in After drying in the air this salt contains It microscopic needles.7H,O of which 4 are lost a t looo and the remainder a t 120O. is fairly readily soluble in cold and easily so in hot water. Found loss a t looo= 18.2 ; loss a t 120"=32-2. CsHSO3NNaSe,7H2O (394.4) requires 4H,O = 18.3 ; 713,O = 32.0 per cent. Salts of m-A cetylaminophe~~lsele~~c Acid, CH,-CO NH=C,H,*SeO,H. Fifty-five grams of m-acetylarninophenylselenious acid were dis-solved in 70 c . ~ . of 10 per cent. ammonia and a litre of hot' water, and mixed with a hot aqueous solution of 26 grams of potassium permanganate. After digestion for a few minutes on the water-bath the slight excess of permanganate was reduced by means of alcohol. The solution was boiled filtered from manganese hydr-oxide and 28.5 grams of barium nitrate were dissolved in it.On evaporating t o a small volume and keeping barium m-acetylamino-pheiiylselenate crystallised out. After recrystallisation from water, 48 grams of the pure salt were obtained. A considerable further quantity was subsequently isolated from the mother liquors. Barium m-acetylaminophenylselenate crystallises from water in hard colourless flat needles containing 4H,O. It is fairly readily soluble in cold very readily so in hot water. Found loss a t 120°=10.1. Found in dried salt Ba=20-8. Sodium m-acet~lamin~phe?~~lse~en~t e was prepared f r am the barium salt by double decomposition with sodium sulphate. It, crystallises from water in colourless woolly needles and from alcohol in prismatic needles in both cases without solvent of crystallisation.It is very readily soluble in water sparingly so in cold alcohol but faJrly readily so in hotl alcohol. @,,H,,0,N2BaSe,,4H,0 (732.0) requires H,O = 9.8 per cent. C,,HIGO,N,BaSe requires Ba = 20.8 per cent. Found Se = 27.9. C,H,O,NNaSe (284.2) requires Se = 27.9 per cent. m-*4 minophenylselenic A cid NH,*C,H,=SeO,H. Forty-five grams of barium m-acetylaminophenylselenate were dissolved in 500 C.C. of boiling water and sufficient sulphuric aci THE N-BUTYLARYLAMJNES. PART 111. 176 was added exactly t o remove the barium. The solution was then boiled filtered from barium sulphate and evaporated to a m a l l volume under diminished pressure when 13 grams of m-amino-phenylselenic acid crystallised from the solution. m-A minophemylseleltic acid crystallises from water in colourless needles which contain 2H,O and after drying a t looo melts and decomposes a t 229O (corr.). It is readily soluble in hot sparingly so in cold water. Found in air-dried substance loss a t looo= 11.4. Found in dried substance C = 32.7 ; H = 3.3. Sodium m-anainlo(plteltylselenate crystallises f rom water in plates, Found in air-dried salt loss atl 120°=19.9. Found in dried salt Se=33-0. TEE WELLCOME CHEMICAL WORKS, C6H70,NSe,l l-H,O requires E20 = 10.9 per cent. CGH70,NSe (220.3) requires c = 32.7 ; €1 = 3.2 per cent. which are readily soluble in cold water. CGH60,"aSe,3$H,0 requires H,O = 20.6 per cent. C,H6O3"aSe (242.2) requires se= 32.7 per cent. DARTFORD KENT. [Received February 4th 19 19.

ISSN:0368-1645    

DOI:10.1039/CT9191500166

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

THE N-BUTYLARYLAMJNES. PART 111. 176 YX.-The n- Butylm-ylamines. P a ~ t III. Constitu-tion of the Nitro-derivatives of n-Butyl-p-toluicline. By JOSEPH REILLY and WILFRED JOHN HICKINBOTTOM. IN Part 11. of this series (T. 1918 113 985) the preparation of 2- and 3-nitro-n-butyl-p-toluidiiies was described and in the pre-sent paper an account is given of the products of reduction of these nitro-compounds the study of which has shown that the constitu-tions previously assigned tmo them are correct. The 3-nitro-derivativeJ on reduction furnishes 3 4-toZylene-4-N-n-butyldiamine (I) which is a readily oxidisable oil and the corre-sponding 3-nitroacetyl derivative gives 2 5-dimethyLl-n-butyl-benzirninazole (IP) which is also obtained by the action of heat on 4acetyl-3 4-toly/lene-4-N-n-butyldiam,ine (111).N H*C,H N( C,H J. Me NAc*C,H, (',NB, \/ CH, (7% PI-" \/ CII CH3 (111.) (1.1 (11.1 I" 176 REILLY AND HXUKINBOTTOM : The coiistitution of 3 5-dinitr0-72rbutyl-ptoluidine is proved by th0 fact that on hydrolysis with sodium hydroxide itl yields n-butyl-amine and 3 5-dinitro-p-cresol. By the action of acids or direct sunlight on 3 5-dinitreptolyl-n-butyl-nitro- or -nitroso-amine tho dinitro-amine is regenerated, and the nitroarnine is similarly decomposed on boiling it with ethyl or n-butyl alcohols. When the nitroarnine is hydrolysed by sulphuric acid or sodium hydroxide nitrous acid is formed. EXPERIMENTAL. *H, \-/ 2 4 - ~ o ~ y ~ e n e 4 - ~ - n - but?y~diarnine CH / \NH=c~H,. 2-Nitro-n-butyl-p-toluidine (3 grams) was mixed with 10 C.C.of concentrated hydrochloric acid and 40 C.C. of water and zinc dust (4 grams) gradually added. Excess of zinc was removed from the colourless solution and the amine was isolated by the addition of sodium hydroxide solution followed by extraction with ether. It formed a pa10 brown powder which was purified by solution in dry ether and precipitation wit'h light petroleum. A white floccu-lent mass was obtained which on drying could easily be powdered. By spontaneous evaporation of t5he ethereal solution it' was obtained in colourless needles melting a t 5 3 O : 0.0956 gave 12.9 C.G. N a t 19.2O and 750 mm. Ci,H,,N2 requires N = 15.72 per cent. 2 4-ToZyle.ne-4IN-n-butyZ~~amine is soluble in most of the common organic solvents sparingly so in water and very sparingly so in light petroleum.With ferric chloride solution it gives a very faint brown coloration which however is not very character-istic. It gives no characteristic colour with nitrous acid or potassium f errocyanide. The hydrochloride is very readily soluble in water. 4-A cet?/Z Derivative ,-Tin foil was added to 2-nitroaceto-n-butyl-p-toluidide (1 mol.) suspended in concentrated hydrochloric acid (6 mols.) until reduction was complete. The sdut-ion was filtered, diluted with water and the tin removed by means of hydrogen sulphide. The filtrate was rendered alkaline and the amine isolated as a brown oil by extraction with ether. It solidified to a mass of brown crystals which on crystallisation from a mixture * In the nitrogen estimations recorded in this paper the gas was collected over 40 per cent.potassium hydroxide solution. A correction has been introduced for the vapour tension of the potassium hydroxide solution. N=15*56. THE N-BUTYLARYLAMINES. PART 111. 177 of ether and light petroleum was obtained in white crystals melt-ing a t 98-99O: 0.0723 gave 8.1 C.C. N a t 20° and 749 mm. The compound dissolves in ether and many of the other organic solvents but is insoluble in light petroleum. The diazo-compound gives with &naphthol a brownish-red mo-dye which dissolves in sulphuric acid with the development of a deep purple-red colora-tion changing to pale brown on dilution. The @cmte of the base crystallises from alcohol in groups of yellow needles melting at 185O.N=12*87. C13H200N requires N = 12-72 per cent. 3 4-Tolylene-4-N-n-butyldiamine. The reductioa od 3-nitro-n-butyl-p-toluidine in the way described f o r the 2-nitro-compound yields the corresponding diamine as an oil which is white when first precipitated but rapidly acquires a deep blue colour and ultimately becomes almost black: 0.1211 gave 16.2 C.C. N a t 2 2 O and 764 mm. C,,H,,N requires N = 15-72 per cent. The compound is readily miscible with most of the ordinary organic solvents. The hyd?-ochZoyide was obtained by passing a dream of dry hydrogen chloride into a solution of the base in dry xylene. The bulk of the xylene was decanted and the rest removed by washing with light petroleum. After being dried at looo the salt formed a white powder.J t is extremely deliquescent) and very readily soluble in water: N=15.57. 0.0552 gave 0.0625 AgCl. C1=28*0. The aqueous solution is very readily oxidised. CllH1,N,,2HC1 requires C1= 25.2 per cent. One drop of ferric chloride solution produces an intense blood-red or deep brown colour. A dilute solution of chromic acid o r a very dilute neutral solution of potassium dichromate produces a brownish-black or black solution depending on the concentration of the oxidising agent. An aqueous solution of bleaching powder yields a deep blue solution. Nitrous acid in dilute solution gives a dirty purple coloration whilst coacentrated nitric acid also gives a purple coloration. The 3 4-diacetyl derivative was prepared by warming the base with acetic anhydride.A dark-coloured oil was obtained which slowly solidified to a mass of dark brown crystals. By repeated crystallisation from a mixture of light petroleurn and acetone o 178 REILLY AND HICKINBOTTOM: from hot dilute aqueous alcohol it was obtained in white crystals melting at 130O: 0.0754 gave 7.1 C.C. N a t 25O and 7'48 mm. The compound is moderately soluble in hot but sparingly so in N=10-62. C,,H,O,N requires N = 10.69 per cent. cold water. 4-A cet yl-3 4-tolylene-4-N-n- butyldiamine (111). 3-Nitroaceto-n-butyl-p-toluidide (4 grams) was dissolved in 50 C.C. of aqueous alcohol (70 per cent.) containing iron filings (10 grams) and to the mixture warmed to 30° glacial acetic acid was slowly added the temperature being kept a t 30°. After an hour the mixture was heated on the water-bath the unchanged iron remo'ved by filtration washed with warm dilute acetic acid, and the filtrate rendered alkaline and heated a t 80° for several hours.The base was extracted with ether and purified by re-crystallisation from a mixture of equal parts of dry ether and light petroleum when it was obtained i n short colourless needles melting a t 102O: 0.0702 gave 8-0 C.C. N2 a t 21° and 738 mm. C13H2,0N requires N = 12.72 per cent. The compound is readily soluble in alcohol ether benzene or carbon tetrachloride but very sparingly so in light petroleum. The diazo-compound gives a red azo-dye with P-naphthol. On heating the base in a flask fitted with a short air condenser a t 200° in an oil-bath globules of water were observed in the con-denser.After heating f o r four to five hours the dark viscous residue was distilled over a free flame when a pale yellow oil was obtained which did not solidify a t Oo and was not a primary amine. From its method of formation it is probably 2:5-&methyZ-l-n-butylbenziminazole (11). The same compound was produced by the vigorous reduction of 3-nitroaceto-m-butyl-p-toluidide in acid solution. The nitro-compound (5 grams) was dissolved in a mixture of glacial acetic acid. (25 grams) concentrated hydrochloric acid (10 grams) and water (15 c.c.). Zinc dust (20 grams) was added, and the solution became very warm. After the reaction had moderated and more zinc dust had been added the solution was heated on the sand-bath for one or two hours.After removal of the excess of zinc the solution was rendered alkaline with potassium hydroxide solution and the precipitated oil extracted with ether. N=12*85 THE N-BUTYLARYLAMINES. PART 111. 119 On distillation it was obtained as a very viscous pale yellow oil boiling a t 335-338O : 0.0746 gave 0.2115 CO and 0.0606 H,O. 0-0794 , 9.9 C.C. Nz a t 23.1" and 736 nun. N=13*92. 2 5-Dimethyl-1 -n-butylbenziminazale is miscible with ether or alcohol. When exposed in an open dish to a moist atmosphere it readily absorbs water and oxygen gradually becoming darker. By the act,ion of an aqueous-alcoholic solution of picric acid on the alcoholic solution of the anhydro-base the picrate was precipitated ; t.his crystallised from acetone in short, yellow needles or prisms melting a t 209O: C=77*34; H=9*09.C13H18N2 requires C= 77.18 ; H= 8.97 ; N = 13-85 per cent. 0,0756 gave 10-7 C.C. N2 a t 2 1 O and 749 mm. It is practically insoluble in water ether or alcohol. N=16.20. Cl,H,,N,,C,H,O,N requires N = 16.24 per cent. Action of Alkalis o n 3 ; 5-Dinitro-n-butyl-p-toluidine. The dinitro-compound (1 gram) was heat'ed under reflux with a solution of 5 grams of potassium hydroxide i n 40 C.C. of water for six to eight hours. The colour of the solution changed rapidly through brownish-red to very dark red or almost black. On dis-tillation into dilute hydrochloric acid n-butylamine hydrochloride was obtained. The alkaline residue in the flask after being cooled and filtered was acidified with dilute sulphuric acid and from the ethereal extract a solid cryskallising in yellow needles (m.p. 8 2 O ) was obtained which proved to be 3 5-dinitro-p-cresol. Action of Acids on 3 5-ninitroip-t~lyl-n-h2Lt?/l-nitroam~.ne and -nitrosoarnine. 3 5-Dinitro-p-t~lyl-n-butylnitroamine (0.5 gram) was dissolved in 2 C.C. of concentrated sulphuric acid (97 per cent.) the solution being kept cod by immersion in ice-cold water. The nitroamine dissolved slowly with the production of a deep reddish-purple colour which changed finally to yellow. After half an hour the mixture was poured on ice when a yellow solid was obtained, which proved to be the colrresponding nitrosoarnine. Nitrous acid was also found to be present. In another experiment 50 C.C. of slightly warmed sulphuric acid (90 per cent.) were added t o the nitroamine (0.5 gram).There was a faint d o u r of nitrous acid, and the colour changes were the same as those described above 180 REILLY AND HICKINBOTTOM : After remaining for twenty days exposed for part of the time to sunlight the colour had changed to deep red. On pouring into water and extracting with ether 3 5-dinitro-n-butyl-p-hluidine was obtained as the chief product. Further the nitroarnine (0.5 gram) was heated under reflux with a mixture of concentrated hydrochloric acid (20 c.c.) and n-butyl alcohol (50 c.c.) for eight hours. The colour of the mixture gradually became darker until it was finally a deep red. After removal of the alcohol a red sub-stance melting indefinitely a t 65-80° was obtained. The melting point was raised to 86-88O by treatment with amyl nitrite in the presence of hydrochloric acid the colour also becoming considerably paler.On warming the nibroarnine with an aqueous solution of per-chloric acid and allowing the mixture t o remain for twelve hours, a slight darkening occurred. The action of glacial phosphoric acid in the cold produced practically no colour change after a week. 3 5-Dinitro-p-tolyl-n-butylnitrosoamine by the action of hydro-chloric acid containing some aniline hydrochloride yields the corre-sponding amine in almost quantitative yield and in a pure condi-tion (compare Pinnow Ber. 1897 30 838). The nitrosoamine (2.4 grams) was heated under refiux for eight hours with alcoholic hydrogen chloride (50 c. c.) containing aniline hydrochloride (1 gram).On evaporating the alcohol 2.1 grams of 3:5-dinitro-n-butyl-ptoluidine identified by the mixed melting-point method, were obtained. When the aniline hydrochloride was omitted the reactioq followed a similar course but required a longer time for completion. Action of Alkalis on 3 5-Dilz/itl.o-p-tol~I-n-bwtyl-nitrolamine m d Izitrosoaminc . Alcoholic potassium hydroxide reacts with alcoholic solutions of the nitroarnine and nitrosoarnine with the production of a dark purple colour which gradually deepens in intensity. In aqueous solution the reaction takes pIace much more slowly. 3 5-Dinitro-p-tolyl-n-butylnitroamine (1 mol.) was heated under reflux with a large excess of a 10 per cent. aqueous solution of sodium hydroxide (15 mols.). The nit,roamine was slowly attacked yielding a purple solution which gradually became almost black when the reaction was considered to be complete.On distillation n-butylamine was obtained. The alkaline residue in the flask which contained sodium nitrite was diluted and after filtering rendered acid in the presence of carbamide to remove nit'rous acid. On extractio THE N-BUTYLAFtYLAMLNES. PART 111. 181 with ether a pale brown oil was obtained which solidified to a yellow crystalline solid. After several crystallisations from aqueous alcohol this melted a t 82* and was shown to be 3:5-di-nitro-p-cresol. When either the nitroarnine or the nitrosoamine was heated with two or three times its weight. of phenol a t 180° and the pro-duct treated with very dilute ice-cold sodium hydroxide solution, f dlowed by extraction with ether 3 5-dinitro-m-butyl-ptoluidine was obtained in good yield and the same result was obtained by heating the nitroarnine or nitrosoamine with a large excess of n-butyl alcohol or ethyl alcohol for several hours in diffused light.Both the nitroamine and nitrosoarnine were finely powdered and exposed in glass and quartz vessels to direct sunlight. After one hour the nitrosoamine had deepened considerably in colour and the melting point was depressed. The nitroarnine on the other hand changed colour only slowly but there was sufficient action in both cases after one montlh’s exposure to detect the presence of 3 5-dinitro-.n-butyl-p-toluidine. In some of the reactions where the decomposition was not complete the melting point alone was not a sufficient guide to determine the cornpositdon of the product. The colour affords an indication of the production of the parent arnine and this was confirmed by the evidegce obtained by the action of amyl nitrite and of nitric acid. I n the decomposition of the nitrosoarnine or of the nitroarnine the production of the parent amine was assumed to have occurred when the action of amyl nitrite or nitrous acid in t’he presence of hydrochloric acid or acetic acid effected a considerable loss of colour and when the melting point was altered. The action of fuming nitric acid in giving a product identical with the original nitroamine showed that the butyl group had not been removed and that only the nitroso-group linked t o the aminic nitrogen atom had been affected. [Received January 16th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9191500175

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

152 LEWIS STUDIES IN CATALYSIS. PART X. XX1.-Studies in Catalysis. Part X . The Applicah-ility of the Radiation Hypothesis to Heterogeneous React ions. By WILLIAM CUDMORE MCCULLAGH LEWIS. IN the previous papers of this series the radiation hypothesis has been applied exclusively to reactions in homogeneous systems. A mode of applying the hypothesis t o reactlions in heterogeneous systems including heterogeneous catalysis having suggested itself to the author more than two years ago it may notl be out of place to indicate1 it briefly here. In attempting to elucidate the mechanism of any chemical or physical process two complementary methods of treatment may be employed. I n the first' the process is considered from the point of view of the material or molecular changes involved; in the second from the point of view of the concomitant or precedent energy exchanges.The radiation hypothesis belongs t o the second method of treatment. The two met'hods are not distinct in the sense t'hat the results obtained in one often furnish a clue to the solution of a difficulty met with in the other. It is necessary, however to possess in the first place some information regarding the most probable material mechanism of the process considered before introducing considerations based on the energy exchanges involved. I n the case of heterogeneous reactlions and catalysis, Langmuir's theory of the spatial distribution of molecules and atoms a t the interface between two phases will be adopted as a basis for the material changes occurring the energy changes being then dealt with from the point of view of the radiation hypothesis.Langmuir's theory (compare J . A4 mer. Ghem. Soc. 1916 38, 2221) is essentially an extension of the work of the Braggs on crystal structure. The surface of a solid is regarded as a checker-board on which atoms or molecules of gases may be condensed by being united to certain atoms in the surface itself. This adsorption effect is ascribed directly to valency in some cases the surface being almost entirely covered or saturated in others only a small fraction of the surface being thus occupied. According to Langmuir this surface layer does not consist of several layers of molecules or atoms in which the density varies continuously. Instead the change from solid to homogeneous gas is abrupt'.This is based on the idea that it is only a layer one molecule or atom in thicknes LEWIS STUDIES IN CATALYSIS. PART X. 183 which would be held sufficiently firmly to the surface especially at the moderately high temperatures a t which heterogeneous reactions proceed in general with measurable velocity. Langmuir’s experi-mental When a gas molecule strikes a surface it is in general condensed. The rate a t which it evaporates depends on the chemical or specific nature Df the molecule and of the layer of atQms in the surface of the solid. Thus nitrogen in which the atoms are already very com-pletely saturated possesses only a feeble external field of force, and in the moZeci(Zar forin therefore will be only slightly adsorbed. Langmuir has found that hydrogen in the atomic form pro-duced by heating a wire in dry hydrogen a t very low pressures has a remarkable tendency to be adsorbed this being regarded as due to the unsaturated affinity of the hydrogen atom.Langmuir has calculated that in this case the adsorbed layer of gas is just one atom in thickness. Oxygen is likewise easily adsorbed by metallic (tungsten) filaments. This adsorbed layer is exceedingly stable, and is evidently distinct from the formation of the compound WO, which volatilises easily in comparison. On Langmuir’s view, the oxygen is retained on the surface in the atomic form. A mole-cule or atom which is strongly adsorbed is capable of displacing one which is feebly adsorbed. Hence addition of a strongly adsorbed gas-which in certain cases may be the resultant of the reaction-may cover the surface of a solid more or less completely, the surface being thereby “p~isoned” with respect to a reaction in which the reactants are only feebly adsorbed.Langmuir has given several instances of such effectls. The essential point for our present purpoee is the dissociation partial o r complete which many substances undergo into tthe atomic statel on being condensed on surfaces the cause of such dissociation being the localised valencies or lines of force which hold the atoms of the condensed substance t o certain atoms of the surface of the solid.* We have now to see how far the radiation hypothesis may assist in extending this view of the mechanism of the process. I n general the velocity constants of heterogeneous reactions are characterised by possessing smaller temperature coefficients than those which are possessed by reactions in homogeneous systems.This means on the basis of the considerations developed in earlier papers that the critical increment in the het’erogeneous process is * The catalytic effect of traces of moisture in the activation of molecules and atoms and therefore possibly of surfaces is not considered in the present paper.. The facts hitherto recorded point to the conclusion that water is effective where ions are required t o enable the reaction to proceed. results support this view in many cases. So much for the nature of the material changes involved 184 LEWIS STUDlES IN UATBLYSIS. PART X. less than it would be for the same process occurring in the homo-geneous system.This in fact appears to be the basis of the accelerating or catalyt'ic effect of a given surface as viewed from the energy required to effect the chemical change. It has already been shown that the reactivity of a substance depends on the magnitude of its critical increment that is the amount of energy which must be added per molecule or per gram-molecule in excess of the average energy content in order to bring the molecule into the active state. The higher the critical increment the smaller is the reactivity or rate of reaction of the substance. This increment is taken account of by the exponential term which appears in the velocity expression developed in previous papers. The term referred to is e - E / R T where E is the critical increment per gram-molecule i? the gas constant per g-ram-molecule and T the absolute temperature.It is this quantity that governs tthe magnitude of the temperature coefficient of a reaction and as is evident the greater tjhe value of E the greater is the temperature coefficient. Let us suppose that a given reaction occurs in a homogeneous system the sum of the critical increments of the reactants being El whilst the sum of the critical increments for the same reaction when a heterogeneous catalyst is present is 3,. Then E ) E . The ratio of the velocity constant in the presence of the catalyst to that when the catalyst is absent is given essentially by the ratio e-Ez:RT/e-Ei/RT or e(Ei-EzYR2'. This is in general a large posi-tive quantity; it may be referred to as the catalytic factor.Let us suppose that the process considered involves th6 dissociation of a gaseous molecule. If this occurs in the homogeneous phase the critical increment is large of the order of 50,000 to 100,000 calories per gram-molecule. This energy has to be supplied by absorption of the radiation present in the system and the greater the amount of energy required the higher must be the temperature in order that a sufficient number of quanta of high frequency may be avail-able. If on the other hand a catalyst is present which is capable of condensing or adsorbing the gas in the atomic fom then the energy required is essentially that of sublimation or de-sorption of the atomic resultants from the surface diminished by the energy of adsorption or condensation of the molecular reactant.Such effects are in general small of the order 5000 t o 10,000 calories per gram-molecule. Hence in this case the catalytic factor would be e(W000-j030)lRT which for the temperature T = 1000° would corre-spond with fe22.5 or 1010 approximately. Itl is evident that the effect which we have been considering is of very great magnitude, and to this extent is in agreement with the known high efficienc LEWIS STUDIES IN CATALYSIS. PART X . 185 of heterogeneous catalysts. From the point of view of the energy changes involved therefore t’he action of a catalyst is to be ascribed t o the substitution of relatively small energy terms of the nature of de-sorption or sublimation effects in place of true critical energies of activation or dissociation.In general the problem is not so simple as the case just considered. Frequently more than one reactant is involved and in some cases partial activation or polar-isation of one or more of the reactants may be effected without such reactant coming into direct contact with the surface of the solid itself. This will naturally occur when the surface is already covered by a reactantl which possesses high capacity of adsorption. I n general however the function of the catalyst is to bring a t least ane of the reactants into the active form which would other-wise only be attained in the homogeneous phase by exceedingly high temperature conditions. The possibilities which present them-selves will be rendered somewhat clearer by a preliminary examina-tion of one or tlwo actual cases.The Reaction between Oxyyeiz und Sulphur. We shall first of all consider the reaction S + O,= SO, as occur-ring in the homogeneous gaseous state. Since the resultant contains two atoms of oxygen the process does not require complete dissociation of the oxygen molecule a a preliminary step. Instead a partial activation or polarisation of the oxygen molecule is sufficient. A value for this quantity may be obtained from a consideration of the thermal decomposition of ozone which has been measured by Chapman and Jones (T. 1910, 97 2463) the reaction being shown to be bimolecular. The details of the calculatioIf will be given in a subsequent paper but it may be stated here that the critical increment of ozme per gram-mole-cub obtained from Chapman and Jones’s results is 10,690 cals.Further the heat evolved a t constant volume when two gram-molecules of ozone decompose into three gram-molecules of oxygen has been determined with accuracy by Kailan and Jahn (Zeitsch. nnorg. Chem. 1910 68 243) the value being 69,000 cals. Apply-ing the quantum expression (compare T.; 1917 111 1086) to the process 20 4 30, we obtain 69,000 = 3 3 ’ 0 - 21,380 whence E’o =30,127 cals. or 30,000 cals. in round numbers. The symbol E’ denotes the critical increment per gram-molecule required for the partial activation o r polarisation of oxygen which will permit three molecules thus activated to react to form two molecules of ozone. A molecule possesses in general different degrees or stages of activation and this may not be the one required in the case o 186 LEWIS STUDIES IN CATALYSIS.PART X. the union of oxygen with sulphur. All partial activations are, however small quantities compared with the activation required to cause complete dissociation of a molecule. So far as order of magnitude is concerned the above value may be employed in this preliminary investigation. I n the temperature range 200° to 500° t9he vapour of sulphur consists mainly of the molecular form S8. Preuner and Schupp (Zeitsch. physikal. Chem. 1909 68 148) have measured the equilibrium of the reaction 4S = 35,. The mean value of the heat effect is 26,500 cals. This heat is absorbed in breaking down 3S8 molecules to 4S6 molecules. The same authors have obtained a fairly accurate value for the heat absorbed namely 58,000 cals.in the gaseous reaction S6 = 3S,. Hence the process $3 + S requires an absorp-tion of heat equal t o 21,542 cals. We have now to consider the heat absorbed in the dissociation of S2 into the atomic state’. Buckle (Zeitsch. anorg. Chem. 1900 78 169) has measured by an explosion method the equilibrium of the reaction S,=28 in the gaseous state over the temperature range 2000° to 2500O. The results do not lead to an accurate value for the heat effect. Budde takes the value 120,000 cals. per gram-molecule. Ton Warten-berg (Zeitsch. m r g . Chem. 1908 56 320) estimates the heat effect to be 90,000 cals. approximately. It has been shown (com-pare T. 1918 113 471) that $he critical increment in the case of the dissociation of a molecule into atoms is connected with the heat absorbed by the relation -Q,=E-$RT.At T=2000° the value of E obtained from Budde’s results is therefore 122,000 cals., but this is liable to considerable error. On the radiation hypo-thesis this energy should be given by Nhv where v is the frequency of the light absorbed N the number of molecules in one gram-molecule and h PJanck’s constant. Martens (Ann. Physik 1902, [iv] 8 603) has calculated that sulphur should possess a band in the. ultra-violet region a t h = 226 pp. The corresponding frequency is 1 3 . 3 ~ 1014 and therefore Nhv or the critical increment per gram-molecule should be 125,550 cals. This is remarkably close to the value calculated from Budde’s data.I n fact the agreement is partly accidental. It is probable that the value obtained from Martens’s data is the more correct. It follows that the heat of dissociation of diatomic sulphur into the atomic state in a gaseous system is 123,000 cals. per gram-molecule. Hence the energy absorbed in the process is8 -f 2 s is (123,000 + 21,540) or 144,500 cals. in round numbers. As might be expected the chief factor in the total energy change from S to atomic sulphur is t’he single process of dissociating the S molecules. The critical increment We have now to consider the activation of sulphur vapour LEWIS STUDIES IN CATALYSIS. PaRT X. 187 required to produce two gram-atoms of sulphur in the gaseous state from the corresponding quantity of S8 molecules is 147,000 cals., and therefore the critical increment per gram-atom is 73,500 cals.We have now to consider the formation of sulphur dioxide from oxygen and sulphur the latter consisting of S8 molecules the system being entirely gaseous. The partial critical increment of the oxygen is taken to be 30,000 cals. per gram-molecule. Hence the total critical increment of the system (S+O,) under the con-ditions stated is (73,500+30,000) or 103,500 cals. The heat of formation of sulphur dioxide from solid sulphur and gaseous oxygen is 69,400 cals. per gram-molecule (Berthelot) (compare Perguson Proc. Nat. Acad. Sci. 1917 3 371). The heat of vaporisation of sulphur is 12,000 cals. per gram-atom in round numbers. Hence the heat of formation of sulphur dioxide from its gaseous components is 81,400 cals.Employing the relat'ion : Heat evolved = Eresultants - Ereactants, we getl 81,400 =ESo - 103,500 whence 3s 0 = 184,900 cals. per gram-molecule. It follows from this value that the frequency of the effective radiation is 19.6 x 1014 and the wave-length A = 153 ,up. Sulphur dioxide is known t o have an absorption band in the extreme ultra-violet region beyond 200 pp (compare Garrett ?Id. Mag. 1916 [vi] 31 SOS) but the position of the band has not as yet been located. Tho above exceedingly high value for the critical increment of sulphur dioxide requires that the molecule should be correspond-ingly stable. Thus it should not be possible to decompose it into its components by a quartz mercury lamp since quart.z does not transmit wave-lengths longer than about 185 pp.As an illustra-tion of its stability it may be mentioned that von Wartenberg (Zoc. c i t . ) was unable to detect any sensible dissociation of sulphur dioxide even a t 2200O abs. For our present purpose it is more important t o observe that the critical increment of the reactants (S+O,) is also very high namely 103,500 cals. The numerical values given above refer t o the reaction non-catalysed. If however the reaction is carried out in the presence of solid or fused sulphur heterogeneous catalytic effects enter. This has been shown experimentally by Bodenstein and Car0 (Zeitsclt. physikal. Chem. 1910 75 30) the sulphur acting as a positive catalyst. The result of the positive catalysis is that the critical increment of the system (S + 0,) is much less than the value given above.From the temperature coefficient obtained hy Boden-sstein and Caro in the region of 250° in the presence of solid sulphur it is found that the critical increment of the reactant 188 LEWIS STUDIES IN CATALYSIS. PART X. ( S + O ) lies between the limits 31,308 and 34,184 cals. the mean value being 33,000 cals. in round numbers. It is possible to account approximately for the order of magni-t,ude of the critical increment obtained when heterogeneous catalysis occurs by supposing that the oxygen is already activated a t the temperature chosen before coming into contact with the sulphur surf ace the increment. of partial activation of oxygen being of the order 30,000 cals. as we have seen already. The sulphur itself is already in the atomic state in the surface layer of the solid and consequently does not require further activation.The heat of volatilisation of the sulphur dioxide per gram-molecule is a quantity of the order 5000 cals. so that in all the apparent increment is of the order 35,000 cals. which agrees moderately well with that observed. I n the above case the catalytic factor a t 250° is e(103j500-3585°0)/Rp or e681000/RT or 1028 approximately. These numbers are simply employed for purposes of illustration; sufficient data have not yet been accumulated to permit of more exact calculation. If such changes in the critical increment are brought about as a result of catalytic effects it is necessary t o conclude that in general the heat effect of a process will be modified by the catalyst, and if this is the case the variation of the equilibrium constant of the reaction in the surface layer with temperature will be affected, so that finally the equilibrium constant of the catalysed reaction will differ from that of tlhe non-catalysed reaction.This con-clusion is in general agreement with that arrived a t by Bancroft ( J . Physical Chem. 1917 21 573) on false equilibria and the effect of heterogeneous catalysis on the position of the equilibrium. The Union of Oxygen and Hydrogen. Bodenstein (Zeitsch. physikal. Chern. 1899 29 665) has found that the temperature of the termolecular velocity constant corre-sponding with the reaction 2H2+0,=2H20 is 1.75 for loo ov0r the temperature range 482" to 509O. The reaction proceeds under the conditions employed almost entirely a t the surface of the porcelain containing-vessel.From the above value of t'he tempera-ture coefficient it would follow that the critical increment for two gram-molecules of hydrogen and one gram-molecule of oxygen is 66,000 cals. and therefore for one gram-molecule of hydrogen and one ha!frgram-molecule of oxygen the increment of the reactants is 33,000 cals. Bodenstein's results have however been crit'icised by Bone and Wheeler (Phil. Trans. 1906 [ A ] 206 l) who find that the reaction is not termolecular but approximately unimole LEWlS STUDIES CATALYSIS. PART X. 189 eular especially unimolecular with respect to the hydrogen. The reaction which appears to occur is therefore H,+O=R,O. Bone and Wheeler have given data for the reaction f r m which the temperature c d c i e n t and critical increment of the reactants may be calculated when nickel is the catalyst.For the temperature range 473O to 493O abs. the critlical increment of the reactants is calculated to be 35,000 cals. which agrees fairly well with the value obtained from Bodenstein’s results for the porcelain surface. Over the temperature range 493O to 513O abs. the results obtained by Bone and Wheeler give an increment of 52,000 cals. in round numbers. This is considerably greater than that obtained a t the lower range of temperature and indicates that the catalytic effect is relatively less efficient a t the higher temperature due pre-sumably to diminished adsorption of the reactants. In both cases, however the increment is a relatively small quantity very much smaller than would be expected from the process occurring in the homogeneous phase f o r the molecule of oxygen which has to be dissociated is very stable.We have now to attempt to account for a quantity of the above order of magnitude on the basis of the energy-mechanism out-lined. Let us assume in the first place that the oxygen is adsorbed and exists in the atomic state attached to certain posi-tions on $he suTface of the catalyst. It is necessary that an activated or polarised molecule of hydrogen shall come into con-tact with an oxygen atom. It is only necessary for the hydrogen to be partly activated. Bohr (Phil. Mag. 1913 [vi] 26 1 476, 857) has investigated the energy changes which occur in the mole-cule and the atom of hydrogen in.various processes involving the removal and addition of an electron. Bohr has calculated that the process of transferring an electron so as to give rise to a system consisting of a positively charged hydrogen atom and a negatively charged one requires an absorption of energy of 21,000 cals. per gram-molecule of hydrogen. We shall employ this value in the present case although there is evideiice that a somewhat higher value is probably more correct. The latent heat of vaporisation of wat8er is in round numbers 9000 cals. per gram-molecule’in the neighbourhod of looo. As before we shall assume that the heat of de-sorption of the water produced in the reaction is of the same order of maghitude. Hence we would expect the critical incre-ment of the process to be of the order 30,000 cals.per gram-molecule of hydrogen and per gram-atom of oxygen. This agrees moderately with the observed value. SufficientIy accurate data are not as yet available for calculating the critical increment of the reactants of the same reaction in th 190 LEWIS STUDIES IN CATALYSIS. PART X. homogeneous gaseous state. It is necessary to dissociate the mole-cule of oxygen and this appears to require a quantum of energy corresponding with approximately the region h = 200 pp whence the critical increment per grain-molecule is of the order 140,000 to 150,000 cals. That is the total increment! of the reactants, reckoned per gram-molecule of hydrogen is 21,000 + 140,000/ 2 or 91,000 cals. The catalytic efficiency is therefore given by the ratio order 1017.These figures are merely illnstxatixre but they serve to indicate the great influence on the velocity which is to be expected on the basis of the treatment suggested. I n dealing with the union of oxygen and hydrogen i t has been assumed above t.hat the oxygen is condensed in the atomic form on the catalyst the subsequent chemical change being H + 0 = E120. From a number of observations made by Bone and Wheeler (Zoc. c i f . ) i t appears that hydrogen is preferentially adsorbed. I n such cases the most probable reactpion because it involves the minimal critical increment. would be represented by H,+O,==H,O, in which the hydrogen and oxygen are partly activated but neither of them is completely dissociated.The formation of water would result from the subsequentl decomposi-tioii of the hydrogen peroxide'. The idea that. hydrogen peroxide is an intermediate stage is of course not new. It appears from such considerations that the specific nature of the catalyst may determine the actual mechanism of a given reaction to a large extent. e-3%00o/RT c %000/RT or e % O O f l / ~ ~ . At 5000 this factor is of the I -The Union of Oxygen and 1S"ilicon. I n the reactions just considered the critical increment of partial activation of oxygen has been taken to be 30,000 cals. approxim-ately this being the value required for t.he formation of ozone. As already pointed out more than one stage of activation may be anticipated up to the limiting activation which corresponds wit?h complete dissociation of the molecule into atoms.Each activation corresponds with a certain size of quantum of radiant energy that! is with a certain frequency. The general conclusion reached in connexion with absorption spect'ra is that frequencies are related to one another in terms of even multiples of some fundamental fre-quency that is various degrees of activation are similarly related. A low degree of activation of the oxygen molecule requires 30,000 cals. of energy to be absorbed per gram-molecule and therefore higher degrees of activation would require 60,000 90,000 cals ., etc. up to the limiting value of complete dissociation whic Ll3WY.S STUDIES IN CATALYSIS. PART X. 191 appears to correspond with a quantity of the order 140,000 to 150,000 cals.Sufficient information is not as yet available t o enable us to say how many of these possible degrees of activation may actually manifest themselves. As an example of partial activation of oxygen which is apparently considerably greater than 30,000 cals., we may take the case of the formation and decomposition of an exceedingly stable coImpound silica or quartz. To decompose a molecule of quartz it is’evident that a quantum in the very extreme ultra-violet portion of the spectrum is required, in order t o supply the necessary energy. It is well known that quartz commences to absorb radiation sensibly beyond the wave-length 185 pp. s. Richardson (Phil. Hny. 1916 [vi] 31 463) finds that the dispersional wave-length of quart’z is 105pp. It does not necessarily follow that the dispersional wave-length or frequency is thab required for complete dissociation of the molecule.That in the case of quartz however the necessary wave-length cannot differ much from 105 pp is rendered probable by the follow-ing consideration. In a quartz mercury vapour lamp it is gener-ally believed t-hat the quartz remains undecomposed ; otherwise it would be difficult t o account for the life and permanence of the lamp. That is quartz can only be decomposed by a wave-length which is shorter than any emitted by the mercury vapour. 0. W. Richardson and Bazzoni (Phil. Mag. 1917 [vi] 34 285) have found that there is a limiting wave-length in the spectrum of a substance; t.hat is no wavelengtlh shorter than a certain value, characteristic of the substance can be emitted.I n t.he case of mercury vapour this limiting wave-length lies between 120 and 100 pp. The mean of these two limits is 110 ,up and we conclude on the above reasoning that quartz can only be decomposed by a wave-length shorter than this value. This points fairly definitely to S. Richardson’s value 105 pp for the dispersional wave-length of quartz as being the wave-length capable of decomposing the molecule. The critical increment corresponding with A = 105 pp is 270,000 cals. per gram-molecule of quartz an enormous quantity which is in qualitative agreement with the known stability of quartz. We have now t o consider the heterogeneous reaction On Langmuir’a view as applied in the present paper we regard the silicon as already in the atomic date.I f x is the necessary critical increment of oxygeii per gram-molecule then x is likewise the total crif8ical increment of the reactants. The heat of the reaction is known to be 184,000 cals. i n round numbers and hence, Si + O,= SiO, 192 LEWIS STUDIES IN (3AThLYSIS. PART X, on applying the quantum-heat exprsssion heat evolved = critical increment of resultants - critical increment of reactants, we obtain 184,000 = 270,000 - 5 whence x= 86,000 cals. Owing tol the error in the observed heat effect and in the value of the critical increment of quartz this value for the critical increment of oxygen may be regarded as agreeing approximately with the value 90,000 cals. expected from the lower degree of activation of the molecule.What is particularly importank is that even this value does not correspond with complete dissociation of the oxygen molecule. We may therefore conclude that the molecule of quartz 0 0 possesses the structure Si<l rather than 0:Si:O. This is an illustration of how a knowledge of the necessary critical increments -which in the present case unfortunately are not known with precision-may lead to information concerning molecular structure. One of the chief difficulties met wi’th in the kinetics of hetero-geneous reactions has its origin in the selective nature of the absorbability of the reactants and the resultants particularly the latter. The so-called catalytic (‘ poisons ” are now generally regarded its owing their effect to marked selective adsorption as a result of which the surface of the catalyst becomes covered with a layer of molecules and is thus no longer capable of catalysing the reaction.I n many cases the resultants of the reaction are adsorbed in this manner and consequently function as a catalytio poison. Since the extent of adsorption diminishes a3 the tmpera-ture rises it is obvious that when such poisoning effects are present the temperature coefficient of the reaction velocity over a certain range of temperature is not comparable with that over a different range for the total observed velocity depends not only on the true effect of temperature on the chemical process itself but likewise on the alteration in the ext’ent of active surface presented to the reactants. The simplest conditions are obviously those in which the adsorption effects are a minimum and such conditions will occur generally when the energy required for sublimation or de-sorption is small. I n the other cases where adsorption effeda are large it is necessary to correct the observed velocity aonstants for the change in the area of the effective surface produced as a result of the change in temperature. Thus in tlhe case in which the resultant is markedly adsorbed and therefore acts as a negative catalyst the temperature coefficient will possess too high a value, and instead of decreasing as temperature rises may even increase. A similar abnormal behaviour is to be anticipated when a reaction proceeds partly in the homogeneous gaseous phase partly in th THE ESTIMATION OE' THE METEOXYL GROUP. 193 surface far as the temperature rises the reaction bride to pre-dominate in the gaseous phase and therefore possesses a higher temperature coefficient. MUSPRATT LABORATORY OF PHYSICAL AND ELECTRO-CHEMISTRY, UNIVERSITY OF LIVERPOOL. [Received .January 227244 1919.

ISSN:0368-1645    

DOI:10.1039/CT9191500182

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年代:1919

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THE ESTIMATION OW THE METEOXYL GROUP. 193 of the MethoxyE Group. By JOHN THEODORE HEWITT and WILLIAM JACOB JONES. SINCE the introduction of the Zeisel method for the estimation of methoxyl groups (Moizutsh. 1885 6 989; 1886 7 406; Benedikt and Griissner Cken2. Zce't. 1889 13 872) numerous attempts have been made to simplify the apparatus and shorten t'he operation. The msthod of rectifying the methyl iodide proposed by Zeisel is effective but troublesome; the inclined condenser has t o be of con-siderable lengkh and consequently occupies some bench space whilst the constant supply of water t o the condenser a t about 50° necessi-tates supervision. A further inconvenience of the Zeisel method is the trouble experieneed. in working up the precipitate of double iodide and nitrate of silver time being lost in evaporating the alcoho'l and obtaining the silver iodide in a pure condition.The use of a rectifying column provided witqh a thermometer in place of the inclined condenser fed with water a t an approximately d e h i t e temperature was recommended by Hewitt and Moore (T., 1902 81 318) and impurities in the hydriodic acid were removed by passing carbon dioxide through the acid a t 130° before-intro-ducing the substance under examination. Considerable saving in bench space was effected and during the operation it was only necessary to control th0 stream of carbon dioxide and the flame under the glycerol bath so as to give the necessary temperatuies in the reaction flask and a t the top of the rectifying colamn. Several modifications of the Zeisel method have been suggested in which ordinary rectification has been relied on in place of inclined condensers in which the temperatare is controlled by running water (Perkin T.1903 83 1367; Zeisel and Fanto t e i t s c l t . anal Chem. 1903 42 549; Stritar ibid. 579; fIewe Ber. 1906 39, 1142). Shortening t'he process by estimation of the methyl iodide ia a more rapid manaer was left. untouched for years. The necessity of esti&iag methyl iodide obtlained from methyl alcoho 194 HEWITT AND JONES: mixtures rapidly and accurately caused the present authors to search €or a quick process. Since combination of alkyl iodides with bases of the pyridine series takes place very rapidly there seemed to be a promising way of obtaining the iodide in an ionisable form and then estimating it volumetrically.After working out a satisfactory process it was found that the same fundamental idea of combining the methyl iodide with a tertiary base had already been utilised (Kirpal and Buhn Ber. 1914 47 1084) but the subsequent volumetric estimation of iodide by standard silver nitrate solution may be con-siderably shortened. Instead of rejecting the excess of pyridine by evaporation and estimating the iodide with standard silver nitrate using a chromat?e as indicator the pyridine and its meth-iodide may be directly diluted with water acidified with nitric acid a known amount of silver nitrate added and the excess of the latter determined by thiocyanate according to Volhard's method. Adoption of this procedure reduces the time of experi-ment considerably.The applicability of Volhard's method to the estimation of methyl iodide after reaction with pyridine was controlled i n a separate experiment. 3.10 Grams of freshly distilled methyl iodide were diluted to a volume of 100 C.C. with pyridine which had been saturated with carbon dioxide. By dilution with water addition of silver nitrate and determination of the excess of silver wit'h thiocyanate 3.13 grams of methyl iodide per 100 C.C. were found. Method. Hydriodic A cid.-The hydriodic acid is prepared by saturating an aqueous suspension of iodine with hydrogen sulphide distilling the resulting solution and collecting the fraction boiling between 123O and 127O (D 1.7) for use. Residues from analyses are redistilled and used again.Pyridime .-Complete separation from picoline is unnecessary ; it is however advisable to remove substances of high boiling point, Pyridine bases as obtained from tar distillers are mixed with two-thirds of their weight of water and fractionated. The fraction distilling betkeen 9 3 O and 97' containing the mixture of constant boiling point is shaken with one-third of its weight of solid sodium hydroxide the upper layer is separated fractionally distilled and the bases distilling between 114' and 1 1 7 O are collected for use, Residues containing pyriding may be accumulated rendered alkaline with onefiftieth of their weight of solid sodium hydroxide distilled, the distillate a t 93-97O collected and worked up THE ESTIMATION OF THE METHOXYL GROUP.195 The Estimation.-The apparatus consists of the usual carbon dioxide generator decomposition flask heated in a glycerol bath to 130° and rectifying column (four-pear or other suitable form). The carbon dioxide carrying the methyl iodide vapour is passed through two tesbtubes in series each containing 10 C.C. of pyridine. For the estimation a suitable weight of the substance i b taken, and 20 C.C. of hydriodic acid (D 1.7) are added. After the experiment has been in progress for one hour the con-tents of the tesbtubes are completely washed into a graduated flask, when they are diluted with water and the iodide is estimated by the process indicated above. In all cases early in the course of t8he experiment a yellow coloration develops in the pyridine.This vanishes on diluting the pyridine a t the end of the experiment. Its appearance therefore, need cause no apprehension to the analyst that free iodine is finding its way into the pyridiiie. Moreover carefully purified samples of metqhyl iodide and pyridine on admixture' develop colour. The behaviour of a mixture on dilution with water was compared with that of an iodine solut.ion of equal depth of colour. On diluting a 3 per cent. solution of methyl iodide in pyridine with a quarter of its volume of water the colour became very pale and with its own volume of water it almost vanished. The iodine solution on being similarly diluted still retained its colour. It would thus appear that the coloration is not due to free iodine. Should how-ever the colour persist on dilution with water it is then advisable to discharge it with thiosulphate solution.Analyses. Substance. Brucine hydrate .................. Methyl oxalate .................. Methyl alcohol ..................... 9 ....................... Y )) ..................... 99 , ..................... Methyl salicylate .................. Percentage of methovyI group /-Found. Calculated 13.5 13.3 50.1 52.5 95.2 96.9 95.2 96.9 96.0 96.9 96.3 96.9 19.7 204 A methylat'ed cellulose which gave 39.1 per cent. of rriethoxyl by the gravimetric Zeisel method was found to contain 39.2 per cent. by the present method. Unsatisfactory results were obtained with a sample of methyl benzoate and with one of hydrated quinine sulphate. This comparatively rapid method for the estimation of methoxy 196 HPWIT!C AND JONES: groups may be applied conveniently to the products of wood dis-tillation or other mixtures containing methyl alcohol.Methyl dcohol has asually been estimated in these products by conversion into methyl iodide and measurement of the volume of the latter compound (Krell Ber. 1873 6 1310; Grodzky and Kriimer ibid. 1492). Zeisel and Stritar's process of weighing volatilised iodine as silver iodide obviates the inexactness due t o determination of the volume of the methyl iodide but time may be saved by combining the methyl iodide with a tertiary base and estimating the iodine volumetrically . A suitable amount (see below) of the liquid to be analysed is heated with 20 C.C. of hydriodic acid (D 1.7) for one hour.The contents of the test-tubes are then completely washed into a graduated flask and made up with water t o 100 C.C. An aliquot portion (see below) of the diluted solution is introduced into a glass stoppered bottle of 250'c.c. capacity 70 C.C. of water are added and tihen in order 25 C.C. of NIIO-silver nitrate solution and 30 C.C. of approximately IOlV-nitric acid. The bottle is well shaken by hand for five minutes and 5 C.C. of concentrated ferric alum indicator are added. N / 10-Thiocyanate solution is now run in until further addition of one drop imparts a permanent orange cdour to the liquid. Suitable amounts of liquids to be taken for analysis are given below. a represents the volume of material to be operated on and its dilution when necessary.b gives the volume of the diluted aqueous pyridine solution, obtained as described above to be actually used in a titration. c is the formula to be used giving the weight in grams of methyl alcohol in 100 C.C. of the liquor analysed where t is t'he number of C.C. of N/lO-thiocyanate solution used in the titration. (Note.-The figure 25 given in the formulze must be multiplied by f the factor for the silver nitrate solution if this is not exactly deci-normal. ) Pyroligncous Acid.-(a) Take 5 C.C. of the original liquor; ( 6 ) 40 c.c.; ( c ) 0.16 ( 2 5 - t ) . Crude Wood Naphtha.-(a) Take 10 c.c. dilute to 100 c;c. with water and use 5 C.C. of the diIuted solution for distillation with hydriodic acid; ( b ) 40 C . C . ; ( c ) 1.6 (25 - t ) .Methyl Alcohol and Mixtures o./ the Alcohol with Acetone.-(a) Take 10 c.c. dilute to 100 C.C. with water and use 5 C.C. of this diluted solution for the estlimation; ( b ) 20 c.c.; ( c ) 3.2 (25- t ) THE ESTIMATION OF TEE METHOXYL GROUP. 197 Amlyses. Art.ificia1 mixtures containing methyl alcohol and other products of wood distillation were made up and analysed by the mebhod described. Composition. No. of grams of methyl alcohol per 100 C.C. of liquor. Number. Actual. Found. Liquor 7-1 ........................ 2.39 2.35 2 ........................ 68.5 68.1 3 ........................ 2.39 2-35 4 ........................ 31-8 31.6 Anklyses of purified methyl alcohol by the present method have already been given. It will be seen that on an average the results are 1 per cent.too low. Stritar and Zeidler (Zeitsch. anal. Ckem. 1904 63, 387) found that the maximum amount of methyl iodide obtainable from pure methyl alcohol in a Zeisel estimation corresponded with a 99 per cent. yield. Liquors 1 and 2 were aqueous solutions of purified methyl alcohol. Liquor 3 contained per 100 c.c. 7-03 grams of acetic acid 0.80 gram of acetone and 2.39 grams of methyl alcohol the remainder being water. It represented a pyroligneous acid. Liquor 4 was an equilibrium mixture prepared from 10.04 grams of acetic acid 39.60 grams of acetone and 31.82 grams of methyl alcohol made up to 100 C.C. with water (1.27 grams). This mix-ture which of course contained methyl acetate represented the first runnings obtained in the rectification of crude wood naphtha.Compounds yielding Meth4yl Iodide other t h m Methyl AZcohd, present in Wood Distillates. The constituents of wood distillates have been examined by Stritar and Zeidler (Zoc. cit.) with a view to determine which yield methyl iodide on treatment with hydriodic acid. They found that acetone gave no methyl iodide whilst the yield from both form-aldehyde and acetaldehyde was negligible. Methyl acetate gave one equivalent. of methyl iodide and methylal and dimethylacetal each gave two. Ally1 alcohol yielded its equivalent of sec.-propyl iodide. Guaiacol and other methyl derivatives of the phenols yielded their equivalent of methyl iodide. Of these substances the quantities of acetd encountered are too VOL. axv. 198 FRANKLAND CHALLXNGZR AND NIOgOLLS : small to be of consequence.According to Grodzki and Kriimer (Zoc. cit.) the amounts of allyl alcohol and of methyl alcohol in raw wood spirit are in the ratio of 2 t o 1000. Stritar and Zeidler find that guaiacol may be .eliminated from aqueous solutions of crude wood spirit by shaking with animal charcoal. They state that on omitting this treatment the amount of methyl alcohol found is t,oo high by about 2 parts in 100 parts. It will be seen that the quantities of alkyl iodide yielded by the amounts of allyl alcohol and of guaiacol present in the aqueous wood distillates, relatively to that yielded by the methyl alcohol present border closely on the experimental error. It is the experience of the authors that where precautions are taken t o eliminate these sub-stances preliminary t o analysis the errors due to losses outweigh the error introduced through ignoring their presence. The present method gives the total methyl alcohol including both the free alcohol and that which is combined as methyl acetate. I f it is desired the amount of ester present may be determined by quantitative hydrolysis. The alcoholic silver nitrate of the Zeisel method of estimating methoxyl may be replaced by pyridine. The pyridinium methyl iodide formed can be determined by Volhard's thiocyanate method. Methyl alcohol in wood dist'illates may be determined by the method described above. [Received January 171h 19 19.

ISSN:0368-1645    

DOI:10.1039/CT9191500193

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年代:1919

数据来源: RSC

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198 FRANKLAND CHALLXNGZR AND NIOgOLL$ : XXILIL-The Prepayati0.n of Moiiomethyladine. By PERCY FARADAY FRANKLAND FREDEEICK CHALLENGER and NOEL ALBERT NICHOLLS. WHEN aniline is submitted to the action of the usual llzethylatillg agents it is difficult to limit the course of the reaction to the intro-duction of a single methyl group. We have investigated the pro-duction of monomethylaniline by three methods with a view t o obtain it in a pure condition. (1) The process described in the German Patent 75854 and with slight modifications in the French Patent 212506 consists in con-densing aniline with formaldehyde and then reducing with zinc dust and concentrated aqueous sodium hydroxide until a test por-tion dissolves t o a clear solution in acetic acid. Any unreduced methyleneaniline CH,:N*C',II, is thereby converted into insolubl THE PREPARATION OF MONOMETHYLAN1L;fNE.199 anhydroformaldehydeaniline (CH,:N*C,H,),. Using 100 grams of aniline we have found the reduction to be completed in twelve to fifteen hours and have obtained about 55 per cent. of the theoretical yield of methylaniline. The Patent Specificatiolns make no mention of the yields obtained. The principal advantage of this method lies in the fact that the product although rich in aniline contains only traces of dimethyl-aniline. The presence of the aniline may be the result of incom-plete condensation with formaldehyde in the first instance or of the hydrolysis of the methyleneaniline by the hot water or of both causes. The primary base can be recovered in the form of its zincichloride which is almost insoluble in water the methylated bases not being affected by this reageat (Monutsh.1888 9 514). The method appears t o work very satisfactorily. Morgan (English Patent 102834) who has also studied the reduc-tion of methyleneaniline suggests that the poor yield of methyl-aniline may be due in addit.ion to hydrolysis to the conversion of some of the methyleneaniline into s-dipheriylmethylenediamine, CH,(NH*C,H,)2 and anhydrof oraaldehydeaniline . We have failed to obtain more than traces of monomethylaniline from the last-named substance (compare however Goldschmidt Chem. Z e i t . , 1904 28 lZZ9) but when s-diphenylmethylenediamine (Eberhardt and Welter Ber. 1894 27 1804; Eibner Annalen 1898 302, 349) is reduced with zinc dust and alkali hydroxide under the con-ditions of the earlier patents aniline and monomethylaniline are produced in equal amounts probably according to the equation CH,(NH*C,H,) + 2H = C,H,*NH2 + C,H,*NH*CH,.We attempted to diminish the hydrolysis by performing the reduction in concentrated alcoholic solution. The yield of methyl-aniline was however only about 46 per cent. No better results were obtained by increasing the quantity of formaldehyde; 1.5 molecular proportions gave rise t o some dimethylaniline whilst with 10 molecular proportions considerable quantities of this base were foxmed.* This appears t'o be due to the interaction of monomethylanihe and formaldehyde giving rise t.0 s-diphenyldimethylmethylene diamine which then undergoes reduction.This reaction would, moreover be analogous to the reduction of s-diphenylmethylene diamine. The condensation productl of formaldehyde and methyl-* Compare the action of formaldehyde on methylaniline in acid solution (Goldschmidt Zoc. cit.) and on methyl-o-toluidine (Braun Ber. 19OS 41 2153), also on ammonium chloride (Werner T. 1917 112 844). Sea also Yinnow,. Ber. 1894,27 3166; Cohn Chem. Zeit. 1900 24 564. K 200 ERANKLAND CHALLENGER AND MUHOLLS : aniline (Braun Ber. 1908 41 2147) was therefore prepared and reduced under the usual conditions with the result that much dimethylaniline was produced. (2) The process described in various works of reference consists in heating aniline hydrochloride with methyl alcohol in an auto-clave to 180-200°.s The best result obtained by us in a series of thirteen experiments was a 55 per cent.yield of monomethylaniline. Experiments in sealed tubes confirmed these results. We have also investigated a variation of the above method in which aniline hydrochloride and methyl alcohol are heated together in the presence of glacial acetic acid (Ber. 1897 30 3072). The most favourable result was a yield of 56 per cent. of methylaniline. (3) The demethylation of dimethylaniline by heating with aniline hydrochloride a t above 1 8 0 O . In the most favourable experinients, a yield of 55 per cent. of methylaniline was obtained. Aniline was also heated’to a high temperature with dimethylaniline hydro-chloride with similar results but it was found necessary to heat f o r a much longer period.This was probably due to the more basic nature od dimethylaniline. A condition of equilibrium between the three bases and hydrochloric acid would appear t o be established. At the time these experimenh on demethylation were performed (1916) we were unable to find any record of similar work on this subject apart from the well-known phenomenon of the transfer a t above 300° of alkyl groups from nitrogen to the ring. According ta Schultz (“ Chemie des Steinkohlentheers,” 1900, 3rd ed. I p. 98) monoethylaniline may be prepared by heating aniline hydrochloride with diethylaniline. No yields or references to the original literature are given but the reactJon is obviously not quantitative since it is stated that the hydrochloride of diethyl-aniline remains in solution.EXPERIMENTAL. Prepmatiom of Monornethyla,n&ne accwding t o D.R.-P. 75854. Materials Used.-One hundred grams of aniline 80.5 grams of formaldehyde (37 per cent.) 30 grams of methyl alcohol 25 grams of sodium hydroxide solution (D 1-38) 150 grams of zinc dust, 1 litre of water and 225 grams of sodium hydroxide solution. monomethylaniline obtained in this way are very contradictory. See Wahl-Atack “Organic Dyestuffs,” p. 70 ; Cdn ‘* Intermediate Products,” p. 61 ; Lunge ‘‘ Chem. Tech. Untersuchungsmethoden,” Vol. III. p. 761 ; Friedkinder, “ Fortschritte der Teerfarbenfabrikation,” 1877-1887 p. 6. * The published statements concerning the yields o THE PREPARATION OF BZON0METRYLANIL;INE. 201 The first four ingredients were mixed in a widemouthed bottle fitted with a stirrer and avreflux condenser the zinc dustl and water then added and the temperature raised to about 90° The remainder of the sodium hydroxide solutio'n was gradually intro-duced and the stirring continued a t this temperature until after about twelve to fifteen hours the methyleneaniline had disappeared.The bases were then distilled in a current of steam extracted with ether and a portion convert,ed into the nitrosoamine. Yield of bases 102 grams. Theory=115 grams. Thirty grams of the mixture gave 23 grams of dry phenylmethyl-nitsosoamine whence t.he total yield of monomethylaniline is 54.5 per cent. of the theoretical. P r e p r a tioia of Monom e t h y la nili n e according to Fr enc 11 Pat e n t 212506. I n these experiments the quantities of material and method of procedure were as described above with the exception that the whole of the sodium hydroxide solution was added a t once.In one case where particularly efficient stirring was employed, the methyleneaniline had disappeared in six and a-half hours. I n this experiment the mixed bases contained 65 per cent, of mono-methylaniline (by the nitrosoamine metho'd of analysis) correspond-ing with a4yield of 51.5 per cent. Other experiments with the same quantities and under similar conditions gave yields of 41.5 and 53.5 per cent. of the theoretical quantity of monomeljhyl-aniline. Reduction in the Presence of Excess of Formaldehyde. I n two experiments on 100 grams of aniline in which 0.5 mole-cular proportion of formaldehyde was used in excess the yields of monomethylaniline were 46.5 and 55 per cent#.I n the first case, about 17 grams of the hydrochloride of p-nitrosodimethylaniline were obtained on nitrosificabion. With an excess of 9 molecular proportions of formaldehyde two experiments according to the German Patent gave scarcely any monomethylaniline ; the reactions proceeded very slowly and in one case much dimethylaniline was produced. Reduction in Concentruted Alcoholie Solution. One hundred grams of aniline 25 grams of formaldehyde (36 per cent.) 840 grams olf alcohol 88 grams of solid sodium hydr 202 FRANKLAND CHALLENGER AND NICHOLLS : oxide 25 grams of aqueous sodium hydroxide (D 1-38) and 150 grams of zinc dust' were vigorously stirred together. The reaction was complete in seven and a-half hours a t about 60° and the yield of methylaniline was 46.5 per cent.of the theoretical. Reduction o f s-niphen?/Zmeth?/leitediamz'ne. Thirty grams of s-diphenylmethylenediamine 125 grams of sodium hydroxide solution (D 1-38) 75 grams of zinc dust 500 C.C. of water and 25 grams of alcohol were mixed and vigorously stirred for ten and a-half hours a t 70-90°. When a portion dissolved to a clear solution in dilute acetic acid (in which s-diphenylmethylene-diamine is but sparingly soluble) the products were distJlled in a current of steam. Twenty-two grams of mixed bases were obtained which gave 13 grams of phenylmethylnitrosoamine corresponding with a yield of 10.2 grams of monomethylaniline. From the diazonium chloride solution 10 grams of phenol mere isolated corresponding with 10 grams of aniline.Rduction o f the Condensation Product of Formaldehyde arid Mon onze t hy Zaniline. Fifty grams of monomethylaniline 19 grams of formaldehyde (36 per cent.) and 5-10 C.C. of aqueous so'dium hydroxide were mixkd well shaken and allowed t o remain overnight. The condensation product was separated by extraction with ether and reduced with a mixture of 150 grams of zinc dust. 1000 C.C. of water 60 grams of methyl alcohol and excess of sodium hydr-oxide solution a t about< 80°. After one and a-half days the bases (44 grams) were removed by steam distillation. Nitrosification showed the product to contain 35 grams of monomethylaniline, whilst 9 grains of ~~-nitrosodimethylanili~ie hydrochloride were obtained.In these experiments the methylaniline was determined as the nitrosoamine and the aniline as phenol after decomposition of the diazonium salt. Dimethylaniline was separated and weighed as p-nitrosodimethylaniline hydrochloride but as some of this always remained in solution the figures for the tertiary base are low THE PREPARATION OF MONOMETHYLANILINE. 203 I n experiment 8 aniline (140 grams) and sulphuric acid (16 grams) were used instemad of aniline hydrochloride. Experiments 9-13 were made in sealed tubes and in Nos. 11 12 and 13 acetic acid (12 grams) was added. Percentqge yield Aniline Time w-Experi- hydro- Methyl Tempera- in Methyl- Dimethyl-ment. chloride. alcohol. ture- hours. Aniline. aniline. aniline. 1 110 32 180" 24 - 48.0 -2 110 32 180 24 27.0 51.5 -3 110 32 180 21 25.5 53.0 16.5 4 220 64 180 '' 36-0 52.0 7.0 5 220 64 190 gi 34.0 55.0 7.0 180 44 26.0 53.0 10.0 180 3 - 45-0 20.0 7 220 96 8 140 84 190 41 32.0 40-5 16.0 10 22 7.0 175 6 13.0 54.0 13.0 11 22 6.4 170 5 - 56-0 -12 22 6.4 225 3 - 41.0 -13 22 6.4 220 3 - 47.5 -above 6 220 64 9 22 6.4 180 32 19.0 58.0 11.0 MethyJatim of Aniline under otlher Conditions, (1) Twenty-six grams of aniline hydrochloride 7 grams of methyl alcohol and 25 C.C.of hydrochloric acid were heated in a sealed tube for six hours a t 200-210°. Nitrosoamine=13.5 grams; yield of methylaniline = 49-5 per cent. (2) Thirty-six grams of aniline zincichloride and 6.4 grams of methyl alcohol were heated in a sealed tube for seven hours a t 1 8 0 O .Nitrosoamine = 7.5 grams ; yield of methylaniline = 28 per cent. (3) Twenty-two grams of aniline hydrochloride 6.4 grams of methyl alcohol and 15 grams of anhydrous calcium chloride were heated a t 160° for three hours. Nitrosoamine=lO grams; yield of methylaniline= 43 per cent. (4 and 5). Twenty-eight grams of aniline (in the presence of 0.2 gram of iodine) were heated in one case with 10 grams in another with 6.5 grams of methyl alcohol f o r nine hours a t about 220° (Knoll and Co. D.R.-P. 250236). I n both cases nitroso-amine= 15 grams. Yield of methylaniline=42 per cent. The Dem e t hylation of Dime t h y luniline. First Series.-Interaction between aniline hydrochloride (13.0 grams) and dimethylaniline (1 2.0 grams) in molecular proportions in sealed tubes 204 THE PRDPARATIOW OF MQNOMETHYLANILLNE.Time Nitr?so- Percentage Experiment. Temperature. in hours. amne. rnonornethyEk2 1 180' 6 12.5 46 2 200 6 16.0 65 3 230-236 5! 15.0 55 Second S e ries.-Inter action be tween cl j met hylaniline hydro-chloride (31.5 grams) and aniline (18.6 grams) in molecular pro-portions in sealed tubes.* Time Nitroso- Percentage yield of Experiment. Temperature. in hours. amine. monomethylaniline 1 180" 3 4 14.5 2 180 6 11.5 21.0 31 200 13 28.0 51.0 1 In Experiment 3 about 5 grams of a white solid separated on diluting the contents of the tube. This melted indefinitely at 144" and after crystellisa-tion from light petroleum indefinitely a t about 160'. It was only superficially examined and appeared to be a tertiary halogen-free base possibly containing methyl groups in the benzene nucleus.When 12 grams of dimethylaniline and 9.5 grams of aniline (molecular proportions) were heated for three hours a t 220° prac-tically no monomethylaniline was produced. Demethylation was found to occur when the two hydrochlorides were heated for three hours atl 180O; thus 13 grams of aniline hydrochloride and 15.8 grams of dimethylaniline hydrochlorid'e (molecular proportions) gave 5 -5 grams of the nitrosoamine corre-sponding with a 20 per cent. yield of monomethylaniline. The Separation of dilailine a d Monomet17??llai1ilinf using Zin\c Chlo.ride. A mixture of aniline and monomethylaniline was treated with an aqueous solution of anhydrous zinc chloride.The precipitate was collected and thoroughly washed with light petro,leum. After evaporation of the solvent the residue of crude methylaniline was weighed and converted into the nitroso-derivative which was removed from the mixture by extracting t7hree times with ether, dried and weighed. The acid liquid which remained after the removal of t h s nitroso-amine and contained traces of benzenediazonium chloride was heated saturated with salt the phenol extracted with ether and finally weighed. The aqueous filtrate from the zincichloride pre-cipitate contained practically no aniline or methylaniline hydro-chlorides. * In Experiment 1 half these quantities were employed EQUILIBRIA IN THE FLEPUCTION OF OXXDEE BY CARBON. 205 The accuracy of this method was checked by regeneration of the aniline from a given weight of the zincichloride Andytical Results.-l’alcem Aniline 20 grams methylaniline 20 grams fused zinc chloride 22 grams water 50 C.C. Obtained .- Zincichloride 37 grams whence aniline= 19.2 grams. Phenylmkthylnitrosoamine 23.7 grams whence methylaniline = 18.7 grams. There was also obtained 0.5 gram of bases from the aqueous filtrate from the zincichloride. Phenol 0.25 gram whence aniline=0*25 gram. THE UNIVERSITY, BIRMINGHAM. [Received February 6th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9191500198

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

EQUILIBRIA IN THE REDUCTION OF OXIDE8 BY CARBON. 205 XXI V .-Equilibria in the Reduction of Oxides by Carbon. By ROLAND EDGAR SLADE and GEOFFREY ISHERWOOD HIGSON. Equilibria of some reactiolns of the type: or have been investigated. I n either of the above systems there are three components, namely metal carbon and oxygen and four phases namely, metlal metal oxide carbon (or carbide) and carbon monoxide (gas). The number of degrees of freedom is thus 3 + 2 - 4 = 1. Therefore a t one temperature there is one pressure of carbon monoxide which determines the equilibrium of the syst'em The following experimental met'hod was adopted. A small quantity of the metal was heated in a vacuum to a certain texnpera-ture and carbon monoxide was then admitted until the pressure was greater than the equilibrium pressure.The reaction pro-ceeded in the direction from right t o left and carbon monoxide was absorbed until the equilibrium pressure was attained. Some carbon monoxide was then removed when the reaction proceeded from left to right until the equilibrium pressure was again attained. If the carbon formed in the first part of the experiment did not remain as a separate phase either as a carbon o r as a carbide but formed a solid solutlon with the metal there would be only t'wo solid phases present with the gas phase; the system would there-metal oxide + carbon carbon monoxide + metal metal oxide + metal carbide t carbon monoxide +metal K 206 SLADE AND HIGSQN EQUILIBRIA IN THE fore have two degrees of freedom and the pressure of carbon mon-oxide would depend on the relative amounts of metal and carbon present as well as on the temperature.When the equilibrium was attained from left to right there was less carbon monoxide present than when the equilibrium was attained from right to left, therefore the equilibrium pressures would have been different in these two cases if there were only two solid phases present. The equilibrium may be caIcuIated from the heat of reaction by making use of the Nernst heat theorem. where M is the weight in grams of any metal combining with 16 grams of oxygen and QC is the heat of reaction; in all cases Qt is positive so that increase in temperature will cause the form-ation of M+CO. That is to say pCo increases with the tempera-ture. This quantity of heat @ may be considered as the differ-ences of two quantities of heat Q1 and Q2 for if we write I n the reaxtion .. . . . . . M+CO=MO+C+Qt (1) (2) M+O=MO+& . . . . . . CO =C + 0 + Q2 (3) . . . . . . . then on addition M + CO = MO + C+ (Q1 + Q2). dissociation of carbon monoxide is - 29,000 calories therefore Q2 t#he heat of . . . . . . . &t= &I- 29,000 (4) Neglecting terms containing % the Nernst heat theorem requires that logpuo = ____- -‘O +1*76 log T + 2 6 . . . ( 5 ) 4.571 T where &, is the heat of reaction a t absolute zero. value given by Weigert in Abegg’s “ Handbuch.” between Q0 and Qt is given by the equation The thermodynamic constant used for carbon monoxide is the The relation . . . . . . . Qo=Qt+3*5T ( 6 ) Limits of the 1nuestigation.-The equilibrium mentioned above could only be determined a t temperatures a t which the equilibrium, is practically completely in the left-hand direction.Rhead and Wheeler (T. 1910 97 2187; 1911 99 1140) have investigated this equilibrium and from their results it is possible to calculate the partial pressure of carbon dioxide in equilibrium with carbon monoxide a t 760 mm. or 50 mm. These values are given in table I. 2co = CO,+ c REDUCTION OF OXIDES BY CARBON. 207 TABLE I. Pressure of carbon dioxide in mm. when prossure of carbon monoxide Temperature. is 760 mm. 850' 53.8 900 17.6 1000 4.6 1100 0.90 1200 0.46 Pressure of carbon dioxide in mm. when pressure of carbon monoxide is 50 mm. 0.23 0.076 0.0020 0.00082 0*00020 From these figures i t is seen that i f the equilibrium pressure is as low as 50 mm.there is no complication due to the presence of carbon dioxide at temperatures from 850° upwards. If however, the pressure is as great as 760 mm. the amount of carbon dioxide present is appreciable up t'o 1200O. If a carbide is present instead of free carbon the ratio of carbon dioxide to carbon monoxide will be greater for we have P2E- = K, Pco2Pc and pc (partial pressure of carbon vapour) will be lower over a carbide than over carbon. I n all our experiments the equilibrium pressures were sufficiently low and the temperature was sufficiently high for the pressure of carbon dioxide to be negligible. The metals with which we could determine the above equilibrium were only such as would fulfil the following conditions (1) The metals must not be volatile a t the temperature of the experiments.At these temperatures the vapour pressure of the metal should certainly not be more than 0.25 mm. o r it will distil rapidly on to parts of the platinum tube which are a t a somewhat lower temperature and probably attack the platinum. Platinum tubes were in fact destroyed by the volatility of boron and manganese. (2) The equilibrium pressure must not be greater than 50 mm. at 850° or the quantity of carbon monoxide in the gas phase will be appreciable. (3) The equilibrium pressure must be sufficiently great to be measurable. It must be a t least 1 mm. a t 1300O. Applying the Nernst heat theorem to the equilibrium we should only expect those elements of which the heat' of oxidation per gram-atom of oxygen lies between 75,000 and 114,000 calories to give an equilibrium pressure measurable in our apparatus.Of sub-stances with known heats of oxidation only silicon boron and manganese lie within this range. The only likely metals for which. K* 208 SLADE AND HIGCSON EQUILIBRIA IN 'THE the heats of oxidation were unknown and which were readily obtainable were vanadium tantalum and chromium. ,4 ppzratzcs.-The furnace which has been described by Slade (Proc. Roy. Soc. 1912 [A] 87 519) consists of a platinum tube 2 cm. in diameter heated by a current of 300 t o 400 amperes a t 2 to 4 volts. The furnace is placed in a vessel which can be ex-hausted to prevent the platinum tube from collapsing under the pressure of the atmosphere.A silver capillary tube is used to connect the furnace with the glass tube leading to the pressure gauge. The temperatures were dete'rmined by means of a platinum platinum (90 per cent.)-rhodium (10 per cent.) thermo-couple. The couple was calibrated up to the melting point, of copper 1083O and higher temperatures were determined by extrapolating by means of the formula log e = 1.22 log t - 2.65, where t is expressed in degrees centigrade and e in millivolts. The cold end of the couple was kept' a t Oo. It was found to be impossible to use a platinum boat for any of the substances investigated for although the temperatures were well below their melting poiints they were rapidly alloyed with platinum.Accordingly boats of unglazed Royal Berlin porcelain were employed. Pressures were read on a mercury vacuum manometer behind which was a glass millimetre scale illuminated by a lamp and a milk-glass screen. The readings were made with a telescope and were accurate to i-0.05 mm. The carbon monoxide was prepared by running pure formic acid into concentrated sulphuric acid a t 70-80°. The gas which was first passed through a long tube of soda-lime and then through a similar tube of phosphoric oxide was collected and stored over mercury in a vessel of 1 litre capacity. The gas was led from the reservoir to the furnace and pressure gauge by means of a tube in which were placed two taps separated by a capillary tube of such dimensions that the volume between the tlwo taps was 0.2 C.C.By filling this tube with carbon mon-oxide a t the ordinary temperature then closing one tap and open-ing the other 0.2 C.C. of carbon monoxide was allowed to flow into the exhausted furnace and the tubes connecting the furnace to the gauge and pump The total volume of this part of the apparaius was about 50 c.c. and when the furnace was heated t o about 1200° ibs effective volume was about 30 c.c. so that the introduc-tion of 0-2 C.C. under a pressure of one atmosphere caused a rise of pressure of o?ahosphere or about 5 mm. of mercury. 3 REDUCTION OF OXIDES BY CARBON. 209 I n most of the experiments 0.1 gram of the metal under investi-That this was sufficient may gation was introduced into the boat. be seen from ths following considerations.M + CO = RIO + C, If the reaction is where 11 is two equivalents of an element then two gram-equi-valents of the element would react wit-h 22,400 C.C. of carbon mon-oxide. I f the pressure) in the furnace was 60 mm. which was the maximum pressure used in several cases the volume of gas con-tained in the furnace was 2.4 C.C. when measured a t N.T.P. there-fore to absorb all t,his gas '.* x 2 = 2.2 x 10-4 gram-equivalent 23,400 of the element would be required. If the equivalent were as great as 100 only 0.02 gram would be required. The metal was usually broken into small pieces as the velocity of the action must be proportional t o the surface exposed. Experiments with Vanadium.-As vanadium is a very refractory substance and is difficultly reducible (that is the oxide has a high heat of formation) it was decided to attempt to measure the reduc-tion equilibrium.Some preliminary experiments were made on the action of vanadium on platinum and the melting point of vanadium. The vanadium was placed in very small pieces (about 0.5 mm. in diameter and less) on a platinum strip which was heakd in an atmosphere of hydrogen by an electric current.. . A t 1400° the vanadium adhered to the strip when the heating had been carried on for some three minutes. The temperature was determined by means of a Wanner pyrometer correction being made for black-body radiation of the platinum. In another experiment the strip was dusted with powdered vanadium and heated rapidly until it fused a t one point. Examination under the microscope showed that the vanadium had then fused into globules just round the portion of the strip which had fused.The melting point of this vanadium is tberefore just below the melting point of platinum, namely 1760O. The vanadium had been prepared in the electric furnacel and contaiqed 4.6 per cent. of carbon. The carbon prob-ably exists as the carbide VC and may be present in solid mlu-tion although the fact that so much carbon is present makes i t seem probable that the carbide exists as a separate phase. Experiments.-O.0636 Gram of the metal was placed in an un-glazed porcelain boat in the platinum tube furnace. The furnace was exhausted and left for sixteen hours when no rise of pressure was noticeable. The temperature was raised to 1000° and the occluded gas from the boat pumped off; 0.2 C.C.of carbon mon 210 SLADE AND HICISOX XQUTLIBBIA IN THE oxide was then admitted and this raised the pressure to 6 mm., at which it remained. Therefore the equilibrium pressure was greater than this or the velocity of reaction a t this temperature was very mall. The latter was found to be the case for when the pressure of carbon monoxide had been increased to 60 mm., there was still no reaction. The temperature was t'hen raised to 1340° and maintained a t this temperature for four and a-half hours During this time the pressure fell a t first rapidly and finally became steady a t 1 - 7 mm. The temperature was then reduced to 1145O where it was maintained for thirty minutes. The pressure fell rapidly to D-55 mm.where it remained constant. The temperature was then lowered to 900° when the pressure fell only to 0.2 mm. On the following day the furnace was heated to 1340O and the temperature kept constant. I n one hour the pressure rose to 1.2 mm. a t which it remained constant for three and a-half hours. The equilibrium pressure a t 1340O was therefore between 1.7 and 1-3 mm. The mean of these values is 1.45 mm. At lower temperatures the equilibrium was attained too slowly to be deter-mined. The reaction is probably The value vo-I-vc -f 2V+CO+Q. p c o = __- 1'45 atm. at 1340' 760 gives by the Nernst heat theorem the value Q0= 80,875 cals. Substituting this in equation ( 5 ) we find that p,,=1 atmosphere a t 1827O. This is the temperature a t which vanadium oxide would be reduced by the carbide under a pressure of one atmosphere.There is no direct evidence as t o the heat of formation of vanadium carbide that is of the reaction v+c -f vc, but usually the heats of formation of carbides are small (Warten-berg Zeitscla. anorg. Chem. 1907 52 299) that is to say not greater than 2000-3000 calories per gram-atom of carbon. If this heat of formatmion of the carbide is neglected an approximate value of the heat of oxidation of vanadium at 20° can be obtained : V.+O=VO+ 111,000 cals REDUCTION OF OXIDES RY CARBON. 211 Not much trust can be placed in this value however for the carbide may be in solid solution in the metal and not as a separate phase. Ezpem'ments with Tan8talum.-The tantalum used was a portion of a specimen obtained from the late Dr.Werner von Bolton and used by von Hevesy and Slade to determine the electrode potential of tantalum. It was in the form of a rolled sheet about 0.25 mm. thick. As only a small quantity of the metal was available 0.035 gram was used in each experiment. If the tantalum was oxidised to the oxide Ta,O this metal would absorb 3.5 C.C. of carbon monoxide. I n the first experiment with t'antalum the metal was in the form of one piece of sheet. At. 1000° 2 C.C. of carbon monoxide were admitted (p=60 mm.); the pressure fell and in two hours became constant a t 0.7 mm. The temperature was then raised to 1200O and 0.6 C.C. of carbon monoxide was admitt'ed so that the pressure was raised to 14 mm. As the pressure did not fall more carbon monoxide was admitted until the pressure was 40 mm.but there was still no action. The furnace was therefore exhausted but no appreciable rise in pressure took place in two hours. It therefore seemed probable that the constant pressure of 0.7 mm. obtained a t 1000° was not a true equilibrium pressure, but that the equilibrium pressure even atl 1200° was very low indeed. I n the next experiment the same quantity of metal was used, but i t was cut into as many strips as possible in order to increase the surface. After pumping outl all gases from the boat a t 1150°, 0.4 C.C. of carbon monoxide was admitted so as to raise the pressure to about 13 mm. In half an hour the pressure fell to 0.2 mm., and then became constant and remained so for half an hour.An attempt was now made to reach the equilibrium from the low pressure side. The furnace was exhausted and the temperature was raised to 1270O. In four hours the pressure rose slightly above 0.1 mm. (perhaps 0.12 mm.) and remained constant for about three hours. Carbon monoxide (about 0.1 c.c.) was then admitted to raise the pressure to 2.5 mm. and in one hour the pressure fell t o 0.1 mm. This value is therefore the equilibrium pressure a t 1270O. It was impossible to determine the equilibrium a t a higher temperature because a t this stage o€ the work the platinum tube had become weakened and slowly collapsed when kept exhausted for several hours a t 1270° although the external pressure on the tube was only 30-40 mm. of mercury. Experiments with Chromium .-The temperature of reduction of chromium sesquioxide was determined by Greenwood (T.1908 93 , 1438) who found that this oxide was reduced at 1195O under 212 SLADE AND HIGISON EQUILIBRIA IN T-nE prmsure of 2 mm. The boiling paint of chromium is 2200O (Green-wood) and from this value the vapo'ur pressure of liquid chromium can be calculated to be 0.07 mm. a t 1000°7 0.078 mm. at l l O O o , 0.7 mm. a t .1200° and 1-12 mm. a t 1300O. It was therefore not safe to heat chromium to a much higher temperature than 1200O in the platinum furnace. The chromium had been prepared by the Goldschmidt method, and therefore contained a trace of aluminium. As aluminium is e a d y and completely oxidised by carbon monoxide it is probable that it would only have a very slight influence on the equilibrium.0.45 Gram of metal in the form of a coarse powder was us'ed in the first experiment'. The furnace was heated to 936O and all adsorbed gases were pumped out. Carbon monoxide was then admitted until the pressure was 100 mm. I n nine and a-half hours the pressure fell to 22 mm. but did not appear to be, approaching a steady value. After remaining for eighty-five hoars, the furnace was heated to 1O1Oo and carbon inonoxide admitted until the preasure was 50 mm. I n six hours the pressure fell t o 0.75 mm. and appeared to be coast'ant. After eighteen hours the temperature was raised to 1292O and carbon monoxide admitted until the pressure waB 63 mm. In forty-five minutes the pressure fell to 6.2 mm. and remained const*ant. Carbon nionoxide was then pumped out until the pressure fell t o 5 mm.In fifteen minutes the prkssure rose to 6.2 mm. and remained constant. The temperature was then raised to 1339O and in twenty-five minutes the pressure had risen to 9.1 mm. and become constlant. The furnace was then cooled and next day was heated t o 1339O. I n twenty minutes the pre-ssure rose to 9.2 mm. The furnace was now cooled to 1292O and carbon monoxide was pumped off until the pressure was less than 1 mm. I n an hour t h s pressure became constant a t 4.4 mm. The furnace was cooled and the next day w m heated to 1292O; the pressure rose t o 4.4 mm. Carbon mon-oxide was then admitted until the pressure was 8.6 mm. I n forty-five minutes the pressure fell to 4.4 mm. The temperature was now raised to 1339O when the pressure rose to 9.2 mm.In the figure are given some of the time-pressure curves obtained. These show how accurately the results could be reproduced. A new sample of chromium (0.45 gram) was now introduced into the furnace and the temperature was raised to 129207 carbon mon-oxide being admitted until the pressure was 15 mm. In twenty minutes the pressure fell to 6.2 mm. and remained constant a t this value for one hour. The temperature was then raised to, 1339O and the pressure rose to 9.1 mm. but the platinum tube began to leak owing to its being attacked by the chromium which had distilled on to i t during this and former experimentn REDUCTION OF OXIDE8 BY OARBON. 213 Table I1 ehows the values for the equilibrium pressure obtained with chromium.All these equilibrium pressures were obtained twice from each side. The high value at 1292O is the value obtained when the furnace had not been raised t o a higher tempera-ture. After the temperature had been raised to 1339O and lowered again to 1 2 9 2 O the equilibrium pressure was 4.4 mm. and this value could be obt'ained again and again. Since chromium easily forms a carbide i t is probable that. the reaction taking place was 5Cr+CO Cr,C+-CrO+Q. 1 2 3 1 1 2 3 Time in hours. Calculating the heat of reaction per gram-atom of oxygen a t 1315O from the Nernst formula and the van't Hoff formula the values given in table I1 are obtained. TABLE 11. Pressure of carbon monoxide Qt calculated &t cdcul&tted, Temperature. in mm.Nernst. van't Hoff. 1292" 6-2 73,600 -1339 9.2 69,200 1292 4.4 69,200) 77,000 The value 77,000 calories is the heat of reaction calculated from the integrated form of the van't Hoff equation, I n this method of calculating Qt an error of 0.1 mm. in the deter-mination of the equilibrium a t 1293O would make a difference of a little more than 1000 calories in the value of Qt. The assump-$ion on which this formula is based however is only that the hea 214 EQTTlTJBRIA IN THE REDTTCTION OF OXIDES BY CARBON. of reaction does not change appreciably between the two tempera-tures. That two different values were obtained for the equilibrium at 1292O according to whether the furnace had been heated up to 1339O or not must be explained by supposing that the substances in equilibrium were different in the two cases.It is very improb-able that the first value is due to the presence of a trace of aluminium in the metal for the presence of aluminium would be expected to lower rather than to raise the equilibrium pressure, and in the two experiments in which the pressure was 6.2 mm., very different amounts of carbon monoxide had been absorbed by the same amount of metal. I n the first experiment 6-7 C.C. of carbon monoxide and in the second case only 0.6 c.c. were absorbed. The equilibrium in the gas phase is represented by = K . P c r r ~ e 2J)oxinr pll,etd The change in the system caused by raising the temperature to 1339O was to give a lower equilibrium pressure a t 1292O and this must be due to (1) increase in the partial pressure of chromium, (2) lowering of the partial pressure of the carbide or (3) lowering of the partial pressure of the oxide. Case (1) might be caused by the existence of a transition point of chromium between 1292O and 1339O. At first the metal is in the Otfom stable at lower temperatures; on heating the metal would change to the other or &form and on cooling to 12920 would not revert to the a-form but remain in the unstable &form, which would have a higher vapour pressure than the a-form. Case (2) might be caused by the formation of an unstable carbide in the first instance which on heating to 1339O changes into the stable form. On cooling now to the lower temperature the un-stable carbide is not formed in the presence of the more stable one. Case (3) might be caused by the chromium oxide combining with t.he silica in the boat to form a silicate but this reaction should not be different after the furnace had been raised to the higher temperature. The first explanation seems the more probable. This investigation was carried out in the Muspratt Laboratory of Physical Chemistry University of Liverpool. BRITISH PHOTOGRAPHIC RESEARCH ASSOCIATION LABORATORY. [Received Pebmary 14th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9191500205

出版商:RSC    

年代:1919

数据来源: RSC

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THE DT980CIATTON PRESSURES OF SOME NTTRIDES. 215 X XV . -The Dissociation Pressures of some Nit rides. By ROLAND EDGAR SLADE and GEOFFREY ISHERWOOD HIGSON. Equilibria of the type 2M+N 2MN, where ill is three equivalents of a metal have been investigated. In this system there are two components namely metal and nitrogen and three phases namely metal nitride and nitrogen. The number of degrees of freedom is thus 2 + 2 - 3 = 1 and there-fore a t one temperature there is one pressure of the nitrogen which determines the equilibrium of the dissociation. If the nitride dis-solves in the metal as a solid solution there are only two phases, and the number of the degrees of freedom is therefore two. The equilibrium will then be determined not only by the pressure of the nitrogen but also by the composition of the solid phase.Applying the Nernst heat. theorem to the equilibrium M + &N,=MN + &, where Q is tbe heat evolved when half a gram-molecule of nitrogen combines with the metal we have and where Qo and Qt respectively are the heats of reaction a t absolute zero and some other temperature T. As the heats of formatioii of the nitrides investigated were unknown i t is impossible to apply these equations to determine the value of pNp but it will be seen that the pressure of nitrogen a t 1127O would be 1 mm. if the heat of formation of the nitride were 70,600 cals. and 60 mm. if the heat of formation were 59,000 cals. Qt=&-,-3*5T, EXPERIMENTAL. The furnace used for the determination of the equilibria is described in the preceding paper.Nitrogen was prepared by heating a solution containing ammonium chloride potassium nit'rate and potassium dichromate. The dichromate served to oxidise any oxides of nitrogen to nitric acid which was absorbed by passing the gas through a long tube of soda-lime. The nitrogen was then dried by passage through a long tube of phosphoric oxide. The equilibria were determined by heating small quantities o 216 THE DISSOCIATION PREBSURE8 OF SOME NITRIDES. the metal to a known temperature introducing nitrogen into the furnace and determining the value to which the pressure fell. Nitrogen was then pumped out and the equilibrium was determined from the low-pressure side. TTanadiunt.-This metal is known to form two nitrides VN and VN,. A t 1203O the equilibrium pressure was found to' be slightly less than 0.2 mm.and a t 1 2 7 1 O slightly less than 1.5 mm. The equil-ibrium pressure is somewhere near these values but equilibrium was attained very slowly and it was impossible t o heat the platinum tube in use a t that time to a higher temperature. Boron ,-An attempt was ninde to determine the dissociation pressure of boron nit.ride at 1 1 0 0 O and 1240O. A t l l O O o the velocity was too low for the equilibrium t o be determined. A t 1240° the pressure of nitrogen fell from 26-4 mm. to 9.4 mm. in six hours and appeared to be approaching the con-stant value of about 9 mm. but the boron attacked the platinum tube and caused i t to leak so that further experiments could not be made. Tantalum.-Tantalum is known to form two stable nitrides TaN and Ta3N,.I n our experiments it is probable that the lower nitride TaN was formed. When the metal was heated a t 1170O in nitrogen under 15 rnm. pressure the gas was slowly absorbed until the pressure fell to 0.5 mm. The furnace was then exhausted to 0.05 mm. The pressure rose in two hours to 0.4 mm. In another experiment' a t 1308O the pressure fell from 9 m, to 1.2 rnm. in one and a-half hours and remained constant for half an hour. Next day it was completely exhausted and again heated t o 1308O. The pressure rose to 0.8 mm. and remained constant a t this value for two hours. The furnace was then allowed t o cool. Summary of Results. Heat of formation of nitride, that is Q0 calculated from Tempera-ture. Pressure of nitrogen. Nernst's formula. 1271 9 9 1.5 7 77,200 ,, Vanadium 1203" Not greater than 0.2 mm. 79,200 cals. Boron ... 1222 9 ? ? 9.4 7 About 69,000 Tantalum 11 7 0 0.4-0.6 mm. 74,700-75,5;0 cals. This investigation was carried out in the Muspratt Laboratory 1308 0.8-1.2 , 79,900-82,800 ,, of Physical Chemistry University of Liverpool. BRITISH PHOTOGRAPHIC RESEARCH ASSOCIATION LABORATORY. [Received February 14th 191 9.

ISSN:0368-1645    

DOI:10.1039/CT9191500215

出版商:RSC    

年代:1919

数据来源: RSC

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NITRO- ARYLAZO- AND AMINO-BLYOXALINES. 21 7 XXVI .-Xitro- Arylazo- and Amino-glyoxalines. By ROBERT GEORGE FARGHER and FKANK LEE PYMAN. THIS investigation was begun with the object of effecting the synthesis of purine derivatives by a method complementary to those which have been employed hitherto. In these the pyrimidine nucleus is first built up and the glyoxaline ring closed subsequently. We proposed to prepare 4-aminoglyoxaline-5-carb-oxylic' acid,* condense it with cyanic acid and eliminate water with t,he production of xanthine. Such a synthesis would be of interest in view of the suggestion that purine derivatives originate from histidine in the animal body (compare Hopkins T. 1916 109 629). Although the starting material for the proposed synthesis, 4-aminoglyoxaline-5-carboxylic acid was unknown we did not anticipate that its preparation woald offer any serious difficulty.We have however so far failed to obtain this substance and now give an account of our attempts to prepare this and other amino-substituted glyoxdines. An account of the investigation may be subdivided under three headings first the preparation of the glyoxalines and their carb-oxylic acids which were required as starting materials ; second, the preparation and properties of nitroglyoxalines; and last the preparation and properties of arylazoglyoxalines. (I) The I'reparatiom o,f Glyoxalines and their Carboxylic Acids. -For the purpose of this investigation it was necessary to prepare considerable quantities of glyoxaline-4 5-dicarboxylic acid the most convenient source of glyoxaline.This acid was first prepared by Maquenne (Ann. chim. phys. 1891 [vi] 24 525> by mixing aqueous solutions of nitrotartaric acid and hexamethylenetetramine, adding ainmoiiia and allofwing the mixture t o become hot and sub-sequently by Dedichen ( H e r . 1906 39 1835) who replaced the ~~er;amethylenetetramilze by formaldehyde. We have carried out a large number of experiments on the best conditions for the pre-* In glyoxalines containing a free imino-group the 4- and 5-positions are equivalent 21s >'ARCHER AND PYMAN: paration of this acid and find that to obtain a good yield it. is essential that the reaction mixture should be kept cold. A number of experiments were carried out? with the object of effecting t.he partial decarboxylation of glyoxaline-4 5-dicarboxylic acid and thus producing glyoxaline-4-carboxylic acid by a more convenient and economical process than that previously employed, where six operations are required in its synthesis from citric acid through 4-hydroxymethylglyoxaline (T.1911 99 668 ; 1916 109, 186). When the acid is heated with water 10 per cent. hydro-chloric acid or concentrated hydrochloric acid little decarboxyla-tion takes place below 180° but above this temperature the action proceeds more readily glyoxaline being the main product whilst a small proportion of glyoxaline-4-carboxylic acid can be isolated provided that the heating has not been too prolonged. m7hen the acid is heated with an excess of concentrated ammonia a t 180° to 200° the main product is glyoxaline," and a similar result is obtained by heating the aqueous solution of the mono-sodium salt.The desired result can be obtained however by boiling the acid with aniline when the aniEide of glyoxaline-4-carboxylic acid is formed in a yield amounting to 45 per cent. of the theoretical. From this the acid is readily prepared by hydrolysis. For the purpose of orientation it was necessary to prepare glyoxalinea substituted in the 2- 4 5- and 2 4 5-positions. The 2-alkylglyoxalines were prepared by suitable modifications of Maquenne's methods. From 2-methylglyoxaline-4 5-dicarboxylic acid 2-met?~ylglyo~aline-4-cnrb ozylic acid was obtained through its nnilide. As representatives of 4 5- and 2 4 5-substituted glyoxalines, 4 5-dimethylglyoxaline and 2 4 5-trimethylglyoxaline were pre-pared by modification of known methods.(2) Nitro~ZyoxaZines.-The nitration of various glyoxalines has led to the formation of mononitroglyoxalines in the hands of several observers. I n some casw the nitro-group evidently enters the 4-(or 5-)position since no other position is vacant; for instance, in the nitration of 2-methylthiol-1-phenyl(and 1-methy1)glyoxaline * We were unable to find any evidence of the formation of the imide of glyoxaline-4 5-dicarboxylic acid from which the desired 5-aminoglyoxaline-4-carboxylic acid might have been obtained by the action of hypobromous acid NITRO- ARYLAZO- AND AMINO-GLYOXALINXS. 219 (I) (Wohl and Marckwald Ber. 1888 22 568 1353) and 2:4di-methylglyoxaline (11) (Windaus Ber.1909 42 758) : >CMe. gH*NH CMe-N (1.1 (11.) The orientation of the nitro-group in nitroglgoxaline itself (Rung and M. Behrend tl?~nalen 1892 271 28; R. Behrend and Schmitz ibid. 1893 277 338) and in nitro-4-methyiglyoxaline has not been determined previously but an indication that the latter contains the nitro-group in the 5-position is afforded by Windaus's observation (ZOC. cit.) of its close similarity to 5-nitm-2 4-dimethyl-gl yoxaline. Moreover whilst) 412it7.0-2-rnethyl~ly~xal~ne is readily prepared, we were unable to obtain a nitro-derivative of 4:5-dimethyl-glyoxaline for in this case part of the base was completely oxidised, whilst a considerable proportion remained unchanged and the only isolable derivative was the nitrate of 4-methylglyoxaline-5-carb-oxylic acid which has been described by Gerngross (Ber.1912, 45 509). The inability of a glyoxaline substituted in both the 4- and 5-positions to form a nitro-derivative indicates that the nitro-glyoxalines contain the substituent in the &(or 5-)position. This view is confirmed by their behaviour on reduction. Wohl and Marckwald (Zoc. cit.) attempted to reduce the 4-(or 5-)nitro-2-methylthiol-l-phenyl-(and l-methy1)glyoxalines to the correspond-ing amines but obtained only decomposition products including methyl mercaptan. Similarly we find that 4-nitro-%methyl-glyoxaline undergoes fission on reduction with tin and hydrochloric acid two of the three atoms of nitrogen in the molecule appearing in the form of ammonia.* Since precisely the same result is obtained with nitroglyoxaline and nitro-4-methylglyoxaline whilst it is shown below that 2-aminoglyoxalines are stable it is clear that these nitro-derivatives are 4-nitroglyoxaline and 5-nitro-4-methyl-glyoxaline respectively.Before we had arrived at this conclusion we were anxious to prepare some of the nitroglyoxaline-4-carboxylic acid which Windaus and Opitz (Ber. 1911 44 1721) obtained by the action of boiling 25 per cent. nitric acid on 4-P-hydroxyethylglyoxaline. ' The first stage in the disintegration of the 4-aminoglyoxalines is probably the elimination of the amino-group as ammonia with the formation of a glyoxalone for certain members of the purine group-also derivatives of 4-aminoglyoxaline-have been shown to undergo hydrolysis in this mmer (compare for instance Tafel and Mayer Bey.1908 41 2546; Biltz Ber., 1910,43 15S9) 220 FARGHER AND PYMAN: These authors state that the yield of $-~-hydroxyethylglyoxaline, obtained by the action of barium nitrite on 4-B-aminoethyl-glyoxaline hydrochloride was so poor that the nitro-compound was not available in sufficient quantity for further study. It appeared to us however that this nitro-compound might be obtaiaed by t’he action of nitric acid on other more readily accessible derivatives of glyoxaline containing a side-chain of carbon atoms in the 4-posi-tion and in the first place we employed compounds containing two carbon atoms in the side-chains like Windaus’s starting material. The results were disappointigg ; 4-P-aminoethyl-glyoxaline when boiled with 50 per cent.nitric acid for nine hours was mainly recovered unchanged whilst 4-cyanomethyl-glyoxaline was converted under the same conditions almost quanti-tatively into glyoxaline-4-acetic acid. Atltempt.s t o nitrate glyoxaline-4-carboxylic acid and glyoxaline-4 5-dica,rboxylic acid were likewise unsuccessful. The prospect of nitrating 4-hydroxy-methylglyoxaline was not hopeful for it has bem shown previously (T. 1916 109 186) that hot concentrated nitric acid converts it into glyoxaline-4-f ormaldehyde and glyoxaline-4-carboxylic acid. It has now been found that the alcohol gives the same products when digested oil the water-bath with fuming nitric acid whilst it can be recovered almost quantitatively after boiling with ten parts of 25 per cent.nitric acid for four hours. On the other hand the nitration of 4-hydroxymethylglyoxaline with nitric and sulphuric acids gave rise to a product which was not obtained in crystalline form but further study of this was olmit,ted in view of the peculiar behaviour of the simple nitroglyoxalines on reduction. (3) A ryluzoglyoxa1ines.-The constitution of the arylazo-deriv-atives of simple glyoxalines has not been settled hitherto. Rung and Behrend (Amnalen 1892 271 ZS) who first isolated benzene-azoglyoxaline considered it to be a diazoimino-compound (I), because boiling acids decomposed it with the formation of nitrogen > CH, EH*N(N:NPh) CH-N’ and glyoxaline. Burian (Ber. 1904 37 696) wno prepared many arylazoglyoxalines from diazobenzenep-sulphonic acid and various glyoxalines adopted the same view of the constitution of these compounds on other grounds namely because all the glyoxaiines substituted in some or all of the 2- 4- and 5-positions which he examined coupled with the diazonium salt whilst 1 -substituted glyoxalines did not.Pauly (Zeitsch. yhysiol. Ghem. 1904 42, SOS) however pointed out the possibility that the arylazo NITRO- ARYLAZO- AND AMINO-GLYOXALINES. 221 glyoxalines were true Cl-azecompounds (11) similar to those obtained from pyrrole and later (ibid. 1915 94 284) attributed the probable formula (111) given below to the compound obtained by the action of diazotised arsanilic acid on histidine owing to its stability towards acids. Whilst in the case of hhese simple glyoxalines the orientation of the arylazo-group is uncertain the constitution of the arylazopurines is known for Hans Fischer (Zeitsch.physiol. Chem. 1909 60 69) has shown that the arylazo-group enters the 8-position of the purine nucleus-the 2-position of its glyoxaline ring-by reducing arylazopurines t o 8-aminopurines. I n view of this result it appeared to us probable that the arylazclderivatives of simple glyoxalines were also C-azo-compounds, as Pauly suggested and it was of interest to determine whether the arylazo-group entered the 2- or the 4-position and the nature of the products obtained on reduction. The benzeneazoglyoxaline of Rung and Behrend was first examined. By the method of these workers it is obtained in poor yield but by the action of benzenediazoniuin chloride on one mole-cular proportion of glyoxaline in an excess of aqueous sodium carbonate it is readily obtained mixed with a little 2 4 5-tm's-b enzeneazoglyoxdine.2-Benzeneazoglyoxaline melts a t 190° (con-.) and it' is therefore evident that the specimen prepared by Rung and Behrend melting a t 177-17807 was impure. The pure substance is reasonably stable towards boiling 10 per cent. hydro-chloric acid for a considerable proportion can be recoverdd un-changed after two hours. The constitution of 2-benzeneazoglyoxaline (IV) was proved by reduction. With zinc dust1 and hot acetic acid it yields aniline and glycocyamidine%* (V) the formation of the latter showing that the benzeneazo-group is attacheld to the 2-position of the ring.>C:NH + PhNH YH,*NH EH*NH CH-N CO-N H >C*N:NPh + (IV.) (V.1 * The conversion of glyoxaline into glycocyamidine and 2-Elminoglyox&ne, both derivatives of guanidine is of biochemical interest firstly because creatinine is the N-methyl derivative of glycocyamidine and secondly on account of the similar behaviour of histidine and arginine in purine metabolism (oompare Hopkins koc.dt.) 222 FARGRER AND PYMAN : This result is confirmed by the formation of a small amount of guanidine on the reduction of 2-benzeneazoglyoxaline with stannous chloride. In this reduction a small quantity of 2-aminogZyoxaline is formed and some aniline but the main product is 2-amino-4-p-amircophenylglyoxaline (VI) a compound resulting from a change of the benzidine type.It is also formed in small proportion in the reduction with zinc dust and acetic acid. (VIII .) Its constitution was proved by the oxidation of its diacetyl deriv-ative with potassium permanganate when p-acetylaminobenzoic acid was formed. This result eliminated the possibility that the compound had one of the two formulze (VII) or (VIII) represent-ing substances formed by a change of the semidine type. The occurrence of a rearrangement of the benzidine type in a five-membered heterocyclic nucleus seems reinarkable at first sight but a cIoser inspection of the formula shows that the conjugated system connecting the 2- and 5-carbon atoms of the glyoxaline ring is similar t-o that existing in the benzene nucleus. NH- NH 6 Is H C*NHS /\ s/\ /\ N/\ 1 I CHI >NH - I 1 1 CHI P H .\/ C \/ I-_-_ \/ CH \P Whilst no other case of the benzidine type od change in a heterocyclic nucleus has been observed previously so far as we are aware Michaelis and Schafer (Annnlcn 1915 407 229) have obtained by the reduction of l-phenyl-3-methyl-4-benzeneazo-pyrazole (IX) the two isomerides (X) and (XI) which result from the two possible changes of the semidine type. N PI1 K P h NPh (IX.) ( X . 1 (XI.) Owing to the formation of 2-amino-4-paminophenyiglyoxaline in the reduction of 2-benzeneazoglyoxaline the yield of Z-amino NITRO- ARYLAZO- AND AMINO-GLYOXALINES. 223 glyoxaline is small so for the preparation of this substance the reduction of an arylazoglyoxaline containing a substituent in the para-position of the benzene nucleus was undertaken.2-p-Bromobenzeneazoglyoxdine is the main product of the inter-action of p-bromobenzenediazonium chloride and glyoxaline in aqueous sodium carbonate only a very small proportion of 4-p-bromobenzeneazogl?/o.xaZine being formed. The reduction of 2-p-bromobenzeneazoglyoxaline with stannous chloride gave 2-aminoglyoxaline in a yield of 56 per cent. of the theoretical, together with aniline guanidine some ?-amino-4-paminophenyl-gIyoxaline and a small quantity of a base C,R,N,Br which is probably 2-Eif -bromo-2~-am~noan~linoylyoxaLine (compare p. 246). 2-Aminoglyoxaline is a monacidic base yielding crystalline salts, but the free base has not been obtained in a crystalline form. 8H'NH>C*NH, CH-N (XII.) (XITI.) For this compound the tautomeric formulz (XII) and (XIII) are possible.The first is supported by the production of a red colour when the substance is mixed with sodium diazobenzene-p-sulphonate and by the fact that after treatment with nitrous acid it couples with phenols. An indication that it can also react according to the formula (XII1)-which represents an unsaturated compound no longer containing the glyoxaline ring-is given by its behaviour towards permanganate for 2-aminoglyoxaline and all t.he substituted 2-aminoglyoxalines described in this paper reduce cold aqueous acid potassium permanganate and in this respect resemble the 2-thiolglyoxalines (compare T. 1911,99 2173), whereas glyoxaline and its homologues are stable t o this reagent, although they reduce alkaline permanganate giving green solutions.2-Aminoglyoxaline yields a mononcet?p? and a monobenzoyl deriv-ative which are stable to cold aqueous acid permanganate. 2-Aminoglyoxaline does n o t combine with benzaldehyde in acetic acid solution. Moreover 2 - am in 0-5 - p-amino p h en y l-4-m ethyl-glyoxaline (XVII) yields only a monoberizylidene compound under these conditions doubtless 2-amino-5-~~-benzylideneaminophenyl-4-methylglyoxaline. This behavio'ur therefore serves to differentiate between 2-aminoglyoxalines and homologues of aniline and is employed later in the determination 01 constitution. The action of benzenediazonium chloride on 4-methylglyoxaline proceeded quite differently from its action on glyoxaline. Instead of the 2-subst,itutsd arylazo-compound being formed predominantly 224 FARGHER AND PYMAN: nearly equal quantities of 2- benzeneazo-4-methylglyozali~e, 5-benzeneazo-4rnethylglyoxaZine and 2 ; 5- bisbenzeneazo-4-methyl-glyoxaline were obtained.The constitution of 2-benzeneazo-4-methylglyoxaline (XIV) follows from the fact that it yields 011 reduction with zinc dust and acetic acid alacreatinine (XV) a compound previously synthesised by Baumann ( A nnalen 1873, 167 83) by the elimination of water from acid (XVI). >C*N:NPh + EMe- N TT CH--N->C:NH f-$lHMe*NH CO-NH (XV. 1 This change is precisely similar to the a-guanidinopropionic pMe*NH>C:NH C0,H NH, (XVI.) formation of glyco-cyamidine from 2-benzeneazoglyoxaline. 2-Benzeneazo-4-methyl-glyoxaline behaves in the same way as 2-benzeneazoglyoxaline on reduction with stannous chloride the principal product of the reaction 2 - amino - 5 - p - nminophenyl - 4 - nzethylglyoxaline (XVII) a compound having similar properties to 2-amino-4-p-aminophenylgl yoxaline.being (XVII.) (XVIII. ) The constitution of 5-benzeneazo-4-methylglyoxaline (XVIII) could not be proved directly as in the case of the 2-isomeride. On reduction aniline and a considerable amount of ammonia were formed,' together with other products which included a base, C,Hl,0N2 (p. 254) when stannous chloride was employed as the reducing agentl and a base C,,H,,ON (p. 255) when zinc dust and acetic acid were used. The disintegration of the molecule indicated by the formation of ammonia is similar to that occurring in the reduction of the 4-nitroglyoxa!ines and affords evidence that the constitution of the compound is represented correctly by the formula of 5-benzeneazo-4-methylglyoxaline.The formula is sup-ported by the fact' that the compound is soluble in dilute aqueous sodium hydroxide which indicates that' the imino-group is unsub-stituted. Moreover it is fairly stable towards boiling dilute acids. Its properties are not therefore in accord with those of a compound represented by the alternative formula 1-benzeneazo4-methyl-gl yoxaline. That aryldiazonium salis are capable of substituting the 4-posi-tion of the glyoxaline ring follows from the reduction of 2-phenyl NITRO- ARYLAZO- AND AMINO-OLYOXALINES. 225 4-p-bromobemzeneazv$yoxaZine C,,H,,N,Br for a compound, C,,HI3N,Br is produced which is evidently derived from the corre-sponding hydrazo-compoand by a change of the semidine or benz-idine type (compare p.257). The polyarylazoglyoxalines-2 4 5-trisbenzeneazoglyoxaline and 2 5-bisbenzeneazo-4-met~hylglyoxaline-are insoluble in dilute mineral acids and are decomposed on boiling with 10 per cent. hydrochloric acid. Nevertheless we regard them as C-azo-com-pounds because they are soluble to some extent in aqueous sodium hydroxide I n the case of the second,compound we have estab-lished the fact that it is precipitated unchanged from its solut,ion in aqueous sodium hydroxide by means of acetic acid. The fact that the number of arylazo-groups in the polyarylazo-compounds corresponds with the number of nuclear methine groups ia the parent glyoxaline points in the same direction.The interaction of glyoxaline-4 5-dicarboxylic acid and diazo-benzene-p-sulphonic acid was studied by Burian (Zoc. cit.) who found that carbon dioxide was liberated and described a product forming yellow needles or red microscopic prisms which gave on analysis results indicating that it was a compound derived from one niolecular proportion of diazobenzenep-sulphonic acid and one of glyoxaline - 4 - carboixylic acid S03H*C6H4-N:N=C3H,N2*C0,H. Burian regarded this as a l-substituted arylazoglyoxaline butl we thought it more probable that t.he arylazo-group had displaced a carboxyl group in the 4-(or 5-)position and that' the compound was 5 -p-sulphobenzeneaz~glyoxaline-4-carl1oxylic.acid (XIX). (XIX.) This compound would yield 5-aminoglyoxaline-4-carboxylic acid if a suitable method of reduction could be found and we there-fore attempted to repeat its preparation but were unable to do so. We can confirm Burian's statement that carbon dioxide is liberated in the reaction but find the yield of this to be only about 40 per cent. of tihe theoretical much less than he states. More-over we have isolated in a yield of about 30 per cent. of the theoretical the condensation product of diazobenzene-psulphonic acid and glyoxaline-4 5-dicarboxylic acid namely 2-psdpho-benzeneazoglyoxdine-4 5-dicarboxylic acid ( X X ) . No other definite compound could be isolated from the reactlion mixture and it appears to us that the colmpound dwcribed by Burian was prob-ably a mixture of our acid with its sodium salt.2-pSulphobenzeneaz~glyoxaline-4 5-dicarboxylic acid yields o 226 FARGHER AND PYMAN: reduction with sodium hyposulphite sulphanilic acid and 2-amino-glyoxaline-4 ; 5-dicarbozylic acid (XXI). With the object of eliminating the elements of carbon dioxide, this acid was heated with water for twelve hours a t 170° whell carbon dioxide and approximately one molecular proportion o i' ammonia were liberated but no other fission product could be identified. On the other hand when boiled with aniline for six hours it gave a quantity of 2-aminoglyoxaline. Whilst we were uiiable to isolate 5-11-sulphobenzcneazo-glyoxaline-4-carboxylic acid (XIX) from the products of the inter-action of diazobenzene-psulphonic acid and glyoxaline-4 5 clicarb-oxylic acid the liberation of carbon dioxide indicates that sub-stlitution in the 4-(or 5-)position takes place t o some extent.More-over we can confirm the fact that 2-methylglyoxa!ine-4 5-dicarb-oxylic acid couples with sodium diazobenzene-psulphonate in aqueous sodium carbonate. On the other hand 2 4 5-trimethylglyoxaline (XXII) which contains a free imino-group but no other hydrogen atom attached >CMe fiMe*NH CMe-N (XXII.) to the nucleus does not couple with sodium diazobenzene-p-sulphonate. Further a striking difference is exhibited between the facilities with which 2-amino-4-p-aminophenylglyoxaline (VI) containing a displaceable hydrogen atom in the glyoxaline nucleus and its methyl homologue (XVII) reach with sodium diazobenzene-psulphonate in aqueous sodium carbonate.The first gives the characteristic intense cherry-red colour immediately whilst the second -gives a pale orange cdour which deepens on keeping and is probably due to the participation of the aminophenyl group. On reviewing these results and those of previous investigators it appears t o us that glyoxalines in order t o be capable of coupling, must contain a free iminwgroup and also a hydrogen atom or some other displaceable group such as the carboxyl group in one of the 2- 4- or 5-positions and that the arylazoglyoxalines hitherto pre-pared are C-azo-compounds. The litmeratwe of the arylazoglyoxalines contains one possible exception to this generalisation-the compound (orange needles melting a t 120-122°) described by Burian (lo$.cit.) as having been obtained by the action of diazotised benzidine on 2-thiol-4 5 NITRO - ARYLAZO- AND AMINO-GLY 0 XALXNES. 2 2 7 diphenylglyoxaline. Since we found that 2-thiol-4 5-dimethyl-glyoxaline and 2-thiol4 5-diphenylglyoxaline only gave pale orange colorations with sodium diazobenzene-p-sulphonate we repeated Burian's preparation. We failed however to confirm his results, but isolated from the product as main constituents much un-changed 2-thiol-4 5-diphenylglyoxaline and a reddish-brown, amorphous compound melting and decomposing above ZOOo which from its low nitrogen content (5.5 per cent.) and the ratio of nitrogen to sulphur (2 1) could not. have been an arylazo-derivative derived from 2-thiol-4 5-diphenylglyoxaline.EXPERIMENTAL. Part I GlyoxcLli?Les a n d t h e i r C a r b o x y l i c A c i d s . l'reparutiuu of G'lyoxali~~e-4 5-clica~boxylic Acid. Twenty-five grams of finely powdered tartaric acid are dissolved in 108 C.C. of nitric acid (D 1*5) and 125 C.C. o€ sulphuric acid are added. The mixture which attains a temperature of about 40° soon begins to deposit crystals and is kept for three to four hours in a cool place. The nitrotartaric acid is collected washed with 50 per cent'. sulphuric acid drained on porous porcelain and stirred immediately with 150 grams of powdered ice until dissolved, when the temperature falls to -5'. The liquid is immersed in a freezing mixture and 100 C.C. of aqueous ammonia (D ,0*880) are added gradually the temperature being kept below Oo.Then 50 C.C. of 40 per cent. aqueous form-aldehyde are added slowly keeping the temperature below loo. The product is removed from the freezing mixture after three to four hours and kept overnight. It is then mixed with a little alcohol and acidified with hydrochloric acid when 15.5 t o 16.0 grams of glyoxaline-4 5-dicarboxylic acid separate that is about 60 per cent. of the theoretical yield calculated on the quantity of tartaric acid employed. Glyoxaline-4 5-dicarboxylic acid melts and effervesces a t 2880 (corr.). It is soluble in about SO0 parts of boiling water and in aboat 2000 parts of cold water. It is practically in-soluble in the usual organic solvents but dissolves sparingly in pyridine. It is soluble in cotncentrated mineral acids but is precipitated unchanged on dilution with water.The moao-aodzz~m salt which crystallism from water as a felted mass Qf feathery needles containing lH,O (Found H20 = 9.4 ; in dried salt Na=12.S. @ale. H20=9'2; Na=12'9 per cent.) is sparingly soluble in water but readily so in aqueous sodium hydr 228 FARGHER AND =MAN: oxide probably owing to %he formation of a disodiitm salt in solu-tion. Moreover the addition of alcohol to a solution of the acid in sufficient aqueous sodium hydroxide; to form the disodium salt causes the precipitation of a granular deposit approximating in composition to the disodium salt. (Found in salt dried at l l O o , Na = 21.2. C,H,O,N,Na requires Na = 23.0 per cent.) The acid is very stable towards nitric acid; after boiling it with ten times its weight of concentrated nitric acid for twenty-four hours more than 90 per cent.was recovered unchanged whilst similar results were obtained in a sealed tube a t 130° and when the acid was boiled with equal parts of nitric and sulphuric acids. The acid is very resistant to esterification for after boiling with alcoholic sulphuric acid for twenty-four hours 95 per cent. was recovered unchanged. ?'he Preparation of Glyoxaline . One hundred grams of glyoxaline-4 5-dicai%oxylic acid were distilled under normal pressure in quantities of 4 grams from a small flask into a long wide air condenser. The distillate which had solidified in the condenser was crystaliised from benzene and gave a 92 per cent. yield of the pure base. GtyoxaZirzc piciute crystallises from water in long fine yellow needles which become orange on drying a t loo@ and then melt a t 2120 (corr.) after sintering from 208O.It contains rather more than 1H,O (Found loss a t 10Oo=7.2; in substance dried a t looo, N= 23.3. GZyoxmTTine hydrogen twtrate crystallises from wat'er in fine prisms of Characteristic trapezoidal shape which are anhydrous and melt a t 202O (corr.). It is readily soluble in cold water and is best crystallised from 50 per cent. alcohol (Found N=12.8. c3H,N2,C,H,0 [218*1] requires N = 12.8 per cent.). Qlyoxaline hydrogen oxalate crystallises from water as a felted mass of prismatic needles which are anhydrous and melt a t 232O (corr.) after sintering from 230O. It is soluble in five or six parts of boiling water but much less so in cold water (Found N= 17.8.Calc. N=17*7 per cent.). C,H,N,,C,H,O,N [297*1] requires N=23.6 per cent,). Action of Boiling Aniline om Glyosalinel 5-dicurboxylic Acid: Fomzatkom of Glyoxaline-4-curb oxyanilide and Glyoxaline. Five grams of glyoxaline-4 5-dicarboxylic acid were h i l e d with 50 C.C. of aniline for nine hours under a reflux condenser whe NITRO- ARYLAZO- AND AMINO-GLYOXALINES. 229 the acid gradually passed into solution. The product was mixed with water and subjected to distillation with steam until the excem of aniline had been removed. The residual aqueous solution was filtered from a small quantity of resinous matter whilst still hot, when the filtrate a t once began t o deposit the anilide as a felted mass of fine needles.The first crop amounted to 2.6 grams and a further quantity of 0.1 gram waa obtained on concentrating the mother liquor. The filtrate from this gave on acidification 0.1 gram of glyoxaline-4 5-dicarboxylic acid but no glyoxaline-4-carboxylic acid was found. The final mother liquor when mixed with sodium carbonate evaporated to dryness and extracted with benzene gave 0.9 gram of glyoxaline. Glyoxaline-4-curb oxyanilide crystallises from boiling water in fine colourless needles which are anhydrous and melt a t 227-228O (corr.). It is fairly readily soluble in alcohol but only sparingly so in boiling water and the other usual organic solvents. C,,H,ON (187.15) requires C = 64.2 ; H = 4.9 ; N = 22.5 per cent. Hydrolysis of the A nilide.-The anilide is only slowly hydrolysed by 10 per cent.hydrochloric acid a t looQ but more readily at 1 3 0 O . One gram of the anilide was heated with 10 C.C. of 10 per cent. hydrochloric acid a t 130° for three hours. The resulting solution was evaporated to dryness to remove the excess of acid the residue dissolved in water basified with sodium carbonate and extracted with ether to remove aniline. Sufficient hydrochloric acid was added to render the solution faintly acid to methyl-orange when crystallisation set in almost immediately and 0.42 gram of glyoxaline-4-carboxylic acid was isolated The properties of the acid and its hydrochloride nitrate and picrate agreed with those previously given (T. 191'6 109 199) for the acid prepared by the oxidation of 4-hydroxymethylglyoxaline and the melting points of mixtures of the compounds from the two sources were not depressed.Fou11d C=64*2; H=5.1; N=22.6. 2-Methylglyoxdine-4 5-dicarboxylic Acid. This acid was prepared in an analogous manner to its lower homologue employing a solution of 15 C.C. of freshly distilled acetaldehyde dissolved in 50 C.C. of ice-water in the place of the aqueous formaldehyde. The yield of 2-methylglyoxaline-4 5-dicarboxylic acid containing 1H20 obtained from 25 grams of tartaric acid was 22 grams that is 67 per cent. of the theoretical. VOL cxv. Maquenne (Zoc. tit.) obtained 50 grams of the product fram 100 grams of tartaric acid that is 38 per cent. of the theoretical. Genetally the properties of this acid &re very similar to those of glyoxaline-4 5-dimrheyl-ic acid and it behaves similarly on acid and alkaline hydrolysis.With sodium diazobenzen~~-sulphonate in aqueous sodium carbonate it gives a faint red colour which deepens on keeping, whilst glyoxahe-4 5-dicarboxylic acid gives a deeper red d o u r in the frrst instance. Action of Boiling Aniline o n 2-Methylglyodine-4 Ei-dicarboxylkc A d . Twenty grams of hydrated 2-methylglyoxaline-4 5-dicarboxylic acid when treated with boiling aniline under the same conditions as its lower homologue gave 11 grams of the hydrated anilide of 2-methylglyoxaline-4-carboxylic acid and 3.8 grams of 2-methyl-gl y oxdine. 2-Methylglyoxaline-4-car b oxyandide crystallises from boiling water as a felted mass of cdourless silky needles which contain rather less than 1H,O.It is sparingly soluble in boiling water, but readily so in alcohol. After drying a t l l O o it melte a t 208O (dorr.) . Found loss a t l l O o in three samples=6.9 7.0 7.2. Found in substance dried at l l O o C=65.1 65.6; H=5'7 5.6; C,,Hl10N3,H,0 requires H,O = 8.2 per cent. N=20.9. C1,Hl1ON (201.2) requires C = 65.6 ; H = 5-5 ; N = 20.9 per cent. 2-Methhylgtyoxaline-4-carboxylic acid is obtained in nearly the theorst$cal yield by the hydrolysis of its anilide under similar con-ditions to those already described for glyoxaline4-carboxylic acid. When placed in a bath a t 250° it! melh and effervesces a t 262O (cam.). It crystallises from water in clusters of prismatic needles containing 1H,O. It is soluble in about twenty parts sf boiling water but is practically insoluble in the usual organic solvents.Found loss a t 110°=12*9. Found in %he substance dried a t l l O o C=47-3; H=4-8; C,H60,N2,H,0 requires H,O = 12.5 per cent. N = 219. C,H602N (226.1) requires C=47-6; H=4*8; N=22*2 per cent. With sodium diazobenzenep-sulphonate it gives a red colmr in The hyd?wochloride crystallises from wahr in which it is readily sodium carbonate solution soluble in minute flattened rhombic prisms which are anhydrous. It melts and effervesces a t 2 6 8 O (corn.). Found N=16*9; c1=21.5. The nitrute crystallises from water in which it is very readily soluble in minute rhombic prisms which melt and effervesce a t 190° (corr.) resolidify and on further heating gradually darken, melting a t about 240O.C,H602N2,HC1 (162.6) requires N = 17.2 ; c1= 21.8 per cent. Found C=31*7; H=4*1. The picrute crystallises from water in minute cubes containing 2H,O which is lost a t looo (Found H,O=9*4. Calc. for 2H20, 9.2 per cent.). It melts to a turbid liquid a t 200° (corn.) which does not become clear until 224O a t which temperature effervescence begins. C,H,02N,,HN03 (189.1) requires C = 31.7 ; H = 3.7 per cent. Found in salt dried a t looo N=19*4. 2-Methylglyoxaline p'crute crystallises from boiling water iB fine Found N = 22.3. 2-Methylglyoxdine hydrogen oxnlate crystallises from water in large rhombic prisms which contain 2H,,O (Found H20 = 17.6. Calc. for 2H20 H20=17.3 per cent.). After drying a t looo it melts a t 160° (curr.) and efferv'esces on further heating.Ib is much more readily soluble in water than the corresponding glyoxaline salt. C5H,02N,,C,H30,N (355.2) requires N = 19.7 per cent. needles which are anhydrous and melt a t 2 1 3 O (corr.). C,H6N2,C,H,0,N (311.2) requires N = 22.5 per cent, Found in dried salt W=16.1. C4H,N2,C2H204 (172.1) requires N = 16.3 per cent. 2-Ethylglyoxali~~e-4 5-dicarboxylic Acid. This acid was prepared in the same way as the methyl substituted acid. From 32 C.C. of propaldehyde and the nitrotartaric acid obtained from 50 grams of tartaric acid 43 g r m s of hydrated 2-ethylglyoxaline-4 5 -dicarboxylic acid were obtained that is 64 per cent. of the theoretical yield; Maquenne obtained 30 per cent. 2-Ethylglyoxaline-4 5-dicarboxylic acid melts and effervesces a t 2 5 9 O (cotr.).L 232 FAROEER AND PYMAN: 2-PhenylgEyoxaline-4 5-dicarboxylic Acid. The nitrotartsric acid from 25 grams of tartaric acid was treated with 100 C.C. of aqueous ammonia in the manner previously described. Then 20 grams of benzaldehyde were added with stirring below Oo and the stirring was continued for seven hours, the temperature of the mixture being gradually allowed to approach that of the room. After keeping overnight 17.1 grams of 2-phenylglyoxaline-4 5-dicarboxylic acid were isolated that is, 48 per cent. of the theoretical yield whereas Maquenne’s yield was only 8 per cent. 2-Phenylglyoxaline-4 5-dicarboxylic acid melts and effervesces at 271O (corr.). When distilled under the conditions previously described in the case of glyoxaline-4 5-dicarboxylic acid it gives 2-phenylglyoxaline in a yield of more than 80 per cent.of the theoretical. 2-Phenylglyoxaline crystallises from water in small prismatic needles which melt a t 148-149O (corr.) and are anhydrous. 2-Phenylglyoxaline nitrate is readily soluble in water but less so in alcohol from which it separates in leaflets containing $H,O, which is lost a t 60° in a vacuum. The dried salt melts a t 135O (corr.). Found in air-dried salt H20=6-1; in dried salt N=20*0. C,H8N2,HN0 (207.1) requires N = 20.3 per cent. The hydrogen oxalate crystallises from water in flattened needles which melt and effervesce a t 219O (corr.) and are anhydrous. It is readily soluble in hot water but less so in cold. Found N ~ 1 2 . 0 . CgH8N,,C2H204 (234.1) requires N = 12.0 per cent.The picrate is sparingly soluble even in boiling water from which it crystallises in fine needles which melt a t 238O (corr.) and are anhydrous. Found N = 18.6. CgH8N2,C,H,0;N3 (373.2) requires N = 18.8 per cent, 4 5-Dijmethyl- and 2 4 5-Ti.irneth~yFglyoxaline. When 4 5-dimethylglyoxaline is prepared by Windaus’ method (Ber. 1909 42 758) it is contaminated with 2 4 5-trimethyl-glyoxaline which results from the interaction of diacetyl and ammonia (von Pechmann Ber. 1888,21 1414). 8.6 Grams of diacetyl were dissolved in 50 C.C. of water 50 C.C. of 40 per cent. aqueous formaldehyde added the mixture cooled to Oo and 80 C.C. of concentrated ammonia solution graduall NITRO- ARYLAZO- AND AMINO-OLYOXALINES.233 added the reaction mixture being stirred and kept below Oo. After the addition was ended the mixture was allowed to remain in a cool place overnight then evaporated to a low bulk saturated with anhydrous potassium carbonate and the oil which separated extracted by ether. The crude extract which was contaminated with hexamine amounted t o 5.9 grams. After destruction of the hexamethylenetetramine by boiling dilute hydrochloric acid the picrates of the constituent bases were fractionated from water, when 5-7 grams of 4 5-dimethylglyoxaline picrate (17.5 per cent. of the theoretical yield) were obtained first and then 3.5 grams of 2 4 5-trimethylglyoxaline picrate. 2 4 5-Trimethylglyoxali~e picrate sinters from 160° and melta a t 1 6 3 O (corr.). It crystallises from water in well-defined prisms, which are often serrated.Found N=20*6. C6H,,N2,C6H,0,N requires N = 20-6 per cent. The hydrochloride previously prepared by von Pechmann, crystallises from alcohol in fine needles which are anhydrous and melt at 316O (corr.) (Found N=19.0; C1=24.2. Calc. N=19*1; C1= 24.2 per cent.). 4 5-Dimethtylglyoxaline hydrochloride crystallises from alcohol in well-defined rhombic prisms which melt and decompose a t 305O (corr) . Found N = 21.1 ; Cl= 26.4. C,H,N,,HCl requires N = 21.1 ; c1= 26-7 per cent. 4 5-Dimethylglyoxaline was also prepared by a modification of Kunne's method (Ber. 1895 28 2039; compare also Jowetti T., 1905,87 407). Nine grams of methyl a-isonitrosoethyl ketone were reduced with stannous chloride as described by Kunne but the temperature of the reaction mixture was maintained a t 1 5 O and, after the removal of the tin the evaporation of the liquor was conducted entirely under diminished pressure.By these means, a yield of 10 grams of crude crystalline methyl a-aminoethyl ketone hydrochloride was obtained as against 4.2 grams of syrup obtained by Kunne. When this product was heated on the water-bath for four hours with 10 grams of potassium thiocyanate and 40 C.C. of water 5.2 grams of 2-thiol-4 5-dimethylglyoxaline separated and this gave 4 5-dimethylglyoxaline picrate in a yield of 85 per cent. of the theoretical when oxidised with the calculated quantity of ferric chloride.* The yield of 4 5-dirnethylglyoxaline from methyl ethyl ketone is thus 23.8 per cent.of the theoretical. The method of oxidising thiolglyoxalines to glyoxalines by means of ferric chloride has been deecribed by one of:rlis (T.j 1911 99 2176) in the CMQ o 234 FARGKER AND PYMAN: Part 11. N i t r o g l y o x n l i n e s . Rung and Behrend ( l o c . cit.) prepared 4-nitroglyoxaline in a yield of 36 per cent. of the theoretical by boiling glyoxaline with a mixture of nitric and' sulphuric acids. The yield can be improved greatly by the method given below. Eight grams of glyoxaline were dissolved in 16 C.C. of nitric acid (D 1-4) cooled and 16 C.C. of sulphuric acid cautiously added. A vigorous reaction ensued, and when this had subsided the mixture was boiled gently for two hours allowed to ml and then poured into icewater when 7.85 grams of 4-nitroglyoxaline separated.The mother liquors yielded a further 0-5 gram of 4-nitroglyoxaline identical with the above, but no glyoxaline and merely a trace of other crystalline material. The total yield of 4-nitroglyoxaline thus amounted to 63 per cent. of the theoretical. 4-Nitroglyoxaline cryshllises from boiling acetic acid or from alcohol in stout rhombio prisms which are anhydrous and melt a t 312-313O (corr.) (Found N=36*8. Calc. : N=37.1 per cent.). It is only very sparingly soluble in boiling water. Although it dissolves in strong mineral acids it is pre-cipitated unchanged on the addition of water and is recovered unchanged when crystallised f r m aqueous picric acid. 4-Nitl.cr-2rnethylglyoxccline was similarly prepared. ItL crystal-lises from water in fine needles which are anhydrous and melt a t 254O (corr.) sintering from 251O.Found N=33.0. C,H,0,N8 (127.1) requires N = 33.1 per cent. 5-Nit~o-4-methylglyoxalinle was prepared by Windaus (Zm. c i t . ) in a 60 per cent. yield by warming 4-methylglyoxaline with fuming nitric acid a t 80°. Using this method we found the main pro-duct to be 4-rnethylglyoxaline nitrate. Proceeding according to the method described for 4-nitroi-2-methylg1yoxaline 5 grams of 4-methylglyoxaline gave 7 grams of 5-nitro-4-methylglyoxaline (Found N=32*8. Calc. N=33*1 per cent.) melting a t 248O (corr.) that is 90 per cent. of the theoretical yield. 2-thiol-4-aminomethylglyoxaline. The low yield of 4-aminornet~ylglyoxdine recorded (56 per cent. of the theoretical) was due to the fact that insufficient ferric chloride had been employed.When the calaulated quantity (16.2 grams) of this reqpnt is med the product is obtained in a yield of 90 per cent. of the theoretical NTTRO- ARYLdeO- AND AMINO-GLYOXALINES. 236; Attempted Nitratioru of 4 54?im$hylglyoxdh~e. To five grams of 4 :5-dimethylglyoxaline dissolved in 15 C.C. of nitric acid (D 1*4) 15 C.C. of sulphuric acid were added. The first vigoraus reaction was controlled by cooling and after it had ended the mixture was heated for two hours on the water-bath. From the reaction product 1-7 grams of 4 5-dimethylglyoxaline were recovered together with 0.3 gram of the nitrate af 4-metbyl-glyoxaline-5-carboxylic acid (Found C = 32.1 ; H = 4.0 ; N = 21.7. Calc.C=31.6; H=3.7; N=22-1 per cent.) which deposited the corresponding acid melting and effervescing at 222O on the addi-tion of the calculated quantity of sodium hydroxide. From the pure acid the hydrochloride which melted and decomposed a t 231° and the nitrate which deccunposed a t 1 8 9 O were prepared. The melting points of the acid and its salts are in agreement with those found by Gemgross (ZOG. cit. j for 4-methylglyaxaline-5-carboxylic acid. Reduction of Nitroglyoxalines with Tim and Hydrochloric Acid. When 4-nitroglyoxaline 4-nitro-2-methylglyoxaline or 5-nitro-4-methylglyoxaline is reduced with tin and hydrochloric acid and the product mixed with sodium hydroxide and distilled into standard acid two of the three atoms of nitrogen present in the molecule are eliminated in the form of ammonia: 0.5609 of 4-nitroglyoxaline gave 0.1746 NH,; calc.as above, 0-4292 of 4-nitrrv-2-methylglyoxaline gave 0.118 NH ; cale. as 0.4931 of 5-nitro-4-methylglyoxaline gave 0.1378 NH ; calc. as That the greater part of the ammonia is actually produced during the reduction and not by the subsequent action of the alkali is shown in the case of 4-uitroglyoxaline by the following experiment . Twelve grams of 4-nitroglyoxaline were reduced by means of tin and hydrochloric acid in the usual manner. The reduced liquors were freed from tin and then evaporated to dryness then moistened with alcuhol and again evaporated to remove water as far as possible. The crude product was extracted with alcohol and left 9 grams of a crystalline solid which proved taa be ammonium chloride (Found N = 26.9 ; C1= 66.0.Calc. N = 26.2 ; 0.1688. above 0.115. above 0.1320 236 FARGHER AND PYMAN: Cl=66*3 per cent.). The residue of the purple alcoholic solution gave 5 grams of an insoluble phosphotungstate after the removal of ammonia. This produet has not yet been investigated. Reduction of Nitroglyoxalines with So&um Hyposulphite. Behrend and Schmitz (loc. cit .) observed that 4-nitroglyoxaline gave a beautiful blue dye when treated with alkaline reducing agents. We can confirm this result. but find that ammonia is also produced in an amount corresponding witlh the loss .of two atoms of nitrogen in this form from three molecules of 4-nitroglyoxaline when this compound is reduced with sodium hyposulphite in aqueous sodium hydroxide : 0.5148 of 4-nitroglyoxaline gave 0.0521 NH,; calc.as above, The liquors remaining from the distillation gradually acquired a dark blue colour on exposure to the air and on acidification with acetic acid deposited rather less than 0.1 gram of a blue compound which did not melt below 300O. The reduction of 5-nitro-4-methylglyoxaline with alkaline sodium hyposulphite led to t.he same result as in the case of 4-nitro-glyoxaline two molecules of ammonia being produced from three molecules of the nitro-compound (0.5311 gave 0.0487 NH ; calc. as above 0,0474). The reduced solution gradually acquired a rose colour on exposure to air but gave no precipitate with acetic acid. 4-Nitro-2-methylglyoxaline behaved differently from the above compounds on reduction with alkaline sodium hyposulphite yield-ing one molecule of ammonia from three molecules of the nitro-compound (0.5084 gave 0.0230 NH,; calc.as above 0.0227). 0.0516. Part I I I . Ary l a x o g l y o x a l i ~ a e s . 2-Benzeneazoglyoxaline (IV p. 221). 23.25 Grams of aniline were dissolved in 62.5 C.C. of hydro-chloric acid and 187.5 C.C. of water and diazotised wibh 18 grams of sodium nitrite dissolved in 100 C.C. of water. The solution was run slowly into a well-stirred solution of 17 grams of glyoxaline and 40 grams of anhydrous sodium carbonate in 1250 C.C. of water, previously cooled to 5O and kept overnight. The insoluble orange powder was collected washed well with water and extracted suc-cessively with 250 125 and 125 C.C.of cold 2.5 percent'. hydrochloric acid. (Extract= A .) The insoluble malerial amounted to 4. NITRO- ARYLAZO- AND AMINO-GLYOXALINES. 237 grams and after crystallisation from alcohol gave 2 4 5-tris-benzeneazoglyoxaline of which only 0.5 gram was obtained in a pure state. This compound decomposes a t about 200° and effervesces a t 208O (corr.). When pure it is only sparingly soluble even in boiling alcohol from which it crystallises slowly in dark brown clusters of crystals of indeterminate shape. (0.84 required 60 C.C. of boiling alcohol.) Found C=66.0 ; *H =4.6 ; N=29*0. C,,HlGN8 (380.3) requires C = 66.3 ; H = 4-2 ; N = 29.5 per cent. Trisbenzeneazoglyoxaline is insoluble in cold dilute hydrochloric acid and is decomposed when boiled with this reagent.It dis-solves to some extent in aqueous sodium hydroxide. The hydrochloric acid extract ( A ) was diluted with water and basified with sodium carbonate when crude 2-benzeneazoglyoxaline was obtained. as a yellow crystalline precipitate which after thorough washing with cold water and drying amounted to 34 grams. On crystallisation from 150 C.C. of alcohol 31 grams of the pure base were obtained that is 74 per cent. of the theoretical. No other definite compound could be isolated from the mother liquor. 2-Benzeneazoglyoxd~ne crystalliees from alcohol in large orange tablets resembling potassium dichromate in appearance. It melts a t 190° (corr.) to a reddish-black liquid. Found C=62*7 62.7; H=4*8 4.9; N=32*3 C,H,N (172.1) requires C = 62.8; H = 4.7 ; N = 32.6 per cent.Rzhg and Behrend’s Method.-By this method in which benzene-diazonium chloride is allowed to react with glyoxaline without the addition of alkali 5 grams of glyoxaline gave 3.3 grams of crude precipitate insoluble in water. Of this 2.2 grams were separated into 0.7 gram of insoluble resin which appeared to evolve gas on keeping and 1*45 grams soluble in acid which gave pure 2-benzeneazoglyoxaline on crystallisation from alcohol. The crude precipitate was less readily purified by direct crystallisation from alcohol. General PropeT t ies of A r y laz ogl y oxalimes .-To avoid repetition, it will be convenient to describe the general properties of the monoarylazoglyoxalines a t this point. 2-Benzeneazoglyoxaline and 2-benzeneazo-4-methylglyoxaline are fairly readily soluble in alcohol ethyl acetate or acetone sparingly so in ether chlore form or benzene.5-Benzeneazo-4-methylglyoxaline 2-p-bromo-benzeneazoglyoxaline and 4-~bromobenzeneazo-2-methylglyoxaline are sparingly soluble in the first three solvents and very sparingly so in the last three. L 238 FARGHER AND PYMAN: These compounds are almost insduble in cold water or in dilute aqueous ammonia or sodium carbonate but dissolve to some extent in dilute aqueous sodium hydroxide. The benzeneazo-compounds dissolve readily in dilute hydrochloric acid and the solutions yield crystalline hydrochlorides on concentration ; the hydrochlorides of the p-brormobenzeneazo-compounds are sparingly soluble in water. The stability of a 2- and a 4-substituted member of the group towards boiling dilute hydrochloric acid was examined.When 0.5 gram of 2-benzeneazoglyoxalLne was boiled with 20 C.C. of 10 per cent. aqueous hydrochloric acid for two hours under a reflux condenser 0.35 gram was recovered little changed on the addition of ammonia and readily gave the starting material in a pure state on crystallisation from alcohol. When 5-benzeneazo-4-methylglyoxaline was boiled with an excess of 10 per cent. aqueous hydrochloric acid for a few minute it was recovered unchanged after the addition of ammonia but after boiling for one hour it was mainly decomposed with the form-ation of resinous compounds. The arylazoglyoxalines dissolve in concentrated sulphuric acid, giving bright - col ou red soh ticrns.The mono a ry 1 azed erivativ e ~ s yield mainly orange or magenta solutions the 2-substituted deriv-atives being more intensely coloured than the 4-substituted com-pounds whilst the solutions of bis- and tris-arylazoglyoxalines are green and still more intense than those of the Z-monoarylazo-derivatives. Reduction of 2-Benzeneasoglyoxaline 'With Stannous Chloride : Zgolation of 2-Amino-4-p-aminophenylglyoxdhae 2-Amino-glyoxalke Gumaidhe and Aniline. Twenty grams of 2-benzeneazog1yoxaline were dissolved in 200 C.O. of boiling 2.5 per cent. hydrochloric acid and mixed with 120 C.C. of stannous chloride solution.* The solution was immedi-ately dwulorised and when mixed with ZOO C.C. of hydrochloric acid deposited a crystalline tin salt ( A ) . This was collected and the mother liquor was evaporated to dryness dissolved in hot water, and freed from tin.It was then evaporated to low bulk mixed with sodium carbonate and extracted with ether which removed 3.0 grams of crude aniline. The alkaline liquor was acidified faintly with hydrochloric acid evaporated to dryness and extracted with alcohol when 3.1 grams of extract were obtained. This was * The sltannoua chloride solution employed throughout this investigation waa mad6 by mising 40 grams of " tin salt " with sufficient hydrochloric mid to make 100 c.c.. of solution MTRO- ARYLAZO- AND BMINO-QLYOXAUNES. 239 mixed with stannio chloride and deposited first 2.2 grams of pure 2-aminogtyoxdine stanniehloride then crops of the crude salt f r m which a further quantity of 1.0 gram of the pure*salt was obtained, the total yield amounting t o 11 per cent.of the theoretical. The final stannichloride mother liquors were deprived of tin by means of hydrogen sulphide and mixed with picric acid. After crystal-lisation from water the first crop of picrate which melted a t 325O, was decomposed by sulphuric acid the picric acid being removed by means of ether. The solution of sulphates was deprived of sulphuric acid by barium hydroxide and from excess of this reagent by carbon dioxide. The resulting solution was neutralised with aqueous oxalic acid mixed with as much more aqueous oxalic acid and concentrated when crude guanidine hydrogen oxalate separated. After recrystallisation from water this amounted to 0-07 gram melting and effervescing a t 172-173O (corr.) alone or when mixed with pure guanidine hydrogen oxalate.The crystalline tin salt ( A ) was dissolved in water treated with hydrogen sulphide filtered from tin sulphide and concentrated, when 18.55 grams of 2-amino-4-p-aminophenylglyoxaline d i h y h o . chZoride separated that is 64.6 per oent. of the theoretical yield. 2-Am.ino-4-p-aminophelzylg.lyozal~~e C,H,,N (VI p. 222). When the dihydrochloride is mixed with an equivalent quantity of sodium carbonate a colourless oil separates which solidifies on keeping. This is a carbonate for it effervesces on treatment with acid and when dissolved in boiling .water disengages carbon dioxide vigorously on the addition of animal charcoal leaving a solution of the free base which crystallises on keeping.This solution becomes brown a t the top owing to oxidation in the air whilst the larninrr become mauve where exposed to the light. To 5-0 grams of the dihydrochloride in 50 C.C. of boiling water, 30 C.C. of hot 10 per cent. aqueous sodium carbonate and a pinch of animal charcoal were added. The solution was boiled for five minutes filtered and kept when 3.1 grams of the base separated and were recrystallised from water. This base cryshllises from water in glistening leaflets which melt and effervesce at 148O (corr.). It contains 1H,O which is not l.ostl in a vacuum or on heating a t looo. Found C= 56.3 ; H = 6.4 ; N = 29.5 29-2. C,H,,N4,H,0 (192.2) requires c f = 56.2 ; H = 6.3 ; N = 29.2 per cent. It is sparingly soluble in cold fairly readily so in hot water; fairly readily soluble in cold readily in hot alcohol and very sparingly so in chloroform or ether.L' 240 FARCHER -4ND PYMAN: An aqueous solution of the base gives with silver nitrate a white precipitate which blackens at once on the addition of ammonia; with Fehling's solution a nearly black precipitate-presumably a copper salt-which is unchanged on boiling the solution ; with cold permanganate instant reduction ; with sodium diazobenzene-p-sulphonate in aqueous sodium carbonate an immediate cherry-red colour. When the base is dissolved in an excess of hydrochloric acid and mixed with sodium nitrite a yellow solution is obtained, which yields with a solution of &naphthol in aqueous sodium hydr-oxide a sparingly soluble purple dye.On the addition of sodium hydroxide to a solution containing 2-amino-4-p-aminophenyl-glyoxaline hydrochloride and sodium nitroprusside a green color-ation changing to1 chestnut-brown is produced. On the addition of dilute sulphuric acid to an aqueous solution of the base or its hydrochloride the very sparingly soluble sulphate crystallises in woolly needles. The dihydrochloride crystallises from dilute hydrochloric acid in colourless prisms which do not melt below 3QOO. It is readily soluble in cold very readily so in hotl water, Found C1= 28.6 ; N = 22.5. The dipkrate forins yellow silky needles which darken a t 245' It is very sparingly soluble even The benzylidene derivative of 2-amino-4-11-aminophenylglyoxaline C,Hl,N4,2HCl (247.1) requires C1= 28.7 ; N= 22.7 per cent.and decompose a t 250° (corr.). in boiling water. was not obtained in a crystalline form. 2- A ce tylamino-4-p-ace tylnmin o pkenylgly oxdin e . 10.6 Grams of 2-amino4-p-a1ninophenylglyoxaline were boiled with 50 C.C. of acetic anhydride for one hour under a reflux con-denser and mixed with aqueous sodium carbonate when 13.9 grams of the diacetyl derivative were obbained that- is 98 per cent. of the theoretical yield. The base forms a colourless crystalline powder which does not melt below 300O. Found N = 21.2. It dissolves in dilute hydrochloric acid but the hydrochloride crystallises almost a t once. It appears to be changed by prolonged boiling with hydrochloric acid, The hydrochloride was consequently prepared by triturating the base with an excess of 10 per cent.aqueous hydrochloric acid drain-ing the insoluble salt? and crystallising it from water when it C,,H,,O,N (258.2) requires N = 21.7 per cent NITRO- ARYTJAZO- AND AMINO-Q~~YOSALTNES. 241 formed colourless prismatic needles which did not melt below 300°. It is sparingly soluble in cold fairly readily so in hot water. Found in air-dried salt loss a t l l O o = l l * l . Found in salt dried a t l l O o C=53.1; H=5-3; N=18*7; C,,H,,O,N,,HCl (294.7) requires C=53*0; H=5*1; N=19.0; (31 = 12.0 per cent. Oxidation .-Ten grams of 2-acet.ylamina-4-p-acetylaminophenyl-glyoxaline were suspended in 150 C.C. of cold water and mixed with 4 grams of 50 per cent. aqueous sulphuric acid when a suspension of the sulphate resulted.To this cold 4 per cent. aqueous potassium permanganate was added until a test portion of the pfo-duct remained pink for a few seconds about 240 C.C. being required. The liquor was then filtered from manganese hydroxide acidified with hydrochloric acid and extracted with ether. The et-hereal extract amounted to 1.5 grams and after digestion with a litt81e warm water left 1.0 grain of p-acetylaminolbenzoic acid which melted at 260° (corr.). After recrystallisation from boiling water, t-he acid formed glistening needles having the same melting point. A specimen of the pure acid from another source and a mixture of the two melted a t the same temperature. The identification was confirmed by analysis (Found C - 59.9 ; H = 5.2 ; N = 7-8. Calc. : C=60*3; H ~ 5 .1 ; N=7*8 per cent.) and by hydrolysis to p-amino-benzoic acid which melted a t 190° (corr.) alone or mixed with t h e acid resulting from the reduction of pnitrobenzoic acid. ClsH,,0,N,,HC1,2H20 (330.7) requires 2H,O = 10.9 per cent. Cl= 11.6. Redzcctiom of 2-Benzeneaxogl~oxal~ne with Zinc Dust and Acetic Acid Isolation of Glycocyarnidine Aniline a d 2-Arnitto-4-p-amino phemylglyoxdine . To a boiling solution of 17.2 grams of 2-beazeneazoglyoxaline in 100 C.C. of glacial acetic acid and 300 C.C. of water 45 grams of zinc dust were added gradually in the course of twenty minutes without further heating. The excess of zinc was removed the liquor diluted with 2 litres of water giving an indigecoloured solution and treated with hydrogen sulphide. After collecting the zinc sulphide-which had carried down t.he colouring matter-the liquor was mixed with 20 C.C.of hydrochloric acid and evaporated to dryness. The residue was dissolved in a little water mixed with sodium carbonate and extracted with ether when 2.7 grams of insoluble black material were deposited ; this contained zin 212 PAWKER AND PYMAN: carbonate and the carbonate of 2-amino-4-p-aminophenylglyoxaline. The ethereal extract left on evaporation 7.0 grams of practically pure aniline. The alkaline liquor was acidified faintly with hydro-chloric acid mixed with a solution of 23 grams of picric acid in 1 litre of boiling water and stirred when 2.6 grams of 2-amino-4-paminophenylglyoxaline dipicrate separated immediately as a brownish-yellow crystalline powder which melted a t 240"; for the identification of this substance the hydrochloride and base were prepared and found to have the properties recorded above.The filtrate from this salt was kept overnight when 21.5 grams of a granular crystalline picrate melting at 196O separated and on concentrating the mother liquor a further 4.8 grams melting a t B O O were obtained. These crops were mixed converted into the hydrochloride and crystallised from alcohol whm eventually 5.9 grams of pure glycocyamidine hydrochloride were obtained that is, 43 per cent. of the theoretical yield. It formed clusters of pris-matic needles which began to darken and sinter a t 205O and melted a t 211-213O (corr.). E. Schmidt (Arch. Phmm. 1913, 251 557) states that it begins to discolour at 200° and melts a t 208-210° (Found C= 26.5 ; H = 4.4 ; N = 30.6 ; C1= 26.3.C3H,0N3,HC1 (135.6) requires C = 2 6 * 6 ; H=4.5; N=31-0; C1= 26-2 per cent.). To complete the identification of this compound the base and some other salts were prepared. The base crystallised from water in colourless prismatic needles which began to darkea slowly from about 220° and quickly from about 250° without melting even a t 300O. It was anhydrous. (Found C=36*4; H=4*8; N-42.3. C3H,0N (99.1) requires C= 36.3 ; H -5.1 ; N = 42.4 per cent.) E. Schmidt (Zoc. c i t . ) states that glycocyamidine darkens from 220°, but does not melt a t 250O. It gave with sodium nitroprusside and sodium hydroxide an orange solution which became Burgundy-red on the addition of acetiu acid (Weyl's reaction).It is stable towards cold aqueous permanganate in acid solution but reduces cold alkaline permanganate yielding a green solution. The platinichloride was obt'ained on spontaneous evaporation of an aqueous solution in large transparent quadrilateral tablets having the composition C3H,0N3,H2PtC1,,2H,0. It begins to darken a t 220° gradually sinters and is quite black by 260* with-out actually melting even a t 300O. E. Schmidt (loc. &.) found that glycocyamidine platinichloride had this composition and did not melt a t 260° but sintered and blackened earlier. The platinichloride was also obtained in an anhydrous form by crystallisation from a hot concentrated solution when it formed clusltere of prisms NITRO- ARYLAZO- AND AMINO-QLYOXALINES.243 The additive compound with gold chloride C3H,0N8,AuC&, melted a t 157-158O (corr.). Eorndorfer (Arch. Phum. 1904, 242 633) found that glycocyamidine gold chloride had this com-position and melted a t 153-154O. The picrate crystallised from water in glistening striated yellow leaflets (flat needles) which melted a t 215-216O (corr,). Jaff6 (Zeitsch. physiol. Chem. 1906 48 430) describes glycocyamidine picrate as forming needles which melt at 210O. 2- and 4-p-Bromobenzeneaaoglyoxaline. 34.4 Grams of p-bromoaniline i n 200 C.C. of hydrochloric acid and 600 C.C. of water were diazotised a t -2O to Oo by a solution of 14-4 grams of sodium nitrite in 72 C.C. of water. The solution was kept for twenty minutes and poured in a slow stream into a solu-tion of 13.6 grams of glyoxaline and 300 grams of sodium carbonate crystals in 2 litres of water previously cooled to 5O.After adding a little more aqueous sodium carbonate the mixture was kept over-night and the insoluble yellow powder collected and washed with water. It amounted to 48.7 grams after drying in the air decom-posed a t 245O and was almost completely soluble in dilute hydro-chloric acid After fractional crystallisation from alcohol there were obtained 37.5 grams of pure 2-p-bromobenzeneaaoglyoxalil.L~ and 5.1 grams scarcely less pure whilst the final mother liquors deposited a mixture of this compound with dark brown w a h , which were separated mechanically and amounted to about 2.5 grams melting atL about 175O. These were dissolved in dilute hydrochloric acid and the solution was filtered from a little dark brown insoluble matter and mixed with ammonia when a yellow, gelatiinous precipitate was formed which readily became crystalline on warming and stirring.This base was collected and crystallised several times from alcohol when 4-p-bromo benzeneazoglyoxali~e was obtained in a pure state. 2-p-Bromob enaeneazoglyoxaline crystallises from alcohol in chestnubbrown prismatic needles which melt and decompose at) 253O (WIT.). Found C = 42.9 ; H = 3.1 ; N = 22.1. C,H,N,Br (251.1) requires C =43*0 ; H = 2.8; N = 22.3 per cent. 4 -p -Brmob enz eneaz ogly o xalin e cry st allises from alcohol in-clusters of brownish-yellow prisms which melt and decompose a t 191O (corr.). Found C=43*2; H=3*1; N=21*9.C,H,N4Br (251.1) requires C=43*0; H=2.8; N=22’3 per cent 244 FARCTHER ANT) PYMAN: On reducing this base (0.26 gram) with stannous chloride and distilling the resulting solution with an excess of sodium hydroxide, the volatile products consisted of pbromoaniline (0.18 gram) and ammonia which gave 0.05 gram OE ammonium chloride. Reduction of 2-p -Br o mo b en z en eaz og ly oxdine with S t ann ow s Chloride Isolation of 2-Aminoylyoxaline p-Bromoaniline, Gwnidine 2- A mino - 4 - p-amin o phe n y lgl y o xalin e and a Base, C,H,N,Br-To 78 grams of 2-p-bromobenzeneazoglyoxaline suspended in 40 C.C. of hydrochloric acid and 1 litre of boiling water 400 C.C. of stannous chloride solution were added. The solution immedi-at8ely became decolorised and after the removal of 0.5 gram of brown insoluble matter was concentrated under diminished pressure.The tin salts which separated were coWected from time t a time and combined so that the product was obtained in two fractions consisting of the crystalline tJn salts and the syrupy residue. The crystalline tin salts were dissolved in water and deprived of tin by hydrogen sulphide. The solution of hydrochlorides was evaporated to dryness dissolved in a little water and mixed with aqueous sodium carbonate when 39.6 grams of p-bromoaniline separated. The filtrate from this gave a further 1.1 grams of the same compound on extraction with ether and was next acidified with hydrochloric acid evaporated to dryness and extracted with absolute alcohol. (Insoluble material = A .) On distilling the alcohol a brown syrup remained which quickly crystlallised and became a rock-like mass of 2-aminoglyoxaline hydrochloride, amounting t o 15.8 grams and melting a t 135-140°.The syrupy tin salts were also dissolved in water and deprived of tin. The resulting solution was evaporated to dryness dissolved in a little water mixed with sodium carbonate and extracted with ether. This on concentration deposited 0.9 gram of colourless needles melting at 1 7 8 O (corr.) which proved to b e 8 base having the composition C9H,N,Br (compare p. 245). The ethereal mother liquor on evaporation left 2.6 grams of dark brown syrup which gradually crystallised and consisted largely of p-bromoaniline. The alkaline liquor was acidified with hydrochloric acid, evaporated t o dryness under diminished pressure and extracted with absolute alcohol.The insoluble salts consisting mainly of sodium chloride were combined with those obtained previously ( A ) dissolved in water and mixed with aqueous picric acid when 2.7 grams of 2-amin~4-p-aminophenylglyoxaline dipicrate melt NITRO- ARYLAZO- AND AMINO-QLYOXAT~TNES. 246 ing a t 240° separated; the identity of this salt was confirmed by its conversion into the hydrochloride and base. The alcoholic extract was evaporated under diminished pressure and left 13.0 grams of brown syrup which crystallised only partly on seeding with 2-aminoglyoxaline hydrochloride. It was converted into the stannichloride and crystallised fractionally from 10 per cent. hydro-chloric acid when 10.2 grams of 2-aminoglyoxaline stanni-chloride melting a t 280° (corr.) were obtained.This is equivalent to 4.9 grams of 2-aminoglyoxaline hydrochloride the total yield of which was therefore 20.7 grams that is 56 per cent'. of the theoretical. The remaining stannichlorides were not readily purified by frac-tional crystallisation and were reconverted into hydrochlorides, which amounted to about 3 grams. This material waq mixed with sodium carbonate evaporated until nearly dry and extracted with hot alcohol.* The extract was distilled and the residue mixed with ail excess of 10 per cent. aqueous oxalic acid when 1.6 grams of guanidine hydrogen oxalate separated in large crystals. After recrystallisation from water this salt formed colourless spears, which melted a t 173-174O (corr.) after drying a t looo and was sparingly soluble in water.It had the campmition CH5N3,C2H204,H,0 previously recorded by Strecker (Amden 1861 118 160). (Found H,O=10.3. Calc. H,O=10*8. Found in dried salt C=24-0; H z 4 . 9 ; N=28*0. Calc. C=24.1; H=4*7; N=28*2 per cent.) The melting point of a specimen of guanidine hydrogen oxalate pre-pared synthetically and that of a mixture of the two preparations was the same. The identification was confirme'd by the prepara-tion of the nitrate and picrate which had the properties previously recorded. The base melt'ing a t 178O (corr.) obtained as a by-product in the above reaction (compare p. 244) forms colourless needles from alcohol or ether. It is sparingly soluble in water readily so in cold and very easily soluble in hot alcohol, but sparingly so in ether.Its alcoholic solution gradually becoma purple when exposed to the air. It contains halogen. Found C=43*0; H=3*9; N=21*9. CgHgN,Br (253.1) requires C=42*7; H=3*6; N=22.1 per cent. 0.122 Gram mixed with an excess of hydrochloric acid and evaporated to dryness gave 0.153 gram of salt which is therefore * The method employed for the extraction of guanidine carbonate is unsuitable and it is probable that a considerable proportion remained behind with the sodium carbonate a dihydrachlode (calc. yield 0.167 gram). This salt qstallised from water in elongated leaflets which after drying a t 1000 melted and decomposed a t 245O (oorr.) after sintering earlier. The (&)pimate crystallises from water in woolly needlee which melt a t 225O (corr.) and are sparingly soluble in hot very sparingly so in cold water.The base decolorises potassium permanganate instantly in cold dilute sulphuric acid solution and gives a Burgundy-red coloration with sodium diazobenzene-psulphonate in aqueous sodium carbonate. When dissolved in dilute hydrochlorio auid and mixed with sodium nitrite it yields a colourless crystalline precipitate, but the product-crystals and mother liquor-when poured into alkaline &naphthol gives no coloration. When an aqueous solution of the hydrochloride is mixed with sodium acetate and benzaldehyde a turbid yellow solution is pro-duced-evidently awing to the f ormation of a benzylidene compound. The compwition and mode of formation of the baseindicate that it is 2-p-bromobenzenehydrazoglyoxaline o r a substance resulting from this by the benddine or semidine change.The formation of a dihydrochloride and a benzylidene derivative rule out the first suggestion whilst the formation of the latter compound also eliminates the semidine-type formula I11 given below. This formula and the benzidine-type formula I are also incompatible with the behaviour of the compound on treatment with nitrous aaid and sodium 8-naphthoxide but the semidinetype formula 11, representing 2 -5 I- b romo- Zf-am~n~rtilillag.ly~x~ine admits the possibility of o-diazoimine formation with nitrous acid and is in harmony with all the observed properties of the compound (com-pare p. 223). \-/ (111.) 2-Aminoglyoxali7ts (XII p.223). For the purification of 2-aminoglyoxaline crystallisation of the The free base can be obtained (1) from the hydrochloride by the stannichloide and hydrogen oxalate has proved to be USQfUl NITRO- ARYLAZO- AXD A.WINO-QLYOXALINES. 247 addition of an equivalent quanGty of sodium carbonah evapors-tion to dryness and extraction with alcohol and (2) from the hydrogen oxalate by treatment with aqueous barium hydroxide, removal of the excess of this by carbon dioxide and evaporatio~l of . t h e solution under diminished pressure. I n either case it is obtained as a nearly colourless syrup which gradually turns brown on keeping. It is miscible with water and alcohol sparingly soluble in chloroform but hardly soluble in ether or benzene. The hydrochloride crystallises from absolute alcohol in long, colourless plates which melt a t 162O (corr.).It is deliquescent, and readily soluble in cold very readily so in hot absolute alcohol. Its aqueous solution reacts neutral to litmus. C3H5N3,HC1 (119.5) requires C=30-1; H ~ 5 - 1 ; N=35*1; C1=29*7 per cent. The stanmichloride crystlallises from two la two and a-half times its weight of 10 per cent. hydrochloric acid in prismatic needles, which are anhydrous and melt at 286O (corr.). It is readily soluble in water. Found C=30.2; H=5-2; N=34-7; C1=299. Found @I = 42.4. (C3H5N3),,H,SnCls (499.6) requires C1= 42.6 per cent. The nitrate separates from water in large transparent tablete, which are anhydrous and after drying a t looo sinter from about 125O and melt a t 135-136O (corr.).Found N = 38.2. C,H,N,,HNO (146.1) requires N =38-4 per cent. The hyd!roge.pz. oxalate crystallises from water in large colourless tablets which are anhydrous and melt and effervesce at 2 1 1 O (wrr.). It is sparingly suluble in cold readily so in *hot water. Found N = 24.0. C3H5N3,C,H,04 (1 73.1) requires N = 24.3 per cent. The @crate separates from water in long glistening silky needles or in shortl prismatic needles both melting a t 236O (corr.) after drying a t looo. It is'sparingly soluble in cold fairly readily so in hot water. Reaction8 of 2-&4 m~~~g~yoxal~~ae.-%-Amino~l~oxalin~ hydro-chloride dissolved in dilute aqueous copper sulphate gives oh the addition of sodium hydroxide a green precipitate which rapidly darkens and becomes purple-brown.The same precipitate-evidently a copper salt-is obtained eventually with Fehling's solu-tion; no reduction of this solution takes plaoei even on boiling. 2-Aminoglyoxaline nitrate in aqueous silver nitrate gives a whit 248 FAROHER AND PYMAN: precipitate on the addition of ammonia; this precipitate is soluble in excess of ammonia and the solution deposits metallic silver on heating. 2-Aminoglyoxaline hydrochloride in aqueous solution decolorises aqueous potassium permanganate instantly ; with ferric chloride it gives no coloration. With sodium diazobenzene-p-sulphonate in aqueous sodium carbonate it gives a deep red colour. On the addition of sodium nitrite to aqueous 2-aminoglyoxaline hydro-chloride a clear yellow solution is produced which gives a soluble, brownish cherry-coloured dye with 8-naphthol in aqueous sodium hydroxide.An aqueous solution of 2-aminoglyoxaline hydro-chloride mixed with dilute aqueous sodium nitroprusside gives on the addition of sodium hydroxide a deep blue colour which slowly changes to a bright chestnut on keeping. 2-Aminoglyoxaline is very stable towards hot acids and alkalis. When boiled with 10 per cent aqueous sodium hydroxide no ammonia is evolved and it can be recovered unchanged from the solution. It can be recovered mainly unchanged after heating with concentrated hydrochloric acid for three hours a t 170° and even after three hours at 200° a small proportion can be recovered, together with ammonium chloride and other unidentified products. An aqueous solution of 2-aminoglyoxaline hydrochloride cont.ain-ing an excesj of sodium acetate gives no coloration or other evidence of the formation of a benzylidene derivative when mixed with benzaldehyde .2-8 cetyZnminogZyoxaZine was prepared by bqiling 2-amino-glyoxaline hydrochloride with anhydrous sodium acetate and acetic anhydride for one hour and mixing the product with aqueous sodium carbonate. It crystallises from water in small prisms which melt to a brown liquid at 287' (corr.) after sintering and darken-ing from about 270O.' It is anhydrous and sparingly soluble in cold wat'er but fairly readily so in hot water. Found C= 47.7 ; H = 5.7 ; N = 33-4. C,H,ON (125.1) requires C=48*0; H=5*6; N=33.6 per cent. The reactions of this substance are described with those of the next compound.2 - B e n z o y l a m i i z ~ g l y o x ~ ~ ~ e was prepared by the Schotten-Bau-mann method. The crude product collected from the reaction liquor appears to be a di- or tri-benzoylaminoglyoxaline. After washing with ether t o remove benzoic anhydride it formed a nearly colourless crystalline powder which contained only a trace of chloride but gave an odour of benzoyl chloride when boiled with dilute hydrochloric acid. When treated with a little hot alcohol NITRO- ARYLAZO- AND AMINO-GLYOXALINES. 249 it dissolved and 2-benzoylaminoglyoxal~ne crystallised from the hot liquor whilst the mother liquor from this left an Ql-appar-ently ethyl benzoate-on distillation. 2-Benzoylaminoglyoxaline was purified by crystallisation from alcohol from which it separates in glistening leaflets melting a t 2 2 7 O (corr.) after sintering earlier.It is sparingly soluble even in hot alcohol and almost insoluble in boiling water. Found C = 63.9 ; H = 4.9 ; N = 22.4. C,,H,0N3 (187.1) requires C=64.1; H=4*9; N=22.5 per cent. 2-Acetylaminoglyoxaline and 2-benzoylaminoglyoxaline are soluble in dilute hydrochloric acid and in aqueous sodium hydr-oxide but not in aqueous sodium Carbonate. They give cherry-red solutions with sodium diazobenzene-p-sulphonateA in sodium carbonate but do not give colorations with sodium nitroprusside and sodium hydroxide. They do not change the colour of cold aqueous acid permanganate but give green solutions with cold aqueous permanganate in sodium hydroxide solution.When mixed with hydrochloric acid and sodium nitrite they do not couple with /3-naphthol in aqueous sodium hydroxide. The S e n z e ? i e n z o - 4 - m e t l ~ ~ l ~ l ~ ~ ~ ~ ~ l ~ ? i e s . 37.2 Grams of aniline in 100 C.C. of hydrochloric acid and 300 C.C. of water were diazotised with 28-8 grams of sodium nitrite in 150 C.C. of water. The solution was run slowly into a solution of 32.8 grams of 4-methylglyoxaline and 100 grams of sodium hydrogen carbonate in 2 litres of water a t loo and kept overnight. The orange precipitate was collected washed well with water (filtrate F ) and triturated successively with 500 250 and 250 C.C. of 2.5 per cent. aqueous hydrochloric acid. The insoluble fraction formed a dark red powder which amounted to 23.2 grams and decomposed at 175O after sintering from 1 6 0 O .On crystallisation from 300 C.C. of alcohol it gave 17.3 grams of pure 2 5-bisbenzene-azo-$-met hylglyoxaline the remainder of the material forming a black resin. The hydrochloric acid extract was basified with sodium carbonate, and gave 40.4 grams of a yellow crystalline powder which sintered from 160° and decomposed a t 195O. On crystallisation from 400 C.C. of alcohol it gave successively 13.1 grams melting a t 235O 3.9 grams melting a t 232O which both gave 5-benzeneazo-4-~nethyZglZyoxaZine on recrystallisation then 7.4 grams melting a t 175O which gave 2-benzeneazo-4-methylglyoxaline on recrystallisa-tion then 12.4 grams of a mixture of the two compounds 250 FARQHER AND PYMAX: Owing to the formation of the bis-mmpound in the above r w tion the benzenediazonium chloride employed wits insufficient to combine with the whole of the rnethylglyoxaline present and it was calculated that 10.5 grams of this remained in the filtrate F .This was accordingly treated with a diazo-solution prepared from 11.9 grams of aniline and gave further quantities of tlhe substances described above 5.3 grams of the bis-compound and 5.6 grams of 5-benzeneazo-4-methylglyoxaline being obtained i n a nearly pure S t a b . 2-Bemzeneazo-4-methylglyoxdcline (XIV p. 224) crystallises from alcohol in orange prisms which melt a t 185O (corr.). Found C=64*8; H=5*6; N=30.1. CIOHIONl (185.2) requires C = 64.5 ; H = 5.4 ; N = 30.1 per cent. 5-Benzeneazo-$-met hytglyoxaline (XVIII p. 2 24) crystallises from alcohol in flat glistening copper-coloured needles which melt and decompose a t 240° (corr.).Found C=64*5; H=5-6; N=30*0. C,,H,,N (185.2) requires C = 64.5 ; H = 5.4 ; N = 30.1 p0r cent'. 2 5-Bisb emzeneazo-4-methylgZyoxaline separates from alcohol in Both forms are prismatic needles and from ethyl acetate in cubes. garnet-red in colour and melt and decompose a t 2 0 6 O (corr.). Found C=66.0 65.9; H=5*1 5.1; N=28.8 28.8. ClGHl4NB (290.2) requires C=66.2; H=4*9; N=29*0 per cent. This substance is readily soluble in alcohol ethyl acetate or acetone fairly readily so in chloroform but sparingly so in ether or bpzese. It is soluble in aqueous sodium hydroxide and is reprecipitated unchanged on the additmian of acetic acid. It is only very sparingly soluble in dilute hydrochloric acid.When boiled wit'h 10 per cent. aqueous hydrochloric acid it is quickly resinified with effervescence, doubtless due to nitrogen and the production of an odour of phenol. Reduction of 2-Benzeneazo-4-met hylylyozaline with Stannow ChluritZe . 1.5 Grams of 2-benzeneazo-4-methylglyoxaline gave 1.4 grams of 2 -amino-5-pamin op hen yl-4 -me th ylgl yoxaliiie d ihy drochloride when reduced with stannous chloride i n the manner previously described for the lower hom'ologue (p. 238). dih ydro c hlo&i?e cry&allise~ from water in diamond-shaped plates which are anhydrous and do not melt below 300O. It is readily soluble in cold very readily so in hot water. 2- A n~ i ~ o - 5 - p-amino phenyl - 4 - IIL e t h y lgl y oxali t I NITRO- ARYLAZO- AND AMINO-GLYOXALINES.261 Found C=46-0 45.9; H=5*5 5.5. Cl,H,,N,,2HC1 (201-0) requires C= 46.0 ; H =5*4 per cent. When boiled with an excess of aqueous sodium carbonate and animal charcoal it yields the mono hycEroc?do&#e unlike the lower homologue which yields the corresponding base under this treat-ment. The mumohydrochZoride crystallises from alcohol in flat needles which sinter a t about 80° become discoloured rapidly about 240°, and melt a t 260° (corr.). It is readily soluble in hot water or alcohol less so in these solvente when cold. Found in air-dried base loss a t 60° in a vacuum 13.2 13.3. C,,H&N,,HCl,2~H20 requires loss of 2H20 = 13.4 per cent. Found in base so dried C=51*5; H=5.6; N=24.0 24.0; C,,H’,,N,,HCl,~H,O (233.7) requires C = 51.4 ; H = 6-0 ; N = 24.0 ; C1=15.2 per cent.The &@crate forms glistening yellow needles which melt and decompose a t 255O (corr.) after darkening earlier. It is very sparingly soluble even in boiling water. An aqueous solution of the hydrochloride reduces cold amrnoniacal silver nitrate. It gives with Fehling’s solution a greyish-green precipitate which becomes pale brown on boiling the liquor ; with cold aqueous acid permanganate instant reduction ; with sodium diazobenzene-p-sulphonate a pale mange colour which deepens un keeping; with hydrochloric acid and sodium nitrite an orange-yellow solution which yields a sparingly soluble claret dye when added to a solution of &naphthol in aqueous sodium hydr-oxide. On the additmion of sodium hydroxide t o an aqueous solu-tion of the hydrochloride and sodium nitroprusside an orange colour is produced which changes to green on the addition of acetio acid.The diacetyZ derivative was prepared by the action of sodium acetate and acetic anhydride on the dihydrocbloride and was purified by crystallisation of the hydrochloride. hydro-chloride crystallises from water in felted silky needles which are sparingly soluble in cold water contain 4H,O and after drying a t looo melt and decompose a t 303O (corr.). C1= 14.9. 2-A ce t ylamino-5 -p-acet ylaminoyh enyl-4-me t hylgZy oxuline Foluiid in air-dried salt loss a t looo= 19.0. Found in salt dried at’ looo C1= 11-4. C,,H,,0,N,,HC1,4H20 requires H,O = 18.9 per cent Cl4Hl6O2N4,RCI (308.7) requires C1= 11.5 per cen 2 52.E'ARBHBR AND PYMAN: On adding ammonia to an aqueous solution of the hydrochloride, the base was precipitated in minute glistening needles which after drying a t looo melted to a red liquid a t 280° (corr.). Nono b enzylidefie Derivative .-To 0.5 gram of the dihydro-chloride in 5 C.C. of water there were added first 0.55 gram of sodium acetate in 5 C.C. of water and then 0.5 C.C. of benzaldehyde, and the mixture was stirred. A yellow colour was developed and the aqueous liquor became turbid and gradually deposited crystals. On adding a few drops pf acetic acid and ether the quantity of crystals was increased. They were collected and washed with water and ether when there remained 0.5 gram of a pale yellow, crystalline powder which proved to be the acetate of 2-amino-5-p-b enz ylideneaminophenyl-4-me t hylglyoxnline .When dried a t 1 OOo, it melts and decomposes a t 208O (corr.) after sintering and darken-ing earlier. Found in substance dried in a vacuum C=67*2; H=6*2; N= 16'2." C,,H,,N,,C,H,O (336.3) requires @= 67.8 ; H = 6.0 ; N = 16.7 per cent. This salt is very sparingly soluble in cold water but slightly so in boiling water with which however it gives an odour of benz-aldehyde and thus appears t o suffer hydrolysis. When mixed with aqueous sodium carbonate it yields the base as a deep yellow in-soluble gum which could not be obtained in crystalline form. When the acetate is moistenel with 10 per cent. aqueous hydro-chloric acid it turns red but does not dissolve until the mixture is warmed when the red colour disappears.Reduction of 2-Benzeneazo-4-metkylglyosaline with Zinc Dust and Acetic Acid. Two grams of the azo-compound were reduced by the method applied to the lower hom?logue (p. 241) and worked up in the same manner as far as the removal of the aniline by extraction with ether. The solvent removed 0.65 gram of crude aniline. The alkaline liquor remaining was acidified with hydrochloric acid, evaporated to dryness and extlracted with absolute alcohol when 1.4 grams of brown syrup were removed. This when dissolved in a little absolute alcohol and kept deposited 0.7 gram of nearly pure alacreatinine hydrochloride. This was converted into the picrate when a very small quantity of 2-amino-5-p-aminophenyl-4-methylglyoxaline dipicrate separated * The substance left a trace of m h on combustion NITRO- ARYLAZO- AND AMINO-OLYOXALINES.253 from the hot solution whilst on cooling alacreatinine picrate crystallised out. After recrystallisation the salt was obtained in a pure state and was converted into the base and hydrochloride by the usual methods. Alacreatinine crystallises from water in stout elongated prisms which resemble carbardde and contain lH,O as previously stated by Baumann (Amalert 1873 167 83). After drying a t looo it melts a t 222-223O (corr.). (Found in air-dried salt H,O=13.6. Calc. 13.7. Found in dried salt C=42*4; H=6-3; N=36.9. Calc. cC=42*5 ; H= 6.2 ; N = 37.1 per cent.) It does not give Weyl's reaction and does -not reduce cold aqueous acid permanganate but gives a green solution with cold alkaline permanganate.The hydrochloride crystallises from absolute alcohol in clusters of prisms which are anhydrous and melt a t 202-203O' (corr.). It is very readily soluble in water sparingly soluble in cold fairly readily so in hot' alcohol. Found C1= 23.6. C,H,ON,,RCl (149.6) requires C1= 23.7 per cent. The picrate separates from water in yellow prismatic needles, which are anhydrous and melt and decompose a t 212O (corr.) after sintering from about 200O. It is sparingly soluble in cold fairly readily so in hot water. Found N=24-5. C4H70N3,C,H30,N (342.2) requires N = 24.6 per cent. R edu c t ion of 5 -Ben? en ea z 134-rn e thy l g l y omxdi n e with Stan no us Chloride. Fourteen grams of the azo-compound were dissolved in a boiling mixture of 70 C.C.of 10 per cent. aqueous hydrochloric acid and 140 C.C. of water and mixed with 80 C.C. of stannous chloride solution. The crystalline and residual tin salts were separated as in the experiments described earlier and decomposed separately by hydrogen sulphide. The crystalline salts gave a solution of hydrochlorides which when evaporated nearly to dryness and mixed with alcohol left 6.1 grams of ammonium chloride undissolved. (Alcoholic mother liquor = A .) The residual salts gave a solution of hydrochlorides which on concentration deposited 1.7 + 0.5 grams of the hydrochZm*de C9H,,0N2,HCl described below and on further concentration and addition of alcohol gave 1.5 grams of ammonium chloride. The alcohoIic mother liquor was combine with A and gave 4.7 grams of aniline together with 3-8 gram of a brown gummy hydrochloride.This was a mixture from which only very m a l l quantities of crystalline campaunds were isolated by various methods of treatment. The hydrochloride C,H,,ON,,HCl cryshallism from water in colourless transparent rectangular tablets which melt and effervesce a t 308O (corr.) after sintering and darkening earlisr. It is readily solublel in hot less so in cold water giving a solu6hn which is strongly acid to litmus. Found in air-dried salt# lms a t l10°=l*7. Found in salt dried a t l l O o c'=54.8 54.8 55.0; H=5.9 5.0, C,H,,0N2,H@1 (198.6) requires C = 54.4 ; H = 5.6 ; N = 14.1 ; The correspanding base is obtained by adding ammonia t o a con-centrated aqueous solution of the hydrochloride.It crystallises from water in InIilliant elongated prisms which are anhydrous and melt a t 185O (corr.). Found C=66*6 66.1; €1=6*2 6.1; N=17-8 17.2. C,H,,ON (162.1) requires C= 66.6 ; H = 6.2 ; N = 17.3 per cent. The base is more readily soluble in dilute aqueous sodium hydr-oxide than in water. With silver nitrate it yields a white pre-cipitate which dissolves on the addition of ammonia; on boiling this solution no reduction takes place The base does not reduce Fehling's solution on boiling. It is stable towards cold aqueous acid potassium permanganate, but slowly reduces cold alkaline permanganate giving a green solution. It gives no coloration with sodium diazobenzeae-r)-sulphonate in aqueous sodium carbonate.When dissolved in hydrochloric acid and mixed with sodium nitrite it fails to couple with /3-naphthol in 8queous sodium hydroxide. The hydrochloride is recovered slightly charred but otherwise unchanged after the action of concentrated hydrochloric acid a t 170° f o r two and a-half hours. The quantity of this compound available was insufficient for the determination of its constitution and we are consequently unable to offer any suggestion as to how one of the carbon atoms of the starting material has been eliminated. It is perhaps worth record-ing that the formula C,R,,0N2 is that of a phenyldihydro-glyoxalone. 5.2; N=13.5; C1=17.2. C1= 17.8 per cent NITRO- ARPLAF;O- AND AIYXNO-GLYOXALINES. 966 Reductim of 5 - R e ? 2 - z e n e a z o - 4 - m ~ t h ~ ~ g ~ ~ o ~ u ~ ~ ~ e m'th Zinc Dust and Acetic A cid.Ten grams of the azoccompound were dissolved in 150 C.C. of boiling 50 per cent,. acetic acid and reduced by adding gradually 16 grams of zinc dust. After removing the zinc as sulphide the liquor was mixed with 20 C.C. of hydrochloric acid evaporated to a syrup and mixed with alcohol when 1.3 grams of ammonium chloride were collected. The alcoholio mother liquor was deprived of the solvent dissolved in water mixed with sodium carbonate, and shaken with ether when 1.6 grams of the base C,,H,,ON,, described below separated as a nearly colourless insoluble crystal-line powder. The ethereal solution left on evaporation 3.3 grams of aniline. From the alkaline liquor 5-5 grams of a mauve varnish were obtained from which only m a l l quantities of crystlalline sub-stances could be isolated by various methods of treatment.The base C10Hl10N3 crystallises from water in small d o u r -less glistening rhomboidal plates which are anhydrous and melt a t 265O (corr.). It is very sparingly soluble in cold water rather more readily in boiling water. Found C= 63.7 ; H = 6.2 ; N = 22.0. ~loBIION (189.2) requires C=63*5; H=5.9; N=22.2 per cent. The hydrochtloride crystallises from absolute alcohol in trans-parent oblong plates which melt a t 206-208° (corr.). It is readily soluble in water concentrated hydrochlorio acid or hot alcohol. The base dissolves slowly in cold 10 per cent. aqueous sodium hydroxide readily on warming and a well-crystallised sodium salt separates from the solution in prismatic needles.This salt is decomposed by carbon dioxide with the regeneration of the base. A solution of the base in aqueous sodium hydroxide gives with Fehling's solution no change iq the cold but a green precipitate on boiling. A solution of the base in nitric acid gives no pre-cipitate with silver nitrate but on the addition of ammonia a white precipitate which dissolves on heating the solution reappears on cooling and is soluble in excess of ammonia. An aqueous solu-tion of potassium permanganate is unaffected by a solution of the base in sulphuric acid but turns green with a solutian of the base in aqueous sodium hydroxide. The base does not couple with sodium diazobeneene-psulphonate in aqueous sodium oarbonate, and when dissolved in hydrochloric acid and mixed with sodium nitrite does not couple with eodium P-naphthoxide.When the hydrochloride is heatled with concentrated hydrochloric Its aqueous solution reacts strongly acid to litmus 256 FARBHER AND PYMAN: acid for two and a-half hours a t 170° it is decomposed with the formation of ammonium chloride and a hydrochloride which crystallises from alcohol in plates melting and decomposing a t about 280° (corr.). 4-Benzeneaeo-2-nte t hytglyoxatine . This was prepared by the action of bonzenediazonium chloride on 2-methylglyoxaline in aqueous sodium carbonate. The crude product readily resinified when boiled with alcohol and only a small proportion was obtained in a pure state. It forms brick-red prisms which melt a t 158O (corr.) and are very readily soluble in alcohol.Found C=64.3; H=5.7; N=30.0. CIOH1,,N4 (186.2) requires C = 64.5 ; H=5.4 ; N= 30.1 per cent. 4-p- Bromob enzen eazo-2-me t hylglyoxaliiz e . This was prepared in good yield by the action of p-brmno-benzenediazonium chloride on 2-methylglyoxaline in aqueous sodium carbonate. It crysballises from absolute alcohol in red, rhomboidal prisms which are anhydrous and melt and decompose a t 200° (corr.). Found N = 21.0. From ordinary alcohol it separates in elongated prisms which lose 2-2 per cent. of water a t 60° in a vacuum. This hydrated form melts a t about 135O when heated quickly and softens a t this temperature when heated slowly finally melting a t about 1900. It can be dehydrate'd by cryst'allisation from absolute alcohol.The reduction of this campound with either stannous chloride or zinc dust and acetic acid led to mixtures of products from which no crystalline compounds except p-bromoaniline and ammonium chloride could be isolated. @,,H,N,Br (265.1) requires N = 21.1 per cent, 2-Phen~l-4-p-7~~~omobenzenea~oglyoxaline. 8.6 Grams of p-bromoaniline were diazotised and the liquor added to 7.2 grams of 2-phenylglyoxaline and 7 0 grams of hydrat?ed sodium carbonate in 4 litres of water a t go the solution being vigorously stirred during the addition Separatim oE an orang NITRO- ARYLAZO- AND AMINO-GLYOXAL~NES. 257 p t d p i t a t e began a t once but was not complete until forty-eight hours had elapsed. The crude product was crystallised from alcobol and gave 13 grams of the pure azo-compound.2-Phenyl-4-p-bromobenzeneazoylyoxoline crystallises from alcohol in clusters of fine orange needles which melt at; 2 0 1 O (corr.) and are anhydrous. Found N = 16.9. C,,H,,N,Br (327.1) requires N = 17.1 per cent. R edzcction of 2-Plzenyl-4-p-b romob enzeneazoglyoxuline with Stawnom Chloride Formation of a Base C,,H,,N4Br. Two grams-of the azorcompound were suspended in 20 C.C. of boiling 5 per cent'. aqueous hydrochloric acid and mixed with 10 C.C. of stannous chloride solution. The solution was Iiltered quickly from a little resinous matter and mixed with 20 C.C. of concentsated hydrochloric acid when a crystalline tin salt separated. This was deprived of tin and the filtrate was evaporated t o a small volume when 0.85 gram of a crystalline hydrochloride separated.This hydrochloride crystallises from dilute hydrochloric acid in nearly colourless needles which after drying in a vacuum melt and decompose a t 255O (corr.). Found C=45*0; H=3.8; N=13.7. C,,Hl3N4Br,2HC1 (402.0) requires C = 44.8 ; H = 3.8 ; N= 13.9 per cent. 0.1530 gave by Carius's method 0.1750 AgCl + AgBr. Calc., It is sparingly soluble in cold water more readily so in hot water. The aqueous solution gradually acquires a purple colour in the air or on the addition of acidified aqueous potassium per-manganate. I n the presence of an exce8s of hydrochloric acid, aqueous solutions are stable in the air. Sodium carbonate or ammonia precipitate the base as a grey flocculent precipitate which is soluble in ether the ethereal solution rapidly assuming a purple colour.On the addition of sodium hydroxide to an aqueous soha tion of the hydrochloride a pale purple solution results. On add-ing sodium diazobenzenepsulphonate to a dilute solution of the compound in the presence of sodium carbonate a dull purple colour is produced. An aqueous solution of the hydrochloride con-taining an excess of hydrochloric acid gives on the addittion of 0.1806 sdium nitrite a deep orange solution which yields a sparingly eoluble purple dye with sodium Fnaphthoxide. On mixing a solu-tion of the hydrochloride in dilute acetic acid with sodim acetate and benzaldehyde there is evidence of the formation of a benzyl-idene derivative. When an aqueous solution of the hydrochloride is mixed with sodium nitroprusside a pale buff precipitate is formed which dissolves in sodium hydroxide giving a deep red soh tioln.The tm'acetyl derivative was obtained by heating the hydro-chloride for one hour on the water-bath with an excess of acetic anhydride and anhydrous sodium acetate. On heating the product with aqueous sodium carbonate it separated as a slate-grey crystal-line powder which did not melt a t 300O. Found C=55*2; H=4.1; N=12-6 12.7; Br=1?.3. C,,H1903N4Br (455.2) requires C-55.4,; H =4.2; N- 12.3; Br=17-6 per cent. It is almost insoluble in boiling water or alcohol and does not dissolve in dilute acids or in aqueous sodium hydroxide. From its mode of forination composition and properties it is dear that the hydrochloride C,,H,3N4Br,2€€C1 arises from 2-phenyl-4-p-br~mobenzenehydrazoglyoxaline by a change of the semidine or benzidine type but it is not possible bo decide ddnitely without further evidence which of the three formulea given below represents its constitution.2-p-Sulphobenaeneasoglyoxalirte-4 5-dicarboxylic A d (XX p. 226). 20.8 Grams of sulphanilic acid were converted into diambenzene p-sulphonic acid and the moist crystals (representing about 20 grams of dry substance) were added tol a cold solution of 16 gram8 of gly~aline-4:5dicarboxylic acid in 240 C.C. of 10 per cent. aqueous sodium hydroxide. After keeping for one and a-half hours the liquor was mixed wikh sufficient glacial acetio acid (36 c.c.) to neutralise tjhe alkali coded and kept for half an hour, when a mass of silky yellow needles-the disodium salt of the ne acid separated.These were recrystalliaed twice from 200 C.C. of wabt and fifinally dissolved in 150 C.C. of hot water afid mixed with 50 C.C. of hydrochloric acid when 12 grams of 2-p-sulphobenzene-azoglyoxaline-4 5-dicarboxylic acid separated in red microscopic prisms mixed with some smaller crystals of glyoxaline-4 5-dicarb-oxylic acid from which it was purified by fractional crystallisation from water. The acid separatm from water with 2H20 which is lost a t 130° in a vaeuum but not a t 100-llOo under normal pressure. Found in air-dried subskance loss at 130° in a vacaum=10*0; C,,H8O,N4S,2H2O (376.2) requires H,O\=9.6 ; C= 35.1 ; H = 3.3; N=14*9; 5=8.5 per cent. It is soluble in aqueous alkalis but not more soluble in dilute aqueous mineral acids than in water.The d’sodizlm salt separates in yellow silky needles which con-tain 3H20 when the acid is dissolved in aqueous sodium hydr-oxide and sufficient acetic acid is added to combine with the alkali. It is readily soluble in hot water somewhat sparingly so in cold. C=35.5; H z 3 . 3 ; N=15.1; S=8.2. It is sparingly soluble in cold water but readily so in hot. Found in air-dried salt loss a t 100°=11-6 12.6. Found in salt dried a t looo S=8*2; X=11.7. C,,B6O7N4SN+~3H20 (438.2) requires 3H20 = 12.3 per cent. CllH,07N,SNa (384.2) requires S = 8.4 ; N = 12.0 per cent. Reduction of 2 - p - SuEphobenzeneasogl?/oxali7e - 4 5 -dz’carboxylic Acid Formatiom of 2-Aminoglyoxaline-4 li-dicmboxylic Acid (XXI p.226). 6-2 Grams of the disdium salt were dissolved in 60 C.C. of 10 per cent. aqueous sodium hydroxide mixed with 12 grams of sodium hyposulphite (80 per cent.) and boiled. The nearly colourless solution was kept overnight acidified with hydrochloric acid, boiled and filtered hot when 1.6 grams of cruds 2-aminolglyvxaline-4 5-dicarboxylic acid separated. This was purified by solution in aqueous sodium hydroxide filtration and reprecipihtion with hydrochloric acid and finally crystallised from about 500 C.C. of dilute hydrochloric acid. 2-A ntinoglyoxaline-4 5-dicarboxyEic acid forms minute pale buff needles which effervesce a t 2 4 5 O (corr.) and then melt. It is very sparingly soluble in cold water a little mom readily in hot 260 NITRO- ARYLAZO- AND AMINO-QLYOXALINES.Found i n substance dried a t l l O o C=34.6; H=3.2; N=24.6. C5H50,N3 (171.1) requires C=35*1; H=3.0; N-24.6 per cent. It is soluble in aqueous alkalis but not appreciably more soluble ia dilub acids than in water. An aqueous solution acidified with sulphuric acid decolorises cold aqueous perrnanganate instantly. When treated with hydrochloric acid and sodium nitrite and poured inta a solution of &naphthol in aqueous sodium hydroxide, it gives a reddish-brown colour . With sodium diazobenzene-p sulphonat,e in aqueous sodium carbonate it gives a reddish-brown colour. It does not give any characteristic colour with sodium nit'roprusside and sodium hydroxide. Action of Water at 170°.-After a preliminary experiment in which it was found that the product contained ammonium carbonate 1-33 grams of the acid and 30 C.C. of water were heated in a sealed tube for twelve hours a t 170° when a dark brown deposit formed. After adding alkali and distilling into standard acid 0-157 gram of ammonia was found whereas 0.132 gram repre-sents the liberation of one molecular proportion. From the resi-due of the distillation small quantities of a crystalline picrate were isolated but in insufficient amount for characterisation. Action of Boiling Aniline.-O.9 Gram of the acid was boiled with 10 C.C. of aniline for six hours under a reflux condenser in which a small quantity of ammonium carbonate collected. The product was distilled wihh steam to remove aniline and left a pale brown aqueous liquor containing some resinous matter. The liquor was cooled filtered and mixed with cold saturated aqueous picric acid when 1.0 gram of a crystalline picrate melting a t about 215O was obtained. After crystallising this from water tlwice it gave 0.4 gram of 2-aminoglyoxaline picrate melting a t 234O (corr.) the pure substance melting a t 236O and a mixture of the two a t 234O in the same bath. From the picrate the hydro-chloride and stannichloride were prepared and identified as the salts of 2-aminoglyoxaline previously described. LONDON E.C.1. THE WELLCOME CHEXICAL RESEARCH LABORATORIES, [Received February 7th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9191500217

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

MERCURY MERCAPTIDE NITRIDES ETC. 261 XXVII -Mercury Mercaptide Nitrites and theb Reaction with the Alliyl Iodides. Part 1V. Chain Compounds of Sulphur (continued). By PRAFULLA CHANDRA RAY and PRAFULLA CHANDRA GUEIA. IN this investigation the reactions of several actual and potential mercaptans some of them cyclic have been studied. It was ex-pected that in these the molecules being of a more complex nature, the radicle especially -SHgNO, would far more readily part com-pany with the parent substance and lead an independent existence as the compound 3(SHgN02),Hg0 (T. 1917 11’1 101). The result has proved to be just the reverse. 5-Thiol-2-thio-3-phenyl-2 3-dihydro-1 3 4-thiodiazole, >C*SH rPh*N c 8--s yields with mercuric nitrite the corresponding mercaptide nitrite (compare T.1916 109 131), RSH + Hg(NO,),= RS*HgNO,+ HNO,. Mercuric nitrite and phenyl mercapt”an furnish a compound, Ph,S,Hg evidently a mercaptide and sometimes another oxy-salt, (3PhS,HgO),. It is only in exceptional cases (see p. 264) that the expected mercaptide nitrite PhS-HgNO, is obtained and then only in an impure form. The reaction appears to proceed in the following stages: PhSH + Hg(NO,) = PhS*HgN02+ HNO,. The nitrous acid thus liberated oxidises another pair of molecules of phenyl mereaptIan to diphenyl disulphide and the latter then forms with mercuric nitrite the compound, PhS*SPh N203 PhS*SPh /\ -+ /\ 0;NHk &02 Hg-0 Two molecules of this compound combine with a molecule of diphenyl disulphide giving rise to the compound, PhSaSPh 2 /\ ,Ph,S,.Hg-0 3-Phenyl-5-methyl-2-thiohydantoin gives the mercaptide nitrite, VOL. cxv. 262 R.kY AND GUHA MERCURY MERCAPTIDE NITRITES Pot e ti tial Mercaptans. The interaction of mercuric nitrite and the aryl substituted thiocarbamides thiosemicarbazides thiocarbazides etc. ? follows the ordinary course but no detachment of the organic radicle takes place. Thus with phenylt,hiocarbamide w-B have N 11 Ph* C( NH2):S Hg(h’oF N1IPh.C (:N H)*S*HgNO + N H Ph* C (1 N H) S( HgN O,)<tg. AttenGon may also here be directed to the interesting analogous case of potassium phenyldithiocarbazinate which combines in itself t,he function of a real and of a potential mercaptnn thus: n’HPh*NH*CS,K so$ NHPh*N:C(SH)*SK + N H Ph*N :C( S*RgNO,)* S(HgNO,)<p.The sulphur atom belonging t o the potential mercaptan alone beconies qu adrivalen t,. Migration of Alkyl Badicles. When thimarbanilide methyl ether is treated with mercuric nitrite the methyl group migrates to the neighbouring nitrogen atom hydrogen taking it,s place thus: NHPh*C(:NPh)-SMe H%o$ NMePh*C(:NPh)*SH+ NMePh*C( :NPh) *S*HgNO,* That the reactions described above are of wide application is borne out by the behaviour of 5-methylthiol-2-thio-3-phenyl-2 3-dihydro-1 3 4-thiodiazole which wiih mercuric nitrite gives the compound, yPhoNMe>(J( HgNO,)*S*HgNO,. cs-s Reaction with the Allcyl Zodides Formation of Mono- Di- and Tm’-sulph~’~m COTIZPOU~S. The reaction follows the general course with this material differ-ence that tFie complex radicle being overweighted can no longer retain its entity but the less stable part of it is usually ruptured.Of special significance from this point of view is the rupture of t.he ring of the heterocyclic mercaptide nitrites. When the mercaptide nitrite of 5-thiol-2-thio-3-phenyl-2 3-dihydro-l 3 4 AND THEIR REACTION WITH THE ALKYL IODIDES. PART IV. 263 thiodiazole is digested with an alkyl iodide the product (I) is obtained and by further action of the alkyl iodide the phenyl HgI R y g 1 YgI i i f 1 - t i I I R*NPhaN:CR*S-- SR NK,-N:CR*S--dK NR,*NR*ClZ,*S--SR , (1.1 (11.) (111.) group is displaced by the alkyl group and the compound (11) is formed. Finally two more alkyl groups are attached with the production of the compound (111). By the action of methyl iodide two compounds corresponding with stages (I) and (111) have been isolated whereas in the case of ethyl iodide only one compound has been obtained,.which corre-sponds with stage (11). When 2-thie3-phenyl-2 3-dihydro-1 3 4-thiodiazole disulphide dissolved in carbon disulphide was heated under reflux with ethyl and mercuric iodides not only was there no rupture of the thio-diazole rings but one of the tertiary nitrogen atoms became quaternary by combining with a molecule of ethyl iodide and the following compound, HgI Et I 1 was obtained. The action of alkyl iodides on phenyl mercaptide nitrite follows the usual course and yields compounds of the general formula PhRS,,HgI,,RI. An interesting monosulphoniuni compound has been obtained from the mercaptide nitrite' of thiocarbanilide.The reaction prob-ably takes place as shown below : N€€Ph*C( :NPh)*S(HgNO,)<p CEt,I*SEtI*HgI. The interaction of mercaptide nitrites of thiocarbanilide alkyl ethers and alkyl iodide t,akes place as follows : NlflPh- C( :NPh)*S*HgNO R'I, BgI R' HgI R' I I I NRPh*C(:NPh)*S-S*C(:NPh)*NRPh + R'*b-SR . i i i 264 RAY AND QUHA MERCURY MERCAPTIDE NITRIDES EXPERIMENTAL. 1iLteraction of the Potassium Salt of 5-Thiot-2-thio-3-phemyl-2 3-dihydro-1 3 4-thiodi‘azole and Mercuric Nitrite Formation of the cor?*espo?zding Nercaptide Nitrite rPh*’ >C*SHgN 0,. c s--s The mercury salt was obtained sometimes anhydrous but often combined with three five or eight molecules of water the degree of hydration evidently depending on the dilution of the reacting substances.They all evolved nitrous fumes when treated with hydrochloric acid : 0.2724 gave 0.1187 Hg. Hg=43-59. 0.1100 , 0.0810 CO and 0.0187 H,O. @=20*08; H=1.89. 0.1420 , 10.2 C.C. N a t 25O and 760 mm. N=8*10. C8HH,0,N3S,Hg requires Hg= 42.46 ; C = 20.38 ; H = 1.06 ; N =. 8.93 per cent . The above with 3&O: Found Hg = 38-05 ; @= 18.28 ; H = 3.29 ; N = 8.30 ; S = 18.56. Calc. Hg = 38.09 ; C = 18.29 ; H = 2.1 ; N = 8.00 ; S = 18.29 per The compound with 5H20 : Found Hg=35.75; C-16.92; H=3.20. Calc. Hg= 35-65 ; C = 17.12 ; H = 2-67 per cent. The compound with 8H20 : Found Hg=32.10; C=15.10; H=3*56; N=6.16; S=15.08. Cab. Hg = 32.52 ; C = 15.63 ; H = 3-41 ; N = 6.83 ; S = 15.61 per cent. cent.Mercuric Nitrite and Phemyt Mercaptam. Three different compounds have been isolated in this case. When an alcoholic solution of phenyl mercaptan is added slowly t o an excess of mercuric nitrite solution the reaction t’akes t.he ordinary course and the mercaptide nitrite PhS*HgN02 is mainly formed. It is a dull yellow light granular powder and is a trim nit8rite. When however the mercaptan is rapidly added in excess, the whole of the mixture assumes a dirty yellow colour and nitrous fumes are evolved. On keeping a white granular powder is obtained which when crystallised from hot benzene until quite pure melts sharply a t 146O. Under slightly varying conditions an oxy-compound (SPhS,HgO), is formed. As is evident i t is not easy t o control the reaction so as to give one product to the ex AND THEIR REACTION WITH THE ALKYL IODIDES.PART IV. 265 clusion of the others. The mercaptide nitrite is always found t o be admixed with t'he other products of this reaction. The mercaptide nitrite gave different results of analysis on different occasions depending on the proportion of the cornpowid, Ph,S,Hg admixed with it; generally however the values were found t o be intermediate between those required for the pxre inaterial and the compound Ph,S,Hg. The compound Ph,S,Hg melting a t 146O gave the following results : 0.1942 gave 0.0864 Hg and 0.3134 BaSO,. Hg=44*48; 0.0964 gave 0.116 CO and 0.0230 H20, S = 22.16. C=32.17; H=2.7. C,,13,,S3Hg requires Hg = 44.44 ; S = 21.30 ; C = 32.00 ; H= 2.30 per cen t4. The campound (3PhS,HgO), gave the following results : 0-4016 gave 0.1506 Hg.Hg=37-50. 0.4333 , 0.5620 BaSO,. S=17*82. 0.1230 , 0.1886 (20,. C=41.81. C,,H,O,S,Hg requires Hg= 38.02 ; S = 18.25 ; C = 41-07 per cent. The above two compounds were proved t o be non-nitrogenous by combustion analysis. Mercuric Nitrite mi3 3-Phe?a?/l-5-met7~?/1-2-thioh~~~~ri toin : FO-NPh CHMe*N >C*S*HgNO,,ZH,O. Formation of the Compound, The compotund was greenish-grey : 0.1981 gave 0.0954 IIgS and 0.1110 BaSO,. Hg=41*61; S = 7.69. -0.1774 gave 0-1586 CO and 0.0582 H,O. 0.2836 , 20.8 C.C. N a t 30° and 760 mm. N=8*10. C=34.38; H-3-65. C,,€I,,O,N,SHg requires Hg = 41.07 ; S = 6.57 ; C = 24-64 ; H= 2.67 ; N=8.63 per cent. P o t e PL t ia 1 .iW e r c a p t a n s. Mercuric Nitriie and Phemylthiocadarnide F o ~ m l i o n of the Compound NHPh*C( NH).S( HgNO,)<p.This was deep yellow: 0.3512 gave 0.2350 Hg and 0.1227 BaSO,. 0.2015 , 11.4 C . C . N a t 26O and 760 mm. N=6*40. Rg=66*9; S=4.S. C7H70,N,SHg2 requires Hg= 65.25 ; S = 5-22 ; N = 6.85 per cent 266 RAY AND QUHA MERCURY MERCAPTIDE NITRIDES Mercuric Nitrite and s-Diphenylthiocarbamide Formation of the Compound NHPh*C( :NPh)*S(HgNO,)<zg . This was a brownish-yellow granular powder : 0.3422 gave 0.1970 Hg and 0.1069 BaSO,. Hg=57-57; S=4.64. 0.39?0 , 0-1141 CO and 0.0244 H,O. C=22*27; H=1*94, C,,H,,O,N,SHg requires Hg = 58-07 ; S = 4.64 ; C = 22.64 ; H = 1.60 per cent. The product gencr-ally obtained conforms t o the formula The above compound is only rarely formed.Hg[NPh*C( :NPh)*S-HgNO,] : 0,1555 gave 0.0947 HgS and 0.0741 BaSO,. Hg=52.51; 0.2275 gave 0.1367 HgS and 0.0992 BaSO,. Hg=51*80; S = 6.55. s = 5.99. C,,H,,O,N,S,Hg requires Hg = 52-43 ; S = 5.59 per cent. Mercuric Nitrite and Thiosemicarbazide Fomnatton of the Compound H g [N (NH,) C( N H ) S HgNO,] . An aqueous solution of the thioi-compound was useld. The pro-0.2715 gave 0.1870 HgS and 0.1362 BaSO,. Hg=68*87; 0.1032 gave 11-8 C.C. N a t 32O and 760 mm. duct was a dull yellow granular powder: S= 6.89. N=12*60. C,H,O,N,S,Hg requires Hg = 68.96 ; S= 7.36 ; N = 12-87 per cent. Mercuric Nitrite amd Diphe.lz~lthiosemicarbcczide Formtion of the Compmd Hg[N(NHPh)*C( :NPh)*S*HgN02},. This is an mange-yellow granular powder : 0-1797 gave 0.0925 Hg.Hg=51.48. 0.2577 , 0.2498 CO and 0,0523 H,O. C=26*21; H=2*25. 0-1380 , 11.7 C.C. N a t 32" and 760 mm. N=9*38. C,,H,,0,N,S,Hg3 requires Hg = 51.11 ; C = 28.57 ; H = 1.87 ; N=9-54 per cent AND THEIR REACTION WITH THE ALKYL IODIDES. P A ~ T IV. 267 Mercuric Nitrite and Diphenylthiocarbaside Formation of the Compmnd Hg[N(NHPh)*C(:N*NHPh)*S*HgNO&. This is a pink granular powder: 0.1667 gave 0-0965 HgS and 0-0607 BaSO,. Hg=49*91; 0.1463 gave 0.1404 CO and 0.0327 H,O. 0.1167 , 11.7 C.C. N a t 30° and 760 mm. N=ll-26. S = 5.00. C=26.14; H=2*48. C2,H,,0,Nl,S,Hg3 requires Hg=49*83 ; S =5.31; C = 25.91 ; H=1*82; N=11*62 per cent. Mercuric Nitrite a,nd Phenylkydrasine Phenyldithiocarb aziriat e : Formation of the Compound, N H Ph h' c ( SHg N 0,) S( HgNO,) < y .This is a blackish-violet granular powder : 0.1971 gave 0.1549 HgS and 0.1031 BaSO,. Hg=67*71; 0.1651 gave 8.5 C.C. N at 27O and 760 mm. S = 7.18. N=5.89. C7H60,N4SzHg3 requires Hg = 67-40 ; S = 7- 19 ; N = 6.30 ; CT = 9.44 per cent. The same compound is formed by the interaction ,of mercuric nitrite and potassium phenyldithiocarbazinate. (Found Hg = 67-97; C=9.24; H=0*98; N=5*88 per cent.) Mercuric Nitrite and Thiocarbanilide Methyl Ether Formation of the Compound NMePh*C(:NPh)*S*HgNO,. This is an orange-yellow granular powder : 0.2301 gave 0.1038 Hg. Hg=39*86. 0.2377 , 0.3027 CO and 0.0738 H,O. @=34-70; H=3*45. 0.2863 , 22.6 C.C. N a t 29O and 760 mm. N=8.99. C,,H,,O,N,SHg requires Hg = 40.90 ; C = 34-50 ; H = 2-67 ; N= 8.86 per cent.Mercuric Nitrite and Thiocarbanilide Ethyl Ether Formatiore of the Compound NEtPh*C( :NPh)*S*HgNO,. The substance is an orange-yellow granular powder : 0-3730 gave 0.1478 Hg and 0.1874 BaSO,. 0.1232 , 9.4 C.C. N a t 32O and 760 mm. N=8.43. Hg=39*63; S=6*91. C,SH,,0,N3SHg requires Hg = 39.92 ; S = 6.39 ; N = 8-38 per cent 26s RAY AND OUHA MERCURY MERCAPTIDE NITRITES ilfercrcric Nitrite and 5-ilf ethylthiol-2-thio-3-phenyl-2 S-dihydro-1 3 4-thiodiazole Formation. of the Conzpound rPh*NMi>C( CS- IJgzu'O,).S* HgNO, 8H,O. A clear solution of the thio-compound in chloroform was vigorously agitated with mercuric nitrite solution for nearly half an hour when an emulsion was formed which after being allowed to remain overnight gave a cream-coloured granular mass : 0.1984 gave 0.1055 HgS and 0.1384 BaSO,.Hg=45.85; 0.1879 gave 0.0884 CO and 0.0296 H,O. 0.1603 ) 10.2 C.C. N a t 30° and 760 mm. N=7.03. S = 9.58. C=12*83; H=1-75. C,H,,O,,N,S,Hg requires Hg= 45-67 ; S = 10.96 ; C = 12.33 ; H=O*91; N=6-39 per cent,. Mercztric Nitrite and 2-Thio-3-phenyl-2 3-dd~gdro-1 3 4-thio-diazole Disulphide Formation of the Cornyoii?zd, NPh*N Yg-? N.7P-l bs--sSC'~-~'CQs-cY NO HgNO, 0.2940 gave 0.1288 Hg. Hg=43*80. 0.1190 ) 9-00 C.C. N a t 30° and 760 mm. N=8*35. (compare T. 1916 109 133): C16H,,0,N6S,Hg requires Hg= 41.75 ; N = 8-77 per cent. R c a c t i o n w i t h the A l k y l I o d i d e s . lnt eraction of t h e Mercapt ide iVitrit e of 5-Thiol-2- t hio-3-phenyl-2 ; 3-&hydro-1 3 4-thiodiazole and Methyl Iodide Formation of the Compound, HgI Me 1 1 I NMe,*NNe*CMeBoS--Sble i I The method of procedure is exactly the same as in the inter-action of simple mercury mercaptide nitrites and the alkyl iodides.After heating with methyl iodide under reflux a portion was left undissolved which when purified by washing several times with acetone melted sharply a t 1 2 7 O . The portion soluble in acetone was purified by precipitation with ether and melted a t 107O AND TEEIR RBACTION WITH THE ALKYL IODIDES. PART xv. 269 0.3129 gave 0.0811 Hg. Hg=25*92. 0.4107 , 0.1066 H g and 0.3718 AgI. Hg=25.96; I=48.72. 0.0844 , 0.0363 CO and 0.0237 H,O. C=11*73; H=2.45. @,H,,N,I,S,Hg requires Hg= 25-32 ; I = 48-23 ; C= 12.15 ; H = 2.66 per cent. The compound insoluble in acetone has the formula HgI Me I I NMePh*N:CMe*S-SMe .f i 0.1867 gave 0.0449 Hg 0.1527 AgI and 0.0870 BaSO,. 0.1070 gave 0.0590 CO and 0.0734 H20. 0.1227 , 4.2 C.C. N a t 35O and 760 mm. N=3.7. Hg= 25.96 ; I = 48.93 ; S = 6-40. C=15-06; I'I=1.39. C,,H,7N,I,S,Hg requires Hg = 24.33 ; I =46.35 ; S = 7-79 ; C=16*06; H=2.87; N=3*4 per cent. Tr~teraction of the above Mercaptide i'CT'itrite and Ethyl Iodide : Formution of the Compound, HgI Et NEt2*N:CEt*S-dEt. I i f (m. p. 73-74O). 0.2316 gave 0-0572 Hg 0.1960 AgI and 0.0972 BaS04. 0.2564 gave 0-0611 Hg. Hg=23-83. 0.1278 , 0.0703 CO and 0.0296 H20. C=15*41; H=2-58. 0.2470 , 7.8 C.C. N a t 3 1 O and 760 mm. N=3*50. C,,H,N,I,S,Hg requires Hg=24.09; I=45*90; S:=7*72; C=15-90 j H=3.07; N=3.57 per cent.Hg =24*69 ; I= 45.74; S=5.77.* PJhenyl Mercaptide Nitrite and Methyl Iodide Formation of the Compound PhMeS,,HgI,,MeI. The pure substance was obtained by repeated crystallisation, 0.4616 gave 0-1252 H g and 0.4353 AgI. Hg=27.12; 1=50.96. 0.1131 , 0.0551 (20,. C=13*29. C,H,,13S2Hg requires Hg=26*6; 1=50*66; C=12.77 per cent. * See footnote p. 271. and was a dull yellow crystalline powder melting a t 90°: M 270 RAY AND GIUHA MERCURY MEROAPTIDE NITRITES Pltenyl Mercaptide Nitrite and Ethyl Zodide Formation of the Compound PhEtS,,HgI,,EtI (m. p. 59O). 0-2994 gave 0.0774 Hg and 0.2673 AgI. Hg=25*85; 1=48*24. 0.1302 , 0.0740 CO and 0.0282 H,O. C=15.5; H=1.86. C,oH,,13S2Hg requires Hg=25.64; 1=48*84; C=15.39; H=1*92 per cent. Interaction of the Compound Ph,S,Hg and MetJiyl Iodide : I €'h Pli I I I Formatiolz of the Compowzd C€T,*S-S-S*CH , I I I HgI I I The product was an oil which on stirring crystallised.It was washed several times with acetone when the colour changed to yellowish-white. It was insoluble in acetone and melted a t 11 1-1 1 2 O : 0.3150 gave 0.0615 Hg 0.2915 AgI and 0.2007 BaSO,. Hg= 19.53; I= 50.00; S = 8.75. 0-1410 gave 0.0902 CO and 0.0390 H,O. C=17*41; H=3.07. C,,H,,I,S,Hg requires Hg= 20.24 ; I= 51.42 ; S = 9.71 ; C= 17-00 ; H=1*62 per cent. It will be noticed that whenever a sulphonium compound con-tains phenyl groups it becomes insoluble in acetone. Mercaptide Nitrite of Thiocarbanilide and Ethyl Zodide : Formation of tlbe Compound CE t,I* SEtI- HgI . I n this case deep purple needle-shaped crystals were obtained 0.3083 gave 0.0890 Hg 0.2920 AgI and 0.1042 BaSO,.0.1214 gave 0.0552 CO and 0.0232 H,O. which were soluble in acetone: Hg=28*73; I= 51.113; 5-4-64. C=12.04; H=2.12. C,H,,13SHg requires Hg=28.09; I=53.51; S=4-49; C=11.80; H=2-11 per cent. Mercaptide Nitrite of Thiocarbmilide Methyl Ether and Methyl Zodide Formatiom of the Cornpmmd Me,E&,HgIz,MeI. The mercaptide nitrite was heated under reflux with methyl It was obtained pure by fractional precipitation from a iodide AND THEIR REACTION WITH THE ALKYL IODIDES. PART IV. 271 concentrated solution the process five or six which melted a t 160-in acetone by adding ether and repeating times when a fairly good crop was obtained -162' : 0.3290 gave 0.0791 Hg and 0.3281 AgI.Hg=29.51; 1=53-89. 0.1150 , 0.0221 CO and 0.0218 H,O. C=5.24; H=2*11, C3H91,S,Hg requires Hg=28*98; 1=55*21; C=5*22; H=1.30 per cent. Memaptide Nitrite of Thiocarbanilide Ethyl Ether and Ethyl Iodide Formation of the Compound Et+S,,HgI,,EtI. The procedure was almost the same as in the previous instance. On concentrating the acetone solution a portion crystallised out, which was purified by repeated fractional crystlallisation ; when pure it melted sharply a t 1 1 1 O : Hg=27*57; 1=51*46. 0.3127 gave 0.0862 Hg and 0.0978 AgI. 0.0861 , 0-0327 CO and 0.0255 H,O. C=10*37; H=3.29. C,H,,I,S2Hg requires Hg = 27.33 ; I = 52.05 ; C = 10.37 ; H = 3-29 per cent. 2-Thio-3-phenyl-2 3-&hydro-1 3 4-thiodiazde Disulphide Mercuric Iodide und E'thyl Zodide Formatioit of the Compound, HgI Et T I 0.3127 gave 0*0512 Hg 0.2366 AgI and 0.3026 BaSO,. 0.1574 gave 0.1066 CO,. C=18.47. C,,H2,N414S6Hg requires Hg- 16.45 ; I = 41.75 ; S = 15.75 ; C = 19.74 per cent. Hg=16*38; I=40*89; S=13*29.* CHEMICAL LABORATORY, COLLEUE OIP SOIENCE, UNIVERSITY OF CALCUTTA. [Received November 8th 1917.) * Owing to the tedious process involved in analysis the values for sulphur and iodine are sometimes too low (compare T. 1916 109 135)

ISSN:0368-1645    

DOI:10.1039/CT9191500261

出版商:RSC    

年代:1919

数据来源: RSC

摘要:

272 HUGHES THE REACTION BETWEEN XXVIII .-The Reaction between Sodium Chloride Solution and Metallic Magnesium. By WILLIAM HUGHES. (>OLD aqueous solutions of various salts including sodium chloride, sodium hydrogen carbonate sodium carbonate and magnesium sulphate were found to react with magnesium powder with con-siderably more speed than one would expect since cold water acts very slowly on the metal and solutions of alkali hydroxides not a t all. That the metal slowly dissolves in solutions of its own salts with the formation of hydrogen the hydroxide or a basic salt has been observed by Kippenberger (Chem. Zeit. 1895 19 269) Vitali (L’Orosi 1895 18 289) Lemoine (Compt. rend. 1899 129 29l), Bryant (Chem. News 1899 79 75) Kahlenberg ( J . Amer. Chem. SOC.1903 25 350) and Roberts and Brown (ibid. 1903 25 801). Liberation of the metal together with hydrogen from various salt solutions by magnesium has been described by Commaille (Compt. rend. 1866 63 556) Clowes and Caven (P. 1897 13, 22l) Divers (P. 1598 14 57) Tommasi (BUZZ. SOC. chim. 1899, [iii] 21 855> and Faktor (Pharm. Post 1905 38 153). Lohnstein (Zeitsck. Elektrochem. 1907 13 612) found that the action of magnesium on acetic acid was catalysed positively by the addition of some salts and negatively by others. Knapp (Chem. News 1912 105 253) found that palladium chloride solutions and Michailenko and Mushinsky ( J . Rziss. Phys. Chem. SOC. 1912 44 181) that the water of crystallisation of certain salts were acted on by magnesium with the evolution of hydrogen.EXPERIMENTAL. I n the preliminary experiments i t was found that 0.329 gram of ordinary magnesium powder and 35-3 C.C. of 2N-sodium chloride solution gave 291.4 C.C. of a gas a t the end of a week. The metal darkened and a white gelatinous solid was disseminated through-out the liquid. The greyish-black powder slowly changed to a compact white solid but the reaction was not quite complete at the end of seven days. The theoretical yield of hydrogen is 325 C.C. a t N.T.P. One C.C. of the original sodium chloride solution and 1 C.C. of the solution which had been acted on by the magnesium gave SODIUM CHLORIDE SOLUTION AND METALLIC MAGNESIUM. 273 tit,re of 13-62 C.C. and 13.70 C.C. respectively with silver nitrate. 38.6 C.C. of the gas after absorption for fifteen minutes over freshly prepared alkaline pyrogallol measured 37.5 C.C.These results were taken to indicate that the gas was hydrogen only and it was determined to seek a relation i f any between the rate of evolution of gas and the concentration of the sodium chloride solution. The method adopted was to add known amounts of magnesium to the different solutions which had been saturated with hydrogen, and to measure the initial velocity of the reaction by reading the volume of hydrogen evolved a t 25* without shaking a t short intervals for a total period of two or three minutes. Magnesium .-A supply of ordinary magnesium powder appar-ently quite bright and free from oxide was fractionally sifted and the portion passing through between sieves of 90 and 60 meshes t o the inch respectively was used.(0.0692 gave 0.3075 Mg2P20 ; by Gibbs’s method Mg=97-03. 0.0258 gave 25.4 C.C. H [dry at 1 6 . 5 O and 726 mm.] Mg=96.45 per cent.) Only traces of aluminium and zinc could be detected in the substance. Since the phenomena investigated seemed to depend on the nature of the solutions and not on the mall amounts of impurity in the mag-nesium it was considered unnecessary to attempt any purification of this reagent. Sodium ChZoride.-Common salt was dissolved in distilled water, liltered and the solution rendered just alkaline with sodium hydr-oxide and filtered again. The slightly alkaline solution was evaporated with continual stirring and the first crop of crystals were well drained and kept over concentrated sulphuric acid.Water.-Distilled water was redistilled in a glass still which had been previously well steamed out. This water was boiled under diminished pressure previous to being used. Hydrogen.-This was prepared from zinc and pure sulphuric rtcid and purified by passing through lead nitrate solution silver nitrate solution a soda-lime tower and then a set of sodium hydr-oxide bulbs and stored over water. The number of molecules of water to each molecule of sodium chloride is repre-sented by c. A pparatus.-At first the1 solution-10 cm. deep-was contained in a test-tube and the hydrogen measured in a nitrometer the volume being read every fifteen minutes. The SoZutiong.-These were made up by weight. The rate was constant. in each case for about five hours 274 HUGHES THE .REACTION BETWEEN initial rate was read from the tangent t o the curve and reduced tQ C .C . a t N.T.P. per gram of magnesium per hour. I n the second case a conical flask was chosen as reaction vessel in order t o have a smaller hydrostatic pressure on the magnesium. It was fitted with a rubber stmopper carrying a delivery tube A (Fig. 1) drawn to a point a t the bottom of the flask for the entry of hydrogen an exit tube B which could be closed and a water manometer C behind which was fixed a millimetre scale. Selected FIG. 1. quill tubing was used in making it, and it was carefully calibrated with distilled water a t 2 5 O and found to be of uniform bore for the part calibrated namely tphe length DE. 1 crm.=0.1880 C.C.a t 2 5 O . Twice distilled water saturated with hydrogen was used in the manometler. The weighed magnesium was floated on a capsule on the solution the volume of which was always 25 c.c. and then the air displaced by and the solution saturated with hydrogen through A and B for not less than ten minutes all being immersed in the bath. The apparatus was quickly shaken and simultaneously a stop-watch was started. The volumes of hydrogen read off every half- or quarter-minute were reduced to N . T . Y . tabulated (table I) and plotted (Fig. 2 curves 1 and 2). The initial rate viras obtained by drawing the tangentt as shown. The kind of induction period a t the start is much more pronounced with the more concentrated solutions and is probably due to surf ace-tension effects chiefly in the manometer.TABLE I. c = 30. 6 minute intervals. 0 1 2 3 4 5 6 7 8 9 10 Manomo ter, A (in cm.). 0.6 0.9 1-7 2.3 2.9 3.4 3-8 4.2 4.5 5.1 4.8 Hydrogen, C.C. 0 0.15 0.55 0.55 1.15 1.40 1.60 1-80 1-95 2.10 2-25 Total pressure (corr .) 753.9 754.4 754.9 755.3 755.7 756.0 756.3 766.5 756.7 756.9 -Hydrogen, corrected. 0 0.0256 0-0941 0.1454 0.1969 0-2397 0-2742 0.3086 0.3344 0.3601 C.C. o a 6 SODIUM CHLORIDE SOLUTION AND METALLIC MAUNESIUM. 275 TABLE I. (continued). c = 38. 4 minute Nanometer Hydrogen Total intervals. A (in cm.). C.C. prossure (corr.). 0 0.36 0 1 0.78 0.21 754.0 2 1-40 0.52 754.4 3 1.98 0.81 754.9 4 2.48 1-06 755.2 FIG.2. Hydrogen, corrected. 0 0.0359 0.0889 0.1387 0-1814 C.C. The greatest precautions were taken that the solutions of sodium chloride were in each case quite free from acid. Immediately at the end of a determination they reacted alkaline. The viscosities were det'ermined with an Ostwald viscosimeter, the essential precautions being observed (Applebey T. 1910 97, 2000; from the equation density of 'solution density of w a t F time of flow of solution time of flow of water ' 17 = vwater X 276 HUGHES THE REACTION BETWEEN The densities were det,ermined with a pyknomet,er the weighings These The curves are plotted in Fig. 2, being carried out with a similarly treated counterpoise. were as shown in table 11.3 and 4. TABLE 11. Concentration. 10 20 30 35 40 50 60 e. 7725". 1.184 1.794 1.099 1.303 1.068 1.198 1.058 1-165 1.051 1-134 1.041 1.101 1.034 1.095 In t'abls I11 are given the initial rates for the diffelrent concell-trations of sodium chloride solutJons. TABLE 111. Pressure Vol. Mag-Time. Tempera- mm. hrs. min. 13 30 2 20 15 1 20 16 15 15 16 4 7 3 2 1.5 0.5 ? 9 9 9 9 9 ? 9 Y 9 3, 9 9 0.25 d-'5 0.25 Y ? 9 ) 9 9 9 9 9 , 9 9 7 9 P? ture. 19" 20 22 25 24 22.5 23 23 25 25 24-1 19.2 20 25 9 , ? ? ?? ? Y 9 7 9 , 9 9 9 9 9 9 Y ? 9 9 99 7 9 > 9 9 9 9 7 Y, ? 9 9 3 (corr. ) 762.3 763.9 766.5 758.7 758.3 766.1 767-1 768.3 749.5 749.5 749.9 749.2 749.2 749.4 749.4 750-5 752.8 752.9 753.2 754.8 752.9 752.3 767.0 753.4 753.4 753.4 753.4 754.8 754.8 754.8 754.7 755-2 750.6 C.C.(corr.) 31.32 11-99 1-87 8.32 2.29 2.42 1-58 1-87 0.72 0.18 0.45 0-51 0.37 0.0425 0.0710 0.0683 0.03845 0.0664 0.0479 0.0944 0.0684 0.0342 0.041 7 0.0135 0.0513 0.0531 0-0454 0.0343 0.041 1 0.041 1 0.0386 0.0429 0.0148 nesium , c. Gram. 9 0.0984 18 0.1069 27 0.0995 45 0-1004 35 0.0985 40 0.1004 44 0.1018 39 0.0977 30 0.1165 30 0.0333 30 0-1798 30 0.1513 30 0.1184 30 0.0840 30 0.1367 30 0.1248 10 0.1590 20 0.1531 30 0.1062 35 0.1702 40 0.1216 50 0.1507 60 0.1343 32 0.0955 34 0.1767 36 0.1940 38 0.1478 45 0.1412 55 0.1518 65 0.1581 75 0.1502 100 0.1722 0-1969 Rate.Remarks. 23.5 First method. 48-1 75.1 62.2 87.3 96.5 62.2 71-6 93.1 1 124.1 J 29.0 ' 52.1 54.2 66.6 67.5 54.4 Quarter niiriute intervals. 74.6 17.0 Metal wetted QC-cidentally during bubbling i n hydrogen. 69.7 65.7 73.6 59.5 65.0 62.4 61-6 '59.7 18-0 Water onl SODIUM CHLORIDE SOLUTION AND METALLIC MAGNESIUM. 277 These rates are plot.ted against concentrations in curve 5. The arrow indicates the rate for water ( c = 00 ) and the crosses denote the' values obtained with the nitromet'er. R e sult s . No great accuracy can be claimed for the numerical values, chiefly because1 the assumption that the total area of equal weights of the sifted magnesium is constant is only approximately true.However it is evidentl that curve 5 passes through a maximum a t r = 32 ; also the surface density of water molecules in contact with niagnesium (neglecting surface concentration effects) is given by { cp/ ( c M + M,)}+ where Mw is the molar weight of water M8 that of sodium chloride and p t.he density of the solution. Values of this expression ( =T) have been found for various concentrations a i d then plot-ted against the corresponding rates in curve 6. This passes through a maximum for a-0.1426 about or c = 3 7 . One would expect a maximum rate f o r c=m -pure water since then the magnesium surface would be apparently open to attack by a denser population of water molecules.Again the values of the viscosity hydrostatic pressure and surf ace tension (Forch Ann. l'hysik 1905 [iv] 17 744) are each greater for c = 3 2 than for weaker solutions so it seems that the maximum a t c=32 is n o t duo to any special ease of expulsion of gas through the solution. Purther the specific conductivity o€ sodium chloride solutions steadily increases to a maximum a t the saturation point so that a t c = 3 2 the1 conductivity is not' best suited for electrolytic action of impurities in the magnesium to take place. Conclusions . (1) Both alkaline and neutral salts positively catalyse the reac-tion between ordinary magnesium and purified water a t the ordinary temperature!. (2) With sodium chloride solut'ions the rate of evolution of hydrogen depends on the concentration the differences being easily detected by the eye. The init.ial rates for approximately equal areas of magnesium in cont'act with different concentrations of sodium chlolride solutions have been measured and a maximum has been found for a solution ob 32 molecules of water per molecule of sodium chloride. (3) It is considered that the existence of this maximum points to a specific effect of the dissolved sodium chloride on the water. BEDFORD MODERN SCHOOL, BEDFORD. [Received October 23rd 1918.

ISSN:0368-1645    

DOI:10.1039/CT9191500272

出版商:RSC    

年代:1919

数据来源: RSC