摘要:

THE ACTION OF MERCURIC CYANIDE ON METALLIC SALTS. 67 X.-The Action of Mercwic Cyanide on Metallic Salts. By LILANANDA GUPTA. THE action of mercuric cyanide on different metallic salts has been the subject of investigation by previous workers for example, Poggiale (Compt. rend. 1846 23 762) Varet (BUZZ. SOC. chim., 1891 [iii] 5 S) Bloxam (Ber. 1883 16 2669) etc. In this paper the action of mercurio cyanide on the chlorides of copper, cobalt nickel manganese cadmium chromium vanadium and aluminium the nitrates of silver and lead and ammonium molybdate has been studied. The method of procedure was how-ever somewhat different from that adopted by Poggiale and others. A concentrated solution of mercuric cyanide was added to an excess of the salt solutions and the mixture evaporated slowly on the water-bath.The precipitate which was obtained in each case was collected and washed as a rule with the minimum quantity of cold water and next -with alcohol. I n the case of the aluminium compound the concentrated solution was evaporated in a vacuum, and the crystals obtained were washed with alcohol alone. It is t o be noted that the general method of preparing a double cyanide of two metals is to bring together their respective cyanide 68 GUPTA THE ACTION OF MERCURIC or to treat an alkali cyanide with some other double cyanide of the metals in question. The action of mercuric cyanide on the chlorides of copper and cobalt and silver nitrate producing respectively, the compounds CuCN,2Hg(CN),,4H20 Co(CN),,Hg(CN),,5H20, and AgCN,Hg(CN),,4H2O described in this paper are thus excep-tions to this general rule.On the other hand Poggiale and Bloxam mention the compounds 2CoC12,Hg( CN),,4H20 and 7AgCN,ZHgO,Hg(CN), as the products of reaction. Hofmann and Wagner (Ber. 1908, 41 319) however obtained the salt AgN0,,Hg(CN)2,2H20 in the last case. Other compounds described in this paper are 4A1C1,,HgC1,,28H20 and MnC1,,Hg(CN),,2R2O. Cryoscopic determinations of the molecular weights in aqueous solutions of these salts have been carried out ; also measurements of the conductivity of the latter salt were made a t different dilutions. EXPERIMENTAL. Compound CuCN 2Hg( CN),,4H20. About 24 grams of cupric chloride were dissolved in 100 C.C. of water and a solution of mercuric cyanide containing 10 grams of the salt was added the final volume of the mixture being 300 C.C.This was evaporated slowly on the water-bath almost to one-third its original bulk and was set aside. Next morning a very fine precipitate had formed which was collected washed first with cold water and finally with alcohol and dried on a porous plate at 25O. The product had a pale violet colour shining like fine sand when held in the sunlight and under the microscope was seen to consist of cubes. It is not appreciably soluble in water but decomposes and passes into solution when treated with sulphuric acid : I. 0.2011 gave 0.0258 CuO. Cu=10*25. 0.2786 , 0-1680 Hg. Rg=60.32. 11. 0.2125 , 0.0262 CuO. Cu=9.97. 111. 0.2618 , 0.0318 CuO. Cu=9.70. 0.3242 , 0'1960 Hg. Hg=60*46. 0.2838 , 26.2 C.C.N a t 32O and 760 mm CN=18.39. 0.2161 , 18-6 C.C. N a t 24" and 760 mm. CN=18-21. CuCN,2Hg(CN),,4H20 requires Cu = 9.47 ; Hg = 60.15 ; CN = 19.54 per cent. Compound CO(CN),,H~(CN)~,~H,O. This was prepared by the action of mercuric cyanide on cobalt The proportions of the salts were as 1 :3 and the method chloride CYANIDE ON METALLIC SALTS. 69 of procedure was exactly the same as mentioned above. A visible reaction took place within ten minutes from the sta.rt; the colour of the solution deepened and slow precipitation commenced. The washings and drying were performed as before. The compound is sparingly soluble in water but decomposes and passes into solution by the action of sulphuric acid as is the case with all sparingly soluble cyanides : 0.3118 gave 0.043 Co.Co=12'79. 0.2440 ,? 0.0977 Hg. Hg=40*04. 0.1875 ,? 25-46 C.C. N a t 2 6 O and 760 mm. CN=27*78. Co(CN),,Hg(CN),,5H20 requires Co = 12-31 ; Hg = 41.40 ; CN = 27.13 per cent. Nicke I Cyanide Ni( CN),,3€€,0. About 20 grams of nickel chloride NiCl,,GH,O were dissolved in 100 C.O. of water and to the cold solution was added a filtered solution of mercuric cyanide ( 8 l O O ) . The details of the procedure were exactly the same as in the foregoing cases. Williams (" Cyanogen Compounds," p. 65) describes the com-pound Ni(CN),,7R2O which he obtained by treating an alkali cyanide with excess of a nickel salt. The compound obtained by the above method is not at all gelatinous it has a fine granular structure and is insoluble in water or dilute acids but is decom-posed by concentrated sulphuric acid.Two- preparations gave the same product in each case: I. 0.3852 gave 0.1751 NiO. 11. 0-2605 gave 0.1186 NiO. Ni=35*71. Ni=35-78. 0.2348 , 35.4 C.C. N a t Oo and 760 mm. CN=31.61. 0.4348 ,? 0.1408 H,O. H20=32.38.* Ni(CN),,3H20 requires Ni=35.75; CN=31.51; H,O=32.74 per cent. The estimation of water in this compound and in subsequent determinations was carried out in the following manner. I n a combustion furnace was placed a hard-glass combustion tube containing a known amount of the substance t o be dehydrated in a weighed porcelain boat. One end of this tube was joined successively to a sulphuric acid wash-bottle a calcium chloride U-tube a soda-lime tower a second sulphuric acid wash-bottle and finally to an air-supply.To the other end a U-tube containing pumice stone soaked in sulphuric acid was attached. A guard tube containing calcium chloride was also joined t o this U-tube. A thermometer was inserted through an opening a t the top of the * The dehydration mas completed at 170" 70 QUPTA TEE ACTION OF MERCURIC furnace just above the glass tube. Air-tight joints were secured, and blank experiments were previously conducted. The boat con-taining the salt was placed a t the end furthest from the U-tube containing pumice stone. The heating was gradual and began from the opposite end. A regular stream of dry air was passed through the combustion tube and the water set free from the sub-stance was condensed and collected in the weighed U-tube contain-ing pumice stone soaked in sulphuric acid.It was finally weighed again and the difference between the two weights gave the amount of water in the compound. Compotbnd AgCN,Hg(CN),,4H20. To 100 C.C. of a solution of silver nitrate containing 12 grams of the salt was added a filtered solution of 6 grams of mercuric cyanide in 100 C.C. of water. This mixture was allowed t o evaporate to half its original bulk. A slight turbidity was noticed almost from the beginning. From the ice-cold concentrated solu-tion milk-white needles were deposited within ten minutes. These were collected and washed first with a little water then with alcohol and dried on a porous plate a t 25O. The compound decomposes slightly in the presence of water and dissolves in dilute sulphuric acid : I.0.8172 gave 0.2403 AgCl and 0.4166 HgS. Ag=22*12; Hg = 43.94. 0.2735 gave 22-2 C.C. N a t 30° and 760 mm. CN=17*64. 11. 0.5797 gave 0.1751 AgCl and 0.2998 HgS. Ag=22.73; Hg = 44.59. 0.7988 gave 0.1196 H,O.* H,O = 14-97. AgCN,Hg(CN),,4H20 requires Ag = 23.5 ; Hg = 43-66 ; CN = 17.07 ; R20 = 15-77 per cent. Action of Mercuric Cyanide on Chromium Trichloride and Vanadium Trichloride. The action of mercuric cyanide on the above-mentioned salt solu-tions was tried in a similar manner but the attempt to bring about a combination failed and the product obtained in each case con-sisted of an oxide of the respective metal. The cyanides were no doubt formed a t first but these being unstable decomposed into * The sdt began to give off water from 85" onwards and the dehydration ww completed at 180' CYANIDE ON METALLIC SALTS.71 the oxide and free hydrocyanic acid the odour of the latter being distinctly perceptible. Thus : A . 2CrC1 + 3Hg(CN) + 6H,O = 3HgC1 + 2Cr(CN) + 6H20. U. 2VC1 + 3Hg(CN) + 3H,O + 0 = 3HgC1 + V,O + 6HCN. 2Cr(CN)3 + 6H20 = 2Cr(OH)3 + GHCN. Action of Mercuric Cyanide om Ammonium Molybdate and Lend Nitrate . These reactions also failed t o yield the expected cyanides; with ammonium molybdate was obtained metallic mercury in the shape of fine globules and the oxide Mo205 as a violet-black powder, whilst in the latter case lead oxide was produced. Compound MnCl,,Hg(CN),,2H20. About 25 grams of manganese chloride were dissolved in 150 C.C. of water and a solution of mercuric cyanide (10 100) was added.The mixture was evaporated on the water-bath for one and a-half hours and the bulk reduced to 100 C.C. This concentrated solution was well stirred and allowed to cool overnight. Next morning a crystalline mass of pinkish-white scales had formed which was powdered washed with the mother liquor and finally with alcohol. The compound was dried on a porous plate for two days a t 24-25O. This salt was found t o be dihydrated whereas Poggiale described i t as being trihydrated. It is very readily soluble in water and iinder the microscope appears to consist of prismatic crystals : Mn=13.41 ; I. 0.1617 gave 0.056 Mn,P,07 and 0.0918 HgS. Hg=48*97. 0.1617 gave 0.1197 AgC1. C1=18-32. 0.3274 , 18.8 C.C. N a t 24O and 760 mm. CN= 12.14.11. 0.2084 gave 0.0724 Mn,P,O and 0.1180 HgS. Mn=13.44; Hg=48.81. 0.2084 gave 0.1485 AgCl. C1=17*63. 0.8353 , 0*0780 HzO. HzO=9*34.* MnC1,,Hg(CN),,2H2O requires Mn = 13.28 ; Hg = 48.30 ; Cl= 17.15 ; CN = 12-56 ; B20 = 8.71 per cent. The conductivity of the salt a t different dilutions was determined. * The salt began t o give off water from 90' onwards. The dehydration was completed at 170' 72 QUPTA TIIE ACTION OF MERCURIC T = 23O. Molecular Dilution. tivity. p, forizinc V. k- chloride. 50 204 207 100 212 216 500 237 231 1000 245 235 i& conduc-The molecular conductivity of zinc chloride a t 23O for different dilutions is quoted from Kohlrausch's table and proves to be almost identical with that of the salt. Assuming the molecular Con-ductivity of zinc chloride and manganese chloride to be the same, as has been shown to be true by Kohlrausch then the above com-pound evidently undergoes dissociation in solution into the ions Mn" and C1' and the undissociated molecule Hg(CN),.This is confirmed by the fact that when treated with silver nitrate silver chloride but no silver cyanide is formed. The determination of the molecular weight of the compound by the cryoscopic method supports the above view. Solvent 19-86 grams of water. Solute. At. M.W. 1 ............ 0.4593 -0*40" 107.3 2 ............ 0-9031 - 0.75 112.0 M.W. calculated for no dissociation = 414. M.W. calculated for dissociation to Mn" Cl," and Hg(CN) = 103.5. Compound 4A1C1,,HgC1,,28H20. s About 25 grams of hydrated aluminium chloride were dissolved in 100 C.C.of water and a cold solution of 10 grams of mercuric cyanide in 100 C.C. of water was added. The mixture was evapor-ated to about 50 c.c. and as no deposit was obtained on allowing the solution t o remain overnight it was placed in a vacuum desiccator over sulphuric acid. After a day a crystalline crust was found to have been formed on the surface of the solution. This was broken and the crystallisation in a vacuum allowed to proceed for a further couple of days. During this interval the crust on the surface was broken from time t o time and through-out the whole process of evaporation a strong odour of hydrocyanic acid was noticed. The crystals were collected washed first with the mother liquor and then repeatedly with alcohol.The com-pound was finally dried in a vacuum for two days CYANIDE ON BIETALLIC SALTS. 73 I. 0.4973 gave 0.0877 HgS and 0.0804 A1,0,. Hg=15*19; A1 = 9.51. 0.4348 gave 0.6548 AgC1. C1= 36.43. 11. 0.4407 gave 0.0777 HgS and 0.0790 Al,O,. Hg=15*20; A1 = 8.57. 0.5995 gave 0.8831 AgCl. C1= 37.25. 4A1C1,,HgC1,,28H20 requires Hg = 15.27 ; A1 = 8.25 ; C1= 37.96 ; H,O = 38.52 per cent. Cryoscopic Determination of t h e Molecular Weight. Solvent 15.7251 grams of water. Solute. At. M.W. 1 ............ 0.0963 - 0.087O 130.84 2 ............ 0.3077 - 0.277 130.94 3 ............ 0.6056 -0.515 137.10 The value found in this way approximates to one-tenth of the molecular weight namely 1309. I n aqueous solution the double salt is decomposed as the solution is found t o be distinctly acid. Since the compound 4A1C1,,HgC~,28H20 is completely hydrolysed to hydrochloric acid aluminium hydroxide and mercuric chloride, the observed molecular weight ought to be one-twelfth of 1309 as the lowering of the freezing point due to the aluminium hydroxide and mercuric chloride is quite negligible. This anomaly is difficult to explain and the molecular weight determination does not there-fore furnish much evidence as to the true molecular weight of the double salt in solution. I avail myself of this opportunity to express my sincere thanks to Sir Prafulla Chandra Riiy for his helpful interest and encourage-ment in this work. COLLEGE OF SOIENCE, 92 UPPER CIR~ULAR ROAD CALCUrnl [Received June 6th 1919.) VOL. OXVII.

ISSN:0368-1645    

DOI:10.1039/CT9201700067

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

74 DIXON AND KENNEDY : XI. -AcyZ Substituted isoThiohydantoins. By ACGUSTUS EDWARD DIXON and RAYMOND THOMAS JOACHIM KENNEDY. CONCERNING the acyl substituted isothiohydantbins practically the whole of our knowledge embodied in two papers one by Wheeler and Johnson (Amer. Chem. J. 1902 28 121) and the other by Johnson Wallbridge McFarland and Cramer ( J . Amer. Chem. SOC. 1903 25 483) may be summarised as follows. isoThiohydan-toins containing an aryl group R in the ring by treatment with thiolacetic acid or with acetic anhydride yield acetyl derivatives of the form MeCO*N:C<NR' the phenylic member of this class s-Sa, being producible also from esher phenylisothiohydantoic acid or thiocyanoacetanilide by means of acetic anhydride. Further ordin-ary /3-naphthylisothiohydautoin gives with acetic anhydride a deriv-ative C ~ H * N ~ C < N ~ c ~ M e ~ * ~ the corresponding o- or ptolyl-bH2 S--isothiohydantoin under like treatment affording a diacetyl deriv-ative.No purely acidic substitution derivative of isothiohydantoin seems yet t o have been described. It was found too by Dixon and Taylor (T. 1912 101 558) that ab-acetylphenylthiocrbamide when heated with chloroacetyl chloride yields ordinary phenylisothio-hydantoin the acyl substituent of the thiocarbamide being expelled in the form of acetyl chloride. Similar results were observed with tri-substituted thiocarbamides containing the acetyl the benzoyl or the carbethoxy-radicle together in each case with two hydrocarbon residues. More recent investigation has shown that less highly substituted thiocarb-amides containing the group *CO*OR (where R=aJkyl or aryl) by means of chloroacetyl chloride are transformable into isothiohydan-toins without the loss of that group.Thus for example carb-ethoxyisothiohydantoin may be obtained from carbethoxythiocarb-amide or a phenylcarbethoxy-analogue from ab-phenylcarbethoxy-thiocarbamide. Consistently with the observations of Dixon and Taylor (Zoc. c i t . ) it has been found that ethyl chloroacetate in alcoholic solution fails to attack the mono-substituted carboalkyloxythiocarbamides ; i f , however calcium carbonate is added to the mixture interaction takes place with the formation of the corresponding mono-substi-Such tri-substitution derivatives are not particularly stable ACYL SUBSTITUTED ISOTHIOHYDANTOINS.75 tuted isothiohydantoins. With di-substituted thiocarbamides, RO*CO*NH*CS*NHPh or with mono-substituted carboaryloxythio-carbamides however ethyl chloroacetate does not react either direotly or in the presence of calcium carbonate. So far as their method of production is concerned the carboalkyl-oxyisothiohydantoins referred to above might have either (or both) of the configurations represented by the formula: N(CO,R)*CO bH2 RO*Co*N:C<. r;rh*(?' and PhN:C<S $-OH2 (1.) (11.1 When hydrolysed by means of hot dilute hydrochloric acid they yield carbon dioxide amiiioniuia chloride and ' phenyldioxy thiazole.' Now Dixoii has shown (T. 1897 71 623) that in the transformat.ion by which a substituted isothiohydantoin furnishes a subst,ituted ' dioxythiazole,' the nitrogen member of the parent ring is exchanged for au oxygen atom thus: whence it follows that the foregoing carboalkyloxyisothiohydantoins have the constitution represented by formula 11.Judgment in the case of mono-substitution derivatives is a less simple matter. Analogy would suggest the formula whioh also is consistent with the fact that on hydrolysis by acid, they rapidly yield carbon dioxide ammonia and dioxythiazole. Moreover that the latter does not result through the hydrolysis of isothiohydantoin possibly formed from a compound, is clear; because whilst the actual hydrolysis is speedily accom-plished that of isothiohydantoin in like circumstances is very slow yet the presence of this compound could not be detected in the mixture.Nevertheless it is conceivable that a substituted dioxythiazole CO,R*N:C<o*?o might be formed and then hydro-S*CH2' lysed with elimination of the group :CO,R. Substances of the class last formulated are unknown. Through the action of chloroacetyl chloride on a-adyl-b-carb-ethoxythiocarbamide it should be possible to synthesise a compound having the structure CO,Et*N:C<NH'~O and if this should S-CH,' E 76 DIXON AND KENNEDY : prove isomeric with that from carbethoxythiocarbamide itself deci-sion would be easy. I n practice however such a check could not be applied all attempts to produce a thiocarbamide of the required configuration being unsuccessful. E X P E R I M E N T A L . Phenylcar b e t hoxyisothioTL?/dantoiit.When ab-phenylcarbethoxyt hiocarbamide was heated on the steam-bath with slightly more than one molecular proportion of chloroacetyl chloride liquefaction occurred with disengagement of hydrogen chloride and rapid deposition of a brown solid the action being complete within a few minutes. By recrystallisation from hot glacial acetic acid which dissolves it freely the product was obtained in white needles sparingly soluble in boiling alcohol benzene acetone or cold acetic acid and commencing to decompose a t about 220° but melting only towards 250O. The substance is very slowly desulphurised by boiling with the alkaline solution of a lead salt but readily yields silver sulphide when heated with ammoniacal silver nitrate. That it contains the group -S*CH,*CO* was shown by boiling the substance with alco-holic potassium hydroxide acidifying the liquor and mixing with ferric chloride followed by ammonia the resultanty purple colora-tion indicating (Andreasch Ber.1879 12 1385) the presence of a-thiolacetic acid. Found N = 1038 ; S = 12.2. C,,H120,N2S requires N = 10.60 ; S = 12-12 per cent. A mixture of ethyl chloroacebate and ab-phenylcarbethoxythio-carbamidc in alcoholic solution was boiled for three hours under reflux with excess of calcium carbonate and filtered whilst hot. From the filtrate as i t cooled the unchanged thiocarbamide sepa-rated in crystals and the mother liquor gave no reaction for a-thiolacetic acid ; in these circumstances therefore neither an ;so-thiohydantoin nor an isothiohydantoic acid had been formed.Hydroiysis.-Hot concentrated hydrochloric acid rapidly dissolved the substance carbon dioxide being evolved and from the solution, as it cooled ' phenyldioxythiazole ' seprated in long flattened prisms melting a t 143-144O. I n dif€crr,ni experiments the yield varied froin 60 to 80 per cent. of the theoretical. The acid liquor from which the crystals had been deposited gave, on evaporation ammonium chloride t,ogether mit!i a little aniline hydrochloride. As phenyldioxythiazole itself yielded no aniline when heated with hydrochloric acid it is possible that the isothio ACYL SUBSTITUTED ISOTHIOHYDANTOINS. 77 N(Cc)2Et)*(?o contained a trace of the CH,’ hydan toin P hN :C< -isomeride CO,Et*N:C<NP S -- * g,. from which aniline would be producible.Ph enylcar b om e t hoxy iso t hioh y dant oin . This was prepared in the manner already described but from a-phenyl-b-carbornethoxythiocarbamide and was similarly recrystal-lised from acetic acid. Marked decomposition occurred during the preparation and the yield was poor. Except that the compound was rather more readily soluble in cold acetic acid it resembled alike in properties and in reactions the carbethoxy-homologue ; when heated it decomposed gradually but did not melt even a t 250O. Found S = 12.45. CllH,,O,N,S requires S = 12.8 per cent. Phenylcnr b oxy -o-t olylisot hiohydant oim. a-Phenyl-b-carboxy-o-tolylthiocarbamide (7.6 grams) in dry ben-zene was heated for three hours under reflux with excess of chloro-acetyl chloride.On cooling crystals were deposited which after recrystallisation from alcohol weighed 1.3 grams the original mother liquor when evaporated giving 3.5 grams of unchanged thiocarbamide; the yield therefore was but 28 per cent. of the theoretical. Found N = 8.42 ; S = 9.85. The substance occurred in white rectangular prisms sparingly soluble in cold alcohol or benzene and melting a t 169-170°. De-sulphurisation by boiling with the alkaline solution of a lead salt was slow and imperfect even on prolonged boiling; but with hot ammoniacal silver nitrate blackening took place readily. By hot alcoholic potassiuni hydroxide a-thiolacetic acid was produced and recognised by Andreasch’s method; owing however to lack of material no further experiments could be made towards deciding the constitution of the substance.The Griginal thiocarbarnide when boiled with ethyl chloroacetate and alcohol in the presence of calcium carbonate afforded not a trace of the above isothiohydantuin. C,,H,,O,N,S requires N = 8.59 ; S = 9.82 per cent 78 DIXON AND KENNEDY: Carbethoxyisot hiohydantoin. Carbethoxythiocarbamide and chloroacetyl chloride were heated with benzene under reflux until hydrogen chloride ceased to escape, the action being complete in about three hours. During the process a yellow solid was deposited consisting of the impure hydrochloride of the above base which latter was obtained by dissolving the prclduct in hot acetic acid filtering off any hydrochloride that sepa-rated on cooling and evaporating the filtrate in a vacuum.More readily it is obtainable from the crude hydrochloride by recrystal-lisation from alcohol mixed with finely divided calcium carbonate. When ethyl chloroacetate was used instead of chloroacetyl chloride no sign of interaction was detectable after three hours’ boiling; but when the experiment was repeated with an alcoholic solution in the presence of calcium carbonate this being filtered off at the end of one and a-half hours the filtrate on cooling deposited the nearly pure base. Carbethozyisothiohydantoin separates from alcohol in white, hard felted needles melting and decomposing a t 173-174O; it is sparingly soluble in cold water moderately soluble in methyl alcohol more readily so in ethyl alcohol and dissolves freely in glacial acetic acid.It is not desulphurised by boiling with the alka-line solution of a lead salt or with ammoniacal silver nitrate but is hydrolysed by hot alcoholic potassium hydroxide with the forma-tion of a-thiolacetic acid. Found N = 14-84 ; S = 17.11. C,H,O,N,S requires N = 14.90 ; S = 17-02 per cent. Hot dilute hydrochloric acid readily dissolved the substance with effervescence due to the escape of carbon dioxide and from the solution when it had been evaporated down to a small bulk crystals were deposited melting a t 120-125O and consisting of nearly pure dioxyt,hiazole. The hydrochloride formed cream-white needles commencing to decompose a t about 160° but not melting a t 200O. Insoluble in benzene it dissolves in hot acetic acid with the loss of part but not all of the combined hydrogen chloride.By dissolution in hot water it is rapidly and completely decomposed the liberated acid convert-ing the base into dioxythiazole ; with boiling alcohol the same change occurs but more slowly. Found S = 14.62. C,H,O,N,S,HCI requires 14.25 per cent ACYL SUBSTI’I’UTED ISOTHIOHYDANTOINS. 79 Carbomet hoxyisot hiohydant oin. From carbomethoxythiocarbamide in benzene and chloroacetyl chloride the hydrochloride was obtained as in the last preparation, and on recrystallisation from acetic acid gave the pure base. Simi-larly from the above thiocarbamide and ethyl chloroacetate in the presence of calcium carbonate (but not in its absence) the free base was obtained. I n respect of general properties and reactions carbomethoxyiso-thiohydantoin closely resembles the aarbethoxy-homologue being, however somewhat less readily soluble in methyl alcohol ethyl alcohol or glacial acetic acid.It has no definite melting point but decomposes from about 170° onwards being still unmelted a t 220O. Found N = 16-05 ; S= 18.24. On contact with hot dilute hydrochloric acid it dissolved with esoape of carbon dioxide the solution when evaporated giving ammonium chloride together with dioxythiazole. (Found, S = 26-85 ; dioxythiazole requires S = 27.35 per cent.) By alkaline hydrolysis it yielded a-thiolacetic acid which was rocognised as before. C,H,O,N,S requires N = 16.09 S = 18.39 per cent. Carbop~enoxyisothiokydarrtoilt. Carbophenoxythiocarbamide in dry benzene when heated under reflux with chloroacetyl chloride gave a yellow crystalline mass of the substituted isothiohydantoin hydrochloride. By treatment with boiling alcohol containing finely divided calcium carbonate in sus-pension the free base was obtained in faintly yellow crystals melting a t 185-186O. Found S = 13.51. Cl,,H,0,N2S requires S = 13.56 per cent. Hydrolysis with hot alcoholic potassium hydroxide gave a solution responding to Andreasch’s test for a-thiolacetic acid. With the foregoing thiocarbamide in alcohol ethyl chloroacetate failed to react even in the presence of calcium carbonate-a result differing sharply from that observed with the carbethoxy- or with the carbomethoxy-analogue. The experiment was repeated carbo-o-tolyloxythiocarbamide being used instead but in this case too no interaction took place. CHEJZISTRY DEPARTMENT, UNIVERSITY COLLEGE, CORK. [Receiued December loth 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700074

出版商:RSC    

年代:1920

数据来源: RSC

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80 DIXON AND KENNEDY XII.-Carboalk yloxythiocadamides. By AUGUSTUS EDWARD DIXON and RAYMOND THOMAS JOACHIM KENNEDY, IN the course of a recent investigation (see preceding paper) pro-gress was much retarded through the difficulty experienced in pre-paring sufficient quantities of certain necessary thiocarbamides, particularly those containing the carbomethoxy- or the carbethoxy-group alone. Although such compounds are known having been obtained both from the corresponding thiocarbimides and ammonia (Doran T. 1896 69 331) and by the hydrolysis of aldehyde-ammonia derivatives of the former (Dixon and Taylor T. 1916, 109 1260) the yields are far from satisfactory-at all events the best yield now attained by eithbr method did not exceed 5 per cent. of the theoretical.From ab-acetylphenylthiocarbamide by heating it with excess of ethyl chlorocarbonate the acetyl radicle is expelled as chloride, with the formation of the corresponding ab-carbethoxyphenylthio-carbamide (Doran T. 1901 79 913); it seemed therefore almost a foregone conclusion that from acetylthiocarbamide in like circum-stances the products must be acetyl chloride and carbethoxythio-carbamide NH,*CS*NH*CO,Et. This forecast proved incorrect, for on experiment? no trace of the latter substance was obtained. By treating with dilute alkali hydroxide the additive compound of a hydrocarbon mono-substituted thiocarbamide and a chloro-carbonate Dixon succeeded in realising the changes C0,Et +RON >CS*CO,Et -+ NH,*CS*NR*CO,Et R*NH NH,>C 8<(y NH2 on the o t k r hand the corresponding non-substituted base, ;2>C S C0,Et , when similarly liberated from its ' hydrochloride,' broke down without yielding carbethoxythiocarbamide (T.1903 83 558 565). I n the last case, the attack of the alkali hydroxide being primarily on the carbethoxy-group i t seemed probable that if alkali bicarbonate were used 'instead of alkali hydroxide the disruption of that group might a t least be hindered for a while. If so-the speed of migration of an acyl radicle from sulphur to nitrogen being often a matter of seconds-even a slight delay in the break-ing down of the carbethoxy-complex might leave time enough for its transference CARBOALKYLOXY THIOCARB AMID ES . 81 Experimentally this prevision has been justified by the produc-tion of the compounds sought namely carbomethoxy- and carb-ethoxy-thiocarbamides ; they have been obtained however only indirectly and through some unexpected intermediate reactions.Briefly the facts are as follows. NH~>C:S<C'~E' in NH2 c1 Thiocarbamide-ethyl chlorocarbonate, aqueous solution yields with sodium hydrogen carbonate a bulky, white precipitate of the corresponding bicarbonate, N H2>C S<COPt NH2 0 * C02H ' an unstable compound which soon changes into a compact mass of prisms consisting of aa-dicarbethoxythiocarbamide ; concurrently, thiocarbamide is liberated and passes into solution along with the sodium chloride. The dicarbethoxyt,hiocarbamide itself stable is readily hydrolysed in alcoholic solution by hydrochloric acid with the formation of the monocarbethoxy-derivative, NH,*CS*NH*CO,Et.Although the bicarbonate soon decomposes especially in the presence of water the change requires a certain time and the bulky precipitate if treated a t once with dilute hydrochloric acid dis-solves thereby furnishing a clear solution of the original salt (thio-carbamide-ethyl chlorocarbonate in aqueous solution gives a picrate identical with that obtained from the above solution of the bicarbonate in acid). The bicarbonate after some twenty-four hours' keeping in a desiccator changed completely into a mixture of thiourea and dicarbethoxythiocarbamide. Thiocarbamide-methyl chlorocarbonate behaves similarly. The spontaneous change of a salt containing but one carbethoxy-(or carbometlhoxy-) group into an aa-di-substituted thiocarbamide is a remarkable phenomenon.That the last-named substance really has the aa-configuration follows from experimental results that will presently be stated; moreover that it is no mere by-product is clear for reckoned on the weight of ' hydrochloride ' employed and calculated from the equation 2NH2>C:S<co,Me O.CO,H -+ NH,*CS*N(CO,Me) -I- CSN2H + 2B2C0, NH, the yield of di-substitution derivative may reach at least 70 per cent. of the theoretical. As regards the migration of an acyl group from sulphur t o nitrogen the process is of a kind now well established as normal. Further if one of the two nitrogen atoms of the acyl-+-thiocarb-amicle is charged already with a hydrocarbon radicle the wander-E 82 DIXON-AND KENNEDY: ing acyl group goes always to join the latter (see for example, Dixon and Hawthorne T.1907 91 lZS) and may either remain there permanently or may again move spontaneously or under stress to the other; but to the already substituted nitrogen atom, it goes in the first instance. Consequently if the group *CO,R has made its normal excursion to yield the substituted thiocarb-amide NH,*CS*NH*CO,R it seems natnral that a second follow-ing in after the first should take up the’ same station a t all everits temporarily. I n the case here considered one may reasonably suppose that the second radicle is furnished by another molecule of the base NH,*C(:NH)*S*CO,R which holds i t only loosely; and the fact that thiourea not initially present is found eventually along with t,he di-substitution product is consistent with such a view.Still i t is a curious change and all attempts hitherto made tQ reproduce it with other acyl sulphonium salts have proved unsuccessful. For the structure NH,*CS*N(CO,R), assigned to the foregoing dicarboalkyloxythiocarbamides the experimental evidence is that the dicarbethoxy-compound by cold concentrated alkali hydroxide, is resolved into thiocyanic acid and the ethyl ester of iminodi-carbonic acid, NH,-CS:N(CO,Et) -+ HSCN + NH(CO,Et),. According to E. A. Werner (T., 1916 109 1124) the yellow diacetylthiourea obtained from acetic anhydride and thiourea in the presence of a mineral acid is a q9-thiocarbamide MeCO*NH*C(:NH)*S*COMe. Whether this really expresses the constitution of the compound it is somewhat difficult to judge from the evidence adduced since partl of the latter-notably the decomposition by heat into acetamide and acetylthio-carbimide-would equally well support the ab-formula.In the present connexion however the sole point of interest was to learn whether the two acyl radicles might possibly be attached to the same nitrogen atom. On treatment with concentrated alkali hydr-oxide however the diacetyl compound afforded not a t<race of thio-cyanic acid a result decisive against that view. Those aa-derivatives are white. E X P E R I M E N T A L . Car b ethoxy-derivatives. To a concentrated aqueous solution of thiocarbamide-ethyl chlorocarbonate,* sodium hydrogen carbonate was added in slight * NH”\C:S C O P Na-/ KCl .This name is not quite so cumbrous as diamino-methylenecarbethoxysulphonium chloride. the compound may be an ammonium salt. Besides it is not impossible tha CARBOALKYLOXY THIO GARB AMID ES. 83 excess ; carbon dioxide was rapidly evolved a crystalline material being deposited which after it had remained for some time was collected washed and dried. The product formed shining white, rectangular plates melting a t 97O with effervescence and with the evolution of carbethoxythiocarbimide easily recognised by its characteristic odour. Practically insoluble in water or in benzene, it dissolved freely in alcohol the solution giving with ammoniacal silver nitrate a black precipitate of silver sulphide but resisting desulphurisation by the alkaline solut*ion of a lead salt even after prolonged boiling.Analysis showed the compound to be a dicarb-et.hoxythiocarbamide. Found N=12-64; S=14*44. C,H,,O,N,S requires N = 12-73 ; S = 14.54 per cent. I n cold concentrated alkali hydroxide' the substance dissolved readily a portion of the liquid when acidified and then treated with ferric chloride giving the reaction of thiocyanic acid. From the remainder ether extracted a material having the properties and giving the reactions of diethyl iminodicarbonate (Found : N = 8-68. When allowed to evaporate spontaneougly the liquor from which the dicarbethoxythiocarbaniide had separated left a residue of sodium chloride mixed with thiourea. Dicarbethoxythiocarbamide is practically insoluble i n dilute hydrochloric acid. Yet the precipitate obtained by means of sodium hydrogen carbonate if treated immediately with a dilute acid dissolved a t once and the solution gave with picric acid a sparingly soluble bright yellow picrate melting a t 150-151O.From an aqueous solution of thiocarbamide-ethyl chlorocarbonate, a picrate was obtained having the same melting point and a mix-ture of the two in equal proportions melted also at 15Q-151°; evidently the bicarbonate precipitate when freehly prepared is transformable into the salt from which it was generated. That precipitate originally voluminous but shrinking as it changes into the thiocarbamide was supposed a t first to be the free base carbethoxy-i)-thiocarbamide NH,*C(:NH)*S*CO,Et. Strange to say this is not so; it is an unstable salt apparently the bicarbonate of the base.When filtered off as rapidly as possible, washed with acetone and dried in bibulous paper it formed rect-angular plates melting and effervescing a t 59-60° having a distinct odour of carbethoxythiocarbimide and dissolving in acid with the evolution of carbon dioxide to a clear solution; in plain water it dissolved appreciably but without effervescence. C,H,,O,N requires N = 8.69 per cent.). Found N=15*2; S=16-4. C,H,,O,N,S requires N =15*64; S= 17.87 per cent. E 2 84 DIXON AND KENNEDY : Naturally the experimental figures are no more than roughly approximate to those calculated. After twenty-four hours’ keep-ing in a vacuum desiccator the substance had completely decom-posed into a mixture (m. p. 70-looo) from which water extracted a portion leaving a residue of slightly impure dicarbeth0xyt)hio-carbamide.The aqueous extracb when treated with hydrochloric acid and potassium nitrite followed by picric acid yielded the picrate of formamidine disulphide recognised by its melting point and by the mixed melting-point method; hence it contained thio-urea. Neither carbethoxythiocarbamide nor aa-dicarbethoxythio-carbamide yields a derivative of formamidine disulphide under the above conditions nor does either of them give a picrate with aqueous picric acid. Further to confirm that the unstable substance is a carbonate (and not the corresponding free base) a quantity of the freshly prepared material in aqueous solution was mixed with a clear solu-tion of basic lead acetate whereon lead carbonate was pre-cipitated.TO the filtrate freed from most of the lead by means of hydrochloric acid and subsequent filtration picric acid was added the picrate of carbethoxy-a)-thiocarbamide (see above) thus being obtained. Carbethoxythiocarbamide is formed when a solution of aa-dicarb-ethoxythiocarbamide in alcohol is acidified with hydrochloric acid ; on keeping the former gradually separates in crystals the yield being about 80 per cent. of that required by the equation More easily it may be obtained by adding excess of sodium hydrogen carbonate to an alcoholic solution of thiocarbamide-ethyl chlorocarbonate and shaking the mixture from time to time; when the reaction is a t an end the turbid mixture is filtered the filtrate being then acidified and set aside for the crystals to separate.Although in relation to the amount,s of thiocarbamide and of ethyl chlorocarbonate originally taken the yield is not very gratifying, yet compared with that of the methods earlier mentioned it is highly productive; the process too is facile of operation because the ‘ hydrochloride ’ may be obtained by passing carbonyl chloride through a suspension of thiourela in benzene and absolute alcohol (compare T. 1903 83 565). NH2*CS*N(CO,Et)z + HZO + NHz*CS*NR*CO,Et + CO + EtOH. Carbomethoxy-derivatiues. Thiocarbamide-methyl chlorocarbonate in aqueous solution gave with sodium hydrogen carbonate a bulky white precipitate melting a t 62*5-63*5O and resembling in general properties the carbethoxy-homologue except for a slightly greater solubility in water.Th CARBOALKY LOXY THIO CARBAMID ES. 85 C0,Me freshly prepared hydrogen carbonate NH2>C:S<o.Co,H, NH2 dis-solved readily and complet.ely in cold dilute-hydrochloric acid the solution yielding with picric acid a sparingly soluble bright yellow ?%crate melting a t 207-210°. Found N = 14.72 ; S = 17-44. To measure the carbon dioxide a portion was treated in the Lunge nitrometer over mercury with excess of dilute hydrochloric acid. C4H,0,N,S requires N 14.28 ; S = 16-33 per cent. Found CO =21-65. Decomposition was slower than in the case of the carbethoxy-derivative the solid even after twenty-four hours' keeping still effervescing slightly on acidification; a t the end of two days how-ever the change was complete.By means of cold water the thio-urea was eztracted a mass of white rhombic plates being left; they were readily soluble in alcohol but practically insoluble in water ether acetone benzene or light petroleum and melted at Theory requires COT= 22.45 per cent. 11 7-1 18O. Found N = 14-44 ; S= 16-54. C,H,O,N,S requires N = 14.58 ; s= 16.67 per cent. Reckoned from the weight of thiocarbamide-methyl chloro-carbonate employed the yield of dicarbomethoxythiocarbamide was about 70 per cent. of the theoretical. I n cold concentrated alkali hydroxide the substance dissolved at once the solution react'ing copiously f o r thiocyanic acid ; hence both carbomethoxy-groups are attached to the same nitrogen atom. The alcoholic solution when acidified with hydrochloric acid, gradually deposited crystals of carbomethoxythiocarbamide. I n this case however as in that of the higher homologue it is un-necessary t o prepare the na-compound ; an alcoholic solution of thio-carbamide-me'thyl chlorocarbonate (which may be prepared from thiourea in methyl alcohol-benzene suspension and carbonyl chloride,) when treated with sodium hydrogen carbonate and then acidified gives the mono-substitut.ion derivative in yield varying from 60 to 70 per cent. of the theoretical. A solution of thiocarbamide-methyl chlorocarbonate in water remained practically clear after some we'eks' keeping and hence had developed neither carbomet-hoxy- nor dicarbomethoxy-thio-carbamide. Decomposition slowly occurred partly with regener-ation of thiourea and partly with the formation of the hydro-chloride of methyl-+-thiocarbamide NH,-C( :NH)=SMe. CHEMISTRY DEPARTMENT, UNIVERSITY COLLEGE, CORK. [Received December loth 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700080

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

86 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. XII1.- Organic Derizyatives of Tellurium. Part I. Dimeth yltelluronium Diha loids. By RICHARD HENRY VERNON. THE first mention of dimethyltelluronium di-iodide TeMe?I, is by Demargay (Bull. SOC. chim. 1883 [ii] 40 99) who merely states that this substance is obtained by the action of methyl iodide on tellurium and that decomposition takw place a t 100-120°. I n 1904 Scott (P. 1904 20 157) confirmed Demargay’s work, mentioned that neither sulphur nor selenium behaves in a similar manner and described the preparation of trimethyltelluronium iodide. The present paper is more in the nature of an introduction to the chemistry of this singular di-iodide and its main object is to show that there are not only two dimethyltelluronium di-iodides, two dibromides and two dichlorides but that these haloid deriv-atives of the bivalent radicle ‘ I dimethyltelluride ” are respectively isomeric.The reason for this duplication is that there are two bases and that each base gives a corresponding series of derivatives. The first or a-base is obtained by treating Demarqay’s red iodide with silver oxide and water. An aqueous solution with markedly basic properties resulte. To prepare the second or P-base the solution of the a-base is evaporated to dryness under specified conditions and the white, crystalline mass redissolved in water. The chemical behaviour towards reagents of these two bases is shown in the following table the solutions in each case being precisely of the same concentration.Aqueous Reagent solution of a-base. AgNO ............ Precipitate of Ag,O. FeCI ............... Precipitate of Fe(OH), when base is in excess. FeCI ............... A red solution becoming H,Pt(=I ............ No precipitate. Picrio acid ......... No precipitate. darker on boiling. Aqueous solution of &base. White precipitate. Becomes White precipitate when No precipitate when FeCl, Yellow platinum salt. Yellow picrate. black on boiling. base is in excess. is in excess VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. 87 The best reaction to distinguish between them is that with silver nitrate and this first directed the auOhor's attention to their exist-ence. Another typical reaction is with ferric chloride. Both these bases form picrates but that of the a-base possesses a much greater solubility than that derived from the &base.Generally speaking, the two bases behave towards metallic salts like the alkalis the p r e cipitates being apparently similar in some cases but showing marked differences in others. Apart from these reactions the chief feature of interest lies in the action of the halogen acids. Thus if the a-base is treated with hydriodic acid the original a-iodide namely Demarqay's is regenerated. TeMe,I 3 TeMe,(OH) TeMe,I, a-Iodide. a-Base. a-Iodide, On treatment of the &base with hydriodic acid in marked con-trast to the a- Demarqay's iodide is not regenerated but a new iodide totally different in chemical and physical properties and this new or &iodide has proved to be isomeric with the a- or Demarqay's iodide.TeMe,I * ~ 2 * TeMe,(OH) ~4 TeMe,(OH) TeMe,I, a-Iodide. a- Base. B -Base. &Iodide. Repeated attempts have so far shown that although the a-base easily changes into the P- the reverse is not the case. Further-more each iodide is converted into its corresponding base on treat-ment with silver oxide and hence the still more generalised equa-tion can be written: The equation now becomes : -+ HX TeMe2X2 % TeMe,(OH) TeMe,(OH) TeXe,X, a-Haloid. a-Base. &Base. B-Haloid. 13 x where X is either chlorine bromine or iodine precisely the same reactions taking place with the other two halogen acids as with hydriodic acid itself. There are thus six dirnethyltelluronium dihaloids of the general type TeM%X, and in future all derivatives of the a-base will be prefixed by the letter a and those of the &base by the letter 8 .This is very necessary because not only do the two haloid series exist but every salt is duplicated. This does not imply however, that they are necessarily isomeric. MeZthg Points.-The following is a comparison of the melting points : a-Chloride 92' a-Bromide 92" a-lodide 127" &Chloride 134O B-Bromide 142" ,%Iodide (no m. p. 88 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. Of these the a-chloride and bromide melt sharply without decom-position and the remainder decompose on fusion. The P-iodide imperceptibly changes into tellurium and inethyl iodide above looo, but no sign of fusion is observed. Colour and A bsorption Spectra.-SoluLions of the dimethyl-telluronium dihaloids have somewhat different colours from the salts themselves and this is particularly marked with the two iodides.The bright red crystals of the a-iodide give a deep orange solu-tion and t'he black or greenish-black crystals of the @iodide a blood-red one. The following table gives the colour of the salts and their solutions : Solution (N/100 in ethyl Salt. alcohol). @-Chloride ............ Colourless. Colnurless. a-Bromide ............ Yellowish. Yellowish. a-Iodide ............... Red. Deep orange. &Iodide ............... Black (greenish- Blood-red. &Chloride ............ Tinged. Tinged. &Bromide ............ Orange Orange. black). Of considerable interest is the absorption spectra in the ultra-violet region photographs of which were obt'ained through the Salt.a-Chloride ................. 6 -Chloride .................. a- Br omide .................. &Bromide .................. a-Iodide ..................... B-Todide ..................... h 2640 2742 2760 2780 2680 2750 2890 2935 3005 3245 3300 3350 3045 3310 3405 3450 3940 4190 4320 4425 4350 442 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. 89 kindness of Mr. J. E. Purvis. Hundredth-mol. solutions in ethyl alcohol were used in each case and fifteen photographs were taken on each plate. The source of illumination was a cadmium spark, and the exposure was two minutes for each photograph. I n no case were any bands observed and the positions where general absorption began are given for thicknesses of 2 10 20 and 30 mm.It will be noticed that (1) the P-haloid has a greater absorbing power than the corresponding a-one and (2) the a-chloride shows the least absorption and the P-iodide the greatest the latter absorb-ing to the extent of complete extinction through a thickness of solution greater than 4 mm. I n view of the enormous absorbing power of the two iodides and especially of the &iodide two extra spectrographs were taken using a ten-thousandth-mole solution (ethyl alcohol) otherwise precisely the same conditions were maintained and although a marked difference between the two was still noticeable no bands were apparent. Constitz~tion.-( 1) The existence of two series of dimethyl-telluronium dihaloids has been established.I n the case of each of the chlorides bromides and iodides i t has been shown* (i) that they have the same percentage Composition (ii) that they have the same molecular weight and (iii) that there is no question of poly-morphism since ( a ) the absorption spectra are different and ( b ) their chemical behaviour is different thus each regenerates its respective base when treated with silver oxide. The conclusion is therefore that these haloids must be respectively isomeric. (2) Since in the a- as well as in the P-series both halogens are ionisable the halogen being precipitated quantitatively by silver nitrate and both the a- and the &bases are strongly diacidic the haloids of both series must be represented by structural formulze of the type ",>Te<$.CH3 (3) The fact that there exist in these simple compounds of quadrivalent t'ellurium two substances corresponding with one structural formula shows that the relationship between the four tellurium valencies must be different from that generally assumed to exist between the carbon valencies in such a compound as methylene iodide that is there cannot be four equal valencies directed towards the solid angles of a regular tetrahedron of which the tellurium atom occupies the centre. * Analytical figures and molecular weights will he found in the experimental part 90 VERNON ORGANIC DERIVATIVES OF TRLT,TJRIUM. PART I. I- --I 1- -CH, EXPERIMENTAL. The a- or Demnrqay's Iodide (a-Dimethyltellzironizcm Di-iodide).According to Demarqay this substance is obtained directly by heating a t BOO a mixture of methyl iodide and tellurium in the proportion of two mols. of the former .to one of the latter. The best method of procedure is to blow a 150-200 C.C. bulb on the end of a 1.5 to 2 cm. glass tube seal up the contents (50 grams of amorphous tellurium and 112 grams of methyl iodide is a convenient amount) and keep in a water-bath a t 80° for thirty-six to forty-eight hours. Very little pressure is developed a t any time and none will be found when the cold tube is opened. This is now broken into a mortar the brittle red mass finely powdered and extracted with chloroform and if the same chloroform is used for repeated extractions very little is necessary.A hot funnel will be required when filtering off the unchanged tellurium. The interaction between methyl iodide and tellurium is very rapid a t first but gradually becomes slow and eventually appears to stop altogether even on prolonged heating. I n one experiment whe VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. 91 50 grams of tellurium and 112 grams of methyl iodide were kept a t 80° for forty-eight hours a yield (the yields are calculated on the crystalline iodide obtained from chloroform) of 50 per cent. was obtained. Precisely the same quantities when kept a t 80° for three weeks, gave only a 55 per cent. yield. The yields are proportionally greater when small quantities are used. The a-iodide crystallises from solvents in varying shades of red and melts and decomposes,at 1 2 7 O : 0.2293 gave 0.0490 CO and 0,0325 H,O.0.1890 in 34.65 benzene gave A t = -0.068O. C2H612Te requires C=5.83; H=1-46 per cent. The reaction between tellurium and methyl iodide is a reversible C=5*83; H=1.57. M.W.=411. M.W.=401. one, So" Te + 2CB31 F+ (CB,),Tel,, 100" proceeding from left to right a t 80° and from right to left a t or above looo. I n order t o show this a weighed quantity of the iodide was placed in a small bulb blown a t the end of a 4 mm. tube the open end being drawn out into a fine capillary tube and bent a t right angles. This constituted a small distilling flask and the iodide when carefully heated to looo in sulphuric acid bath began to decompose. The temperature was gradually raised t o 180° and the distillate collected in a weighed tube kept in ice: 1.2912 gave Te (residue) =0.4206 ; CH,I (distillate) =0.8352.Te=32; CH,I=65. C,H612Te requires Te = 31 ; CH,I = 69 per cent. These figures are not in close agreement but are sufficient to show that methyl iodide is the product of decomposition and not dimethyl telluride. The distillate also was quite free from the overpowering odour of the telluride. The a-iodide is soluble in most organic solvents the best being chloroform and benzene. To obtain good crystals boiling saturated solutions should be allowed to cool and when cold the solvent a t once decanted otherwise polymerisation sets in. The a-iodide is not soluble in cold water but on prolonged boil-ing an orange-red solution is obtained which on cooling deposits the iodide leaving a perfectly colourless solution.The salt is partly hydrolysed and the reaction is reversible. TeMe,T2 + 2H,O T'II? TeMe,(OH) + 2HI A curious state of equilibrium between the a-base and hydriodic acid results when a boiling saturated solution of the iodide i 92 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. suddenly poured into a large excess of cold water. A fine yellow precipitate a t once forms and as quickly disappears the aqueous solution remaining quite colourless. The base is now in equilibrium with the hydriodic acid and will remain so indefinitely. I f this perfectly colourless solution is evaporated crystals of the iodide appear. If hydriodic acid is added the iodide1 is a t once precipitated.The action of alkalis and of both aqueous and dry ammonia on the iodide will be dealt with in a separate paper. A remarkable reaction which is almost unique is that between the iodide and mercury diphenyl. I f boiling chloroform solutions of the two compounds are suddenly mixed the mixture will remain perfectly clear and quiescent for a few seconds (this period depend-ing on the concentration of the solutJons and on the temperature, decreasing with an increase of concentration and inversely) and then in a flash the reaction sets in and the perfectly clear solution instantly becomes opaque. The explanation for this reaction probably lies in the formation of an oil (an excessively unstable form of the mercury compound), which is moreover very readily soluble in chloroform.At a given moment this oil suddenly changes into the more stable crystalline form which is quite insoluble in chloroform. Experi-ment shows the existence of such an oil and the complete insolu-bility of the crystalline mercury compound in chloroform rather confirms this hypothesis. This mercury diphenyl reaction is very characteristic of the a-iodide and although similar compounds are formed with other aliphatic tellurium derivatives such as with diethyltelluroriium di-iodide (a lemon-yellow salt) the reaction does not take place in this curious manner. Fuming or concentrated nitric acid precipiliates the iodine from the a-iodide and if the mixture is evaporated on the water-bath the iodine is gradually expelled and the colourless solution deposits white crystals of the a-nitrate which melts sharply and without decomposition at 142O.This nitrate is explosive when suddenly heated. The a-iodide gives a green platinum salt with chloro-platinic acid. Tke a-Base. This is obtained from the a-iodide by the action of silver hydr-oxide. Thirty-six grams of silver nitrate and 10 grams of sodium hydroxide are each dissolved in 500 C.C. of water and the boiling solutions mixed. The mixture is vigorously boiled until the silve VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. 93 hydroxide becomes granular when it is collected and washed with 5 litres of boiling water. Twenty-four grams of the iodide are now ground in a mortar with the freshly prepared silver hydroxide and sufficient water to make a thin paste.When the red crystals have completely dis-appeared the reaction is completed but i t is preferable to allow half an hour to elapse with occasional grinding before filtering. The reason of this is that a crystal of the iodide is very liable t o become coated with silver iodide thus impeding further action ; hence thorough grinding is necessary. The silver iodide and mortar are now washed with boiling water, and the filtrate (150-200 c.c.) which is generally somewhat opal-escent contains the a-base. The quantities indicated in this p r e paration allow for an excess of silver hydroxide. This strongly alkaline solution behavm in a very similar manner to the mineral bases and with silver nitrate gives silver hydroxide, probably according to the equation 2AgNO,+ TeMe,(OH) = 2AgOK + TeMe2(M0,),.With halogen acids the a-haloid series results and undoubtedly a great number of a-derivatives could be prepared with bot'h mineral and organic acids. The standard method of preparing these a-salts is not by the action of the acid on the base involving the preparation of the base from the iodide but the direct interaction between the iodide and the silver salt of the acid according to the general equation TeMe,I -t ZAgR = TeMe,R + 2AgI. In this manner the benzoate which crystallises in white needles melting a t 1 5 4 O and the yellow picrate crystallising in fine plates, were prepared. The &Base. To prepare the &base the a-base is evaporated a t 100° under about 15 mm. pressure t o complete dryness. The reaction can be closely followed by taking samples and testing with silver nitrate.The point a t which the transition from the a- t o the &base is just about t o take place is reached when the violent ebullition ceases and an oily liquid remains in the evaporating flask. A sample of this oil dissolved in water still shows the presence of the a-base with silver nitrate. I f however the evaporation is continued for a few minutes longer this oil which has momentarily remained perfectly quiescent will suddenly begin to bubble violently apparently giving off water and a white leaf-like, crystalline substance which adheres to the side of the evaporating flask is obtained. Due to the sparing solu- 'This is the &base 94 VERNON ORGANIC DERIVATIVES OF TELLURIUM.PART I. bility of silver hydroxide in water the base is invariably more or less coloured the shade varying from pale to dark brown. To obtain the colourless P-base it is only necessary to redissolve the discoloured preparation in water filter and evaporate again to dryness. From 24 grams of the iodide 6-7 grams of the base are usually obtained this representing a yield of about 70 per cent. of the theoretical calculated from the equation TeMe,I + 2AgOH = TeMe,zO + 2AgI + H,O. Owing to its extremely hygroscopic nature and the difficulty of thoroughly drying this base a combustion gave but little inform-ation as to its constitution: This operation can be repeated if necessary. 0.3488 gave 0.1610 C02 and 0'1041 H,O. C2H,0,Te requires C = 12-54 ; H = 4.18.C=12.58; H=3*31. C,H,OTe requires C = 12-83 ; H = 3.46 per cent. As will be observed the value obtained for carbon would indicate a dimethyltelluronium dihydroxide but that obtained for hydrogen approaches more nearly to dimethyltelluronium oxide. A certain amount of evidence tends to show that the IS-base is dimethyltelluronium oxide namely it's molecular weight in water, and analysis of the silver salt obtained by treating the base with silver nitrate : 0.5990 in 47.75 water gave A t = - 0 ~ 1 4 3 ~ . M.W.=163. The hydroxide requires M.W. = 192 and the oxide M.W. = 173." Analysis of the extremely unstable silver salt gave : 0.2814 gave 0.0403 CO and 0.0305 H,O. C=3.91; H=l-20. 0.1952 , 0.1088 AgC1. Ag=41.95.t C,H,0Te,2AgN03 requires C=4*66 ; H= 1-17; Ag=42.00 per cent.These figures would therefore point to the existence of a dimethyltelluronium oxide giving additive produch with metallic salts such as silver nitrate ferric chloride etc. It would therefore not be surprising if similar additive com-pounds of the general type TeMe20,2HX were formed with halogen acids these constituting the /3-series. Analysis alone is sufficient to refute this hypothesis. Consideration of the analytical figures for the six haloids un-questionably shows that whatever the constitution of the &base may be a salt results when it is treated with halogen acids which must correspond in percentage composition and molecular weight * Two other values were 175 and 183. t Other values for Ag were 41.90 and 42.00 VERNON ORGANIC DERIVATIVES OF TELLURIUM.PART I. 95 with the formula TeM%X, and in consequence the P-base must either have a similar constitution or a t least a constitution that lends itself to the formation of such derivatives. This base also possesses alkaline properties has a powerful odour, is very hygroscopic and is readily soluble in both water and alcohol. With halogen acids the P-series reaults and probably a great number of fl-salts both of inorganic and organic acids could be prepared. As previously remarked the transition from the a- to the &base readily occurs but all attempts to obtain the reverse reaction have completely failed. Prolonged boiling as well as repeated evaporations to dryness, of an aqueous solution of the B-base etc. have not produced the slightest change.That the P-form is the most stable of the two is unquestionably the case. The #3-iTodide (P-Dimethyltelluronium Di-iodide). This iodide is prepared by the action of hydriodic acid on the &base. This obtained as previously described from 24 grams of the a-iodide is dissolved in about 100 C.C. of water and the acid (D 1.5) is run into it from a burette the solution being contained in a mortar. A few C.C. are run in at first and a black viscid, tarry mass is a t once formed which on trituration becomes very brittle and can be finely powdered. This operation is repeated until further addition of hydriodic acid (about 17 C.C. are required) no longer produces a precipitate. This fine purple powder which is very heavy settles rapidly and the clear supernatant liquid can be poured off.The crude iodide is collected and kept in a vacuum desiccator over calcium chloride and sodium hydroxide. The dry salt is now dissolved in a minimum quantity of methyl alcohol and the solution filtered through a hot funnel. The deep blood-red solution should immediately deposit crystals and when cold these should be collected a t once. The crystals can be re-crystallised from methyl alcohol. It also appears to be advantageous-to add one or two drops of hydriodic acid to the solvent. A point to be noted is that it is useless to evaporate mother liquors containing the fl-iodide as not only polymerisation, but partial decomposition with precipitation of tellurium takes place. The crystals of the &iodide vary somewhat in colour being at times nearly black and at others of an iridescent green.The yield 96 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. are necessarily low on account of loss during crystallisation but 4 or 5 grams can usually be obt'ained: 0.8538 gave 0.1828 CO and 0.1168 H,O. 0.3138 , 0.3578 AgI. 1=61.62. 0.4482 in 32.55 acetone gave E= 0.046O. C=5*84; H=1.52. M.W. = 509. C,H,I,Te requires C = 5.83 ; H = 1.46 ; I= 61.72 per cent. M.W. =411.* The a-Bromide (a-Dime t hyl t ellumnium Bibromide). The a-bromide can be prepared by the action of hydrobromic acid on the a-base. The solution of a-base prepared as described from 24 grams of the a-iodide usually has a volume of between 150 and 200 c.c. and should be evaporated t o about 100 C.C.The acid (D 1.3) is now run in from a burette until no further pre-cipitation takes place. The crude bromide is collected and crystal-lised from ethyl or methyl alcohol. A pure salt is a t once obtained, and after thoroughly drying over calcium chloride and sodium hydroxide the leaf-like crystals melt a t 92O. Unless the pre-paration is entirely freed from acid by drying over sodium hydr-oxide the melting point will invariably be low. A more direct method consists in dissolving the a-iodide in aqueous ammonia precipitating the iodine with an ammoniacal solution of silver nitrate and treating the dimethyltelluronium dinitrate with hydrobromic acid. This reaction is very complicat>ed but can be summarised by the equations : (1) TeM%I2 + ZAgNO = TeMe2(N0,) + 2Ag1, (2) TeMe2(N0J2+ 2HBr =TeM%Br + 2HNO,.Concentrated aqueous ammonia is run drop by drop from a burette on 15 grams of the a-iodide (an exothermic reaction) until the red salt is completely transformed into a pasty greyish-white mass. This will need but a few c.c. and it is advisable to stir thoroughly during the reaction as the greyish-white precipitate has a tendency to cake thus preventing further action of the ammonia. This precipitate is now dissolved in about 200 C.C. of water with a drop or two of ammonia i f any of the undecomposed * Another determination gave M.W.=707. These values are high owing to polymerisation of the salt in the solvent. Experiment has shown that : (1) the molecular weight increases regularly with the concentration and (2) the molecular weight is higher in boiling acetone than it is in freezing nitrobenzene for the same concentration.This polymerisation is more marked in the case of the &iodide than it is with the 8-bromide. The &chloride shows no sign of polymerisation and correct values are obtained VERNON ORGANIC DERIVATIVE8 OF TELLURIUM. PART I. 97 iodide is observed. Fifty C.C. of an aqueous solution containing 12.4 grams of silver nitrate with just sufficient ammonia t o re-dissolve the precipitate of silver hydroxide are now added and the mixture is boiled and filtered. The filtrate is evaporated on a water-bath until the odour of ammonia has completely disappeared, diluted again t o 200 c.c. and any silver iodide removed by filtration. A drop of hydrobromic acid is added to the boiling solution and if a yellow insoluble precipitate forms this indicates an excess of silver nitrate.I n this case a further addition of acid is necessary. Any silver bromide is now filtered off and the solution evaporated t o about 100 C.C. The cold filtrate is treated with acid (hydrochloric or hydro-bromic according as t o whether the a-chloride or a-bromide is desired) until no further precipitation takes place. The crude salt can now be crystallised from ethyl or methyl alcohol. The yields are good and about 5 or 6 grams are usually obtained after a second crystallisation from alcohol : 0.7248 gave 0-2004 CO and 0.1246 H,O. 0.3350 , 0.3956 AgBr. Br=50-25. 0.6512 in 31.42 acetone gave E=0*105°. C=7.54; H=1*91. M.W.=335.C,H,Br,Te requires C = 7.56 ; H = 1-89 ; Br = 50.39 per cent. M.W. =317. The &Bromide (P-L)imeth?/~tellzcronium Dibromide). The P-base from 24 grams of the a-iodide is diluted to about 150 c.c. and hydrobromic acid (D 1.3) is run in from a burette (25-35 C.C. of acid are generally required). So long as an excess of base is present the white gelatinous precipitate redissolves. On continued addition of acid a somewhat granular insoluble precipitate separates which on further treat-ment becomes bright orange and crystalline. This is the bromide, which can be recrystallised from ethyl alcohol etc. I n this preparation mother liquors containing a little free acid can be evaporated on a water-bath and allowed t o crystallise. A certain amount of tellurium due to slight reduction is liable to precipitate on treatment of the base with the acid and this is especially the case when a too concentrated solution of the base is used.The crude bromide is therefore liable to be more or less discoloured. It is also not advisable t o have a marked excess of acid as this appears to react further with the p-bromide giving a brown 98 VERNON ORGANIC DERIVATIVES OF TELLURIUM. PART I. additive compound. crude bromide can usually be obtained. a t about 135O and melt and decompose at about 142O. crystallisations of this bromide do not alter the melting point: The yields are good and 6 or 7 grams of the The leaf-like crystals or bright orange crystalline powder darken Repeated 0-6944 gave 0.1914 CO and 0.1206 H,O. 0.3564 , 0.4218 AgBr.Br=50.36. 0.3034 in 46-61 nitrobenzene gave At = - 0.123O. C=7.52; H=1.93. M.W. = 370. C2H,Br,Te requires C = 7.56 ; H = 1-89 ; Br = 50.39 per cent. M.W. =317.* The a-Chloride (a-D,imet k y l t el Zzwonium Dichloride) . This is prepared in exactly the same manner as the a-bromide, both by the action of hydrochloric acid on the base or directly from the a-iodide. It is the most stable of all the dimethyltelluronium dihaloids does not appreciably polymerise and can be crystallised from water alcohol etc. From concelntrated solutions leaf-like crystals deposit and from dilute aqueous solutions long needles, with the same melting point of 92O are obtained: 0.5693 gave 0.2196 CO and 0.1340 H,O. 0.3618 , 0.4560 AgCl. C1=31.17. 0.2224 in 19.38 acetone gave E = 0.085O. C=10*52; H=2.62. M.W. =229. C,H,Cl,Te requires C = 10.50 ; H= 2.62 ; C1= 31.05 per cent. M.W. = 228. The 6-Chloride (&Dime t h?ylt elluronium Dichloride) . To prepare this chloride the directions given for the preparation of the P-bromide are followed. The precipitation of tellurium when hydrochloric acts on the base is not quits so marked as with the &bromide but the crude chloride is generally somewhat dis-coloured. The leaf-like crystals melt sharply a t 134O: 0.3496 gave 0.1346 CO and 0.0830 H,O. 0.2206 , 0.2777 AgC1. C1=31.11. 0.1648 in 19.11 acetone gave E=0*065°. C=10.50; H=2*64. M.W. =226.-l-C,H,Cl,Te requires C = 10.50 ; H= 2-62 ; C1= 31-05 per cent. M.W. =228. UNIVERSITY CREMICAL LABORATORIES, * Other values obtained for the molecular weight were 400 445 (nitro-t Other values found were 230 223 (acetone). CAMBRIDGE . [Received October 21& 1910.1 benzene) 430 459 525 (acetone)

ISSN:0368-1645    

DOI:10.1039/CT9201700086

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

THE ACTION OF AQUA REQIA ON GOLD-SILVER ALLOYS ETC. 99 XIV.-The Action of Aqua Regia on Gold-Silver Alloys in the Presence of Ammonium Salts. By WILLIAM BRANCH POLLARD. THE most practical method of dissolving gold and its alloys is undoubtedly by means of aqua regia. With gold alloys containing upwards of 15 per cent. of silver a coating of silver chloride forms on the surface of the metal and protects it from the further action of the acid. By rolling out these alloys until they are very thin solution can often be effected the coating on the metal never becoming sufficiently thick to stop the reaction; thicker pieces are only superficially attacked. With alloys which are very rich in silver “rolling out” is not sufficient to effect solution and a black coating forms and resists all further action of the acid.I n order to study the matter further the following alloys were prepared the composition being stated in parts per thousand: CU. 500 500 -333 667 -250 750 -453 277 270 -Au. Ag. 625 375 The alloys were rolled out to about a tenth of a millimetre in thickness and portions of them were used in the subsequent tests. It seemed probable that the best way t o effect solution of these alloys would be to try and increase the solubility of the silver chloride in the liquid; of the various chlorides which are known to dissolve silver chloride ammonium chloride appeared to be the most promising for this purpose. To test the point a gram of each of the above-mentioned alloys was placed into a bottle aqua regia (containing one part of con-centrated nitric acid and three parts of concentrated hydrochloric acid) added and the bottle placed on a hot asbestos board.The action of the acid started almost immediately but stopped very quickly the surface of the metal being covered with a black coat-ing. Ammonium chloride was now added to the hot liquid as long as it was dissolved. I n a very short time the black coating on the metal had completely dissolved leaving a bright metallic surface in each case. The acid now began to attack the meta 100 POLLARD THE ACTION OF AQUA REGIA ON GOLD-SILVER again and continued to do so until all had dissolved; no silver chloride separated and a clear yellow solution was obtained. On diluting the solutions with water copious precipitates of perfectly white silver chloride separated.Even pure silver was found to be soluble in a mixture of aqua regia and ammonium chloride, although the action was not very rapid and the volume of liquid required was large in comparison with the amount of metal dis-solved. It is to be noted that aqua fortis and sal-ammoniac were used by the alchemists for dissolving gold. It seems most prob-able that this mixture was used to dissolve native gold which sometimes contains enough silver t o prevent dissolution in aqua regia alone. The chief objection to the use of aqua regia and ammonium chloride seemed t o be that the action of the acid was very slow, and when much silver was present the volume of the solution became large. It was noticed that the alloy containing gold 453 silver 277, and copper 270 dissolved very easily in a mixture of aqua regia and ammonium nitrate the silver chloride remaining insoluble.Alloys of gold and silver only did not dissolve so easily in this mixture but when ammonium chloride was added as well a most marked improvement took place. For most alloys a mixture of 5 grams of ammonium chloride, 5 grams of ammonixun nitrate and 5 to 10 C.C. of aqua regia was found t o give quite satisfactory results. The amount of metal which can be dissolved depends on the amount of silver present. I f silver chloride separates this shows that enough ammonium chloride has not been added. I f on the other hand the action becomes slow more aqua regia may be required. With 5 grams of each salt and 5 to 10 C.C.of aqua regia 0.5 to 1 gram o l alloy could be dissolved easily and quickly the total volume of the solution being quite small. Considerably more gas is evolved when gold dissolves in the presence of ammonium salts than when i t is dissolved in aqua regia alone; on collecting the gas i t appeared to consist prin-cipally of nitrogen. The solution of the gold therefore does not take place in accordance with Priwoznik’s equation (Oesterr. Zeitsch. Berg.- u. Hiittenw. 1910 58 649) a secondary action occurring whereby the ammonium salts become oxidised with evolution of nitrogen. During the attlack of gold-silver alloys by aqua regia in the presence of ammonium chloride and nitrate it often happene ALLOYS IN THE PRESENCE OP AMMONIUM SALTS. 101 that purplish-brown crystals separated in the liquid.When water was added they disappeared and nothing remained but silver chloride. A specially good yield of these crystals was obtained when 2 grams of an alloy of the composition Au 625 Ag 375 were treated with a mixture consisting of 10 grams of ammonium chloride 3 grams of ammonium nitrate 5 C.C. of concentrated nitric acid and 15 C.C. of concentrated hydrochloric acid. The alloy in the form of thin sheet was heatTed gently in a beaker with the above mixture. When all the metal was dissolved the bottom of the beaker was found to be covered with very small, purplish-brown crystals. They were instantly decomposed by water with the formation of silver chloride and chloroauric acid, but were found to be fairly stable in conceiitrated hydrochloric acid.When prepared in this way it' was found difficult to prevent the crystals being contaminated with ammonium chloride. The following method was theref ore devised. Preparation of the Salt.-Twenty-five grams of gold were dis-solved in 50 c . ~ . of nitric acid and 150 c . ~ . of hydrochloric acid, the liquid being then saturated with about 30-35 grams of ammonium chloride. Three grams of silver nitrate dissolved in 10 C.C. of water were then added and a copious precipitate of silver chloride formed in the liquid. On adding a few crystals of ammonium chloride the silver chloride began a t once t o change into brown crystals. On heating the liquid the crystals were con-verted into silver chloride and on cooling again reappeared.This change could be repeated any number of times. The crystals were allowed t o remain in contact with the mother liquor for two or three days t o ensure all the silver chloride being converted into the brown salt. The mother liquor was then poured off saturated with ammonium chloride and a further amount of silver nitrate added to the solution. A second crop of crystals resulted and these were heated and allowed t o cool as before. The formation of the salt in a hot solution gives rise to larger and better formed crystals than when the preparation is made in a cold .solution. The process was then again repeated four preparations in all being obtained before the gold became exhausted in the mother liquor. The crystals were freed from the mother liquor in a centrifuge and afterwards dried at looo.They were then placed in a Soxhlet thimble and extracted with ether (distilled from sodium) until no more gold was removed. They were afterwards heated a t 1 5 5 O in an air-oven for some taime and the remainin 102 THE ACTION OF AQUA REQIA ON GOLD-SILVER ALLOYS ETC. traces of ammonium chloride sublimed away. A second treat-ment with ether followed after which the crystals were dried and analysed. Found Ag = 15.58 ; Au= 37.99 ; NH4= 6.88 ; C1= 39-44. 3AgC1,4AuC1,,8NH4C1 requires Ag = 15 - 62 ; Au = 38.06 ; NH4 = 6-97 ; C1= 39.35 per cent. Crystallographic E'xamination. The crystallographic examination was made by Miss I. E. Knaggs in the Miiieralogical Laboratory of the University of Cambridge under the direction of Dr.A. Hutchinson for whose help and assistance the author wishes t o express his gratitude. Crystal System.-Orthorhombic. Class.-Holohedral. Axial Ratio.-a b c=0-5376 1 0-3210. Forms Observed.-B(Ol O) M( 1 10) e( 101). No. of measure - Mean Calcu-Angle. ments. Limits. observed. lated. mB =(010) (110) ...... 4 61'43'-61'45' mm//'=(ii~) (iio) ...... 7 56'28'-56"35' me =(110) (101) ...... 5 63'10'-G3' 11' ee' =(101) ( i o l ) ...... 3 61'39'-6 1'45' 61 '44' 61 '44' 56'32' -61'42' 61"41' 63OlOi' -d a b i t .-The crystals available for measurement consisted of minute prisms sometimes modified by the brachypinakoid (OlO), and terminated a t either end by the macrodome (101). Some of the preparations consisted of larger crystals showing (110) an INTRAMOLECULAR REARRANGEMENT OF ALKYLARYLAMINES.103 (010) in approximately equal development. and were not suited for accurate measurement,. These had rough ends Cleavage .-None observed. Optical Characters.-The crystals were very dark red by reflected light and owing to their intense absorption it was difficult to make determinations of their optical characters. Some of the smallest and thinnest prisms when mounted so that light traversed them along the P axis we're found to be strongly pleochroic, absorption being almost complete for rays vibrating parallel to the axis of 2 whilst red light was t8ransmitted fairly freely by vibrations paralled to the axis of X. When the crystal was rotated so that light traversed it along the X axis strong absorption was observed of the ray vibrating parallel to P as well as of that vibrating parallel to 2. No characteristic interference figure could be observed in convergent light nor was it possible to determine the refractive indices either by the prism methods or by total reiflection. By the immersion method they were found 'to be high -greater than 1.74. GOVERNMENT LAB ORATORY, CAIRO. [Received October 17M 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700099

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

INTRAMOLECULAR REARRANGEMENT OF ALKYLARYLAMINES. 103 XV.-Intramolecular Rearrangement of the Alkyl-arylamines Formation of 4-Amino-n-but;ylbenxene. By JOSEPH REILLY and WILFRED JOHN HICKINBOTTOM. AN important reaction of many of the N-substitution products of the arylamines is their rearrangement to C-substitution compounds. This change occurs with the majority of the common substituent groups such as halogen nitro- nitroso- sulphonyl and alkyl. The intramolecular change of the chloroarylamines may be explained in terms of the variable valency of the nitrogen atom (compare Blanksma Rec truv. chim. 1903 22 290; Orton and Jones Rep. Brit. Assoc. 1910). The formation of pchloroacetanilide from X-chloroacetanilide is accompanied by the formation of an additive compound (compare Armstrong T.1900 77 1051). The presence of a catalyst is necessary in many molecular changes involving the migration of a nitroso- or nitro-group as in the production of p-nitrosoalkylanilines from nitrosoarnines and of nitroanilines from nitroamines. Whilst the bromo- and chloro-aniline derivatives have been thoroughly investigated as well as the nitroso- and sulphony 104 REILLY AND HICHINBOTTOM INTRAMOLECULAR substituted alkylanilines the intramolecular change of the alkyl-arylamines has not been dealt with in such detail. The earlier work in the production of aminoalkylbenzenes showed that they could lje formed either by heating ( a ) aniline hydro-chloride and the alcohol or ( b ) the alkylaniline hydrochloride a t temperatures above 300° (compare Hofmann Ber.1872 5 729). Since methylaniline hydrochloride on heating in a current of hydro-gen chloride yields methyl chloride it has been generally assumed that a somewhat similar reaction would occur in an autoclave or sealed tube on heating the alkylaniline hydrochloride. On heating n-butylaniline hydrochloride in a sealed tube amino-n-butylbenzene was the n?ain product. I n addition ammonia, aniline and 4 -butylamino-rhbutylbenzene were formed together with smaller amounts of more highly butylated products. There was also obtained a portion soluble in concentrated hydrochloric acid and precipitated on dilution which probably contained di-phenylamine derivatives. I n addition to the hydrochloride the alkylaniline zincichloride and certain other compounds with metallic salts also undergo this transformation on heating.The chief product resulting from the intramolecular rearrangement of n-butyl-aniline is however 4-amino-*butylbenzene. To explain the f orma-tion of this compound from n-butylaniline it might be supposed that the latter decomposes partly to aniline and n-butyl chloride or butylene; either of the last two might then be supposed to react with aniline. The production of n-butyl chloride is probably excluded in the case where zinc chloride replaces the hydrochloric acid. By heating n-butylaniline hydrochloride in a sealed tube or in an open flask a small amount of a gas is obtained which resembles butylene in being unsaturated. It appears possible that butylene may result as an intermediate product in the change.By heating n-butylaniline hydrochloride under atmospheric pressure a certain amount I of 4-aminobutylbenzene~ is produced. I f butylene is formed as an intermediate product some sec.-butylbenzene should be obtained. An examination of the end-products shows that amino-sec.-butylbenzene is present generally at t7he most, only in traces. The orientation of aminobutylbenzene (I) obtained by t-hei intra-molecular rearrangement of n-butylaniline was determined by con-Js H Br Br /\ \/ " I 1 -+ I ! + 1 1 /\ \/' \/ UO,H C ' A C4H9 (111. REARRANGEMENT OF THE ALKYLARYLA4MINES. 105 verting the purified aniino-derivative into bromobutylbenzene (11), which on oxidation with chromic acid gave p-bromobenzoic acid It cannot be assumed with certainty that 1%-butyl alcohol and aniline zincichloride will yield a compound containing a 12-butyl group.An examination of the literature shows that a rearrange-ment of the alkyl group often occurs when it is introduced into the benzene ring. The rearrangement of the n-butyl chloride and isobutyl chloride in the f orination of butylbenzenes by the Friedel and Crafts reaction is well established. The rearrangement of alkyl groups in the formatioii of aminoalkylbenzenes also appears to take place. Effront (Bey. 1584 17 2324) by the action of isobutyl alcohol on o-toluidine hydrochloride obtained 5-t ert .-butyl-o-tolu-idine which by the diazo-reaction yielded a phenol identical with that obtained by heating tert.-butyl chloride o-cresol and zinc chloride (compare Baur Ber.1894 27 1615). It is also probable that by the action of isobutyl alcohol on aniline hydrochloride amino-tert.-butylbenzene is obtained. The recorded physical con. stants of the derivatives of 4-aminoisobutylbenzene and 4-amino-tert.-butylbenzene are practically identical and doubt must be thrown on their existence as two compounds (compare Studer, Anmalelt 1882 211 234; Senkowski Ber. 1890 23 2412; Mal-herbe Ber. 1919 52 [B] 319). It became necessary therefore to determine the configuration of the butyl group of the primary amine from n-butyl alcohol and aniline. By heating aniline zincichloride with aec.-butyl alcohol an amine was obtained boiling a t 240° or ZOO lower than that obtained from the normal alcohol and yielding a different series of derivatives.As there was only a small quantity of this amine available it. was not possible to determine the orientation of the butyl groups. Any doizbt that the primary amine from rrt-butyl alcohol boiling a t 258O was not a normal derivative was removed by preparing from it the other two monoamino-compounds. A com-paiison of the derivatives of the amines thus prepared shows that the amine from sec.-butyl alcohol differs from the one from n-butyl alcohol in the configuration of the butyl group. By the nitration of 4-acet?/lamino-n-bzctylbe~~zene followed by hydrolysis 3-mit~o-4-nntirzo-n-bz~tylbenzene (IV) was obtained as a red solid of low melting point. The orientation of the nitro-group was determined by converting the compound into a diamine which condensed with b e n d t o yield 2 3-diphen,yl-6-n-b.utyl~uinoxaline (XVIII).On eliminating the amino-group from 3-nitro-4-amino-butylbenzene 3-nitro-n-bzctylhenzene (V) was obtained as a pale yellow oil boiling at 275-277O. (111). VOL. CXVII. 106 REILLY AND HICKINBOTTOM INTRAMOLECULAR (VIII.) (XVIII.) Nitration of 4-amino-n-butylbenzeiie in the presence of sulphuric acid gave 2-nitr0-4-amino-n-butylbelzlzelze (VII) melting a t 52", which by the diazo-reaction yielded 2-nitro-n- butylbenzene (VIII) a yellow oil distilling with some decomposition. Reduction of 2-ni tro-and 3-nitro-rr-butylbenzenes gave primary aniines the derivatives of which are distinct from those obtained from the primary aniine boiling a t 240° from sec.-butyl alcohol. It must be concluded, therefore that in the intramolecular transformation of wbutyl-aniline 4-amiiio-n-butylbenzene is obtained.The following table shows clearly the difference between the amines obtained : Acetyl compound Benzoyl compound, m. p. m. p. 2-Amino-n-butylbenzene . . . . . . 100" -3-Amino-n-butylbenzene . . . . . . Not obtained 68" 4-Amino-wbutylbenzene . . . . . . 105" 126" crystalline. 4-Amino-sec.-butylbenzene . . . 126' -Although n-butyl alcohol reacts with aniline zincichloride to yield 4-amino-n-butylbenzene it gives with phenol in the presence of zinc chloride hydroxy-sec.-butylbeiizeiie. The constitution of the latter coinpound was shown by its identity with the hydroxy-deriv-ative obtained from 4-ainino-sec.-butylbenzene (XI) by the aid of the diazo-reaction.NH*CHMeEt NHo OH OH /\ & /\ /\ \/ \/ () --+ I) -+ I I t- I 1+CH2EteCH2*OH CHMeEt CHMeEt REARRANGEMENT OF THE ALKYLARYLAMINES. 107 It has been shown by Mailhe and Godon (Compt. rend. 1918, J66 467) that methylaniline and methyltoluidine are stable a t moderately high temperatures as they may be produced by passing a mixture of niethyl alcohol and the primary arylamine over a suitable catalyst heated to 400O. No intramolecular rearrangement is observed when methyl- or ethyl-aniline is passed over heated nickel; instead a decomposition into aniline and methane or ethylene occurs (Sabatier and Gaudion C'onzpt. end. 1917 165, 309). It has been found that wbutylaniline may be heated for several hours a t 240-260° without the production of any amino-butylbenzene.Furthermore the addition of substances which show no tendency to conibine with butylaniline such as calcium sulphate sodium chloride or silica does not bring about any migra-tion of the alkyl group to the nucleus. The formation of 4-amino-7b-butylbenzene from n-butylaiiiline has been observed to take place only when a substance is added which combines with butylaniline. Substances such as hydrochloric acid zinc chloride cobalt chloride, and cadmium chloride have been chiefly employed and with all these salts the additive compounds have been isolated. It appears that for intramolecular rearrangement of the alkylarylamines to occur the presence of a substance which is capable of uniting with the amino-group is necessary. The rearrangement of wbutylaniline cannot be satisfactorily explained by assuming the intermediate formation of either butyl chloride or butylene.Orton (Zoc. cit.) has suggested that amino-benzenes and their M-substituted derivatives are capable of existing as dynamic isomerides. It is possible that the transference of the alkyl group to the nucleus might occur during one of these phases. To attempt to explain the int'ramolecular rearrangeinent of alkyl-arylamines the alkyl groups attached to the aminic nitrogen are assumed tentatively to exist in a state of oscillation following a system of vibration which is definite as long as the external condi-tions remain constant. The calling into play of the residual valency of the nitrogen atom will have the effect of introducing more groups round the nitrogen atom with the result that a rearrangement of the alkyl groups may occur.The disturbing effect will depend on several factors such as the space occupied by each group its vibra-tion path and also the polarity of the group. The groups already attached to the nitrogen will have the effect of hindering the entry of another group corresponding with the space occupied by them. They will also tend to be displaced farther away from the nitrogen atom according to the hindrance produced by them and there will be a tendency for the alkyl groups to be removed in the order of their steric relations to one another. s 108 REILLY AND €IICI<INBOTTOM INTRAMOLECULAR Experiments were carried out in order to measure the relative ease with which differing alkyl groups were expelled from the alkyl-anilines.The earlier measurements were made by heating the monomethyl- and nionobutyl-anilines separately in sealed tubes under similar conditions so far as possible with various substances. The results indicate that n-butylaniline undergoes intramolecular change the more readily but the method is open to several objec-tions. It was impossible to ensure absolutely identical conditions for each substance such as the same temperature and pressure inside each tube. It is also likely that in the formation of the additive compounds of the alkylanilines steric effects may have an influence so that the rearrangement caused in the molecule may be counterbalanced to some extent by the steric hindrance due to the alkyl group.To overcome these probable sources of error the intra-molecular rearrangement of dissimilarly substituted tertiary alkyl-anilines has been investigated. Methyl-n-butylaniline (XIII) was heated in a sealed tube in the presence of hydrogen chloride zinc chloride or cobalt chloride. The products of the rearrangement should then indicate whether the larger alkyl groups are the more readily removed. Thus methyl-n-butylaniliiie should yield as a first step methylaminobutylbenzene (XVI) or butyltoluidine (XIV), according to whether the butyl or the methyl group is the more mobile. / (XIII). (XIV.) (XVI.) (XVII. ) The constitution of the product was determined by dissolving the mixture of amines in dilute hydrochloric acid and adding in slight excess a solution of sodium nitrite.The secondary aniines were removed as nitrosoamines which could be converted into solid nitro-derivatives. Any diazoiiium salt in the soIution was con-verted into the corresponding azo-@-naphthol derivative whic REARRANUEMENT OF THE ALKYLARYLAMINES. 109 would serve to identify the primary amine originally present. An examination of the products of nitration of the secondary amines resulting from the intramolecular rearrangement of methyl-n-butyl-aniline indicated that a mixture was present from which 3:5-di-nitro-n-butyl-p-toluidiiie and 2 4 6-trinitrophenylmethylnitroamine were isolated in small quantities. It has not yet been possible to determine the complete composition of the mixture. The azo-S-nnpht h 01 compounds were reduced yielding the original primary amines present after intramolecular change had taken place.Analytical results showed that these aniines were amino-methylbutylbenzenes although in one case p-tolueneazo-/3-naphthol was isolated in small amount by recryst,allisation of the azo-P-naph-thols. It appears therefore that in the reaction both the methyl and butyl groups have undergone intraniolecular rearrangement, and until a method has been elaborated f o r determining the composition of the products it is not possible tol determine, accurately the rellative ease with which the different alkyl groups are removed. The elimination of alkyl groups of alkylanilines on heating in a current of hydrogen chloride was also investigated. The secondary amines present in the mixture were isolated as nitrosoamines and these were nitrated in glacial acetic acid by means of fuming nitric acid and converted int'o the corresponding trinitrophenylalkylnitro-amines.It was found that methyl-n-butylaniline yielded a mixture of secondary amines and 2 4 6-trinitrophenylmethylnitroamine was isolated from the mixture of nitroamines. The melting point of the nitration product was lower than either that of trinitro-phenylmethylnitroamine or the corresponding butyl derivative and was probably a mixture containing these two compounds. I n experiments on the elimination of alkyl groups from dissimi-larly substituted alkylarylamines it is essential to use a pure tertiary amine unmixed with any secondary amine. The methyl-n-butyl-aniline employed was purified by fractionation followed by heating it with phenylcarbiniide.The boiling point of the amine obtained iii this way differed considerably from that recorded by Komatsu (iyem. Coll. ScZ. rand Eny. Xzyoto Imp. Univ. 1912 3 371) who also prepared this amine. EIe records the boiling point as 225-230°, and states that it yields a picrate melting a t 143O. Methyl-n-butyl-aniline purified in the manner indicated above boils at 242-5O and yields a picrate melting at 90°. The melting point of the picrate is thus brought into agreement with those of other tertiary butyl-anilines. By increasing the size of the alkyl group in alkylbutylanilines the melting point of the picrate is raised. The following table show 110 REILLY AND HICKINBOTTOM INTRAMOLECULAR the effect of displacing the methyl group in methylbutylaniline by larger groups.Methyl-rt-butylaniline boils a t 242*5G. The picrate melts at 90'. Ethyl+t-bubylaniline , 248O. 9 7 7 , looo. Di-n-butylaniline , 260-263'. 7 7 7 , 1 2 5 O . The nitration of tertiary alkylanilines was also studied. On nitrating methylbutplnniline under vigorous conditions the princi-pal product is 3 4 6-trinitrophenylmethylnitroamine showing that the larger group has been eliminated. Meldola and Hollely (T., 1915 107 610) have found that in the nitration of acetplated as-dialkylpLenylenediamines a similar action occurs the larger groups being removed in the nitration in preference to the smaller groups. On nitrating ethyl-n-butylaniline both trinitrophenylethylnitro-amine and trinitrophenyl-n-butylnitraamine are produced.The difference in the relative proportions of the two products of the nitration appears to be less than in the case of methyl-n-butyl-aniline. Trinitrophenylmethylnitroaniine is also obtained on nitrating climethylaniline under vigorous conditions. Toward the end of the operation there is the usual vigorous effervescence due to the elimina-tion of the methyl group as carbon dioxide. I n nitrating di-n-bu tylaniliiie under similar conditions there is practically no eff er-vescence and from the mixture after nitration a volatile fatty acid was isolated which was identified as n-butyric acid by means of its distillation constant. E x P E R I M E N T A L . The Amino-derivative of n-BTctylbenzene 4-A mino-n-hiGt?yl-6 enzene.In the preparation of 4-amino-n-butylbenzene n-butyl alcohol was allowed to react with aniline in the presence of a suitable conden-sing agent such as zinc chloride. Approximately molecular quanti-ties of aniline and dry rt-butyl alcohol were mixed with fused zinc chloride (0-5 mol.) and the mixture was heated in an electrically wound autoclave for twenty-four hours a t 230-240O. The product was washed first with water to remove uncombined zinc chloride and firally with ether or light petroleum (b. p. 80-100°). I n this way secondary amines and other by-products were removed leaving behind the zincichlorides of the primary amines from which a mixture of these amino-compounds was obtained by treatment with warm concentrated sodium hydroxide solution.Fractionation of the mixtiire of bases yielded 4-amino-n-bntylbenzene. By usin REARRANGEMENT OF THE ALKYLARYLAMINES. 111 amounts of zinc chloride less than the molecular proportion-even as low as one-seventh of the amount quoted above-4-amino-n-butyl-benzene was still produced but the yield was not so good. The Aydrochloride is precipitated on adding an excess of concen-trated hydrochloric acid t o an aqueous suspension of the base. It is readily soluble in water or alcohol7 but only sparingly so in an excess of hydrochloric acid : 0.1063 gave 6.9 C.C. N at 21° and 751 mm. N = 7.5." 0.1420 , 0.1093 AgCl. C1=19.0. The hydro bromide crystallises from aqueous solution containing It is readily soluble Cl,H1,N,HC1 requires N = 7.5 ; C1= 19.1 per cent.free hydrobromic acid in large white plates. in water or alcohol: 0.0'785 gave 0.0654 AgBr. Br=34*6. The sulphate crystallises from moist ether in a felted mass of 0.1002 gave 6.1 C.C. N a t 20° and 737 mm. 0.3502 ? ? 0.2058 BaSO,. H,SO = 24.7. (C,oH,,N)2,H2S04 requires N = 7-1 ; H,S04 = 24.7 per cent,. From warm alcohol i t separated as a mass of colourless crystals which under the microscope had the appearance of interlaced laths. The plntinichloride is .a pale brownish-yellow powder sparingly soluble in water and more readily so in alcohol. It crystallises from absolute methyl alcohol in small needles melting and decomposing at 200-202° : C,oH,,N,€IBr requires Br = 34.7 per cent. white crystals. It is sparingly soluble in water : N = 6.9.0.1203 gave 0.0330 Pt. Pt=27.4. (C,,H,,N),,H2PtC1 requires Pt = 27.6 per cent. The acetyl derivative obtained from 4-amino+-butylbenzene by the action of acetic anhydride crystallises from alcohol in white plates melting at 105O: 0.1426 gave 8.8 C.C. N a t 1 7 O and 755 mm. C1,Kl70N requires N=7-3 per cent. The benzoyl derivative obtained by the Schotten-Baumann reac-tion crystallises from alcohol in bulky groups of fine needles melting at 126O: N=7*3. 0.1015 gave 4.65 C.C. N a t 17O and 748 mm. N=5*3. CliH1,ON requires N=5*5 per cent. * In the nitrogen estimations recorded in this paper the gas was measured over 40 per cent. potassium hydroxide solution and the pressure hae been corrected for vapotir tension 112 REILLY AND HICKINBOTTOM INTRAMOLECULAR a-Phey l-b-4-n- but~Z~henylcarba?nide C,H,*C,H,*NH-CO *NHP h.4-Amino-n-butylbenzene was treated with a solution of one mole-cular proportion of phenylcarbimide dissolved in light petroleum (b. p. 6’0-80°) and after remaining a t the ordinary temperature for two or three hours the precipitate was collected washed several times with small quantities of light petroleum and dried : 0.1002 gave 0.2790 CO and 0.0678 H,O. 0.1012 )) 9.1 C.C. N a t 20° and 757 mm. N=lO.5. C,,H,,ON requires C = 76.1 ; H= 7.5 ; N = 10.4 per cent. It orystallises from aqueous alcohol in bulky masses of small, white needles melting a t 160O. It is soluble in ether acetone, ethyl acetate or glacial acetic acid but sparingly so in water or light petroleum. 4-Bromo-n-buty Zbenzene.The orientation of the butyl group was determined by converting the amino-n-butylbenzene into a derivative that could yield a sub-stituted benzoic acid by oxidation. For this purpose the amino-group was displaced by bromine by the Sandmeyer reaction. 4-Amino-n-butylbenzene was dissolved in three molecular propor-tions of hydrobromic acid and diazotised by the addition of sodium nitrite solution. On adding a solution of cuprous bromide in hydro-bromic acid followed by distillation in a current of steam 4-brorno-n-butylbenzene was obtained as a pale yellow oil of pleasant ethereal odour denser than water and boiling at 242-243O/755 mm. : C=56.4; H=6.0. C=75*9; H=7.5. 0.0853 gave 0,1762 CO and 0.0460 H,O. That the bromo- and alkyl groups are in the para-position follows from the production of p-bromobenzoic acid by oxidation.Half a gram was heated in a sealed tube with 12 C.C. of a 6 per cent. solu-tion of chromic acid for seven hours a t 150-200°. There was practically no pressure on opening the tube which contained a green amorphous mass together with tarry matter and some white, glistening needle-shaped crystals. The contents of the tube were rendered alkaline and after removing the suspended matter a grey solid was precipitated on adding dilute sulphuric acid. It was puri-fied by dissolving in sodium carbonate solution and any traces of volatile bromo-compounds were removed by means o€ a current of steam. The addition of dilute hydrochloric acid precipitated a white solid which crystallised from ether in small needles melting a t 250O.This melting point is almost identical with that recorded for p-bromobenzoic acid (25l0) and is considerably higher than those of the other two monobromohnzoic acids. CloRl3Br requires C = 56.3 ; H = 6-1 per cent REARRANGEMENT OF THE ALKYLARYLAMINES. 113 Diazoamino-4-n-butyl b enzene. The base (I iaol.) was dissolved in glacial acetic acid (3 mols.) and the solution diluted. On adding sodium nitrite solution a yellow semi-solid mass separated which quickly became hard. The diazoamino-4-n- butylbenzene was collected and after washing several times with water to remove any traces of nitrous acid, crystallised from light petroleum from which it separated in masses of slender sulphur-yellow needles melting at 75O : 0.0743 gave 9.0 C.G.N a t 24O and 742.5 mm. When exposed to the light it darkened slowly. N=13*7. C2,H2,N requires N = 13.6 per cent. 4-n-Bzctyl b enzeneazo-&naphthol. A solution of the hydrochloride oE the base was diazotised and, after removing the excess of nitrous acid by means of carbamide it was poured into an alkaline solution of &naphthol. The red azo-compound crystallised from hot alcohol in bright red bunches of slender needles melting a t 80°: 0.1088 gave 9.8 C.C. N a t 15'3O and 741 mm. 4-n-Butylbenzeneazo-&naphthol is insoluble in a 30 per cent. solution of potassium hydroxide. It dissolves in concentrated sul-phuric acid with the production of a brilliant purple colour which gives place to a faint brown coloration on dilution. N=9*4.C2,H2,0N requires N = 9.2 per cent. 4-n-Butylbenzeneazoph enyl-fi-n*aph thylamine. This derivative was prepared by adding a diazotised solution of 4-aminw-butylbenzene freed from excess of nitrous acid to one molecular proportion of phenyl-f3-naphthylamine dissolved in acetic acid. An excess of so,dium acetate was then added and the red product was allowed to remain a t the ordinary temperature for two to three hours with occasional stirring. Water was added to com-plete the precipitation of the azo-compound which was collected and purified after being washed with warm water: C2,H,,N requires N = 11.1 per cent. I n the presence of a small amount of ether the azo-compound dissolves in concentrated hydrochloric acid to yield an intense purplish-blue solution.After some time the colour disappears with the produc-tion of a dark precipitate which becomes red after keeping for a 0-1080 gave 10.2 C.C. N at 1 7 O and 750 mm. It is readily soluble in chloroform benzene or ether. N-11.1. F 114 REILLY AND HICKINBOTTOM INTRAMOLECULAR further period. Concentrated sulphuric acid dissolves it with the production of an intense dark blue coloration becoming red on dilution. 4-n-Butyl benzeneazob enzoylacetone. A diazotised solution of 4-amino-n-butylbenzene (1 mol.) freed from nitrous acid by means of carbamide was added to an alcoholic solution of benzoylacetone (1 mol.). The addition of sodium acetate produced a bright yellow turbidity from which a dark-coloured oil separated. On keeping overnight in the ice-chest the oil solidified to a mass of dark yellow crystals which were colleoted dried on a porous plate and recryst allised.The compound separated from ether in stellate groups of yellow crystals melting a t 97-looo: 0.1588 gave 12.2 C.C. N a t 18O and 747 mm. C,,H,O,N requires N = 8.7 per cent. The substance is soluble in alcohol or ether and dissolves in sul-phuric acid with the production of a brown colour giving place to a yellow opalescence on dilution. Sulphuric acid containing a small amount of dissolved chromic acid also produces a similar coloration. N=8.9. 4-n-Bzcty l b enz eneaz o- 2 7-di Jzy droxy naph t h d e n e. This compound was obtained as a dark red powder on adding a solution of the diazotised aniine to an alcoholic solution of 2 7-di-hydroxynaphthalene in the presence of an excess of sodium acetate.It was purified by washing with a dilute aqueous solution of sodium hydroxide followed by extraction with chloroform. It crystalliseci horn hot glacial acetic acid in small bronze-coloured crystals melt-ing a t 2OO-20lo: 0-1588 gave 12.2 C.C. N2 a t 18O and 747 mm. N=8.9. C2,H2,,02N2 requires N = 8.7 per cent. 4-H y dr o x y -n - b u t y 1 b e n z en e . 4-Amino-12-butlylbenzene (9 grams) was added to an aqueous solu-tion containing sulphuric acid in excess (five molecular proportions), and after cooling diazotised by the additiou of sodium nitrite. The mixture was stirred continuously when the suspended sulphate gradually passed into solution. The solution was filtered to remove any unchanged sulphate treated with a large excess of concentrated sulphuric acid and subsequently distilled in a current of steam.4-Hydroxy-n-b2~tylbenzene passed over as a pale yellow oil and wa REARRANGEiUENT OF THE ALKYLARYLAMINES. 115 obtained pure by distillation. ing a faint phenolic odour and boiling at 248O/765 mm.: It is an almost colourless oil possess-0.0818 gave 0.2387 CO and 0.0686 H,O. C=79*6; H=9*3. C1,H140 requires C = 79.95 ; H = 9.4 per cent. 4-a-Butylphenyl Ph enylcnrbnmat e C,H,*C,H4*O* CO*NHPh. 4-Hydroxy-n-butylbenzene was heated on the water-bath with slightly more than one molecular proportion of phenylcarbimide. On cooling the solid mass was passed on a porous tile and crystal-lised from alcohol from which it separated in white needles melting a t 1 1 5 O : 0.1059 gave 4.7 C.C.N a t 20° and 744 mm. N-5.0. C17H1902N requires N = 5.2 per cent. 2-2Vit ro-4-amino-n- b zc t y l b e i t z e ne .'K 4-Amino-n-butylbenzene was dissolved in two hundred times its weight of concentrated sulphuric acid and after cooling to - 5 O , the calculated amount of nitric acid (1 mol.) dissolved in three times its weight of sulphuric acid was added gradually. During the addition of the acid the mixture was continually stirred and the temperature not allowed to rise above 5O. After eighteen hours the mixture was poured into ice-water when a sparingly soluble sizlphate was precipitated which was collected and decomposed by the addition of aqueous ammonia. I n this way a brown crystal-line solid was obtained consisting of 2-nitro-4-anzi~~o-n-butylbenzerte.A further quantity was isolated by treating the acid filtrate with aqueous ammonia and extracting the solution witb ether. It was ohtained pure by dissolving it in aqueous methyl alcohol and pre-cipitating with water followed by recrystallisation from warm light petroleum (b. p. 80-1130°). It forms golden-yellow scales, readily soluble in ether and melting a t 5 2 O : 0.0739 gave 9.3 C.C. N a t 17'5O and 735 mm. N=14*5. No evidence was obtained of the existence of the other isomeride. The hydrochloride was obtained as a white precipitate by adding hydrochloric acid to an ethereal solution of the base and evaporat-* The nitration of n-butyl-p-toluidine has been previously described as yielding 2-nitro-n-butyl-p-toluidine as a red oil (T.1918 113 988). On keeping over the winter it solidified t o a mass of bright red crystals melting at 18-19'. By converting the substance into its hydrochloride crystallising from alcohol and decomposing with aqueous ammonia 2-nitro-n-butyl-p-toluidine was obtained in large rectangular red plates which melted at 19". C,,H,,O,N requires N = 14.4 per cent. F* 116 REILLY AND HICKINBOTTOM INTRAMOLECULAR ing the ether. It crystallises from warm absolute methyl alcohol in ma.sses of slender colourless needles. On heating the colour changes to yellow. A specimen melted at 190-195O after immer-sion in the bath at 150° a rapid darkening in colour taking place a t 185-190°: 0.1017 gave 0.0638 AgCl. C1=15*5. CloH1402N,,HCl requires C1= 15.4 per cent.The sulphate is sparingly soluble in dilute sulphuric acid. It crystallises from warm alcohol containing some sulphuric acid in small white plates which are hydrolysed by water : 0.0811 gave 6-35 C.C. N a t 13'2O and 761 mm. N=9*4. Cl,Hl,0,N2,H,S0 requires N = 9.6 per cent. 2 -ATi t r o-n-b u t y l b e n x e n e . 2-Nitro-4-amiiiobutylbenzene (2.5 grams) was diazotised in aqueous alcoholic solution in the presence of sulphuric acid a small amount of insoluble matter was removed and the diazo-group was eliminated by heating with an excess of alcohol when 2-nitro-n-bu.tyZbenzene was obtained. It is a pale yellow oil possessing a characteristically pleasant odour. It is readily volatile in steam, and apparently so in alcohol vapour for on removing the alcohol by distillation after eliminating the diazo-group appreciable amounts of the nitro-compound were obtained in the alcoholic distillate.It distils with some decomposition a t about 260° under the ordinary pressure : 0.0814 gave 5.4 C.C. N a t 20° and 746 mm. N=7.6. C,,H,,O,N requires N = 7.8 per cent. 2-A nzino-n- b u t y l b e m ene. Reduction of the nitro-compound was effected by means of zinc dust or tin foil and hydrochloric acid. The amine was isolated by extraction with ether after rendering the acid liquid alkaline. 2-Amino-n-butylbenxene is a yellow oil possessing a rather un-pleasant odour recalling that of aniline : 0-0746 gave 5.9 C.C. N a t 16O and 750 mm. The acetyl derivative crystallises from warm aqueous methyl 0.0819 gave 5.5 C.C.N a t 20.5O and 749 mm. The melting point of thk compound is very close to that of N=9-3. C,,H,,N requires N = 9.4 per cent. alcohol in masses of small white needles melting a t 1000: N=7*7. Cl,H,,ON requires N=7.3 per cent RBARRANGEMENT OF THE ALKYLARYLAMINES. 117 4-acetylamino-n-butylbenzene. It; was shown to be distinct from that substance for a mixture of these acetyl derivatives commenced to melt at 7 5 O and had completely melted a t 8 5 O . 3-Nitro-4-amino-n-bz~tplbenzene. The most convenient method of obtaining this compound in a pure state was to nitrate 4-acetlplamino-n-butylbenzene by means of fuming nitric acid afterwards eliminating the acetyl group. 3-Nitro-4-acetylanaino - n - butglberuene.-The acetyl compound (2 grams) was dissolved in 20 C.C.of glacial acetic acid the solution cooled t o - 5 O and 15 grams of nitric acid (D 1.5) were added slowly so that the temperature did not rise above 5O. After an hour the mixture was poured into ice-water and the yellow precipi-tate collected. The nitro-compound is soluble in most of the common organic solvents except light petroleum and crgstallises very readily from hot alcohol in slender canary-yellow needles melting a t 7 6 O : 0.0649 gave 6.8 C.C. N a t 20° and 746.6 mm. N=12.0. Titration with Tifanous Chloride.-O*01522 required 16.6 C.C. TiCI (1 C.C. =0*001297 gram Fe). Calc. as C,,H,,O,N,= 100.4 per cent. On triturating it in a mortar with a 50 per cent. solution of potassium hydroxide the colour changed from pale yellow to deep brown.After remaining for some time there was still a considerable amount of the unchanged acetyl derivative together with some 3-nitr0-4-amino-n-butylbenzeize. The latter compound was obtained more conveniently by hydrolysis with alcoholic hydrogen chloride. To the nitroacetyl compound dissolved in ten times its weight of alcohol an amount of hydrochloric acid insufficient to precipitate the nitro-compound was added and the mixture was heated under reflux until on pouring into dilute hydrochloric acid no precipitate was obtained. On evaporation 3-nitro-4-amino-n-butylbenzene was left as a reddish-brown oil which solidified in the ice-chest to a mass of reddish-yellow needles melting a t about 1 3 O . The substance was purified by converting it into the hydrochloride and decomposing this with water or dilute ammonia: C,,H,,03N requires N = 11.9 per cent.0.0880 gave 11-0 C.C. N a t 1 8 * 5 O and 745 mm. N=14*4. Titration with Titanozts Chlor~de.-0*01038 required 13.3 C.C. Calc. as C,,H,,O,N,=100.8 per The hydrochloride crystallises from a mixture of alcohol and ether C,H,,O,N requires N = 14.4 per cent. TiCl (1 C.C. =0*001344 gram Fe). cent. in flat shining plates. It is readily hydrolysed by water 1 18 REILLY AND HICKINBOTTOM INTRAMOLECULAR Reduction of the base by adding zinc dust to a warm solution in hydrochloric acid gave 4-n-butyl-o-phenylenediumine as a viscous oil which is very readily oxidised on exposure to the air. On this account i t was not isolated in a pure state for analysis and the condensation product.with benzil was prepared from its solution. 3-Nitro-4-aniino-?z-butylbenzene (1.4 grams) was dissolved in an excess of 50 per cent. aqueous acetic acid and after raising the solution to the boiling point small quantities of zinc dust were added until the reduction was complete. Benzil (1.5 grams) dissolved in warm sodium hydrogen sulphite solution was added and the mix-ture boiled for five minutes. A reddish-brown oil was produced, which on cooling settled to the bottom of the flask as a semi-solid mass. It was collected and after pressing on a porous tile crystal-lised from hot methyl alcohol. Pale yellow flocculent masses of small crystals were obtained on rapid cooling and small pale yellow needles nielting at 8 2 O by slow cooling. By spontaneous evapora-tion of an elthereal solution large well-defiiie'd groups of needlet-shaped crystals separated : 0.0988 gave 6.8 C.C.N at 15-0° and 768 mm. N=8*3. 2 3-Diphsnyl-6-n-butyly?Lir~oxal.ine (XVIII) is readily soluble in chloroform. It dissolves in cold concentrated sulphuric acid with the production of an orange colour which on dilution gives place to a white turbidity. It is also soluble in a large excess of concen-trated hydrochloric acid giving a yellow solution. C,,H,,N requires N = 8.3 per cent. 3-Nitro-4-ami1~olz-butylbenzene was dissolved in hydrochloric acid (2.5 mols.) mixed with an equal volume of alcohol and the solution cooled to -5O. A slight excess of sodium nitrite solution was added and after about an hour some red resinous matter was filtered off and the filtrate heated with an excess of ethyl alcohol under reflux for two hours.The alcohol was evaporated on the water-bath and the volatile nitro-compound removed from the residue by distillation in a current of steam. 3-Nitro-n-bzit?/lbenzen~ was obtained as a yellow liquid having a pleasant odour : 0.0766 gave 5.4 C.C. N a t 20° and 747 mm. The compound distils a t 275O/752 mni. with no appreciable decomposition. It is apparently volatile to some extent in alcohol vapour for on removing the excess of alcohol from the product of the diazo-reaction some of it was obtained in the distillate. It is N=8*1. C,,H,30,N requires N = 7.8 per cent REARRANGEMENT OF THE ALKYLARYLAMINES. 119 miscible with chloroform nitrobenzene pyridine or light petroleum.3- A mino-n- butylb enzene. To the nitro-compound suspended in concentrated hydrochloric acid small pieces of tin foil were added from time to time until the reduction was complete. The tin in solution was removed as sul-phide and after rendering the liquid alkaline with sodium hydr-oxide solution the amine was removed by extraction with ether. It was further purified by distillation in a current of steam. 3-Aminro-n-btctylbenzene is it pale yellow oil lighter than water, and possesses a faint agreeable odour : 0.1454 gave 12-5 O.C. N a t 25O and 727 mm. C,,H,,N requires N = 9.4 per cent. The addition of an excess of warm concentrated hydrochloric acid yielded the hydrochloride as an oil which solidified on cooling to an interlaced mass of small flattened jagged needles.The acetyl compound was obtained as an oil which slowly hardened to a vitreous mass on keeping it in a desiccator : 0.0744 gave 4.9 C.C. N2 a t 2 5 O and 745 mm. C,,HI70N requires N= 7.3 per cent. The b en zoyl derivative prepared by the Schotten-Baumann reac-tion separates from alcohol in small white needle-shaped crystals, which melt a t 68O: N=9*6. N=7*4. 0.1610 gave 7-8 C.C. N at 17O and 748 mm. Nz5.7. C,,H190N requires N = 5.5 per cent. 4-L4mino-sec.-bzctylbenzene. To show that no intramolecular rearrangement of the butyl group had occurred when n-bu tyl alcohol and aniline zincichloride inter-acted the corresponding amine was prepared from see.-butyl alco-hol which was obtained from n-butyl alcohol through the inter-mediate formation of butylene.In the presence of sulphuric acid, butylene yielded see.-butyl alcohol which was obtained pure by repeated fractionation. It boiled at 99.6-99'9O. Aniline zincichloride was heated with one molecular proportion of see.-butyl alcohol in an autoclave a t 180° for sixty hours the product being treated in exactly the same way as described above when n-butyl alcohol was used. The mixture of primary amines from the zincichloride was fractionated and yielded among other distillates a fraction boiling between 230° and 250O. On redistil-ling this portion several times a primary amine was obtained boiling at 238O/762 mm. From the mixture of secondary amines solubl 120 REILLY AND HICKINBOTTOM INTRAMOLECULAR in light petroleum a primary amine was isolated by means of its sulphate boiling at 238O and identical with the amine obtained from the mixture of primary bases: 0.1909 gave 16.0 C.C.N a t 19'5O and 740 mm. C,,H,,N requires N = 9.4 per cent. 4-Amino-sec.-bzcty?/lTeelzzene on keeping slowly changes in colour from very pale yellow to dark red. The diazonium salt gives a red azo-compound with &naphthol in alkaline solution. With bleaching powder solution the amine gave no colosration. The addition Q€ a solution of chromic acid in concentrated sulphuric acid pro-duced a dirty green coloration changing through purple to wine-red on dilution. Nitric acid added in small amount to the sulphate of the amine suspended in concentrated sulphuric acid coloured the solid matter purple and the solution yellowish-brown.The hydrochloride is precipitated from aqueous solution on the addition of an excess of hydrochloric acid: 0.0987 gave 0.0750 AgC1. C1= 18.8. C,,H,,N,H@I requires C1= 19.1 per cent. The sulphate is sparingly soluble in cold water but more readily so in hot water from which it separates in masses of white crystals. The acetyl derivative crystallises from aqueous alcohol in lustrous, white plates melting a t 125-126O : 0.1540 gave 10.0 C.C. N a t 1 9 O and 744 mm. It is soluble in acet'one ether or ethyl acetate and sparingly so No coloration is obtained by the addition of a solution With fuming nitric acid in glacial acetic acid solution it yields a N=9*6. N=7*5. Cl,Hl70N requires N=7.3 per cent. in water. of chromic acid in concentrated sulphuric acid.yellow crystalline nitro-derivative. a-Ph eny I-P-4-sec.- b zctylphenylcarbamide, CHMeE t* C,H,-NH*CO*NHPh. This derivative is prepared by the addition of phenylcarbimide to It crystallises from aqueous alcohol in 4-amino-sec.-butylbenzene. silky needles melting a t 144O: 0.0730 gave 6.5 C.C. Ni a t 14O and 756 mm. It is soluble in ether acetone or toluene but only sparingly so in light petroleum (b. p. 60-80O). In addition to amino-sec .-butylbenzene other amines were obtained from the product of the action of heat on the mixture of set.-butyl alcohol and aniline eincichloride. At 270-28W a fraction N=10*6. C,,H,,ON requires N = 10.4 per cent REARRANGEMENT OF THE ALKYLARYLAMRQES 121 was obtained oonsisting mainly of a primary amine which on further purificatipn boiled mainly between 2 7 4 O and 278O.This consisted apparently of aminodi-see.-butylbenzene. A small quan-tity of a residue of a still higher boiling point was obtained but it was not further investigated. The fractions of lower boiling points contained a considerable amount of a secondary amine which was freed from the greater part of the primary amine by treatment with dilute sulphuric acid. I n this manner a fraction was obtained boil-ing a t 225-235O consisting chiefly of sec.-butylaniline which was obtained in a pure state by the action of sec.-butyl chloride on aniline. Aniline (1 mol.) was heated under a reflux condenser with sec.-butyl ch!oride (1.5 mols.); this contained a small amount of dissolved iodine and was added gradually over a period extending over twenty-four hours.The purplish-blue product was rendered alkaline and from the ethereal extract the sec.-bzctylaniline was precipitated as the zincichloride the base being purified by distilla-tion. It distilled a t 224-225O/765 mm. as an almost colourless oil which had a pleasant floral odour distinct from that of the corresponding n-butyl derivative : 0.0928 gav,e 0.2732 CO and 0.0866 H,O. C = 80.3 ; H= 10-4. 0.0835 , 6.7 C.C. N2 a t 14O and 756 mm. N=9-5. C,,H,,N requires C = 80.5 ; H = 10.1 ; N = 9.4 per cent. It is miscible with most of the common organic solvents. The addition of a solution of chromic acid in concentrated sulphuric acid led to the production of no characteristic coloration. On adding a small quantity of nitric acid t o a solution of the amine in concen-trated sulphuric acid a reddish-brown coloration was observed.The hydrochloride was obtained as a hard crystalline mass by saturating a benzene solution of sec. -butyIaniIine with dry hydrogen chloride : 0.1324 gave 0.1030 AgC1. C1=19-2. It cryst-allises from warm benzene in hard nodules which in bulk are grey. By the action of nitfrous acid on the solution of the hydrochloride phcnyI-sec.-butyliaitro.sonml;ne was obtained as a pale yellow oil, possessing an agreeable odour. It is volatile in steam: C,,H,,N,HCl requires C1= 19.1 per cent. It is very readily soluble in water. 0.0924 gave 12.6 C.C. N at 1 8 . 7 O and 753 mm. N=15.9. C,,H,,ON requires N = 15.7 per cent. p-se c . -Bzc t y 1 pheno I .On diazotising amino-see. -butylaniline sulphate and boiling the solution nitrogeln was evolved and tQhe liquid assumed a reddish 122 REILLY AND HICKINBOTTOM INTRAMOLECULAR brown colour due to t,he production of p-8ec.-butylphenol. It wag purified b)7 distillation in a current of steam followed by fractiona-tion. At 238O psec.-butylphenol passed over as a pale oil solidifying to a mass of long hair-like white needles melting a t 59O. The melting point was not altered after two crystallisatioils from light petroleum. (Estreicher Ber. 1900 33 436 gives in. p. 53-54'? b. p. 239.5-240.5O/750*6 mm.) The substance is very readily soluble in alcohol or ether and when treated with a dilute solution of chromic acid in concentrated sulphuric acid gives no character-istic coloration o t h k than the production of a transient red tint..Ferric chloride also gives no coloration. (Found C = 79.9 ; H = 9.9. C,,H,,O requires C=79.95; H=9*4 per cent.) It is miscible with most of the common organic solvents. This compound was also obtained probably in an impure state by the action of n-butyl alcohol on phenol. In this reaction a rearrangement of the alkyl group occurs. The boiling point of the phenol agrees with that of the substance prepared by the diazo-reaction. It was not however obt,ained crystalline nor were any crystalline derivatives prepared from it. It seems probable that p-sec.-butylphenol is not the only product of the interaction between n-butyl alcohol and phenol in the presence of zinc chloride.Phenol (100 grams) was heated with fused zinc chloride (240 grams) and n-butyl alcohol (80 grams) for twelve hours. On cool-ing the mixture had separated into two layers. The addition of wates dissolved the lower layer consisting mainly o'f zinc chloride, whilst the dark-coloured oil was removed. It consisted chiefly of p-sec.-butylpbenol together with some ethers which were removed by dissolving the phenol in sodium hydroxide solution. On distilla-tion the main fraction was collected between 235O and 245O as a colourless 6il of agreeable odour. Further fractionation gave a colourless viscous oil distilling a t 237-240O. On the addition of a diazotised solution of /3-naphthylamine to a solution of the phenol in dilutel potassium hydroxide solution a brown liquid was obtained from which a reddish-brown azo-corn-pound was isolated on rendering acid and extracting with solvents.It was not however obtained in a pure state. The acetyl derivative prepared by heating 5 grams of p-sec.-butyl-phenol with an excess of fused sodium acetate and 10 grams of acetic anhydride for three hours was obtained as a colourless oil boiling a t 244-246O/T60 mm (Estreicher Zoc. c i t . gives 255*5'/ 743.9 mm.) REARRANGEMENT OF THE ALKYLARYLAMINES. 123 The benzoyl derivative obtained by the Schotten-Baumann method is an almost colourless viscous oil: 0.0686 gave 0.2023 CO and 0.0430 H,O. By nitrating crude p-sec . -butylphenol with concentrated nitric acid mixtures of man@ and dinitro-derivatives were obtained. A better yield of t-he former was obtained by using dilute nitjric acid.p-sec.-Butylphenol (2.5 grams) was added to nitric acid (6 grams : D 1.5) and water (9 grams) the mixture being cooled in a stream of cold water. After sixteen hours the supernatant layer of acid was poured off and the residual oil distilled in a current of steam. Nitro-p-sec.-b?ctylphenol was obtained in this way as a red oil, which was purified by distillation under diminished pressure when it distilled a t 196-200°/80 mm.: C = 80.4; H = 7.0. CuH,,02 requires C=80*3; H=7*1 per cent. 0.1452 gave 9.0 C.C. N at 1 6 O and 741 mm. C,,H,30,N requires N = 7.2 per cent. The addition of aqueous ammonia precipitated the ammonium salt and solutions of sodium and potassium hydroxides precipitated the corresponding alkali salts.N=7*2. Reaction with F'henylcar bimide. By heating psec.-butylphenol prepared from n-butyl alcohol, a t looo with one molecular proportion of phenylcarbimide a viscous oil was obtained which was purified by extracting it several times with light petroleum. It was dried first a t SO" for a short time and finally over solid potassium hydroxide under diminished pressure. On cooling to Oo i t was obtained as a brittle solid which became viscous a t the ordinary temperature. Intramolecular Rearrangement of n-Butylan iline. The experimental details for the production of 4-amino-n-butyl-benzene have already been described (p. llO) and it has been mentioned that other substances are produced in the reaction. The primary amines which were separated by the use of zinc chloride were distilled.Aniline was obtained in the first fractions the amount being dependent on the experimental conditions. The prin-cipal fraction was 4-amino+~-butylbenzene but there was still a residue of amines boiling at above 270O; this on distillation proved to be a complex mixture from which a primary amine boiling a t 295-300° was isolated and was probably 4-amino-1 3-di-n- butyl-benzene 124 REILLY AND RICKINBOTTOM INTRAMOLECULAR 0*0900 gave 5.3 C.C. N a t ZOO and 737 mm. C,4H,,N requires N=6.8 per cent. It yields a sparingly soluble sulphate and after treatment with nitrous acid in the cold combines with alkaline &naphthol with the formation of an mo-compound. A fraction of still higher boiling point which also contains a primary arnine was not investigated, The ethereal washings of the zincichloride (p.110) obt'ained by the action of n-butyl alcohol on aniline zincichloride were shaken with dilute sodiuni hydroxids solution to remove a portion ( A ) con-taining phenolic substances and then several times with dilute hydrochloric acid to remove a portion (B) containing secondary and tertiary amines. There was finally obtained an ethereal solution containing for the most part substances which are soluble only in concentrated hydrochloric acid and are precipitated on dilution. These substances boil a t above 290° under the ordinary pressure, and their sulphuric solution in the presence of nitrous acid develops an intense bluish-black colour. The behaviour and properties of these substances suggest that they may be diphenylamine deriv-atives but they were not further investigated.The separated por-tions were examined as follows ( A ) The phenolic substances were isolated by acidifying the alkaline solution and extracting with ether. They appeared to be a mixture of phenol and butylphenol, for on distillation two definite fractions were obtained one a t about 200-210° and the principar fraction a t 240-245O. These phenols do not appear to be constant constituents of the products of the reaction being usually present a t the most in small amounts. ( B ) The amines on distillation gave a secondary ainine boiling a t 235-245O with small amounts of a primary amine a t 255-265O, which was shown t o be 4-amino-n-butylbenzene. Between 275O and 290° a secondary amine probably 4-n- butylnmino-n-butylbenzene, was collected in an impure condition.It was dissolved in dilute hydrochloric acid and treated with nitrous acid when 4-n-butyl-phenyl-n-b.rctyl.nitrosoam~~~e separated as a yellowish-red oil volatile in steam and having a pleasant odour : N=6*7. 0.0703 gave 7.4 C.C. N a t 17.8O and 744 mm. C,,H2,0N2 requires N = 12.0 per cent. The amount of this secondary amine present in the mixture resulting from the actlion of n-butyl alcohol on aniline zincichloride is usually small and the yield appears to depend on the experi-mental conditions. The residue of higher boiling point yielded a t about 300° aminodibutylbenzene which was isolated as a sparingly soluble sulphate and a mixture of amines yielding fractions up to 360O.Amines of still higher boiling points were obtained on dis-N=12.1 REARRANGEMENT OF THE ALKYLARYLAMINES. 125 tilling under diminished pressure until only a semi-carbonised mass remained in the flask. This distillate which contained primary, secondary and tertiary amines was not further investigated but no doubt consisted of amino-compounds containing more than two butyl groups in the nucleus. The formation of 4-amino-n-butylbenzee by the action of dry n-but'yl alcohol on aniline zincichloride may be due t o the initial formation of n-butylaniline followed by intramolecular change or to the direct entry of the butyl group into the nucleus. The former sug-gestion agrees better wit'h the experimental results for by reducing the time of the reaction and the temperature at which it occurs n-butylaniline is obtained in greater amount than usual whilst the yield of 4-amino-n-butylbenzene is much smaller.I n one experi-ment the temperature was allowed to rise gradually to 180-200° over a period of six hours. !rhe products were aniline and ebutyl-aniline only a small quantity of 4-amino-n-butylbenzene being formed. It was also found that pure n-butylaniline in the presence of zinc chloride and also certain other salts underwent intramolecular change on heating a t temperatures between 200° and 240° for about six to eight hours. n-Butylaniline and Cobalt Chloride. n-Butylnniline (6.5 grams) was heated in a sealed tube at tem-peratures between 200° and 240° for seven hours with anhydrous cobalt chloride (2 grams).There was only a slight pressure on opening the tube and the cont,ents which were initially pale green, changed to a deep blue crystalline mass. After treatment with warm water and dilute sodium hydroxide solution the mixture of amines had the following composition : Primary amine ... ... ... ... ... 62 per cent. Secondary amine . * - 14 >? , ... ... ... Bases insoluble in dilute hydrochloric acid ... 23 , ,, The primary amine gave an acetyl compound melting at 103O after one crystallisation which was identical with 4-acetylamino-n-butylbenzene. Other experiments were carried out by heating pure n-butyl-aniline under pressure in the presence of various substances such as zinc chloride and sodium chloride. The results obtained are given in the following table 126 REILLY AND HICKINBOTTOM INTRAMOLECULAR Percentage composition of resulting amines.Substance. added. NaCl .................. SiO .................. C&O ............... CaCl ............... coa ............... CUCl ............... ZnC1 ............... COCI ............... HgCI ............... -Duration of heating. Primary. 8 hours. 1 8 97 1 8 ?9 8 9 7 8 Y Y 2 7 9 9 62 8 Y Y 11 7 9 9 47 8 9 7 50 8 ? 7 20 --* Not determined. Insoluble in Secondary. dilute acid. 99 100 -99 100 I 98 -14 23 50 37 16 20 30 --* * The temperature in every case varied between 200° and 240° except in the case of n-butylaniline which was heated alone at 240-260O. The experiments are however not comparable.When the amine was heated with cupric chloride the mixture a t the end of the reaction was very dark and contained small bright red, metallic particles presumably of copper. The yield of amines insoluble in dilute hydrochloric acid was also high. I n the experi-ment with melrcuric chloride some metallic mercury was obtained. It was observed that the intramolecular rearrangement of the butylaniline was accompanied by the combination of the secondary amine with the substance added. Some of these additive compounds have been isolated. n-Butylaniline cobaltockloride was obtained by heating butyl-aniline with an excess of finely powdered anhydrous cobalt chloride in the presence of chloroform. After collecting the excess of sus-pended metallic salt the chloroform solution was evaporated to dry-ness when the cobaltochloride was obtained as a greenish-blue, vitrecus mass which becomes viscous after heating a t 1000.It is decomposed by water with tlhe formation of cobalt chloride and butylaniline : 0.4226 gave 0.4265 AgCl. C1= 25.0. C,,H,,N,CoCl requires C1= 25.4 per cent. n-Du tylaniline zincichloride was obtained as a grey vitreous niass by heating n-butylaniline in chloroform solution with an excess of zinc ohloride. The solution was filtered from the zinc chloride and the scjlvent removed by distillation. On washing with small quan-tities of light petroleum to remove the excess of butylaniline the zincichloride remained in a pure condition : 01.1450 gave 0.1458 AgCl. Cl=24*9.It-Butylaniline and cadmium chloride also form an additive com-C,,H,,N,ZnCb requires C1= 24.9 per cent REARRANGEMENT OF THE ARKYLARYLAMINES. 127 pound which in common with those of the chlorides of cobalt and zinc is readily decomposed by hot water. The instability of the zinoichloride toward water explains the readiness with which primary amines may be separated from secondary by the use of zinc chloride. Evidence was obtained of the formation of compounds with ferric chloride and cupric chloride by warming the chlorides with a chloro-form solution of butylaniline. With ferric chloride a very dark green substance was obtained soluble in aqueous alcohol (75 per cent.) giving a bright green colour. Cupric chloride gave a deep violet chloroform solution yielding a solid which was almost black.With the chlorides of calcium or sodium or with calcium sulphate and silica no indications were obtained of the formation of additive compounds. Additive Compounds of 4-A mino-n-butylb enzene with Metallic Salts. The products of intramolecular change apparently contained addi-tive compounds of the primary amine with the salt employed. A few of these compounds were prepared and analysed. 4-Amino-n-butylbenzene zincichloride was obtained as a caseous mass by adding an aqueous solution of zinc chloride to 4-amino-n-butylbenzene : C1= 16.2. (C,,H,,N),ZnCl requires C1= 16.3 per cent. 0.2355 gave 0.1540 AgC1. It is sparingly soluble in water alcohol or ether. Dilute acids hydrolyse it rapidly. 4-A mino-n- butylbenzene cobalt ochloride was prepared by mixing alcoholic solutions of anhydrous cobalt chloride with an excess of the base.After being crystallised from absolute methyl alcohol it formed a bright blue powder which is decomposed by water into its components slowly in the cold but more quickly on warming: C1= 16.2. (C,,H,,N)2,CoC1 requires Cl= 16.6 ; Co = 13.8 per cent. 4-A mino-n-butylbenzene cadmichloride was obtained as a white, bulky mass by mixing the components in methyl-alcoholic solution. It crystallises from hot methyl alcohol in small white crystals with a nacreous lustre and tends to form crusts of crystals on the surface of the solution. It is hydrolysed on boiling with water. 0.0858 gave 0.0562 AgC1. 0.2155 , 0.0793 COSO,. C0=14.0 128 REILLY AND HICKINBOTTOM INTRAMOLECULAR -4 ction of Heat on n-Butylaniline Hydrochloride.Crude mono-rz-butylaniline was converted into its hydrochloride by evaporating it with an excess of concentrated hydrochloric acid until the solution was of a syrupy consistency. On keeping over-night it had solidified to a hard mass of crystals which were trans-ferred to a retort and heated in an oil-bath at 260-300°. The dis-engaged vapours were passed through a condenser to remove any liquid. A considerable amount of a liquid was condensed nearly all of which boiled between 80° and 83O indicating the presence of mbutyl chloride. The gas which escaped condensation was passed through bromine and after removing the excew of bromine by means of sodium hydrogen sulphite a small amount of a colourless liquid was obtained which was not further examined.I n this experiment an excess of hydrochloric acid was originally present. Another experiment was carried out taking precautions to avoid an excess The hydrochloride1 was dried on a steam-bath f o r twelve hours and exposed to the air for a further period after which it was heated a t 280-300O for one hundred hours. During the earlier stages of the experiment a liquid ( A ) was condensed which became darker as the heating proceeded. The gas evolved was passed through bromine when a liquid dibromide was obtained in small amount. From the distillate ( A ) there separated a small quantity of flat, grey crystals which consisted of aniline hydrochloride. The liquid portion after being rendered alkaline gave on distillation a frac-tion boiling b'etween 70° and 80° chiefly a t 77-80° which was n-butyl chloride.There was also a fraction boiling chiefly between 200' and 250° containing principally a primary arnine mixed with some secondary the former being identified as aniline. The residue in the flask which was black and tarry was rendered alkaline and the resulting amine treated with an excess of zinc chloride solution in order to separate the primary amines from the other products. The insoluble zincichlorides gave a mixture of amines boiling between 200° and 255O and yielding a considerable fraction a t 240-255O'. The ethereal washings of the zincichloride contained a secondary amine Foiling between 230° and 250° whilst a t 250-260° a mixture of primary and secondary amin- was obtained.There were also present bases which were insoluble in dilute hydrochloric acid but soluble in the concentrated acid and were probably diphenylamine delrivatives. Preparation of n - h t ylaniline Hydrochloride . n-Butylaniline hydrochloride has previously been obtained by Kahn (Rer. 1885 18 3361) by evaporating a solution of n-butyl REARRANGEMENT O F TRE ALKYLARYLAMINES. 129 aniline in hydrochloric acid to crystallisation. A more convenient method was to pass a stream of dry hydrogen chloride into a solution of butylaiiiliiie in an equal volume of benzene or toluene. A con-siderable amount of heat was generated sufficient t o evaporate some of the hydrocarbon. On cooling n-butylaniline hydrochloride crystallised out and was collected washed and dried.The filtrate, which still contained much of the salt was precipitated by the addition of ether when the hydrochloride was obtained in very small white crystals having a silvery appearance. They were col-lected washed with further amounts of ether and dried first at 60° and later at looo. n-Butylaniline hydrochloride crystallises in very small irregular plake from hot ethyl acetate in which i t is readily soluble. It is only moderately soluble in the Gold solvent. Comparative Experiments on ,4 lkylarylamines with various Alkyl Groups. A comparison was made of the stability of alkylarylamines con-taining alkyl groups of different weight. For this purpose methyl-and n-butyl-arylamines were employed. In the earlier investigatioiis the experiments were carried out on the intramolecular rearrange-ment of methyl- and n-butyl-aniline.The secondary amines were heated in sealed tubes with a molecular proportion of substances which aid the formation of amiiioalkylbenzenes. The tubes were arranged in iron shields in such a manner that the temperature and the duration of heating were approximately the same in each case. The results are given in the following table. The resirlts show that there is a difference although not very marked in the behaviour of the two amines n-butylaniline undergoing intramolecular change =ore readily. In this case the action is characterised by the forma-tion of appreciable quantities of substances ol the nature of diphenylamine which are either absent in the case of methylaniline or present only in small amount.Substance. Time of added. heating. CoC1 ......... 5 hours. CdC1 ......... 6 .. HC1 ............ 6 .. HC1 ............ 8 .. CoCl (+ mol.) 5 ,, HCl ............ 4 .. n - Bu t ylaniline. 7’7 Primary Secondary. Per cent. Per cent. 73 10 52 24 * 20 68 18 * 33 * 33 * Not estimated. Meth ylaniline. c A . Primary. Secondary. Per cent. Per cent. 57 32 43 24 - 95 * 2 50 * 4 130 REILLY AND HICKINBOTTOM INTRAMOLECULAR It was observed that methylaniline yields additive compounds with cobalt chloride zinc chloride and Gadmiurn chloride similar to those described in the case of rt-butylanilinel (p. 126). ilfethylaniline cobaltochloride was obtained as a dull blue powder 011 triturating anhydrous cobalt chloride with an excess of freshly distilled methylaniline and heating the mixture on a steam-bath for a short time the excess of methylaniline being then extracted by means of chloroform.On long keeping the salt became greenish-yellow : 0.1157 gave 0.1402 AgCl. C1=30.0. 0.4312 , 0.2818 CoSO,. C0=24.9. Methylaniline cadmichloride was prepared in a similar way. It is 0.4099 gave 0.4016 AgCI. C1= 24.2. 0'3045 , 0.2150 CdSO,. Cd=39*0. C,H,N,CdCl requires C1= 24.6 ; Cd = 39.0 per cent. I n the formation of the additive compounds of alkylanilines with metallic salts the steric effects of the alkyl group may affect the formation of the compounds to a different extent and for this and other reasons (difficulty of ensuring the same temperature and pres-sure in each tube) the experiments are probably not strict.ly compar-able.The comparison of the relative stability of methyl and wbutyl groups was therefore carried out with tertiary amines such as methyl-n-butylaniline. The intramolecular rearrangement of this compound proceeds in two stages namely the formation of a second-ary amine followed by conversion into a primary amine. It there-fore became necessary to prepare the compounds that may possibly occur in the mixture. C,H,N,CoCl requires C1= 30-2 ; Co = 25.1 per cent. a white powder which is decomposed by water : Me t h y l -n- b ZL t y lani Zin e . This substance was prepared in three ways namely by the inter-action of ( a ) n-butyl bromide and methylaniline ( b ) n-butyl chloride and methylaniline (c) methyl iodide and n-butylaniline, and the products in each case were the same.It was found that to obtain pure methyl-n-butylaniline by distillation was a %edious operation leading to losses. I n the earlier work the process of puri-fication consisted in converting the crude methyl-n-butylaniline into its picrate and then crystallising the picrate until pure. This pro-cedure was abandoned later and the secondary amine was removed by heating the crude tertiary amine with a slight excess of the theo-retical amount of phenylcarbimide. The excess of the reagent was removed by warming with water followed by distillation in a cur REARRANGEMENT OF THE ALKYLARYLAMINES. 131 rent of steam. pale yellow refractive liquid boiling at 242-243O1766 mm. : ~fethyl-n-bzctylaniline was obtained in this way as a 0.1071 gave 0.3180 CO and 0.0987 N,O.0.0988 , 7.7 C.C. N2 at 2 8 O and 748 mm. N=8*8. C11H17N requires C = 80.9 ; H = 10.5 ; N = 8.6 per cent. The hydrochloride was obtained as an oil on passing a stream of dry hydrogen chloride into an ethereal solution of the base. After repeated washings with small quantities of dry ether and keeping over potassium hydroxide under diminished pressure it solidified to a mass of white glistening laniinz: C=81.0; H=10*3. 0.1633 gave 0.1170 AgC1. C1=17*7. It is extremely soluble in water or alcohol moderately so in nitro-benzene and sparingly so in toluene. From an aqueous solution of the hydrochloride containing a slight excess of free acid the platinichloride was obtained as an orange-yellow precipitate sparingly soluble in water : CllHl,N,HC1 requires C1= 17.8 per cent.0.1152 gave 0.0304 Pt. 0.2234 ? 7.0 C.C. N at 1 8 O and 738 mm. N=3.6. The picrate crystallises from a methyl-alcoholic solution of the components in small yellow crystals melting at 90'. Titration with Titanow Chloride.-O.OlO required 20.3 C.C. TiCl, (1 C.C. TiC1,=0'0.01257 gram Fe). Calc. as CllH17N,C,H,0,N3= 100.5 per cent. The melting point of this compound differs from that recorded by Komatsu (Zoc. cit.) who gives 141-142O. The picrates from the amine obtained by introducing the alkyl groups in different order were found to be identical and a mixture of them also melted a t goo. p-Nitrosomethyl-n-bzLtyZoniline.-Nitrous acid acted on a solution of methyl-n -butylaniline hydrochloride containing free hydrochloric acid yielding a reddish-brown solution and the addition of icecold dilute aqueous ammonia precipitated the base as an oil which was removed by means of ether.It was obtained as a greenish-blue liquid which was steel-blue by reflected light: 0.1184 gave 0.2981 CO and 0.0909 H,O. 0.1282 ) 16.2 C.C. N a t 15O and 745 mm. N=14*8. C,,H,,ON requires C = 68.7 ; H = 8.4 ; N = 14.6 per cent. On heating the base under reflux with an excess of a 10 per cent. aqueous solution of sodium hydroxide decomposition occurred with the production of a volatile amine probably methyl-n-butylamine. 4-Meth~lnm~~o-n-b.ut~lbenzene was obtained by heating 4-amino-Pt =26*4. (Cl,H17N),,H,PtC1 requires Pt = 26.5 ; N= 3.8 per cent.C = 68.7 ; H = 8.5 I32 REILLY AND HIUKINBOTTOM INTRAMOLECULAR nlbutylbenzene with methyl iodide. The addition of a dilute solu-tion of sodimn hydroxide liberated the base as an almost colourless oil boiling a t 262-265O/760 mm. : 0.1042 gave 7.6 C.C. N a t 1 5 O and 759 mm. By the action of nitrous acid 4-n- butylphenylmethylnitrosoanzine, CllH,,0N2 was obtained as a pale yellow oil. This was nitrated by dissolving it in glacial acetic acid and cautiously adding ten times its weight of fuming nitric acid in the cold. After a short time the reaction was completed by heating on the water-bath until the mix-ture was pale red or yellow. This was then poured on crushed ice, and the nitro-derivative collected and crystallised by dissolving it in cold fuming nitric acid.On keeping dinitro-n-butylph enyZ-4-methylnitroamine C,,H,,O,N, was obtained in pale yellow plates. From warm glacial acetic acid it crystallises in very pale yellow, glistening plates a t 86O. Et hyl-n-butylaniline was obtained by the acltion of n-butyl chloride on ethylaniline and also by allowing ethyl iodide to react with butylaniline. It was obtained pure in the manner described for methylbutylaniline and is a pale yellow oil boiling at 248O/ 768 mm. : N=8*7. C,,H,7N requires N = 8.6 per cent. 0.0968 gave 0.2880 CO and 0*0891 H20. 0.0836 , 5.9 C.C. N at 25O and 748 mm. N=8.0. The picrate crystallises from aqueous alcohol in bright yellow, thin prisms or narrow plates melting a t looo: 0.010 required 20.0 C.C. TiCl (1 C.C. TiC1,=0*00125 gram Fe).Calc. for C,2H,,N,C,H,07N3 = 99.3 per cent. p-Nitrosoethyl-n-butylaniline was obtained as an oil having a dark blue metallic colour when viewed by reflected light : 0.017 gave 12.1 C.C. N a t 24O and 741 mm. N=13*7. C,,H,,ON requires N = 13.6 per cent. p-Nitrosoe thyl-n- butylaniline zincic hloride was prepared by mix-ing alcoholic solutions of the components and evaporating the alcohol under diminished pressure but it was not obtained cryst?alline. 4-Ethylamino-n-butylbenzene is a liquid of agreeable odour and boiling a t 270-272O/ 762 mm. : 0.1024 gave 7.5 C.C. N a t 2 2 O and 746 mm. The nitrosoamine is a yellow oil : 0.0999 gave 11.65 C.C. N at 20° and 746 mm. C = 81.1 ; H = 10.2. C,,H,,N requires C= 81.3 ; H= 10.8 ; N= 7.9 per cent.N=8.2. C,,H,,N requires N= 7.9 per cent. N=13*4. Cl2H1,ON2 requires N = 13.6 per cent REARRANGEMENT OF THE ALKYLARYLAMINEB. 133 2-A mino-5-n-butyltoluene. Molecular proportions of n-butyl alcohol and o-toluidine were heated at 200-240° for twenty-four hours and the mixture was treated in the manlier already described €or 4-amino-n-butylbenzene. 2-Amino-5-n-butyltolzcene was obtained as a very pale yellow liquid boiling a t 265-26B0/765 mm. : 0.0960 gave 7.1 C.C. N at 20° and 757 mm. The hydrochloride crystallises from warm dilute hydrochloric acid N=8*6. C,,H,,N requires N = 8.6 per cent. in rosettes of white needles: 0.1176 gave 0*0840 AgC1. C1=17*8. It is precipitated from aqueous solution by the addition of a11 The acetyl derivative crystallises from dilute aqueous alcohol in 0.1039 gave 6.0 C.C.N at 1 5 O and 750 mm. C,,H,,ON requires N = 6.8 per cent. On diazotising the hydrochloride and adding the solution to alka-line P-naphthol 5-n-bzctyltolzcene-2-azo-&naphthol is precipitated. It crystallises from hot glacial acetic acid in bulky masses of small, bright red needles melting at 105-107°. It is only moderately soluble in alcohol and dissolves in concentrated sulphuric acid with the production of a purple coloration. C,,H,,N,HCl requires C1= 17.8 per cent. excess of hydrochloric acid. white masses of crystals melting a t 89O : N=6*8. 4- Amino-3-n-butylt oluene. This amine was obtained by the action of n-hutyl alcohol on p-toluidine zincichloride in the manner already described for the preparation of 4-amino-n-butylbenzene.It is a liquid boiling a t 265-270° under atmospheric pressure : 0.1496 gave 11.3 C.C. N a t 19O and 762 mm. C,,H,,N requires N=8.6 per cent. The acetyl derivative separates as a white mass on cooling the product of interaction of 4-amin0-3~~butyltoluene and acetic anhy-dride. It crystallises from alcohol in tufts of white slender needles melting at 1 2 9 O : N=8.9. 0.1113 gave 0.3105 CO and 0.0953 H,O. C=76.1; H=9-5. C,,H,,ON requires C = 76.0 ; H = 9.3 per cent 134 REILLY AND HICKINBOTTOM INTRAMOLECULAR The In tminoleeular Rearrangement of Methyl-n-butylaniline. Pure methyl-n-butylaniline was heated in a sealed tube with one molecular proportion of either zinc chloride or cobalt chloride. In one experiment methyl-n-butylaniline hydrochloride was employed.The temperature varied between 200° and 250° and the heating was allowed to continue for about six to eight hours. On opening the tubes there was usually a pressure due to the presence of an inflam-mable gas. The contents of the tube were rendered alkaline and the amines were obtained by distillation in a current of steam. The mixture of amines obtained in this way was treated with zinc chloride solution which removed the bulk of the primary amines. The ethereal washings of the zincichloride were washed with dilute hydrochloric acid to remove primary secondary and tertiary amines. From this acid solution the secondary amines were separated as nitrosoamines and the primary amines converted into the corre-sponding diazonium salts.The nitrosoamines separated in this way were nitrated yielding in each case an oily product which was obtained crystalline only on keeping in contact with concentrated nitric acid for several days. By pressing on a porous tile to remove oily impurit.ies and by repeated recrystallisation from glacial acetic acid a small amount of a pale yellow crystalline substance was obtained melting a t 93O and the melting point was raised to 94-95O by the addition of 3 5-dinitro-p-tolyl-n-butylnitroamine. It is probable that the latter compound was present in the nitration product indicating the existence of n-butyl-p-toluidine in the mixture of amines from the intramolecular rearrangement of methyl-n-butylaniline. It was not found possible to isolate any other nitro-compound in a pure state from the mixture, although appreciable amounts were present.It is probable that in the mixture dinitro-n-butylphenylmethyl-nitroamine was also present as only n-butyl-p-toluidine and 4-methyl-amino-n-butylbenzene would be expected to occur in any appreciable amount. In one case small amounts of 2 4 6-trinitrophenylmethylnitro-amine were isolated and the primary amine from it indicated p-toluidine. By crystallisation of the azo-compounds from this experiment p-tolueneazo-&naphthol melting a t 129O was isolated, and this melting point was not depressed by the addition of pure p-tolueneazo-&naphthol. The small amounts of derivatives of methylaniline and p-toluidine isolated were due probably to the rearrangement not proceeding to completion REARRANGEMENT OF THE ALKYLARYLAMINES.135 Action of Heat on Methyl-n-bzltylanilirLe Hydrochloride. Methyl-n-butylaniliiie (4.2 grams) was dissolved in an excess of concentrated hydrochloric acid in a small glass retort which was heated in an oil-bath a t 150-200° a stream of hydrogen chloride being allowed to pass through the retort during the period of heat-ing. A portion of the residue in the vessel was removed and after diluting and adding more hydrochloric acid it was cooled to Oo and treated with a slight excess of an aqueous solution of sodium nitrite. A nitrosoarnine separated which was removed by extraction with ether. The ethereal solution was washed several times with water and dilute sodium hydroxide dried and evaporated and the residue was dissolved in glacial acetic acid nitrated by heating it on a water-bath with fuming nitric acid until the colour of the inixture had changed t o a pale red.On pouring the mixture into water an oily product was obtained which when crystallised from fuming nitric acid melted at 90-92O. The addition of trinitro-phenylbutylnitroamine (m. p. 99O) depressed the melting point to about 89-93O whilst the addition of trinitrophenylmethylnitro-amine raised the melting point to 110-115°. The secondary amine resulting from the elimination of alkyl groups from methylbutyl-aniline in a stream of hydrogen chloride is therefore probably a mixture of methyl- and butyl-aniline. The further examination of the products of this reaction is deferred until thel physical constants of mixtures of trinitrophenyl-methylnitroarnine and trinitrophenylbutylnitroamine have been determined.The Ni.tration of Diallcylanilines. The method usually adopted to nitrate dissimilarly substituted dialkylanilines was to add cautiously about 10 to 15 times their weight of fuming nitric acid to a solution in glacial acetic acid. The reaction was completed by heating on the water-bath until the dark colour of the mixture had given place to a pale yellow or red. The nitration product was then isolated by pouring on ice when it was collected and purified by crystallisation from fuming nitric acid. Dibutylaniline when treated in this way gave trinz"tropheny2-n-butylnitroamine in very pale yellow plates melting a t looo: 0.1093 gave 20.3 C.C.N a t 20° and 748 mm. CloH,,08N requires N = 21.3 per cent. It is soluble in alcohol or acetone and can be conveniently recrys-tallised from hot glacial acetic acid. An alcoholic solution of N=21*3 136 INTRAMOLECULAR REARRANGEMENT OF ALKYLARYLAMINES. sodium hydroxide in the cold gives a deep orange-red coloration. It dissolves in cold concentrated sulphuricl acid without any development of colour but on dilution a yellow turbidity is produced. This substance was shown to be identical with the nitro-derivative obtained on nitrating phenyl-n-butylnitrosoamine. It was also obtained by nitrating dibutylaniline in the presence of nitric and sulphuric acids. Dibutylaniliiie (10 grams) dissolved in concen-trated sulphuric acid (18 grams) was slowly added to a mixture of sulphuric (50 grams) and nitric acids (150 grams) the temperature being maintained between 35O and 4 5 O throughout the reaction.After all the aniine had been added the mixture was maintained for some time a t 50° and then thrown on crushed ice when the nitro-compound was collected as a viscous red substance and purified in the usual manner by crystallisation from fuming nitric acid. The strongly acid aqueous portion was found to contain butyri? acid. The nitro-compound was removed by filtration through a thick layer of glass-wool. It was found necessary to take these precau-tions to remove the last traces of the nitro-compound in order to prevent contamination of the products at a later stage. To the acid filtrate iron filings were added gradually care being taken to avoid a too-vigorous action. After remaining overnight the solution was distilled in a current of steam. The distillate which still contained a small amount of nitric acid was neutralised and evaporated to a small bulk. It was then rendered acid by adding an excess of sul-phuric acid and the last traces of nitric acid were removed by a further treatment with iron filings. A further distillation in a current of steam gave a distillate which contained a volatile acid, and this was identified by means of its ‘‘ distillation constant ” determined in an apparatus described by the authors (Sci. Proc. &oy. Dubl. SOC. 1919 15 513). The constant agreed with that for n-butyric acid mixed w i t h a small proportion of an impurity and its presence was confirmed by its odour and by its reaction with ferric chloride. Comparative experiinents were also carried out using dimethyl-aniline. Methyl-n-butylaniline was nitrated by fuming nitric acid dissolved in glacial acetic acid following the method described above. The product melted at 123-125O after crystallisation from fuming nitric acid. It was recrystallised from glacial acetic acid and was found t o be identical with 2 4 6-trinitrophenylmethylnitroamine, for no depression of the melting point occurred when a mixture was prepared with this nitro-compound and trinitrophenylmethylnitro-amine from another source. Ethyl-n-butylaniline on nitration with fuming nitric acid or wit THE CONDENSATION OF ETHYL ACETOACETATE ETC. 137 a mixture of nitric and sulphuric acids gave a product which on crystallisation from fuming nitric acid furnished a mixture yielding trinitrophenyl-n-but.ylnit,roamine on crystmallisation from glacial acetic acid. [Received November 4th 1919.

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DOI:10.1039/CT9201700103

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年代:1920

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THE CONDENSATION OF ETHYL ACETOACETATE ETC. 137 XV1.- The Conderbsation of Elhyl Acetoacetate with p-Dirnethylaminobeiualdehyde and Ammonia. By LEONARD ERIC HINKEL and HERBERT WILLIAM CREMER. THIS work was interrupted by the war and as there seems no possibility of it being continued jointly it was considered advisable to place on record such results as were obtained. The investigation arose from a desire t~ study the influence of substituent groups in aliphatic and aromatic aldehydes in Hantzsch’s pyridine condensa-tion. It was thought that the introduction of basic groups would retard it and for this purpose p-dimethylaminobenzaldehyde waa chosen. The condensation was found to take place very slowly even on heating the best results being obtained by allowing the mixture to remain for about one hour a t the ordinary temperature and then heating under pressure for seven to nine hours.The yield of the dihydro-derivative could not be increased by longer heating o r by employing excess of ammonia. The viscous filtrate from the dihydro-compound was subjected to steam distillation but no aldehyde passed over with the steam. The filtrate was soluble in hydrochloric acid and reprecipitated unchanged by alkali. I n all probability the filtrate contained a cyclo-ketone formed by the further condensation of the 1 5-diketone first produced along with the dihydrecompound. The filtrate was not further examined. The dihydro-derivative can also be produced by condensing the aldehyde with ethyl acetoacetate (1 mol.) and ethyl &amino-crotonate (1 mol.).This method was also employed with pdimethylaminobenzaldehyde and also for comparison with benzaldehyde. In the first case the yield was 21.7 per cent., whilst with benzaldehyde it was more than 90 per cent. showing in a striking manner the effect of the p-dimethylamino-group on the condensation. The oxidation of the dihydro-derivative could not be carried out according to the usual method by nitrous fumea. Even at low temperatures brown needle-shaped crystals readily VOL. CXVII. 138 HINEEL AND CREMER THE CONDENSATION OF ETHYL formed which were found to be p-nitrosodimethylaniline nitrate. The readiness with which the p-dimethylaminophenyl group is eliminated is probably due to the influence exerted by the dimethyl-amino-group since it has been shown (Schiff and Puliti Ber.1883, 16 160; Epstein Annulen 1885 231 1) that phenyl- and styryl-dimethyldihydropyridinedicarboxylic esters are readily oxidised by nitrous fumes without elimination of the phenyl or styryl groups. EXPERIMENTAL. E t h y 1 4-p- Dimet h y Zantinophenyl-2 6-dimet h y Z-1 4-dihydro-pyridine-3 5-dicarboxylate, CM6-- NH--CMe CO,Et *E C H ( C6H,*NMe2).;C;'* CO,Et A mixture of 30 grams (1 mol.) of p-dimet.hylaminobenz-aldehyde 52 grams (2 mols.) of ethyl acetoacetate 3.4 grams ( 1 mol.) of ammonia and 70 C.C. of alcohol contqained in a closed flask was allowed to remain for an hour and then heated for nine hours over a rapidly boiling water-bath. Considerable pressure was developed in the flask which was therefore suitably protected against explosion.On cooling about half of the contents of the flask crystalliseld and the crystals were collected and washed with a small quantity of alcohol. The residue was evaporated over a water-bath until viscid and when cold diluted with an equal volume of alcohol; on stirring a small further quantity was obtained the total yield being 40 grams or 53-7 per cent. of the theoretical. The crude yellow crystals were1 purified by crystal-lisations from alcohol acetone and ethyl acetate and were obt'ained finally in nearly colourless fine needles melting a t 158'5O: 0.2452 gave 0.6047 CO and 0.1702 H,O. 0.1617 , 10.8 C.C. N (moist) a t 7-5O and 750 mm. N,=8.0. The ester is very similar to the trimethyl ester prepared by Hantzsch. It is stable to boiling dilute alkali and boiling alcoholic potassium hydroxide slowly acts on it bringing about complete decomposition.When heated witlh concentrated hydrochloric, sulphuric or phosphoric acid the compound is also decomposed, with the elimination of two molecular proportions of carbon dioxide. By virtue of the dimethylamino-group however it possesses basic properties and readily forms sparingly soluble additive compounds with hydrogen chloride and with methyl iodide. C=67.26; H=7-7. C,,H,,O,N requires C = 67-64 ; H = 7.52 ; N = 7-52 per cent ACETOACETATE WITH P-DDIETHYLAMINOBENZALDEHYDE ETC. 139 UorLclerLsatiom of p-Dimethyluminob enzaldehyde Ethyl 9 ceto-ace tat e and Et h y I &,4 minocrotonat e . A mixture of 6 grams (1 mol.) of p-dimethylaminobenzaldehyde, 5-2 grams (1 mol.) of ethyl acetoacetate and 4-5 grams (1 mol.) of ethyl /3-aminocrotonate was heated a t 120° for several hours.After two days the viscous mass was dissolved in an equal volume of hot alcohol and left to crystallise. The product after recrystal-lisation from ethyl acetate was identical with the ester just described the yield being 3'2 grams or 21.7 per cent. of the theoretical. The hydrochloride C2,H,,04N,,HC1 prepared by dissolving the substance in dilute hydrochloric acid separates as a fine white, crystalline powder especially on dilution with water. It was washed with water and alcohol and dried in a vacuum: 0.1827 gave 0-4130 C O and 0.1257 H,O. C=61.6; H=7-63. 0.1613 , 9-4 C.C. N (moist) a t 14O and 751 mm. N=6*85.0.1466 , 0.0527 AgCl. Cl=8.60. C,,H,04N,,HC1 requires C = 61-68 ; H = 7.09 ; N = 6.85 ; C1=8.68 per cent. It melts a t 201° and when heated above its melting point, rapidly decomposes yielding dimethylaniline among the products. Met hiodide C,,H,0,N2,CH31 .-A mixture of the substance with excess of methyl iodide in acetone solution was gently heated for a short time over a water-bat.h. The clear hot liquid was then poured into an evaporating basin and stirred with a glass rod until the mass solidified. The crude methiodide was washed with acetone and purified by crystallisation from hot acetone and finally from ethyl acetate. It melts a t 182-183O: 0.1532 gave 0.2892 CO and 0.897 H,O. C=51*48; H=6*50. C,,H,80,N,,CH31 requires C = 51.36 ; H = 6-05 ; 1 = 24.7 per cent.0.2052 , 0.0952 AgI. 1=25*06. Ethtyl 4-p-Bimethylam.inopheny1-2 6dimethylpyrdine-dicarb oxylate. A mixture of 37.3 grams of the dihydro-ester and 3.2 grams of sublimed sulphur was gently heated at 150O. The mixture melted, and hydrogen sulphide was rapidly evolved the heating being con-tinued until the liquid became clear and free from gas bubbles. When cold the mass solidified and wils dissolved in boiling alcohol, from which it crystallised on cooling. The crude crystals were freed from any uncombined sulphur by dissolving them in excess a 140 QOODSON CONSTITUENTS OF THE of dilute hydrochloric acid and filtering. The ester was precipi-tated as a white flocculent mass from the acid solution by means of sodium carbonate solution. It was washed with water and re-crystallised from alcohol and finally from light petroleum.The yield was almost quantitative. The ester is readily soluble in benzene ether chlorof o m or hot alcohol sparingly so in warm light petroleum and melts at 124-5O: 0.1853 gave 7.65 C.C. N (moist) a t 3O and 778 mm. C,,H,0,N2 require5 N = 7.57 per cent.. HydroZysis.-Fifteen grams of the ester were mixed with 30 grams of potassium hydroxide dissolved in 100 C.C. of alcohol and the mixture was heated to boiling under a reflux condenser for several hours. On cooling the potassium salt separated out in fine crystals which were collected and quickly washed with a little absolute alcohol and dried in a vacuum. A further yield was obtained from the filtrate on concentration. The potassium saltl is yellow and very deliquescent in air changing to a deep yellow mags. It is sparingly soluble in boiling alcohpl. The neutral aqueous solution is deep yellow but the addition of either acid or alkali instantly destroys the colour which can however be restored by the careful neutralisation of the excess of acid or alkali. N=7-65. CHEMICAL DEPARTMENT, KING’S COLLEGE, LONDON. [Received November 23rd 1919.

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DOI:10.1039/CT9201700137

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年代:1920

数据来源: RSC

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140 QOODSON CONSTITUENTS OF THE of the Leaves of Helinus ovatus. By JOHN AUGUSTUS GOODSON. Helinus ovatus E. Meyer (Nat. Ord. Rhamnaceae) is a climbing shrub indigenous to South Africa where it is found growing on the borders of woods and thickets. No species of this genus which, according to Oliver (“Flora of Tropical Africa”) is confined to Africa and India appears to have been examined previously, although the constituents of the genus Rhamnus from which the order is named are fairly well known including as they do such well-known drugs as cascara sagrada m d buckthorn. The resulh of the present investigation show that H . ovatus contains aconitic acid quercetin a saponin and scyllitol. The last-mentioned substance was first isolated from certain plagio-stomous fishes including the spur dogfish but has since then bee LEAVES OF HELINUS OVATUS.141 found in a number of plants such as the acorns of the common oak and the leaves of Cocos plumosa and C nucifera. The occurrence of scyllitol the second of the two known meso-inositols in these plants is of considerable biological interest in view of the suggestion made by Winterstein Contardi and others (compare Posternak Compt. rend. 1919 169 37) that phyt*in, which is believed to be the usual organic phosphorus reserve con-stituent of plants is a mesoinositol hexaphosphate. The material came from Komgha Cape Province and was sup-pliqd by Mr. I. B. Pole Evans Chief of the Division of Botany, Union of South Africa who stated that it is used medicinally by the natives and is known locally as “soap-plant,” since the leaves have the property of yielding a lather when rubbed in the hands with water.Preliminary Examination. The leaves contained 9.5 per cent. of moisture and 9.2 per cent. of ash of which 20.2 per cent. was potash (K,O) equivalent to 1.8 per cent. in the leaves. No alkaloid or cyanogenetic glucoside could be detected by the usual reagents. The finely ground leaves gave the following percentages of extract on exhaustion in a Soxhlet apparatus with solvents in the order named petroleum (b. p. 35-60°) 2.2 ; ether 2.3 ; chloro-form 2.2; alcohol 23.0. Isolation of Ceryl Alcohol. The petroleum extract consisted of brown waxy matter of which about one-third remained undissolved when digested with ether. This was boiled with alcoholic potassium hydroxide solution to remove traces of oil and wax.The residue left after removal of the alcohol was crystallised from ethyl acetate and then melted at 7 8 O ; a specimen of ceryl alcohol melted at 81O in the same bath, and a mixture of the two at 79O. (Found C=82*0; H=14*0. Ceryl alcohol C&H,,O [Henriques Ber. 1897 30 14151 requires C=81*6; H=14.2 per cent.) The remaining extracts were systematically examined with results which showed that the quantity of plant available (650 grams) could best be dealt with by extraction with chloroform to remove wax and resinous matter and then in succession with alcohol and water 142 GOODSON CONSTITUENTS OF THE Examination of the Alcoholic Extract. The buik of Ghe alcohol was removed and the1 rwulting syrup set aside for some days when it deposited a considerable quantity of potassium chloride The filtrate was poured into about four times its volume of water and treated succewively with lead acetate and basic lead acetate.The lead was removed from the two pre-cipitates and from the filtrate by hydrogen sulphide in the usual manner. Isolation of Quercetin. The aqueous solution of the material recovered from the lead acetate precipitate contained a considerable amount of tannin. Extraction with ether removed a small quantity of a yellow sub-stance probably quercetin (see below). The1 liquor was then acidified with hydrochloric acid boiled to hydrolyse glumsides, cooled and again extracted with ether the extract yielding a yellow substance crystallising in rosettes of needles.This was recrystallised from a mixture of alcohol and chloroform and then melted a t 309O. On acetylation i t formed matted colourless needles melting at 1 9 5 O and this melting point was not depressed when the substance was mixed with penta-acetylquerceth. The yellow colouring matter is therefore quercetin. The aqueous solution of the material recovered from the basic lsad acetate precipitate also contained tannin and a small amount, of yellow colouring matter which could not be obtained in a crystalline condition. The filtrate after removal of the lead as sulphide was concen-trated and extracted with butyl alcohol which removed a saponin. The latter was purified by solution in water and precipitation with basic lead acetate the lead precipitate being decomposed with hydrogen sulphide in the usual manner and the filtrate evaporated to dryness under diminished premure.The quantity of saponin obtained was so small that no further purification could be effected. The material frothed strongly in aqueous solution gave no com-pound with cholesterol in alcoholic solution did not reduce Fehling’s solution and was not hzemolytic. It was hydrolyseld by boiling with dilute hydrochloric acid the resulting solution yield-ing a small amount of apparently crystalline sapogenin on extrac-tion with ether. The residual aquelous solution reduced Fehling’s solution strongly but did not give a crystalline phenylosazone. The aqueous liquid after extraction with butyl alcohol was con-centrated under diminished pressure and set aside when a furthe LEAVES OF HELINUS OVATUS.143 quantity of potassium chloride separated. d-phenylglucosazone on treatment with phenylhydrazine. The filtrate yielded Examination of the A pueozcs Extract. The aqueous extract was treated successively with lead acetate and basic lead acetat,e and the two 'precipitates were collected. The lead acetate precipitate was suspended in water and decom-posed by hydrogen sulphide. The filtrate was concentrated under diminished pressure and extracted with ether which removed 12.6 grams of a crystalline substance corresponding with 1.9 per cent,. in the leaves. This on recrystallisation from water formed minute prisms melt-ing a t 19l0 and gave all the reactions of aconitic acid including that described by Taylor (T.1919 115 886). (Found C=41.3, 41.4; H = 3.9 3-6. Acon-itic acid C,H,O, requires C =41-4 ; H = 3 - 5 per cent.) Isolation of Scyllitol. The basic lead acetab precipitate was decomposed in the usual manner and t h s filtrate concentrated under diminished pressure, wheln slightly brown crystals separated. Two crops of the crude substance amounting to 3 grams and corresponding wit.h 0-46 per ceat. in the leaves were obtained. The product was purified by recrystallisation from hot water from which it separated in anhydrous monoclinic rhombs. (Found C = 39.7 40.1 ; H = 6.8, 6.9. Scyllitol C,H,,O, requires C =40.0 ; H = 6.7 per cent.) The properties of the substance agreed closely with those recorded for scyllitol (J.Muller Ber. 1907 40 1821 and H. Muller T., 1907 91 1767; 1912 101 2383). When recrystallised slowly from cold water it separated in transparent hexagonal prisms, which on removal from the solvent became opaque and friable owing to loss of water of crystallisation. Crystals freed as rapidly as possible from adhering mother liquor lostl on exposure to air, 24.9 per cent. of water. C,€€,,0,,3H20 requires H,O=23*1 per cent. H. Muller noted this change in crystal habit and transparency, but did not establish the fact that it is due t o loss of water of cryst<allisation (T. 1907 91 1772) 144 HENDERSON AND SMEATON CONTRIBUTIONS TO THE When heated the scyllitol obtained from H . ovatus leaves coloured slightly a t 300° darkened considerably a t 320° and melted and effervmced at 353O as recorded by a mercury thermometer. J. Muller (Zoc. cit.) gave the solubility of scyllitol in water as about 1 gram in 100 C.C. a t 1 8 O ; the author finds a solubility of 1-03 grams in 100 grams a t 18O for his specimen whereas H. Muller (Zoc. c i t . ) gave it as 1.7 grams in 100 C.C. a t 1 5 O . Its identity with scyllitol was confirmed by the preparation of the hexa-acetyl derivative which melted a t 291O. H. Muller (Zoc. c i t . ) gives 290-291O (corr.). (Found C=50-1; H=5*6. Hexa-acetylscyllitol C,H,(C,H,O),O requires C = 50.0 ; H = 5.6 per cent.) The filtrate from the lead precipitates after removal of the lead, contained merely inorganic salts. I n conclusion the author desires to express his warmest thanks to Dr. Henry for his advice and criticism throughout the course of the work. WELL~OME CHEMICAL RESEARCH LABORATORIES, LONDON E.C. 1. [Received January ZFith 1920.

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DOI:10.1039/CT9201700140

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年代:1920

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144 HENDERSON AND SMEATON CONTRIBUTIONS TO THE ~VIII.-Cont9.ibutions to the Chcnzistry of the Teqmnncs. Part X I X . Synthesis of a m-Menthadiene from m-iso Cymenc. By GEORGE GERALD HENDERSON and THOMAS FREDERICK SMEATON. SEVERAL menthadienes have been prepared by various synthetic methods but none that belongs to t.he met'a-series and may there-fore be considered a derivative of m-isocymene had been synthe-sised until the problem was successfully attacked by W. H. Perkin, jun. and his collaborators (compare T. 1905 87 1083; 1907 91, 480; 1908 93 1876; 1910 97 2129; 1911 99 118). Sylvestrene, carvestrene and the other meta-ment*hadienes prFpared synthetic-ally by these investigators contain one ethylenic linking in the nucleus and one in a side-chain hence it appeared desirable to obtain a menthadiene of the meta-series containing two ethylenic linkings in the nucleus in order to compare its properties with those of the corresponding para-menthadienes.Starting with m-isocyrnene obtained by the action of phosphoric oxide on fenchone we first prepared misocymene-6- sulphonic-aci CHEMISTRY OF THE TERPENES. PART XIX. 145 a d converted this into the corresponding phenol 6-hydroxy-m-zio-cymene by fusion with alkali. The succeeding steps in the procma, which was similar to that previously adopted by one of us for the synthais of menthadienes from thymol and carvacrol respectively (Henderson and Boyd T. 1911 99 2159; Henderson and Schotz, T. 1912 101 2563) were briefly as follows (1) Preparation of m-menthan-6-01 (1 -rnethyl-3-isopropglcyclohexan-6-01) C,,H,,*OH, from 6-hydroxy-m-isocymene by hydrogenation in the presence of active nickel.(2) Dehydration of the m-menthanol by heating with oxalic acid with the formation of a mmenthene (l-methyl-3 - isopropylcycZohexene) CloHI8. (3) Preparation of the mmenthene dibromide C,,H,,Br,. (4) Conversion of the di-bromide into a m - menthadiene (1 -methyl - 3 - isopropylcydo-hexadiene) ClOH16 by elimination of two molecular proportions of hydrogen bromide through treatment with alcoholic potassium hydroxide. It is evident that dehydration of 1 -methyl-3-isopropylcycZo-hexan-6-01 (I) might result in the formation of either l-methyl-34sopropyl-A5-cycZohexene (11) or l-methyl-3-isopropyl-A~-cycZo-hexene (111) The dibromide of the former hydrocarbon would yield on treatment with alcoholia potassium hydroxide 1 -methyl-3-isopropyl-A4 %ycZohexadiene (IV) whilst from the latter either of two isomerides l-methyl-3-isopropyl-A~~5-cycZohexadiene (V) or l-methylene-3isopropyl-h5-cycZohexadiene (VI) might be produced in a similar manner.Direct evidence of the constitution of the hydrocarbon CloH18, which we obtained from the m-menthanol is lacking but its proper-ties are very similar to those of a m-menthene which was prepared by Knoeveaagel (Annulen 1897 297 169) by heating l-methyl-3-isopropylcycZohexan-5 -01 with phosphoric oxide at 1 10-130° and should therefore be either 1-methyl-3-isopropyl-A4-~ycZohexene or l-methyl-3-isopropyl-A~-cycZohexene : ’HMe*CH,*?HPrS CHMe-CHI,- 8H P r a j CHMe- CH,*CHPrP &H,-CH=c!H f- bH2=CH(OH)* H ~ H = c H - ~ H ~ a 146 HENDERSON AND SMEATON CONTRIBUTIONS TO THE The physical constants of the two hydrocarbons are as follows: B.p. D. n,. MD. H. and S. ......... 167-168" 0.8222 1.45683 45.61 K. .................. 167-168" 0.8197 1-45609 45-67 Comparison of the figures suggests the conclusion that the sub-stances are identical and therefore that the hydrocarbon which we obtained from I-methyl-3isopropylcycZohexan-6-01 is l-methyl-3-&opropyl-A5-cycZohexene (11). If this is the case the dibromide prepared from it is 5 6-dibromo-l-methyl-3-isopropylcycZohexane, and therefore the hydrocarbon C10H16 which the dibromide yields on treatment with alcoholic potassium hydroxide is in all proba-bility l-methyl-3-isopropyl-A4 :6-cycZohexadiene (IV).The follow-ing evidence in support of this view may also be quoted. Harries and Antoni (Annalen 1903 328 88) obtained a " dihydrocymene," Cl0HI6 by distilling the phosphate of 1 3-diamino-m-menthane, which should be either A4 :6- or A1 :5-l-met~hyl-3-isopropylcycZo-hexadiene. The properties of this hydrocarbon-boiling point 172-174O DiiZ 0.8423 mi,"5 1-47936-do not correspond at all closely with those of our m-menthadiene which are as follows: boiling point 169-171° DE 0.8515 rz 1-47270. ' Apparently, therefore the latter is not the ,l1:6-isomeride whilst i f the m-menthene from which it is derived has the A5-structure as appears probable formula VI is also excluded. Of the three possible formulze for the menthadiene there is none in which conjugated double bonds are absent and indeed the fact that it is not capable of uniting additively with more than one molecular proportion of bromine although containing two ethylenic linkings in its molecule shows that i t has this conjugated structure.Nevertheless the value found for its molecular refraction was normal instead of showing an exaltation as might have been expected. A t the same time it should not be forgotten that, according to Auwers and Eisenlohr (Ber. 1910 43 SO) the presence of conjugated ethylenic linkings in a compound can be established with more certainty from consideration of its molecular CI,H,,J=2 DX 0.8515. Dqo 0.8500. Molecular refraction. -. Line. n20. Found. Calculated. A. D ..................... 1.47270 44-89 45-24 - 0.36 C .....................1.46964 44.65 44-97 - 0.32 c f ..................... 1.48802 46-21 46.39 -0.18 Molecular dispersion (M,-M,) . Found. Calculated. A -7 1.56 1.426 0-134 =9.4 per cent CHEMISTRY OF THE TERPENES. PART XIX. 147 dispersion than from t,he molecular refraction and as shown in the above table the figures obtained for the m-menthadiene confirm the view expressed regarding its structure. EXPER IYENTAL. YMt =CH-gPrP C(OH):CH*CH 6-Hydroxy-m-isocymene, mAoCymene (1 -methyl-3-isopropylbenzene) was prepared from fenchone by treatment with phosphoric oxide according to Wallach’s method (Annalen 1893 275 IS$) and converted into 6-hydroxy-m-isocymene by the process described by Kelbe (Annalen 1881 210 30) with certain modifications.On warming with concentrated sulphuric acid m-isocymene yielded readily a mixture of m - is0 cy m ene 6 -sul p honi c acid and mis o oy m en e- 4 -sulphonic acid the latter only in small proportions. The sulphonic acids were converted into their barium salts in the usual way and the salt of the 4-acid which is more readily soluble in water was separated from the sparingly soluble salt of the 6-acid. The potassium salt of the 6-acid was obtained by heating the barium salt with a concentrated aqueous solution of potassium carbonate, and purified by crystallisation from water from which it separates in lustrous plates. Finally the potassium salt was fused with six times its weight of potassium hydroxide the fusion dissolved in water the solution acidified and the 6-hydroxym-&ocymene dis-tilled over in a current of steam.From the distillate it was separated partly by means of a tap funnel and partly by extrac-tion with ether dried and distilled (b. p. 231O). It is a colourless, refractive liquid the vapour of which has a very irritating effect o n the lungs. 1 -Me t h y 1-3-isopr o p y 1 cy cloh e xan- 6 - 01 (I ) . The 6-hydroxy-m-isocymene was converted into 1 -methyl-3-iso-propylcyclohexan-6-o1 by treatment with hydrogen in the preselnce of active nickel. I n order to obtain the nickel in an active form, t,he hydroxide of the metal was precipitated by the addition of potassium hydroxide to a solution of the pure nitrate the pre-cipitate washed exhaustively with water formed into a paste by admixture of granules of pumice and dried.The greater part of a long combustion tube was filled with the mixture and the oxide of nickel reduced with pure hydrogen at 280O. The 6-hydraxy-nt isocymene was placed in a boat in the front part of the tube which was maintained a t 170-180° while a steady stream of carefully G* 148 HENDERSON AND SMEATON CONTRIBUTIONS TO THE purified hydrogen was paased through. The hydrogenation pro-duct distilled slowly into the receiver as a colourless liquid. Attempts to crystallise the compound from various solvents or by cooling having proved unsuccessful it was purified by distillation under diminished pressure. 1 -Me t h y l-3 -iso;~ropylcyclohexan-6 - 01 is a colourless somewhat viscous liquid with a pleasant odour. It is very sparingly soluble in water and readily so in alcohol or ether.Its physical constants are as follows boiling point 119-121°/28 mm. DZ 0.9156, $' 1.46659 MD found 47.30 calc. 47.55. l-Methtyl-3-isopropyLA~-cydohexene (11). I n order to effect dehydration the purified 1-methyl-3-isopropyl-cydohexan-6-01 was mixed with about twice its weight of finely powdered anhydrous oxalic acid and boiled for several days in a flask provided with an air condenser until the process appeared to be completed. The contents of the Aask were distilled in a current of steam when a clear oily liquid passed over and floated on the surface of the aqueous layer. The distillate was saturated with ammonium sulphate and extracted with ether the ethereal extract washed with water and dried over anhydrous calcium chloride and the ether removed by distillation.The residual liquid was dis-tilled and two fractions were collected the larger one boiling at 165-185O and the other at 185-205O. The latter wils set aside for further treatment with oxalic acid and the fraction which boiled at 165-185O was redistilled over sodium until a product of constant boiling point was obtained. l-MethyZ-3-is~propyLA5-cyclohexene is a colourless mobile liquid with an agreeable odour. Its boiling point is 167-168°/760 mm. DZ 0.8222 nD 1.45683, MD found 45-61 calc. for C,,H,8,\= 45-39. It is unsaturated, immediately decolorising solutions of potassium permanganate and of bromine. H M e-CX.,-y HPr 6 8 HBr*CHBr* CH 5 6-Dibrmo- 1 -methtyl-3-isopropylcyclohexame, A cooled solution of bromine (1 mol.) in glacial acetic acid was added gradually to a solution of the m-menthene (1 mol.) in the same solvent cooled with ice-water and stirred continuously.After addition of the bromine the solution was left for half an hour and then poured into ice-water. The dibromo-derivative settled down as a heavy oily liquid almost colourless which was washed with water until free from -tic acid and used for the next operation without further purificatio CHEMISTRY OF THE TERPENES. PART XIX. 149 l-Meth yl-3-isopropyE-A4 :6-cycloh ezadiene (IV) . The dibromo-derivative was boiled for several hours under a reflux condenser with an excess of alcoholic potassium hydroxide until no further separation of potassium bromide took place. The mixture was then distilled in a current of steam and the oily distillate separated from ths water with the aid of light petroleum.The extract was washed with water and dried over anhydrous potassium carbonate and the petroleum then distilled off. The liquid which remained was fractionally distilled over sodium in an atmosphere of dry hydrogen; no signs of decomposition were observed during the process and the distillate was perfectly colour-less. After several fractionations a product of constant boiling point was obtained. 1 -Methyl-3-isopropyl-A4 :6-cyclohezadiene (A* L6-m-menthadiene) is a colourless limpid liquid with an agreeable d o u r . It boils a t 169-171°/760 mm. and has DZ 0.8515 1.47270 M found 44.89 calc. for C,,HI6 I= 45.24. The hydrocarbon is unsaturated, at once reducing an alkaline solution of potassium permanganate, but is not 'capable of combining additively with more than one molecular proportion of bromine.With sulphuric acid it gives a red with sulphuria acid and alcohol a reddish-brown and with acetic anhydride and sulphuric acid a violet coloration. From the results of the determination of its physical constank shortly after purification and again after an interval of ssven days i t evidently undergoes change probably polymerisation on keeping. Thus the following results were obtained with a specimen which had been set aside for a week after purification Dg 0.8614 nz 1.47437, M found 44.44. The m-menthadiene appears in fact to behave in a similar way to cyclopentadiene . (compare Auwers and Eisenlohr Zoc. cat.). We take this opportunity of expressing our gratitude to Mr. W. G. Birrell for valuable assistance in the experimental part of the work and to the Research Fund Committee of the Carnegie Trust for a grant in aid of the expenses. UNIVERSITY OF GLASGOW. [Received January 15th 1920.

ISSN:0368-1645    

DOI:10.1039/CT9201700144

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

150 TIZARD AND WHISTON EFFECT OF CHANGE IN TEMPERATURE X1X.-The Efect of a Change in Temperature on the Colour Changes of Methyl-orange and on the Accuracy of Titrations. By HENRY THOMAS TIZARD and JOHN REGINALD HARVEY WHISTON. IN a former paper (T. 1910 97 2477) one of us gave the results of quantitative measurements of the depth of colour of solutions of methyl-orange containing varying concentrations of hydrogen ions. The results could be quantitatively accounted for on the simple theory that methyl-orangel was a (pseudo-) acid of a strength of about 4-2 x 10-4 a t about 25O and that the depth of d o u r of the red (un'dissociated) form of the acid was 18.8 times that of the yellow dissociated form or acidic ion in solutions of the same strength. The calculation of the1 dissociation constant depends directly on the latter measurement for (see previous paper) if a is the degree 04 dissociation of the indicator acid and C, the depth of colour of the undissociated molecule compared to that of the dissociated molecule as unity the collour of a solution cont'aining a fraction a of the acid in the dissociated form is: C=C,,(l-a)+a .. . . . . (1) and the concentration of the hydrions in t,he solution is given by (2) C = K . - - - - . 1-a . . . . . a If Co a d C are measured a can be calculated from (1) and K from (2). A mistake in the value of C of course alters the calcu-lated value of K . The results recorded in the present paper agree at 25O very well wit,h the older measurements in not too acid solutions. When more acid is present they are consistently lower.This may be partly due to the fact that a different sample of methyl-orange was used but it is more likely that the depth of colour in the more strongly acid (red) solutions was previously overestimated. This would mean that the value of K a t 25O calculated in the previous paper was too high; present measurements give 3.8 x at 25O instead of 4.25 x 10-4. It is naturally difficult t o compare accurately the depths of colour of solutions which differ in tint, even though the difference is very slight as in the present case. The determination of the concentration of hydrions in aqueous solutions by means of '' indicators " has been frequently used durin ON THE COLOUR CHANUES OF METI-IYL-ORANGE ETC 151 the last few years.It has been generally assumed that the effect of temperature on the depth of colour of solutions containing methyl-orange was practically negligible. It was poiqted out, however in a paper read before the British Association in 1912 that this was probably not the case. There seems very little doubt that indicators in general use are pseudo-acids or bases. Now t5he strength of pseudo-acids usually increases considerably with the temperature; in other words their dissociation constants have a very high temperature-coefficient. The sensitiveness of an indicator depends however directly on its dissociation constant; i f the constant increases the indicator will become less sensitive t o hydrions and therefore the dept>h of colour in a solution of any definite hydrion concentration (within the range of sensitiveness) will diminish.'A qualitative experiment showing this effect is as follows if an N/ZOO-solution of acetio acid containing methyl-orange is heated the colour of the solution will change from orange to yellow and increase again on cooling. Since no quantitative experiments have been made on the effect of temperature on the changes of indicators it was thought advis-able to determine the depth of colour of methyl-orange in solutions of varying acidity a t three different temperatures. The measure-ments were carried out exactly as before with a modified Donnan colorimeter constructed by Kijhler in Leipzig . The colorimeter tubes were jacketed outside with tubes through which a stream of water could be passed.The temperature of the solutions in the colorimeter tubes was thus kept constant by siphoning water through the jacketed tubes from a reservoir kept a t the desired temperature. The temperature inside the tubes was (at the higher temperatures) a few degrees lower than that of the bath but could easily be kept constant within lo during the series of experiments. The solutions of varying hydrion concentration were made by mixing known quantities of equivalent solutions of ammonia and acetic acid. These two substances are of practically the same strength and further 'their strength and especially that df acetic acid alters only slightly with the temperature as the following numbers taken from Lund6n's tables show: 18" 25" 40" Ammonia ............1-4 1-77 1.87 x Acetic acid ......... 1.82 1-86 1.81 x 10-5 Now if we add z C.C. of ammonia to (say) 10 C.C. of.an equivalent solution of acetic acid then if z is less than 10 we have a solution containing (10-2) equivalents of acid and z equivalents of salt (ammonium acetate) which may be considered to be completel 152 TIZARD AND WHISTON EFFECT OF CHANUE IN TEMPERATURE dissociated in dilute solutions. tion the concentration of hydrions is given by K x (con’centration of acetio acid) = (concentration of acetion) x Hence Then if V is the (unknown) dilu-(concentration of hydrion). and is independent of V provided this is neither too small nor too large and also of the temperature since h7 alters so little with the temperature. This is by far the easiest way of preparing solutions of any definite concentration of hydrions between and 10-7 (the neutral point).It is not necessary t,o know the strengths of the acid and alkaline solutions absolutely so long as their relative strengths are known accurately. For this purpose i t is best to titrate the acid solu-tion direlctly against standard baryta using phenolphthalein as indicator and the ammonia solution using methyl-red as indicator, against a solution of hydrochloric acid which itself has been titrated against the same haryta solution. The effect of temperature on the “end-colours” of methyl-orange that is on t’he depth of colour in highly acid and in neutral or alkaline solutions (C,<lO-7) is practically zero. No difference in the depth of colour of the red acid form could be detected when the temperature ranged from loo to 40°; this means that whatever is the form of the undissociated acid which imparts the distinctive red colour to the solution its concentration is altered very little with rise of temperaturel.The depth of colour of the yellow (alkaline) solution which one may suppose to contain only the ion N( CH,),*C,H,*N~N*C,H,*SO,’ appeared to increase slightly when the temperature was raised from loo to 40° but the. increase is within the unavoidable errors of measure ment a t these temperatures. The mean of many experiments gave 17.5 as the molecular colour of the undissociated acid taking that of the yellow dissociated form as unity. The depths of colour of solutions containing concentrations of hydrions within the limits of sensitiveness are given in the follow-ing tables; from the results the following values for the (apparent) dissociation constant of the indicator were obtained : Temperature...... 15” 24” 37” K ................. 2-7 3.7 5 . 2 ~ 1 0 - 4 The valuea for the depth of colour in the various solutions calcu-lated from these numbers are given in the third column of th ON THE COLOUR CHANGES OF METHYL-ORANGE ETC. 153 tables. The r s u h previously obtained for 2 5 O are included in the t'able for 240. The agreement' is very satisfactory except in the more acid solutions; it should be remembered that the former results were all obtained in dilute solutions of hydrochloric acid. Temperature 1 5 O ; K=2-7 x 10-4; C,=17-5. Concentration of hydrions.1-3 x ............... 5-9 ,, 2-8 x ............... 7.0 ............... 3.34 ,) 5.0 , . . . . . . . . . . . . . . . 1.0 x 10-9 ............... 2.0 ,, 3.7 ............... 1.0 x 10-1 ..... * ......... . . . . . . . . . . . . . . . 1.6 xi'o-4 ............... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 xi'o-2 ............... Colour (observed). 1-10 1-33 2.67 4-45 7-00 10.0 11-7 14-3 15.3 16.0 17.1 17.8 Colour (calculated). 1.12 1-35 2-55 4.38 7.14 10.1 11.7 14.0 15.5 16.4 17-1 17.5 Temperature 2 4 O ; K=3.7 x 10-4; Co= 17%. Concentration of hydrion. 0.16 x 10-4 ......... 0.365 , .. .. . . . . . 0.91 , ... .. . . . . 2.15 , ......... 5.0 , . . . . . . .. . 3.7 x 10-5 ......... lo-' (N/lO-HCl) Colour (observed). 1.66 2.50 4.28 7.10 10-4 15-7 17.4 Colour (calculated). 1.68 2.48 4-25 7-06 10.5 16.0 17-5 Previous measurements at 25".* 1-65 2-41 4.13 7.03 10-6 18-3 -* T. 1910 97 2477. Temperature 3 7 O ; H=5.2 x 10-4; C0=17*5. Concentration of hydrion. o m x 10-4 ............ 0-535 , .. . . . . . . . . . . 1-58 , . . . . . . . . . . . . 2-15 , .. .. .. . . .... 5.0 , .. . . . ...... . 1.0 x 10-3 ............ 2.0 ,, 3-7 ,, 1.0 x 10-2 ..... ....... . . . . . . . . . . . . .... . . . . . . . . 10-1 ... ...... . . . Colour (observed). 1.90 2-61 4.54 5-60 9.20 11.6 14.0 15.4 16-3 17.5 Colour (calculated). 1.84 2.54 4.84 5.82 9.10 11.4 14.1 15.5 16.7 17.4 In the diagram depths of d o u r are plotted against concentra-tion of hydrions.The three curves represent the results at the three temperatures chosen; it will be seen that the effect of raising the temperature is to shift the colour curve to the left. The dis-sociation constant increases linearly with the temperature j extra 154 TIZARD AND WHISTON EFFECT OF CHANGE IN TEMPERATURE polation gives the following values for the temperatures loo 25O, and 40°: Temperature . . . . . . . . . 10" 25" 40" Dissociation constant 2- 1 3.8 5 . 5 ~ 10-4 It can be easily shown (see equation 2) from these results that the concentzation of hydrion necessary to produce any definite depth of colour is doubled by raising the temperature from 1 5 O to 40°.Discussion of R eszclts. The very great temperature-coefficient of the dissociation constant of methyl-orange may be taken as strong evidence of the truth of 10 1 lo-" 10-3 10-4 10-5 10-6 Concentration of hydrions. the modern theory that this indicator is a pseudo-acid. No other case in the literature orf the subject can be found of an acid of this order of strength (I! = lo-*) increasing in strength appreci-ably within these limits of temperature. A t the same time it is necessary to reconcile this conclusion with the fact that the red colour of the undissociated acid form of the indicator does not change in depth when the temperature is altered. The obvious explanation of the high temperaturecoefficient of the dissociation constant of pssudo-acids is that the equilibrium between the pseud* and true acid forms of the acid which we may express by the formula HXO HOX ON THE COLOUR CHANGES OF METHYL-ORANGE ETC.155 alters considerably with the temperature. I f this is true of methyl-orange why does not the colour. alter ? The following seems to be a satisfactory explanation of this difficulty. Methyl-orange or rather helianbhin is a sulphonic acid. If it were not a pseudo-acid we should therefore expect it to be a strong acid, comparable’ with sulphuric acid with a dissociation constant of about 1. Assuming this we may say that since its dissociation constant is actually found to be of the order 3 x 10-4 (at the ordinary temperature) then the undissociated form of the acid must be an equilibrium mixture consisting almost entirely of the red pseudo-form (or forms) IIXO whilst only a fraction, 3 x of it is in the yellow “true acid form” HOX.Increase in temperature to 40° means that this fraction is increased to 5.5 x without appreciably altering the proportion in the pseudo-acid form. Hence the colour remains practically unchanged. Since the depth of colour of methyl-orange in a solution con-taining an N/5000-concentration of hydrogen ions (C = 10-3-7) is 5.45 at 40° and 9.1 at 10°-an increase of 65 per cent. for a fall in temperature of 3Oo-it is clear that if the methyl-orange method is employed for determining quantitatively the concentration of hydrions in a solution it. is important to ,ke8ep the temperature constant during the measurements.The effect of a change in temperature on the accuracy of an ordinary titration is however, only very slight. The concentration of hydrogen ions in a solu-tion of a salt made up of a weak base and strong acid is approxim-ately where Kw and lirb are the dissociation constants of water and tho base respectively and? is the concentration of the salt in mols. per litre. The effect of the increase of the dissociation constant of methyl-orange with the temperature is that the concentration of hydrions ‘ I indicated ” is greater the higher the temperature. Since how-ever /”- also increases with the temperature the two effects tend to cancel each other and the accuracy of the titration is not impaired. Taking collidine (JKb = 1-6 x 10-7 a t 1 8 O and 3 x 10-7 a t 40°) as an example of a base for the titration of which methyl-orange is a suitable indicator the concentration of hydrions at the “equivalent” point if V=20 is 4 x 10-5 a t 18O and 7 x 10-5 at 40°. The dissociation constant of methyl-orange increases from 1 ‘% K 156 HINSHELWOOD THE RATE OE’ 3 x 10-4 to 5.5 x 10-4 for this range of temperature and the depth of colour of methyl-orange in solutions of the above concentration would be 3.0 at 18O and 2.8 a t 40° respectively a difference which is of course negligible. The accuracy of a titration in such cases depends mainly on quite other factors chief of which+is the e$ect of a small excess of acid or base on the hydrolysis of the salt and this depends only on the strength of the acid or base in question, and not at all on the indicator. In other words a change in temperature witlhin reasonable limits can never necessitate a change of indicator. We are much indebted to the Research Fund Committee of the Chemical Society for a grant which partly defrayed the cost of the colorimeter. OXFORD. [Received January 6th 1920.

ISSN:0368-1645    

DOI:10.1039/CT9201700150

出版商:RSC    

年代:1920

数据来源: RSC