摘要:

174 COHEN AND MILLER: OXIDATION OF THE XXl.-The InJuence o f Substitution iqa the Nucleus o n the Rate of Oxidatioiz OJ’ the Side-chain. I. Oxidation of the Mono- mid Di-chlorotolTcenes. By JULIUS BEREND COHEN and JAMES MILLER ISOLATED observations on the effect of different oxidising agents, and on the influence OF certain groups in accelerating or retarding oxidation of the side-chain, have been made by different observers, but the subject has never been systematically investigated. Wroblewsky (Ber., 1882, 15, lO?l), without giving experimental details, states that if benzene with hydrocarbon side-chains in which hydrogen is re- placed by a halogen or a nitro-group is submitted to oxidation by chromic acid mixture, those side-chains pass into carboxyl which are farthest from the halogen.” Lellmann’s Organische Xynthese, p.196, contains the following statement : ‘‘ Negative atomic groups in the ortho-position protect the alkyl group from the action of oxidising agents, whereas alkaline oxidising agents attack this group.’’ The exact reference is not given, but the statement is apparently based on that of Wroblewsky and also on certain observations of W. A. Noyes (Amer. Chern. J., 1885, 7, 145; 1886, 8, 185; 1889, 11, 161). The latter investigator found that o-bromotoluene is oxidised with difficulty to o-bromobenzoic acid by means of potassium ferricyanide ; also that m-nitrotoluene is less readily oxidised by this reagent than its isomer- ides. Schopff (Bey., 1891, 24, 3778) concludes from the results of his attempts t o oxidise o-brorno-na-xylene that “ the oxidation of a methyl group in the ortho-position (to bromine) with acid oxidising agents is effected slowly and with difficulty.” Rupp ( B e y ., 18\12, 25, 347) ex- perienced t h e game difficulty with tetrachloro- and tetritbromo-p-xylenes, and only succeeded with a mixture of nitric acid and permanganate. It is clear that no satisfactory generalisation can be drawn from these isolated facts, Certain points which were noticed in the courseMONO- AND DI-CHLOROTOLUENES. 175 of the researches in which one of us has been engaged in collaboration with H. D. Dakin (Trans., 1901, 79, 1111) and with S . H. C. Briggs (Trans., 1903, 83, 1213) on the oxidation of the halogen derivatives of toluene suggested the present inquiry. The method which we have adopted is to heat about a gram of the substance with dilute nitric acid in a sealed tube for a length of time insufficient for complete oxidation, and to estimate the proportion of acidic product and unchanged substance.In our first experiments, the substance was weighed in small specimen tubes which were slipped into the tube containing the acid. The sealed tubes were heated in a cylindrical, jacketed, tin-plate air-bath which was fixed horizontally, the required temperature being attained by boiling turpentine con- tained in the outer jacket. The results of the experiments with this apparatus were not con- cordant. We attributed this partly to the specimen tubes, which to some extent pro- tected the substance from the action of the acid.These tubes were therefore discarded and the substance introduced directly into the acid. We found, moreover, that the inner compartment of the air-bath was about 5' hotter at the bottom than at the top, SO that the lower tubes were at a higher temperature than the upper ones. The horizontal, air-bath was therefore replaced by a vertical one, jacketed as before, and covered with flannel as shown in the figure. The liquid in the jacket was coal-tar naphtha boiling at 140-150'. Although there was still a difference of about 3' between the temperature of the top and bottom of the inner compartment, yet as the tubes, which / f were approximately of equal length, were placed vertically, they were consequently exposed t o the same conditions of temperature. Care was taken t o prevent direct contact between the tubes and the metal of the bath by fixing a cork pad a t the bottom and covering the tubes with flannel.Under these modified conditions, concordant results were obtained. The substances employed were the three monochlorotoluenes and the six dichlorotoluenes, all of which were carefully purified by fractional distillation, and in the case of 3 : 5-di- chlorotoluene by crystallisation. T h e monochlorotoluenes were ob- tained quite colourless by distillation under diminished pressure, but this treatment was not found necessary in the case of the dichloro- toluenes. N 2176 COHEN AND MILLER: OXIDATION OF 'I'HE The following are the boiling points of the substances employed : b. p. mm. b. p. b. p. Monochlorotoluenes.Dichlorotoluencs. Ortho- looo 129 2 : 3 - 200-20Z0 2 : 6- 192-154' Meta- 102 130 2 :4- 194.5-195.5 3 : 4 - 203-204 Para- 85 61 2 : 5 - 195-157 3 : 5- m. p. 26-27 A weighed quantity of the substance (about 1 gram) was intro- duced into tho tube, and about six times this amoiint of dilute acid (1 vol. nitric acid of sp. gr. 1.4 to 2 vols. water) was added and the tube sealed. I n order to ascertain the effect of the length of the tube on the rate of oxidation, equal quantities of 3 : 5-dichlorotoluene were heated in two tubes, oce of which was about half the length of the other. It was found that the acid formed in the shorter tube was less pure and rather larger in amount, but the difference was insignificant and would be inappreciable in tubes so nearly of the same length as those which we employed.The air-bath was closed loosely by a cork holding a thermometer and heated until the temperature was constant. The tubes were then introduced, and when the temperature of the inner compartment reached 138-140' the tubes were left for 14 hours, during which the temperature of the interior did not exceed 145O. The bath was then allowed to cool and the tubes removed and opened. The method of analysis was as follows: the contents of each tube were in turn rinsed into a separating funnel with ether, the contents being then vigorously shaken, whereby the ether dissolved out the whole of the organic compounds. The acid layer was then drawn off and sodium carbonate solution added in excess to the ether and well shaken to extract the organic acid.The alkaline layer was removed and the ethereal extract washed with a small quantity of water, the washings being added to the alkaline liquid. The ethereal solution, which con- tained the unaltered substance (possibly also a little aldehyde), was dehydrated over calcium chloride, decanted into a tared flask, the ether removed, and the residue weighed. The alkaline liquid was acidified with hydrochloric acid, extracted with ether, the ethereal solution dehydrated over calcium chloride and treated as described above. The purity of the acid was in each case ascertained from the melting point. This and the total quantity of products obtained when com- pared with the substance taken was a satisfactory check on the result, although, of course, the method lacks the precision of an exact analytical process.I n the following experiments, all the tubes were heated together under precisely the same conditions,MONO- AND DI-CHLOROTOLUENES. 0'932 1'089 177 146-149 235-236 Chloro- toluene. Ortho. Meta- Yara- 2 :3- 2 : 4 - 2 : 5 - 2 : 6 - 3 : 4- 3:5- 3 : 5- I (short tube) Actual amount taken. _____- 1.005 0.989 0-964 1 *a32 1.035 1 -065 1.036 1 -024 1.046 0.988 1st series. Calculated to 1 gram. E:kzi 1 Unchanged acid. substance. 1*011 1.092 1 *G58 0.942 1,073 0.864 0.825 1 -060 0.726 0.759 ' 0.040 ~ 0.029 0.019 0.135 , 0.051 0.157 0 -236 0.047 0.297 0.228 .____ Total. 1.051 1'121 1.077 1.077 1'124 1.021 1'061 1.107 1 '023 0.987 m. p. of acid. 135-1 36' 145-148 233-234 159-162 160- 161 139-142 123-132 200-201 183-1 84 18 4-205 Correct m.p. of acid. 137" 153 236 163 ? 60 153 139-14 0 200-201 182-183 It will be seen from the above table that the monohalogen com- pounds are more rapidly attacked than the majority of the dihalogen derivatives, for the former are almost completely converted into acid, whilst only two of the latter are completely oxidised. The dihalogen compounds show well-marked differences ; the 3 : 5-compound is least attacked. The next in order being the 2 :5- and 2:6-isomerides, which are oxidised to approximately the same extent, although the 2 : 6-compound yields a very impure acid. The 2 : 3-compound comes next,, and finally the 2 : 4- and 3 : 4-derivatives, which may be bracketed together as being almost completely oxidised. As the rnonobalogen compounds were too far oxidised for any con- clusions to be drawn as to their relative rates of oxidation, a second experiment was made i n which the tubes were heated for only half an hour at 140-145O.I Calculated t o 1 gram, Ortho- Meta- Para- 1.015 0.687 0.307 1.011 0'384 0548 1.007 I 0.998 1 0.091 1 3 i " 153 236178 OXIDATION OF THE MONO- AND DI-CHLOROTOLUENES. It is therefore evident that the meta-compound is least affected, then follows the ortho-derivative, and finally the para-isomeride, which is almost entirely converted into the corresponding chlorobenzoic acid. Two other series of experiments which were made with the dihalogen compounds confirm the results of the first series. 2nd Series. Dichloro- toluene. 2 -3 2 *4 2.5 2.6 3'4 3 '5 Chloro- toluene. 2-3 2.4 2'5 2 '6 3 '4 3'5 Amount taken.__ 0.993 0 '974 0.989 1 '044 0.997 1 -000 Amount taken. ____ 1 *076 1 '030 1.165 1.093 1.165 1*000 Calculated to 1 gram. 0.762 I 0'290 0.949 0.119 0,614 0.381 0.546 1 0'4.51 1 '025 0.470 1 i::i 1.052 1.068 0'995 0.997 1.105 0.965 3rd Series. Calculated to 1 gram. Dichloro - benzoic acid. 0'773 1'017 0.631 0'640 1.060 0.357 J n changed substance. Total. 0.247 0496 0.373 0.342 0.055 0.581 1 -020 1-113 1.004 0'982 1'115 0.938 I j __ I 159-161" 163" 138-143 159-1 59.5' 1 , 8 ~ ~ 1 8 3 160 11 5-129 139-140 200-201 200-201 183-184 m. p. of acid. 162-163" 16 0-16 1 139-142 114-128 200-201 182-1 83 Correct m. p. of acid. - _ ~ .- 163" 160 153 139-140 200-201 182-183 So far as the special conditions of the above experiments are con- cerned, namely, the use of halogen compounds on the one hand and of nitric acid as oxidising agent on the other, the results are perfectly definite.The meta-compounds retard oxidation, and the para-compounds assist it, whilst the ortho-compounds occupy an inter- mediate position. Thus, rn-chlorotoluene and 3 : 6-dichlorot oluene are least attacked. p-Chlorotoluene and the two dichlorotoluenes sub- stituted in the para-position (2 : 4 and 3 : 4) are most readily oxidised. It is not clear why the 2 : 3-dichloro-compound should be more readilyDERIVATIVES OF HIGHLY SUBSTITUTED ANILINES. 179 oxidised than the 2 : 5-derivntice, for they are both substituted in the meta- as well as in the ortho-position with respect to the methyl group, nor is it evident why the 2 : 6- and 2 : 5-compounds should be oxidised to the same extent. It is interesting to note that, Noyes, when working with the nitrotoluenes and potassium ferricyanide, found that the meta-compound is less readily oxidised than the other two isomerides. On' the other hand, Wroblewsky's observation (vide ante) seems to be only true in part, unless, indeed, chromic acid has a very different action from that of the other two oxidising agents. It is difficult to account for the behaviour of the different isomerides. I t is clear that (contrary to the view which we were led to adopt as the result of our preliminary experiments) it is not a question of steric hindrance. The only process which seems to offer any analogy to the present one is that of substitution in the nucleus in which the formation of meta-compounds is sharply differentiated from that of the ortho- and para-compounds, yet it is difficult to see how any process of substitution in the nucleus can be applied t o explain the conversion of a side-chain into a carboxyl group. We have accumulated a number of facts in regard t o the oxidation of simple and mixed dihalogen derivatives and nitro-halogen compounds of toluene, which we hope shortly to publish. THE YORKSHIRE COLLEGE, LEEDS.

ISSN:0368-1645    

DOI:10.1039/CT9048500174

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

DERIVATIVES OF HIGHLY SUBSTITUTED ANILINES. 179 XXI1.-Derivutives of Highly Substituted Anilines. By FREDERICK DANIEL CHATTAWAY and JOHN MELLO WADMORE. A NUMBER of acyl derivatives of the 2 : 4-dihalogen and the 2 : 4 : 6-tri- halogen anilines have been prepared during the last few years in the course of an investigation on the phenomena of intramolecular re- arrangement in aromatic amines, and their properties are here placed on record. The aniiides can be obtained by heating the substituted aniline with the equivalent amount of propionyl or benzoy 1 chloride. Vigorous action generally occurs a t 160-180°, and the heating is preferably con- tinued so long as hydrogen chloride is evolved. The product can be crys- tallised from either alcohol or a mixture of chloroform and petroleum.The nitrogen chlorides may all be prepared by adding an excess of a cooled solution of bleaching powder to the anilide dissolved in glacial acetic acid, complete conversion being ensured by extracting with chloroform and vigorously shaking the solution with fresh, slightly180 CHATTAWAY AND WADMORE : DERIVATIVES OF acidified calcium hypochlori te for some hours. The cliloroform solution, when dried over calcium chloride and evaporated in a current of dry air, yields the chloroamine derivative in the form of a viscid liquid which a t once solidifies on cooling and stirring with light petroleum, and can then be crystallised from petroleum or from a mixture of this solvent with a little chloroform, A pure anilide invariably yields a product which solidifies at once and crystallises readily in lustrous, well-shaped crystals ; whereas the presence of even a very small quantity of an admixed isomeride renders the product incapable of solidification.If such a mixture is dissolved in warm petroleum, no crystvls form on cooling, but a viscid, semi-solid mass separates, which only occasionally becomes partly crystalline. 4-Chloro- 6- b ~ o mo benxnrtilide, C,H,CIBr-NH CO*C6H5, separn tes from alcohol in slender, coloiarless prisms and melts at 130.5'. 0.2486 yielded 0.2662 mixed AgCl and AgBr. Halogen = 37.30. C,,H90NCIBr requires halogen = 37.17 per cent. The percentage of halogen throughout has been calculated on the assumption that silver chloride and silver bromide are present in the precipitate in the same proportion as the respective halogens in the anil ide.1 -BenzoyZchZoroami~ao-4 -c?~Zoro-6-b~omobenxene, C6H,ClBr*NC1*COPh, separated in colourless plates melting atl 62O. 0.5084 required 29.2 C.C. N/lO T. 4-Cl~Zoro-6-bromopropionaniZide, C,H,ClBr*NH*COEt, forms slender, 0.2332 yielded 0,2947 mixed AgCl and AgBr. C,H90XC1Br requires halogen = 43.95 per cent. 2-Ci~Zoro-4-b~omobenxaniZide, C,H,CIBr*NH*COPh, cryst allises f1 om alcohol in transparent, colourless, flattened prisms, and melts a t 1 4 5 O . C1 (as NCl) = 10.18. C,,H,ONCl,Br requires Cl (as NCl) = 10.28 per cent. colourless prisms and melts at 128.5". Halogen = 44.03. 0.1868 yielded 0.2007 mixed AgCl and AgBr. Halogen = 37.43. C,,H,ONClBr requires halogen = 37.17 per cent. 1-BenxoylchZo~oam~~ao-3-chZoro-4-bromob~nzene, C,H,ClBr*NCl*COPh, forms colourless plates melting a t 74".0.4294 required 24.7 C.C. N/10 I. C1 (as NCl)= 10.36. C,,H,ONCI,Br requires C1 (as NC1) = 10.28 per cent. 2 - C'ldoro - 4-~romopropionnni~i~e, C6H,C1Br cdourless, hair-like needles and melts at 129O. H *COEt, crys t allises inHIQKLY SUBSTI'CUTTED ANILINES. 181 0.2036 yielded 0.2581 mixed AgCl and AgBr. Halogen = 44.16. C,H90NClBr requires halogen = 43.96 per cent. C,H2Br3*NC1'COPh, which separates in glistening, coloiirless, rhombic plates with domed edges, melts at 1 1 5 O . 1 -BenzoyZchloroamino-Z : 4 ; 6-tribrornobenxene, 0.2368 required 10 C.C. n ; l l O I. C1 (as NCI) = 7.48. C,,HyONC1Br3 requires ctl (as NC1) = 7.57 per cent. 4-Chloro-2 : 6-dibrornobenznniZide, C,H,ClBr,*NH*COYh, forms trans- parent, colourless plates and melts at 194".0.21 14 yielded 0.2802 mixed AgCl and AgBr. Halogen = 49.88. CI,H,0NC1Br2 requires halogen = 50.16 per cent. 1 - Benxoy ZchZo~~oamino-4-ci~Ioro- 2 ; 6-dib*onaobenxene, C,H,C 1 Br;NCl*COP h, was obbained in short, colourless, transparent, four-sided prisms with domed ends melting at 111". 0.2352 required 11.1 C.C. N/lO I. C1 (as NC1) = 8-37. C,,H70NC1,Br, requires C1 (as NC1) = 8.36 per cent. 4-Chloro-2 : 6-dibromopropionanilide, C,H2C1Br;NH*COE t, separates in long, colourless, flattened prisms melting a t 185'. 02388 yielded 0.3646 mixed AgC1 and AgBr. Halogen = 57.45. C,H,ONCl Br, requires halogen = 57.21 per cent. 1 - Propiony Zchloroanaino-4-chloro-3 ; 6-dibromobenxene, C,H,CIBr,*NCl*COEt, forms slender, transparent, colourless prisms and melts at 74".0-2602 requires 13.7 C.C. N/10 I. C1 (as NC1) = 9.33. C,H70NC12Br2 requires C1 (as NCl) = 9.43 per cent. 2 : 6-DichZo?*o~4-bromobenxaniZide, C,H,Cl,Br*NH*COPh, crystallises i n short, colourless prisms and melts at 195'. 0.2448 yielded 0.3345 mixed AgCl and AgBr. Halogen = 43-43. C,,HsONC12Br requires halogen = 43.73 per cent. 1 -Be~zzoyZc?~Zoroc~mino-2 ; 6- dich Zoro-4-bronzo6enxene, forms transparent, colourless plates and melts at, 95". C6H2CI,Br*NCl*COPh, 0.2030 requires 10.7 C.C. N/lO I. C1 (as NCI) = 9.34. C,H?ONCl,Br requires C1 (as NCI) = 9-34 per cent.182 DERIVATIVES OF HIGHLY SUBSTITUTED ANILINES. 2 : 6-Dic~Zoro-4-bromopropionctnilid~, CdH,Cl,Br*NH*COEt, crystal- lises in colourless, flattened prisms melting at 184'.0.2418 yielded 0.3843 mixed AgCl and AgBr. Halogen = 50.51. C,H,ONCI,Br requires halogen = 50.80 per cent. 1-Benxoylchloroumino- 2 : 4-dichZoro-6-6~~omo6enxene, C,H,Cl, Br*NCl*COPh, forms transparent, colourless, f our-sided prisms with steeply domed ends and melts at 92O. 0.2204 required 11.7 C.C. N/10 I. C1 (as NCY) = 9.41. C1,H70NC13Br requires C1 (as NC1) = 9.34 per cent. '3 : 4-Dichloro- 6 - brom.o~ropionaniZide, C,H,Cl ,Br -NH CO E t , crystal- h e s in colourless needles and melts a t 165'. 0,2089 yielded 0.3338 mixed AgCl and AgBr. Halogen = 50.78. C,H,ONCl,Br requires halogen = 50.80 per ceu t. 2-Chloro-4 : 6-dib~omobenxaniZide, C,H,CiBr,*NH*COPh, which was obtained in colourless, short prisms terminated by pyramids, melts at 192O. 0.1704 yielded 0.2272 mixed AgCl and AgBr. Halogen = 50.17. C,,H,ONCIBr, requires halogen = 50.16 per cent. 1 - Benxo~ZchZoroan~ino-2-clilol.0-4 ; 6-dibromobenxene, C,H2C1Br2*NC1-COPh, separates in colourless, short, four-sided prisms with domed ends and melts at 9 7 O . 0.2240 requires 10-7 C.C. N/10 I. C1 (as NC1) = 8.46. Cl3H70NCI2Brl requires C1 (as KCl) = 8.36 per cent, 2-Chloro-4 : 6-dibromopropionanilide, C,H,CIBr,*NH°COEt, forms colourless needles melting at 185-5'. 0.1862 yielded 0.2828 mixed AgCl and AgBr. Halogen = 57.15. C9H80NCIBr2 requires halogen = 57.21 per cent. QT. B4RTHOLoMEW'8 HOSPITAL AND COLLEGE.

ISSN:0368-1645    

DOI:10.1039/CT9048500179

出版商:RSC    

年代:1904

数据来源: RSC

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THE CONDENSATION OF FURFURALDEHYDE. 183 XXIII.-The Conderm&m of Furfuraldehyde with Sodium Succinutc. By ARTHUR WALSH TITHERLEY and JAMES FREDERICK SPENCER, B. Sc. IN the course of an investigation on the higher acids of the succinic series, the authors, in seeking new methods of synthesis, selected fur- furaldehyde as a starting point with the intention of converting it into acids of the type C4H,0eCH:CH*[CH2],*C0,H, and these into suberic acid and its homologues, by processes similar to those by which Baeyer obtained .n-pimelic acid, CO2H-[CH,],*CO,H, from furylacrylic acid, C4H,0*CH:C'H*C02H (Bey., 1877, 10, 695, 1358). It was anticipated that /3-furfurylidenepropionic acid (furylisocrotonic acid), C,H,O*CH:CH*C H,*CO,H, the simplest compound of the above type, would be readily formed, according to Fittig's method, by the condensation of furfuraldehyde with sodium succinate in the presence of acetic anhydride (Annalen, 1883, 216, 97 ; 1889, 255, 1-142).C,H,O*CH:O + C0,H I p 2 J 3 CH,*CH,*CO,H --f C,H,O*(!H*CH*CH,*CO -+ Fury lparaconic acid. C,H,O*CH: CH*CH,*CO,H Furylisocrotonie acid. A considerable number of experiments, which have been carried out under a great variety of conditions, show beyond doubt, however, that furf uraldehyde behaves abnormally. Neither furylparaconic acid nor f urylisocrotonic acid could be isolated, but two unexpected deriva- tives, Cl,HloO, and C,,H,O,, were obtained, but in such comparatively small yields that their investigation has been attended with consider- able difficulty. I n dealing with the two compounds resulting from the condensation, it was at first suspected that the anomalous results might be due to the acetic anhydride having taken part in the reaction, but further investigation disproved this assumption, and it was ultimately shown that one of the products, C,,H,,O,, could be obtained, in the absence of acetic anhydride, by the interaction of furluraldehyde, sodium succinate, and succinic anhydride.The compound C,,H,O,, which crystallises in long, dark orange- coloured needles melting at 187O, has the properties of a substituted succinic anhydride, and the other, C13H1004, which forms yellow, crys- talline plates melting at 213', was found to be a monobasic acid ; both substances, which are distinctly unsaturated, are produced by the184 TITHERLEY AND SPENCER: THE CONDENSATION OF condensation of 2 molecules of furfuraldehyde with 1 molecule of sodium succinate ; the orange-coloured compound being dif urfuryl- idenesuccinic anhydride, C4H30 cH:~'cO>O, whilst the yellow C,H,O C H: C*CO compound is ay-difurfurylidenepropionic acid (a-furf urylidenef uryliso- crotonic acid), Since the orange-coloured compound is insoluble in cold aqueous alkali hydroxides, whilst the yellow compound dissolves in these solutions, the separation of the two products is readily effected.Un- fortunately, their production is accompanied by large quantities of resinous substances having both acid and neutral properties, a fact which renders the purification very tedious, I n spite of a large number of experiments carried out under widely differing conditions, no evidence was obtained of the formation of the monofurfurylidene derivatives.The interaction of furfuraldehyde and sodium succinate in the presence of acetic anhydride may be represented as occurring in the following stages : C,H,O*CH:QH C,H,O CH:C*CO,H CH, *CO,Na C,H,O CH:y*CO,Na + 2H,O. --+ C,H,O CH: C*CO,Na 2C,H30*CH:0 + ),H,.CO,Na The dicarboxylic acid is liberated from the sodium salt by the acetic acid, resulting from the action of the eliminated water on a portion of the acetic anhydride, the excess of the latter reagent then converting the dicarboxylic acid into its anhydride. At the same time, carbon dioxide is removed from another portion of the dicarboxylic acid, giving rise to the monobasic acid : >o C,H,O* CH : CO C,H30* CH C*CO,H /' -."o -----* C,H,O*CH:C-CO The final product of the reaction contains, therefore, in addition to a certain amount of the unchanged reagents, the orange-coloured anhydride, the yellow acid and its sodium salt, sodium acetate, acetic and succinic acids, some succinic anhydride,* and traces of furylacrylic * I t has been shown beyond question, by separate experiments, that succinic anhydride and sodium acetate ar0 formed when sodium succinate and acetic adiydride are heated together.A double decomposition of this nature was assumed by Fittig and Ott (Annalen, 1885, 227, 79) to take place between sodium isobutyrate and acetic anhydride, giving rise t o isobutyric anhydride and sodium acetate, but although the results obtained by theso authors could only be interpreted on this assumption, the change was not demonstrated experimentally.FURFURALDEHYDE WITH SODIUM SUCCINATE.185 acid. Carbon dioxide is steadily disengaged during the course of the reaction, especially if the temperature is allowed t o rise, and whilst the production of yellow acid increases at higher temperatures, that of the orange-coloured anhydride decreases t o a corresponding extent. The succinic anhydride formed as a secondary product in the reaction does not appear t o play any special part in the formation of the orange- coloured anhydride, such as might at first be suspected. There can be no doubt that i t is the sodium salt alone which enters into action with the aldehyde, as with other condensations of this order (Fittig, Eoc.cit.), for furfuraldehyde could not be made t o condense with succinic an- hydride in the absence of sodium succiuate, either by varying the tem- perature or by adding acetic anhydride or other dehydrating agents. Difurfurylidenesuccinic anhydride has a bright scarlet colour re- sembling that of azobenzene ; i t is stable towards hydrolytic agents, and is attacked only slowly by boiling aqueous sodium hydroxide, yielding the sodium salt of the corresponding dicarboxylic acid. The acid itself is a pale yellow powder which melts at 1 8 5 O , regenerating the original orange-coloured anhydride. The marked stability of the latter is comparable with that of pyrocinchonic anhydride and the tetra-alkylsuccinic anbydrides, and there can be little doubt that the cyclic structure, ~*‘>O, in the orange-coloured compound is more c*c closely allied t o the furan nucleus than t o the ring present in succinic anhydride.This configuration is, moreover, present in the two fury1 groups, and the colour of the compound must in some way be associated with this peculiarity in constitution, and possibly with a special structure in the furan nucleus, having chromogenic char- acters, like the quinonoid grouping in the benzene nucleus. The chromogenic intensity becomes enhanced when bromine is added to the molecule, and the tetrabromide has marked fluorescent properties (see During this investigation, large quantities of furfuraldehyde were used up in abortive attempts to increase the yields of the yellow and orange-coloured compounds, but a1 though the cocditions were varied as f a r as possible, the yields never exceeded 5 per cent.of the calcul- ated amount, except in one instance when an 8 per cent. yield of the yellow substance was obtained. In many other experiments, traces only were produced. p. 190).186 TITHERLEY AND SPENCER: THE CONDENSATION OF EXPERIMENTAL. Action of FurfuraZdsi4yde on Sodium Succinate in presence of Acetic Anhydride. For mat ion and JSepamt ion of Difurf ur y Zidene- succinic Anhydride and ay-BifiLrfurg Zidenepropionic Acid. An intimate mixture of furfuraldehyde, thoroughly dried sodium succinate, and freshly distilled acetic anhydride, contained in a flask fitted with an air condenser, was cautiously heated in a paraffin-bath. The reaction commenced a t 100' and proceeded so vigorously above this temperature that occasionally, when large quantities were em- ployed, i t became uncontrollable, snd gave rise to black, resinous products.The most favourable yields were obtained by heating together at 90-looo for 6 hours, 20 grams of furfuraldehyde, 30 grams of sodium succinate and 45 grams of acetic anhydride. It was found necessary to employ the sodium salt in the form of a very fine pcwder, which was dried at 140° just before the experiment. During the condensation, small quantities of carbon dioxide were evolved and the contents of the flask darkened, the final semi-solid pro- duct having a dark gi-eenish-brown colour. The relative proportion of orange-coloured anhydride and yellow acid produced varied consider- ably with the conditions (time and temperature), but in general the yellow acid increased at the expense of the anhydride if the tempera- ture was allowed to rise above 100' and if the heating continued for more than 6 hours, whilst in many cases under these circumstances the anhydride was not isolated.It was, moreover, impossible to obtain the anhydride exclusively by working at lower temperatures. These two products were isolated and separated by one or other of the following methods. 1. Ether Extraction.-The contents of the flask were treated with ether, and the solid residue, after filtering, further extracted in a Soxhlet apparatus for 4 or 5 hours, this treatment being necessary owing to the sparing solubility of the yellow and orange-coloured substances in ether.The dark ethereal extracts, on evaporation, slowly yielded these two compounds, together with succinic acid and succinic anhydride, the mother liquor containing acetic acid and its anhydride, furfuraldehyde and resin. The crystals, which were much discoloured, assumed a bright orange colour after draining on a porous plate. They were now treated with dilute ammonia, in which the orange- coloured anhydride remained undissolved as a granular powder. This product was purified by recrystallising from hot glacial acetic acid, and finally from hot benzene. The highest yield of difurfurylidene- succinic anhydride thus obtained, after about thirty separate synthesesFWRFURALDEHYDE WITH SODIUM SUCCINATE. 187 had been carried out in order to ascertain the best conditions of treat- ment, was about 5 per cent.of the calculated amount. I n order to isolate the yellow acid (ay-difurfurylidenepropionic acid) which accompanies the anhydride, the ammoniacal filtrate from the latter was acidified with hydrochloric acid. A dirty yellowish-brown precipitate of the impure acid was deposited, which was found to be very difficult to purify, owing to the presence of brown, oily resins having an acid nature, these substances were also precipitated, and rendered it almost impossible to dry the product. When gently warmed, the impure material melted to a black tar, which could not be effectually purified. By repeated crystallisation of the dried pre- cipitate from hot benzene, however, it was at length found possible to separate the less fusible, yellow, crystalline acid in a fairly pure con- dition from the oily resins.An alternative, and much more satisfactory method of purification was ultimately devised, depending on the fact that the sodium salt of the yellow acid is not very soluble in water and crystallises readily, whilst the sodium salts of the impurities are more soluble and do not crystallise. The impure product, obtained by acidifying the above ammoniacal solution, was therefore washed, dissolved in a slight excess of sodium hydroxide solution, and the resulting dark brown solution of the sodium salts concentrated carefully on the water-bath until crystals commenced to separate. On cooling, the entire mass became crystalline, and the sodium salt, whencollected a t the pump and dried on a porous plate, was obtained in large, transparent, orange-yellow plates.The mother liquor generally yielded a second crop of crystals. The ay-dif urf urylidenepropionic acid obtained from this sodium salt by the action of hydrochloric acid was absolutely pure and melted 5' highsr than that obtained by the foregoing method of crystallisation from benzene. The maximum yield was about 5.5per cent. of theory, this being obtained only by carrying out the original reaction at l l O o , so as to diminish the production of the orange-coloured compound. 2. Treutmeizt with Wccter.-A method of treatment similar to ttlat employed by Fittig (Zoc. cit.) was adopted by the authors in a number of experiments made in endeavouring to isolate furylparaconic and furyl- isocrotonic acids. These acids could, however, not be detected.The steam distillate contained only furfuraldehyde ; the residue in the flask contained a large quantity of oily resin, which was filtered off whilst hot. The filtrate was yellow, and on cooling became turbid, and in the course of two to three days a bright yellow, micro-crystalline powder appeared in the form of crusts on the surface of the liquid and sides of the vessel; this substance melted at about ZOO', and was fairly pure ay-difurfurylideneproyionic acid. It was crystallis&188 TITHERLEY AND SPENCER: THE CONDENSATION OF repeatedly from benzene. The aqueous filtrate from the yellow crusts contained only acetic acid, succinic acids, and their sodium salts. The tarry matter was also examined, and, although i t was found to contain a relatively considerable proportion of the yellow ay-difur- furylidenepropionic acid (which was extracted by repeated treatment with hot water, in which this acid is appreciably soluble), no other acid, except the resin acids, could be obtained from it.The quantity of tarry matter or pitch obtained in all the experiments was very great, and a t once explained the very small yields, but it was impossible under any conditions to prevent, its formation, although by carefully regulating the temperature at which the condensation was effected its quantity could be more or less minimised. The resin was closely inves- tigated and, by repeated solution in alkali and reprecipitation with acids, was obtained in the form of a brown, amorphous powder, which was distinctly unsaturated, had slightly acid characters, and exhibited properties analogous to the yellow, crystalline ay-dif urf urylidene- propionic acid. It had, however, no definite melting point, and evidently consisted of a mixture of several substances (probably poly- merised derivatives), and, although numerous attempts were made to separate them by means of solvents, definitely pure compounds could not be isolated.The mixture was instantly oxidised by cold potassium permanganate, giviDg large quantities of oxalic acid. This investi- gation mas accordingly abandoned. >o. C,H,O*C H:?*CO C,H,O*CH: C-CO Di~~rfuryliclenesuccinic Anhydride, This acid crystallises in fine, silky needles from benzene, but forms thick prisms when separating slowly from glacial acetic acid; i t melts a t 187".0.1123 gave 0.2684 CO, and 0.0351 H,O. C=65*18 ; H=3.47. 0.0872 ,, 0.2080 CO, ,, 0.0270 H,O. C = 65.05 ; H= 3.43. C,,H,05 requires C = 65.62 ; H = 3.12 per cent. A determination of its molecular weight was carried out by the ebullioscoyic method in benzene solution. . Solute. Solvent. Rise of b. p. M. W. I. 0.1524 34.168 0.045 264 IT. 0-2926 34.1 68 0.090 254 C,,H,O, requires M. W. = 256. Difurf urylidenesuccinic anhydride is only very sparingly soluble in the usual organic solvents, but the solutions have a bright orange colour. I n benzene, i t is fairly readily soluble in the hot, but only slightly so in the cold solvent (1 part in 350 a t 14').FUKFURALDEHYDE WITH SODIUM SUCCINATE.189 It is insoluble in and unaffected by water, aqueous sodium carbonate, ammonia, &c.; also by cold aqueous sodium hydroxide, but in a boiling solution of this alkali it is slowly attacked and disappears, forming a pale yellow solution of the sodium salt of the corre- sponding dicarboxylic acid. Attempts made t o reduce dif urf urylidenesuccinic anhydride by zinc dust and glacial acetic acid, and other reduciug agents gave no satis- factory results, mainly owing t o insufficiency of material. On cautiously oxidising the substance with nitric acid, potassium permanganate, or chromic acid, oxalic acid was formed, this result being due to the presence of the furan nucleus. An appreciable quantity of a syrupy acid was simultaneously formed, but this sub- stance could not be purified or identified owing to its small amount. Action of Bromine on D~~rf~icl.~Eidenaswccin~c Anhydride.Owing to the markedly unsaturated character of the anhydride and the presence of two furyl groups, bromine interacts with great vjgour and its chloroform solution is instantly decolorised. It is probable that the first action consists in adding two and then four atoms of the halogen at the points of double union outside the furyl groups thus : C4H,O*CH:p2O Brz C,H,O'CHBr*yBr*CO >o :!$ C,H,O*CH: C .CO >O ---+ C,H,O*CH:C-CO >o, C,H,O*CH Br YBr-CO C,H3O0CKBr GBrmCO further addition then taking place in the furan nucleus. The action is further complicated by the fact that substitution simulta- neously occurs, with evolution of hydrogen bromide and formation of viscous bromo-derivatives.When, however, the bromine is carefully added, comparatively little substitution occurs until four atoms of bromine have been introduced. Experiments were then made with the view of introducing bromine in successive stages corresponding with 2, 4, 6, and more atoms. A saturated solution of the orange- coloured anhydride in chloroform was treated with the requisite volume of a solution of bromine in the same solvent added drop by drop; the solvent was then allowed to evaporats and the residue purified. It was found impossible to isolate in a pure condition any product other than the tetrabromide. I n the experiments in which two atoms of bromine only had been added, a mixture of granular and viscous substances remained which were found to contain the tetrabromide and unchanged difurfurylidenesuccinic anhydride, but no dibromide.From those experimectn, also, in which an excess of VOL. LXXXV. 0190 TITHERLEY AND SPENCER: THE CONDENSATION OF bromine had been used, the chief product isolated was the tetra- bromide, the remainder being a syrupy mixture from which no definite substance could be isolated. >o- C4H,0'CHBr*f)BreC0 C,H ,O*CHBr*CBr -CO This compound was obtained in largest quantity by the addition of four atoms of bromine to difurfurylidenesuccinic anhydride. The residue, after removing the chloroform, had a brown, vitreous appearance; i t was washed several times with cold alcohol and recrystallised from benzene, being then obtained in micro-crystalline, yellow needles melting a t 195-1 96".0.1 736 gave 0*2270 AgBr. C,,H80,Br4 requires Br = 55.55 per cent. The tetrabromo-derivative is fairly readily soluble in chloroform, benzene or acetone, but only sparingly so in alcohol; its solutions have a yellow fluorescence, which is destroyed by alkalis and restored by acids. An attempt was made to obtain the dibromo-derivative by using glacial acetic acid as a solvent for the bromine. On adding water to the product of reaction, a yellow powder was deposited, which, when dissolved in acetic acid and reprecipitated with water, melted indefinitely at about 112" and contained 33-46 per cent. of bromine. The dibromide, C14HS05Br2, requires Br = 38.46 per cent. By further treatment with acetic acid and water, it was obtained apparently pure, and melted a t 135", but unfortunately the quantity was too small for analysis. Br = 55.1 6.The orange-coloured anhydride was digested with about twice the theoretical quantity of a 30 per cent. solution of pure sodium hydroxide in a silver vessel at 100' for several hours until the last traces of orange-coloured needles had disappeared. A slightly yellow solutiontreeulted, which, after cooling, was acidified with hydrochloric acid. A pale yellow, crystalline precipitate was gradually deposited, the total yield being theoretical. The acid was purified by dissolving in aqueous sodium carbonate and reprecipitating with acid. The pure substance melted at 185-187', but at 185' it rapidly assumed a deep orange colour and then melted to a blood-red liquid, evolving steam and yielding the anhydride (m.p. 187').FURFURALDEHYDE WITH SODIUM SUCCINATE. 191 0.0724 gave 0.1639 CO, and 0.0244 H,O. C,,H,,O, requires C = 61.31 ; H = 3.64 per cent. The acid is fairly readily soluble in alcohol and acetone ; it dissolves very easily in glacial acetic: acid, but is insoluble in benzene and chloroform. It forms ,z yellow, crystalline sodium salt and a bright yellow, insoluble silver salt. When the acid is warmed with acetyl chloride, it dissolves, and the colour of the solution rapidly changes from yellow to blood-red, then almost instantaneously the pure anhydride separates as a net-work of bright orange-coloured needles melting at 187'. C= 61.73 ; H= 3.74. a y-B;fiLrJurg Zidenepopiowic ,4 cid (a- Furf ur ylidene f u ~ y l i socrotoizic A c it2 >, C,H,O*CH:$X€ C,H,O*CH: C*CO,H* The isolation of this compound from the product of interaction of furfuraldehyde, sodium succinate, and acetic anhydride bas already been described.An 8 per cent. yield of this acid was obtained by using succinic anhydride as dehydrating agent instead of acetic anhydride. By this method, the formation of difurfurylidenesuccinic anhydride was prevented. The use of large quantities was avoided, the prepara- tion being carried out on a small scale. Eig& grams of sodium succinafe (dried at 140°), 6 grams of succinic anhydride, and 5 grams of furfuraldehyde were intimately mixed and heated at 120' in a paraffin bath for 4-5 hours. The solid product, which had darkened considerably, was pulverised in a mortar and digested with aqueous sodium carbonate at 40' for about 2 hours.A considerable quantity of brown, insoluble, resinous matter remained, which was filtered off, and the yellow solution, after cooling, acidified with hydrochloric acid. The yellow precipitate, which was somewhat oily, was washed thoroughly and purified by conversion into its sodium salt (compare p. 187), the acid being subsequently liberated by treatment with hydrochloric acid. The purest specimen OF the acid obtained in this manner melted a t 213'. A number of specimens in the earlier experi- ments, which had been purified by recrystallisation from benzene and other solvents, melted a t 205', evidently owing to traces of adherent resinous matter. rn. p. 205'. (2-67.23 ; m. p. 205'. C=67*21 ; 0,1096 gave 0.2702 CO, and 0.0423 H,O. 0.1858 gave 0-4569 CO, and 0.0732 H,O. H = 4.28. I3 = 4.39. m. p. 213'. 0.2169 gave 0.5419 CO, and 0,0865 H,O. c f = GS.07 ; H = 4.43. CI3Hl0O4 requires C = 67.S.3 ; H = 4-34 per cent. 0 2192 JOWETT : THE CONSTITUTION OF EPINEPHRINE. uy-Di f ur Furylidenepropionic acid is practically insoluble in water, slightly soluble in ether, cold alcohol or benzene, but may be crys- tallised from its hot solution in the last two solvents in long, yellow needles ; it is readily soluble in glacial acetic acid, and is reprecipi- tated by water as a bright yellow precipitate. The acid at once dissolves in aqueous alkali hydroxides, including ammonia, and is slowly soluble in sodium carbonate solution, being reprecipitated from these solutions by mineral acids or acetic acid. The sodium salt is sparingly soluble in water and crystallises in large, transparent, orange-yellow plates, which at 100' lose water and crumble to an opaque, bright yellow powder. The silver salt is precipitated from neutral solutions on adding silver nitrate as a bright yellow, colloidal precipitate. 0-0720 gave 0.0232 Ag. Ag= 32.22. C,,H90,Ag requires Ag = 32.05 per cent. In pure water, the salt is fairly soluble, forming a pale yellow solution. UNIVER~ITY OF LIVERPOOL.

ISSN:0368-1645    

DOI:10.1039/CT9048500183

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

192 JOWETT : THE CONSTITUTION OF EPINEPHRINE. XXIV .-The Constitution of Epinephrine. By HOOPER ALBERT DICKINSON JOWETT. I‘ EPINEPHRIN,” the name given by Abel and Crawford to the active principle of the suprarenal gland, was first isolated by them in an impure condition in 1897 (Johns Hopkins Hospital Eulletin, No. 76), and a similar substance, also more or less impure, but prepared by a different method, was obtained by von Furth (Zeit. yhysiob. Chew., 1900, 29, 105), who called it In 1901, the active principle was isolated in a crystalline condition by Takamine (Amev. J. Pitarm., 1901, 73, 523) and called by him “adrenalin,” and shortly afterwards it was prepared by a different method by Aldrich (Amer. J. Physiol., 1901, 5, 457). The three names “epinephrin,” ‘‘ suprarenin,” and ‘‘ adrenalin,” therefore refer to the same substance, although Abel (Be?*., 1903, 36, 1839) has since adopted the term “epinephrin hydrate.” A s this author mas the 6rst to isolate the substance, although in an impure condition, it mould seem that the name originally assigned by A be1 to the active principle should be the one adopted.Takamine, from the results of analyses of crystalline epinephrine, proposed the formula suprarenin.”JOWETT : THE CONSTITUTION OF EPINEPHRINE. 193 C10H1503N, and showed that, although it acted as a mono-acidic base, i t gave no reaction with the usual alkaloidal reagents. Aldrich, however, preferred the slightly different formula CgH1303N. Abel, who carefully purified his material, adopted the formula CloHl,0,N,~H20, but adduced absolutely no evidence to show that it contained any water of crystallisation. His results agree equally well with Aldrich’s formula C,H,,O,N.This is seen from the following numbers calculated for each formula : (Aldrich’s formula) C,H,,O,N requires C = 59.0 ; H = 7.1 ; N = 7.6. (Abel’s formula) CloH,,O,N,&H,O requires C = 58.8 ; H = 6.9 ; N = 6.9. Abel actually found C = 58.4 to 58.7 ; H = 6.8 to 7.2 ; N = 7.1 to 7.6 Von Fiirth (Monatsh., 1903, 24, 261) confirmed the formula C,H,,O,N by analyses and molecular weight determinations. Pauiy (Ber., 1903, 36, 2545), from the results of the analysis of very carefully puri6ed material, also confirmed this formula, so that i t must be considered the most probable of those proposed. No crystalline salts or derivatives have been described, but von Fiirth prepared a tribenzoyl- and a tribenzenesulpho-derivative. He also showed that i t contained no methoxyl group, and that it yielded methylamine by treatmeut with concentrated acids, Of the degradation products of epinephrine, only protocatechuic acid, formed by fusion with potassium hydroxide, has been posi- tively identified, although substances giving the pyrrole, skatole, or catechol reactions have been obtained by different observers.Von Fiirth suggested for the base the partially developed formula [ CH3*NC,H*OH]C,H,(OH),, and Pauly, who determined its specific rotation, suggested that it contained a hydroxylated benzene residue attached to one of five possible complexes, of which the most probable were the following : per cent. *$?H*NH*CH, CH2*OH ’ and *YH*OH CH,*NH*CH, I n this way, the formation of catechol, skatde, or pyrrole deriva- tives would be easily explained.In the present investigation, I have confirmed the formula CgH,,O,N, first proposed by Aldrich, by analyses of carefully purified material and by molecular weight determinations. By fusion with potassium hydroxide, a small quantity of a crystalline substance giving the reactions of protocatechuic acid was isolated, but the amount was so small that i t was doubtful whether the presence of this complex in the original substance could be correctly deduced from its formation.194 JOWETT : THE CONSTITUTION OF EPINEPHRIWE. By oxidation with permanganate, oxalic and formic acids and methyl- amine were obtained.By methylation and subsequent oxidabion wi tli permanganate, trimethylamine and veratric acid were obtained, t h n s proving the existence of the complexes C,H,(OH),-C and NH(CH,) in the original base. From these results, the following constitutional formuh of epine- phrine may be deduced : OH OH O H /\OH (\OH ()OH I ' \/ VH*NH*CH, \/ \/ $,'H*OH p 2 C H,*NH*CH, CH(OH)*N K*CH, CH,*OH I. 11. 111. Of theseformulze, I is the more probable, for if I1 were correct, then, after methylation and subsequent oxidation, we should expect the product to yield homoveratric acid, C,H,(OH),*CH2-C0,H, whereas veratric acid was actually obtained, whilst I11 would not so readily explain the formation of pyrrole or skatole derivatives. Formula 1 may therefore be considered to represent correctly the constitution of epinephrine, and it serves t o explain the ordinary reactions of the base as well as the formation of pyrrole, skatole, or catechol derivatives as degradation products.EXPERIMENTAL. The B'ormulcc and Properties of Epirzephrine. The crude crystalline material was first freed from inorganic impurities by the method previously adopted by other observers, namely, solution of a salt in alcohol and fractional precipitation with ether. It was finally purified by fractional precipitation of the base from the aqueous solution of its hydrochloride by ammonia. The analyses of four different specimens were sufficient to confirm the formula C,H,,03N. 0.1184 gave 0.2546 GO, and 0.0798 H,O. C = 58.6 ; R -- 7.5. 0.1082 ,, 0.2306 GO, ,, 0.0720 H,O.(3-58 1 ; H=7*4. 0.1238 ,, 0.2642 CO, ,, 0.0816 H,O. C=58.3 ; H=7 3. 0.0990 ,, 0.2136 GO, ,, 0.0644 H,O. C=58*8 ; H = 7 . 2 . 0.1342 ,, 9.2 C.C. N a t 15' and 755 mm. N = 7.8. 0.0946 in 24.78 glacial acetic acid gave At - 0.11". C,H1,03N requires C = 59.0 ; H = 7.1 ; N = 7.6 per cent. M. W. = 135. M. W. = 183.JOWETT : THE CONSTITUTION OF EPINEPHRINE. 195 The determination of the specific rotation of the base in dilute acetic acid solution gave the following result : a, = - 10' ; I = 0.25 dcm. ; c = 2.084; [a],= - 32.0'. Pauly (Zoc. cit.) found [a],,- 43O, but considering the small observed angle (10') the above figures do not vary beyond the limits of experimental error. The general statements of previous observers as to the solubility of epinephrine in various solvents and its behaviour towards alkaloidal reagents mere confirmed.The base did not react with phenyl- hydracine. Oxidation with Permanganate. Five grams of epinephrine were dissolved in dilute sulphuric acid and oxidised at the ordinary temperature with a 1 per cent. solution of permanganate, 30 grams of this reagent being required to produce a permanent colour. , Tbe product yielded methylamine, which was identified by its platinichloride. 0,1646 gave 0.0688 Pt. Tile acids obtained were formic and oxslic acids. Pt = 41.8. (CH,N),,H,PtCI, requires Pt = 41-3 per cent. Fusion with Potassium Hydroxide. Five grams of epinephrine were added t o 25 grams of potassium hydroxide and the mass fused a t as low a temperature si3 possible. The melt was then dissolved in water, acidified, and extracted with ether.The residue, after distilling off the ether, was obtained crystal- line and gave the characteristic protocatechuic acid reaction on adding successively ferric chloride and sodium carbonate. The amount ob- tained was insufficient to admit of further examination. Jfethylation cmd Subsepent Oxidation with Permanganate. Four grams of epinephrine were dissolved in 50 C.C. of methyl alcohol, in which 1 gram of sodium had been dissolved, and 8 grams of methyl iodide added. The mixture was then heated in a sealed tube a t 100" for four hours, the alcohol distilled off, and the operation repeated with the residue. After the second methylation, the residue was dissolved in water and then added to an aqueous solution of 17 grams of silver nitrate, the silver iodide quickly filtered off, and the filtrate saturated with hydrogen sulphide and again filtered. The filtrate was then oxidised with a 2 per cent.solution of perman-196 JOWETT : THE CONSTITUTION O F EPINEPHRIN &. ganate at the ordinary temperature, when 10 grams were required to produce a permanent colour. The product, when worked up in the usual way, yielded a volatile base which was identified as trimethyl- amine. 0.1588 Pt salt gave 0.059 Pt. (C,H,N),,H,PtCl, requires Pt = 37.1 per cent. The crystalline acid obtained from the ethereal extract, mas recrystallised from hot water until its melting point was constant; it formed white, acicular crystals, sparingly soluble in cold water and melting sharply a t 179".The aqueous solution gave no reaction with ferric chloride. 0.1128, dried at 110-120°, gave 0,2446 CO, and 0.057 H,O. C = 59.1 Pt=37*1. H=5*6. CSH,,O, requires C = 59.3 ; H = 5.5 per cent. This compound was therefore identi6ed as veratric acid. The Constitution of Epinephrine. Since the product obtained by exhaustive methylation yields veratric acid by oxidation with permanganate, epinephrine must contain the complex : OH As i t yields trimethylamine by the foregoing treatment and methyl- amine by oxidation of the original base, it must therefore contain the group *NH(CH,), which, being split off by simple oxidation, is most probably attached to the side-chain and not to the benzene nucleus. As epinephrine yields tribenzoyl- and tribenzenesulpho-derivatives, it probably contains three hydroxyl groups, of which two are attached to the benzene nucleus.The only probable formulae which would comply with the above conditions and also conform to Pauly's hypothesis (Zoc. cit.) are those indicated on p. 194. Of these, I is the most probable, for if I1 were correct we should expect after methylation and subsequent oxidation to obtain homo- veratric acid and not veratric acid. Moreover, I11 would not 80 readily explain the formation of pyrrole or skatole derivatives. Formula I is therefore the most probable formula for epinephrine, as by it the formation of catechol or protocatechuic acid is easily explainedTHE RESOLUTION OF UP-DIHYDROXYBUTYRIC ACID. 197 as well as the reducing properties of the base. It also contains one of the t w o side-chains regarded as probable by Paiily (Zoc. cit.). By the union of the nitrogen atom to the benzene ring, pyrrole derivatives would be formed, as has been stated to be the case. Addendum-Since this paper was written, a communication by Abel has appeared (Bey., 1904, 37, 368) in which he still adheres t o the formula C,oH,,O,N,+H,O. He states, however (Zoc. cit., 381'), that 0.2288 gram of the base, when heated for one hour a t 145' and sub- sequently for one hour at 155,-160° in a vacuum, lost only 0*0014 gram or 0.6 per cent. This experiment apparently only affords further evidence that the base contains no water of crystal- lisation. THE WELLCOME CHEMICAL RESEARCH LABORATORIES, LONDOK, E.C.

ISSN:0368-1645    

DOI:10.1039/CT9048500192

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

THE RESOLUTION OF UP-DIHYDROXYBUTYRIC ACID. 197 XXV.-The Resolution of aS-Dihydroxybutyric Acid into i t s Optically Active Constituents. ROBERT SELBY MORRELL and EDWARD KENNETH HANSOX. THE two inactive ap-dihydroxybutyric acids, obtained by Fittig and Kochs on oxidising the a- and p-crotonic acids with barium perman. ganate (Annalen, 1892, 268, 8 and 16), are characterised mainly by the different solubilities of their salts in water. If the a- and p-crotonic acids are represented by the formuls CH;k&CO,H and CH;C=C%CO,H, the two ap-dihydroxybutyric acids @-methyl- glyceric and ,8-methylisoglyceric acids) should have the formuls H CH H H H H HO H CH,*6-6*C02H and CH3*k-6*CO,H. H6 dH H CjH I n connection with an investigation on the oxidation of carbo- hydrates which is being carried out by one of us, it seemed advisable to investigate the properties of these acids more completely and to prepare their salts with optically active bases, with the view of resolv- ing the racemic forms into their optically mtive components,198 MORRETJT, AND HANSON : THE RESOTAUTION OF I n this paper, we communicate the results of an investigation of the properties of the Z-modification of ap-dihydroxybutyric acid and of one of the salts of the d-modification.In the course of our investigation, we were led Lo believe that a more complete separation of p-crotonic acid from a-crotonic acid could be effected, but this por- tion of the work will form the subject of another paper. The resolu- tion of P-methylg!yceric acid can be easily effected by the fractional crystallisation of the quinidine salts.The quinidine Z-P-methyl- glycerate is sparingly soluble in water and yields the Z-acid, having a specific rotation of - 13.5'. The barium h a l t is more strongly laxo- rotatory, [ a ] , - 20°, and the rotation of this salt is greater than t h a t of calcium glycerate ( - 11 * 6 6 O ) , derived from d-glyceric acid, which has [ a]r + 2*14* ; moreover, the rotation of barium Z-P-methylglycerate has the same sign as that of tho acid (compare Frankland and Frew, Trans., 1891, 59, 56, 101). The specific rotation of an aqueous solution of ap-dihydroxybutyric acid is unchanged when allowed to remain for 12 hours, and since it is slightly lower than that of the barium salt there is probably no anhydride present in the solution. In the case of d-glyceric acid, there is evidence of the formation of an anhydride on the evaporation of an aqueous solution (Frankland and Frew, Trans., 1891, 59, 56).Comparison with the specific rotation of Z-a-hydroxy- butyric acid shows that the introduction of a hydroxyl group lowers the rotation of the acid. The specific rotation of Z-P-hydroxybutyric acid is [.ID - 24*8', whilst that of the corresponding sodium salt is [a]D - 14.5' (Mackenzie, Trans., 1902, 81, 1402). Mackenzie states that the rotations of P-hydroxybutyric acid and its salts are exceptional, in that the salts have lower rotations than t.hat of the free acid. A n aqueous solution of P-hydroxybutyric acid contains some anhydride, but the rotation of the anhydride differs very little from that of the free acid (Zoc.cit.) By the action of lime water on an oxycellulose, Faber and Tollens obtained isosaccharic acid, CH,( OH)*CH(OH)*CH,*C(OH)(CH2* OH)* CO,H, and a dihydroxybutyric acid. This dihydroxybutyric acid was found to have a specific rotation [ a ] , - 2 * 6 O , in freshly prepared aqueous sola- tion, but after three days the specific rotation had changed to + 13.7' (Zoc. cit.). The acid is probably the optical isomeride of the Z-ap-hydroxybutyric acid obtained by us. The formula H H CH;&-bCO,H H6 i)H cH~>C(OH).Co,H, ought to be assigned to Faber CHAOH) rather thana@-DIHYDROXYBUTYRTC ACID INTO ITS CONSTITUENTS. 199 and Tollens's acid. The optical isomerism of these two acids perhaps might be considered as affording some slight evidence in favour of the existence of a methylpentose residue in cellulose.The oxycelluloses are characterised in certain cases by the presence of active carbonyl groups, by methoxyl radicles, and by yielding furfur- aldehyde as a product of acid hydrolysis (Cross and Bevan, Cellulose, p. S2). The production of furfuraldehyde indicates generally the presence of a pentose nucleus, although it may also be obtained from glycuronic acid and glucosone, which are derived from hexoses. EXPERIMENTAL. P-Methylglyceric acid, which was prepared from solid crotonic a d by oxidation with barium permanganate according to the directions given by Fittig and Kochs (Zoc. cit.), was converted into its salts with brucine, quinine, strychnine, morphine, and quinidine.Brucine P-Methylglpcemte. --This salt is exceedingly soluble in water and fairly soluble in hot absolute alcohol, one part of the salt dissolving in 15 parts of the boiling solvent ; it crystallises from a concentrated alcoholic solution in small needles, but if the solution is more dilute, nodular aggregates of needles slowly separate. It melts a t 236' with decomposition. 0.2012 gave 9.8 C.C. moist nitrogen at 22'and 765 mm. N=5.58. C23H2604N2,C4HS04 requires N = 5-45 per cent. The specific rotation of the salt was determined in :both alcohol and water. I (1) I n alcohol : I = 1 ; c = 1.333 ; C I ~ - 0.2'; [ax - 15'. (2) I n water : Tykociner found that the specific rotation of a brucine salt of an inactive acid dissolved in water was approximately - 34'. The Grucine salt is apparently that of the inactive acid (Eec.trav. chhn., 1892, 11, 148). Fractional crystallisstion of the salt failed t o alter its rotation appreciably, and a determination of the specific rotatory power of the last crop of crystals from the aqueous solution gave the following numbers : Z = 1 j C = 10.123 ; d = 1.0277 ; a r - 2.89'; [u]F - 27.8'. The acid was produced by decomposing successively the brucine salt by baryta and the barium salt by the exact amount of sulphuric acid; it crystallised from a mixture of dry acetone and dry ether in200 MORRELL AND HANSON: THE RESOLUTION OF aggregates of needles and was found to be identical with the inactive acid obtained by Fittig and Kochs (Zoc. cit.). and 0,1125 H,O. 0.1830 (dried in a vacuum over sulphuric acid) gave 0.2695 GO, C: = 40.16 ; H = 6.8.C,H,O, requires C = 40.0 ; H = 6.66 per cent. An aqueous solution of the acid gave : On adding boric acid, in the proportion of 1 gram-molecule of the acid to 1 gram-molecule of the methylglyceric acid, the angle observed mas -0*18O. The specific rotation was now only From these data, it is evident that the solubilities of the d- and I-brucine salts in alcohol are so nearly equal that their separation by fractional cry stallisation is impossible. Quinine J4ethyZglycerccte.-This salt is exceedingly soluble in water and absolute alcohol, but very sparingly so in benzene; it melts at 174' without decomposition. The determination of the optical activity in absolute alcohol and in water gave the following numbers respectively : - 1-32'., c = 2 ; 1 = 1 ; aT-2.6'; [a]? - 130'. ~ ~ 4 . 5 3 5 ; Z=1 ; aF-4.94'; 108.93'. The specific rotation of quinine in alcohol is [ a]2:" - 166.6' (c = 2 ) (Oudemann's Annnlsn, 1876, 182, 44). The salt dissolves so sparingly in benzene and is so very soluble in water and alcohol, that i t was quite impossible to separate its active components by fractional crystallisation. The cinchonine, strychnine, and morphine salts are exceedingly soluble in water and in alcohol; the cinchonine salt is sparingly soluble in benzene. We have not as yet obtained the salts of these three bases with P-methylglyceric acid in a crystalline form. Quinidine /3-MethyEgZycerate.-This salt was prepared by neutralis- ing a hot aqueous solution of P-methylglyceric acid with quinidine.On concentrating on the water-bath, the salt separated out in clusters of six-sided plates. The mother liquor gave a second crop of these crystals, but, after further concentrat ion, needle-shaped crystals appeared. The first crop of crystals melted a t 113-114' without decomposition, and contained two molecules of water of crystallisation. 0.3 air-dried salt gave 15-6 C.C. moist nitrogen a t 1C'and 763 mm. 0.1823 air-dried salt gave 0,4015 GO, and 0.1220 H,O. C=60*06 ; N = 6.08. H = 7.43.~&DIHYDROXYBUTYRIC ACID INTO ITS CONSTITUENTS. 201 0.581 1 air-dried salt lost 0-338' a t 105'. C,oH,,0,N,C4H804,2H,0 requires N = 5.71. C = 60.0 ; H = 7.5 ; C20H24N20,C4H,0,,1 &H,O requires N = 5.S2. C = 59.87 ; H = 7.27 ; H,O = 5.73 per cent.H,O = 5.81. H,O=7*5. . The specific rotation was determined in aqueous and in alcoholic solutions, (a) I n water. (6) In alcohol. The specific rotation of quinidine in alcohol is + 236.8'. After six crystallisations from water, neither the melting point nor The sixth fraction melted at 114O, and had a specific rotation The determination of the solubility of the salt in water gave the follcwing numbers. 8.2738 grams of a saturated aqueous solution of quinidine P-methyl- glycerate at 14.9Ocontained 0.1368 gram of the salt ; this result corre- sponds with a solubility at 14.9' of 1.64 grams in 100 grams of the solution. 1 - p- M ethylgly ceric Acid. I = 1 ; c = 3.310 ; a:" + 4.75' ; [a]:' + 143.46'. Z=1; c=3.7916; aT0+4*72O; [a]l,"o=159.04'. d = 0.772. optical activity underwent any appreciable change.[a]:" + 142.2'. The pure quinidine salt (m. p. 114') was dissolved in about 10 parts of wzter, and the quinidine was precipitated by means of baryta solu- tion. The excess of baryta was removed by carbon dioxide, and, after filtration, the solution was found to be strongly lsvorotatory. The solution of the barium salt was concentrated to a small bulk in, vucuo at 50' and poured into absolute alcohol. The precipitated barium salt is somewhat soluble in alcohol, and, on evaporating off this solvent, a further quantity of the salt was obtained ; i t was purified by recrystallisation from a very small volume of water, when it separated in fine needles and dried a t 110'. Ba = 36-52. 0,2032 gave 0,1267 BaSO,. The determination of the specific rotation gave the following (C,H704)2Ba requires Ba = 36.53 per cent. numbers : I = 1 ; c = 6.2683 ; ago - 1.36' ; [ U,]Y - 20.63' ; and after 12 hours the rotation was unchanged.To obtain the free acid, the barium salt was decomposed exactly bp dilute sulphuric acid; the filtrate from the barium sulphate was202 THE RESOLUTION OF Ufl-DIHYPROXYBUTYRIC ACID. evaporated at 50' under diminished pressure to a syrup, which mas extracted with dry acetone ; the solution was filtered and the filtrate treated with dry ether until a permanent turbidity ensued. The ether-acetone solution was poured off from the syrup which separated, and allowed t o evaporate a t the ordinary temperature. The acid, which was left as a syrup, after being stirred with a glass rod became solid.The white, crystalline solid mas washed with dry ether and dried in a vacuum over sulphuric acid until its weight became constant. It was found t o be quite free from ash. The I-methyl- glyceric acid crystallises in hexagonal plates and melts at 74-75'. Fittig and Kochs (Zoc. cit.) give the same melting point for the in- active acid. 0.1808 gave 0.2655 CO, and 0,1122 H,O. C = 40.05 ; H = 6.89. C,H80, requires C = 40.0 ; H = 6.66 per cent. l The determination of the specific rotation gave the following numbers : The acid is exceedingly hygroscopic; it is very soluble in alcohol and acetone, and dissolves very sparingly in dry ether. d-P-Metlag Iglyceric Acid. The mother liquors from the quinidine I-salt contain the more soluble d-salt. It was found impossible t o separate the h a l t completely from the d-salt by fractional crystallisation. Since the barium I-salt is somewhat soluble in alcohol and the inactive barium salt is insoluble in that solvent, it was thought that a separation of the barium &-salt from the racemic salt might be effected by means of alcohol. The impure quinidine d-salt was decomposed by barpta, and after filtration from the precipitated quinidine the concentrated solution of the barium salt was poured into absolute alcohol.The salt which separated out was quite inactive, and contained 36.5 per cent. of barium. The alcoholic filtrate was concentrated to a syrup, which soon became solid. After digestion with rectitied spirit, the inactive salt was left undissolved, and from the alcoholic filtrate, the d-salt was obtained as an uncrystallisable syrup.In order to remove as much as possibie of the inactive salt, the treatment with rectified spirit was repeated twice and the syrup was dried a t 130' and analysed. 0.21479 gave 0.1350 BaSO,. Ba= 36.95. Ba(C,H,O,), requires Ba = 36.53 per cent.THE CHEMICAL REACTIONS OF NICKEL CARBONYL. PART I. 203 A determination of the specific rotatory power gave the following numbers : I = 1 ; c = 7.058 ; d = 1.040 ; UF + 1.25' ; [U]T + 17.03'. The specific rotation of the barium d-/I-methylglycerate agrees fairly well with the value obtained for that of the barium h a l t . The yield of the barium d-salt was so small, owing to the difficulty in separating i t from the inactive salt, that the d-methylglyceric acid could not be isolated. The racemic barium methylglycerate is much less soluble in water than either the d- or h a l t , and crystallises from a concentrated aqueous solution in stellar aggregates of obliquely terminated needles ; it contains two molecules of water of crystallisation, which are expelled at 110'. 0.6456 (air-dried) lost 0.0544 H,O. H20 = 8.4. Ba(C,H,0,),,2H20 requires H20 = 8.75 per cent. We are under very great obligations to Mr. A. E. Bellars for valuable assistance in the experimental part of the paper. Our thanks are due to the Research Fund Committee of the Chemical Society for a grant defraying the cost of the materials used in this investigation. GONVILLE AND CAIUS COLLEGE IAABORATORY, CAMBRIDGE.

ISSN:0368-1645    

DOI:10.1039/CT9048500197

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

THE CHEMICAL REACTIONS OF NICKEL CARBONYL. PART I. 203 XXVI.- The Chemical Reactions oj- Nickel C a ~ b o ~ ~ y l . Reactions with the Halogens mad othei* Part I. Inorganic Substances. By JAMES DEWAR and HUNPHREY OWEN JONES. THE previous investigation of the physical properties and stability of nickel carbonyl (Proc. Rog. Xoc., 1903,51, 427) having shown that the compound was much more stable than had hitherto been supposed, i t was thought of interest to study its chemical reactions and stability more fully. A few of the simpler decompositions of the compound were observed by Dr. Mond and his collaborators (Trans., 1890, 3’7, 749), some further observations were recorded by Berthelot (Compt. rend., 1891, 113, 679), and the product of oxidation in moist air has been studied by the last-mentioned chemist and by Lenher and Loos (Amer.CAem. J., 1899, 22, 114).204 DEWAR AND JONES: THE CHEMICAL REACTIONS OF The authors have studied a number of the reactions of the com- pound with the view of throwing further light on its chemical nature and structure, and its possible use as a synthetical agent. The present paper contains an account of its interactions with certain elements and simple inorganic compounds, studied mainly from a thermochemical point of view. The heat of formation of liquid nickel carbonyl from metallic nickel and gaseous carbon monoxide, as determined by Mittasch (Zeit. PhySikid. Chenh., 1902, 40, 49), lies between 51 and 55 Cal., the mean value being 52.17 Cal. Reicher had previously obtained the value 59.5 Gal.from the combustion of the compound. Taking the lower value and Thomsen’s values for other nickel compounds, it might be expected that nickel carbonyl would be readily decomposed by chlorine or bromine, but not by iodine or sulphur, whereas it is actually decom- posed completely by the four elements with the production of the corresponding nickel compounds and carbon monoxide. I n no case in which nickel carbonyl has been decomposed by elements has any combination of the carbon monoxide with the element been observed. This is remarkable since it might be ex- pected that combination would take place more readily when the monoxide was in the so-called ‘ nascent state. Again, in the decomposition with hydrogen iodide and hydrogen sulphide, carbon monoxide is set free, and combination with hydrogen does not occur to any appreciable extent, if at all.T h e H a l o g e n s a n d their C o m p o u n d s . The reaction with the halogens was investigated in solution in pure, dry carbon tetrachloride, the mode of procedure being briefly as follows. Standard solutions of the carbonyl derivative and the halo- gen were made, varying in strength from normal to decinormal, 1-10 C.C. of the carbonyl solution were introduced into a Lunge nitrometer over mercury followed successively by some tetrachloride and a very slight excess of the solution of the halogen, the mixture being then shaken and the volume of gas evolved measured after the reaction was completed. This volume was theu corrected t o normal temperature and pressure by comparison with another nitrometer containing a known volume of air enclosed over carbon tetrachloride, and the gas was afterwards examined to ascertain whether it was pure carbon monoxide.Experiments were also made at low temperatures t o see whether the liquid or solid halogens had any action on solid nickel carbonyl.NICKEJi CARBONPL. PART T. 206 Chlorine. On mixing normal solutions in carbon tetrachloride, a brisk evolution of gas takes place at once and a grey solid is precipitated. From 1 C.C. of normal nickel carbonyl solution and 1.1 C.C. of normal chlorine solution, 49-0 C.C. of gas at 16’ and 755 mm. were evolved, the volume when corrected to 0” and 760 mm. being 45.2 C.C. The volume of carbon monoxide theoretically obtainable being 44.8 c.c., it is clear that complete decomposition has taken place into carbon monoxide or a mixture of this gas and carbonyl chloride.The gas, when tested for carbonyl chloride by treatment with water or aqueous sodium carbonate, gave indications that at most only a trace of the gas was formed, even when a considerable excess of chlorine had been used. The solid product when collected and analysed was found to be pure anhydrous nickel chloride, The heat of the reaction [Ni,CI,] is given by Thomsen (Thermo- chemische untersuchungen, 3, 307) as 74.53 Cal., hence the reaction [Ni(CO),,CI,] should occur with the evolution of 22-36 Cal. : a con- siderable rise of temperature does occur during the reaction. No action occurs in a mixture of solid chlorine and solid nickel carbonyl, but when the chlorine becomes liquid the reection seems to begin and to proceed steadily.Bronzine The reaction between norma.1 solutions in carbon tetrachloride takes place rapidly and ends almost immediately after complete mixture, as in the case of chlorine. The gas evolved was pure carbon monoxide and the solid on analysis was found to be pure anhydrous nickel bromide. One C.C. of nickel carbonyl solution and 1.1 C.C. of normal bromine solution gave 47.2 C.C. of gas a t 1 2 O and 758 mm. The corrected volume of the gas is 44.5, whereas theory requires 44.8 as before. Thomsen (Zoc. cit.) gives the heat of the reaction (Ni,Br,,aq) as 71.82 Cal., so that, unless the heat of hydration of nickel bromide is exceptionally great and the heat of solution exceptionally small, the reaction [Ni(CO),,Br2] should nevertheless occur with evolution of heat, as is actually found to be the case : a distinct rise of temperature takes place during the reaction.Solid nickel carbonyl and solid bromine did not react, and whenthe mixture was gradually warmed it underwent no change until t h e bromine became liquid, when the reaction between the solid carbonyl and the liquid bromine proceeded rapidly. VOL. LXXXV. P206 DEWAR AND JONES: THE CHEMICAL REACTIONS OF When a normal solution of nickel carbonyl in carbon tetrachloride was mixed with an N/5 or N/10 solution of iodine in the same solvent, a brown or black solid was deposited and carbon monoxide was slowly evolved. C)n examination the solid proved to be nickel iodide. The reaction between 1 c c .of the carbonyl solution and 5 C.C. of &/5 iodine solution was completed i n about half an hour, and the theoretical quantity of carbon monoxide was produced, as i n the other cases. Analysis of the solid, after heating at looo, gave Ni=l8-9. I = 80.6. Calculated for Ni12, Ni = 18.9. Thomsen (Eoc. cit.) gives the heat of the reaction (Ni,I,,aq) as 41.4 Cal. Now, unless the sum of the heats of hydration and solution of nickel iodide is negative, the reaction [Ni(CO),,12] should be endo- thermic. A rough experiment was made which showed that the com- bined heat of solution and hydration of nickel iodide was positive, but small, being approximately 6 14 cal. It was therefore important to determine whether any considerable fall of temperature occurred during the reaction.Experiments were made in which a definite volume of normal nickel carbonyl solution in different solvents was placed in a bulb, which was broken in an excess of N/10 iodine dissolved in thesame solvent and contained in a bottle, insulated as far as possible from extraneous sources of heat. The mixture was stirred, and the change of temperature observed by means of an accurate thermometer. A mixture of 80 C.C. of N/5 iodine and 8 c.c, of normal nickel carbonyl in carbon tetrachloride, was initially a t 15O, and in the course OF 13 minutes the temperature fell to 13*S0, the reaction being by t h a t time nearly completed. A mixture of 80 C.C. of N/10 iodine, and 7 C.C. of normal nickel carbonyl in alcohol, was initially at 15*4O, but after 23 minutes, when the reaction was practically completed, the temperature had fallen to 14.7'.I n both these cases the fall is scarcely greater than would be ex- pected to occur by the evaporation of a quantity of the liquid necessary t o saturate the carbon monoxide evolved with its vapour at the temperature of the experiment. Suficient data are not available to calculate the expected fall of temperature accurately, but the rough estimate which can be made with the incomplete data obtainable is of the above order, It became, therefore, interesting to ascertain the source of the energy necessary t o carry out the reaction. Experiment 8 described I = 81 -1 per cent.NICKEL CARBONYL. PART T. 207 below on the velocity of the evolution of the carbon monoxide show that the reaction proceeds steadily at the ordinary temperature, and is a normal bimolecular reaction, as might be expected.The energy cannot be derived from radiant light or heat, since the reaction proceeds quite as rapidly when such radiations are screened off as completely as possible. An indication of the possible source o€ the energy was obtained when the reaction was carried out in ethereal solution. In this case the nickel iodide is usually first deposited as a viscid brown liquid, which then changes into a mass of large pale green, tabular crystals, but very occasionally the green crystals seem to be formed directly. These crystals, when filtered off rapidly, change to the black iodide, and give off ether in the process ; they may therefore be considered as consisting of nickel iodide united with ether of crystallisation." The loss of ether is so rapid when the crystals are taken out of the solvent, that it is quite impossible to analyse them.Somewhat similar phenomena have also been observed in other solvents, for example, in chloroform the iodide is deposited in brown, tabular crystals, which rapidly change when removed from the solution, and it is therefore probable that the nickel iodide forms molecular complexes either with the solvent or with iodine, even when there is no visible evidence of their existence, and thus gains the energy necessary to carry out the reaction. However, the tendency to form these complexes cannot be very great, since the anhydrous iodide does not combine with these solvents when mixed with them at the ordinary temperature.This hypothesis as to the source of the energy required receives some slight support from the fact that solid iodine has scarcely any action on liquid nickel carbonyl, although this is partly due to the fact that the halogen is insoluble in the latter. The ode?* of the Reaction and its velocity in Chloroform. On investigating the velocity of the reaction in chloroform solution by observing the rate of evolution of carbon monoxide, it was found that the reaction proceeded quite normally at the ordinary temperature and, by altering the concentration, it was found t h a t the reaction was of the second order as might be expected from the equation Ki(CO),+ I, = NiI, + 4C0, providing that the iodine molecules are diatomic in chloroform solution.The experiments were made as simple as possible, the object being merely to see that the reaction proceeded steadily. Three experiments are quoted and the results are shown by the appended curves, in which the ordinates represent the number of cubic Compare the formation of MgBr,,2(CzH&O and MgI,,2(C2H,),0 (Compt. rend,, 1901,152, 836) and (J. Buss. Phys. Chem. Soc., 1903, 35, 610), P 2208 DEWAR AND JONES: THE CHEMlCAL REACTIONS OF centimetres of gas evolved and the abscism represent the time in minutes, the temperature being 1 2 O . Curve I, 10 C.C. iV/5 Ni(CO), + 30 C.C. 3/10 iodine in 50 C.C. ,, 11, 5 ,, N/5 Ni(CO), + 30 ,, 3/10 iodine in 50 ,, ,, 111, 5 ,, N/5 Ni(CO), + 15 ,, N / l O iodine in 50 ,, It is readily seen that the evolution of gas proceeds steadily without cessation from the beginning to the time when the observations ceased.c. c. niinutes, The order of the reaction was calculated by means of the formula logdC,/dt/dC, fdt $q)=-..-.-------- 'ogC,lC, for three pairs of experiments I and 111, and the following three values of n were obtained, 2.03, 2.20, and 2.00, so that the reaction is evidently one of the second order, In calculating the velocity constant, very eatisfaotory results cannotNICKEL CARBOKYL. PART I. 209 be obtained, probably owing either to some lag in the evolution of the gas from the solvent or to some disturbing side reactions. The value of k, however, appears to be about 04005, the unit of time being a minute. Cyanogen. Gaseous cyanogen appears to have no action on gaseous or liquid nickel carbonyl.Cyanogen gas, enclosed in a Lunge nitrometer over mercury, when mixed with a little nickel carbonyl immediately in- creased in volume owing to the high vapour pressure of the carbonyl; but afterwards the volume remained constant for several days and no solid was deposited. With an alcoholic solution of cyanogen, however, a reaction took place with moderate ease, nickel cyanide and carbon monoxide being produced. The reaction proceeded t o the end, and the theoretical quantity of gas was evolved. The heat of formation of hydrated nickel cyanide is 50.5 Cal. (Varet, Conzpt. rend., 1896, 122, 1123), it is therefore slightly greater than that of nickel iodide, so that the reaction here, again, must be pro- moted by the formation of molecular complexes as in the case of the iodide.l o cliize Honocld oride . When the brown solution of iodine monochloride in chloroform is mixed with a solution of nickel carbonyl in the same solvent, a violent reaction immediately takes place, a light brown solid is precipitated, and the solution becomes purple. The rate of evolution of gas then diminishes appreciably and the payple colour of the solution gradually disappears. The gas evolved is carbon monoxide, and the solid product of the reaction is a mixture of nickel chloride and iodide. The reaction obviously proceeds in two distinct stages according to the equations 2ICl + Ni(CO), = NiCI, + I2 + 4CO the first stage taking place rapidly with liberation of iodine, which then reacts more slowly with a further quantity of nickel carbonyl.I, + Ni(CO), = NiI, + 4C0, The reaction here proceeds exactly as in the case of the monochloride. The brown solution in chloroform or carbon tetrachloride a t once be- comes purple and gas is evolved very rapidly; the evolution of gas then becomes slower and the purple colour gradually disappears. The210 DEWAR AND JONES: THE CHEMICAL REACTIONS OF reaction clearly occurs in two distinct stages, as in the case of the monochloride, the chloride being formed in preference t o the iodide as would be expected from their respective heats of formation. Cyanogen Iodide. When the colourless alcoholic solution of cyanogen iodide is mixed with a similar solution of nickel carbonyl, a light drab precipitate is at once formed, carbon monoxide is evolved and the solution turns browo.The precipitate is nickel cyanide and free iodine remains in the solution. The evolution of gas continues, and a darker precipitate is produced which now consists of nickel iodide. A chloroform solution of cyanogen iodide, which is also colourless, behaves similarly, gas is evolved and a light drab precipitate produced, the solution becoming purple and containing free iodine. The evolu- tion of gas continues and the precipitate turns black, or, if the tube is not shaken, a black precipitate of nickel iodide settles on the top of that first formed. Here, again, it is clear that the reaction proceeds in stages, nickel cyanide and free iodine being first formed according to the equation and then the iodine reacts with a further quantity of nickel carbonyl to produce nickel iodide.This shows clearly that the heat of forma- tion of nickel cyanide is greater than that of the iodide in alcoholic or chloroform solutions, just as in aqueous solution. Ni(CO), + 2ICN = Ni(CN), + I, i- 4C0, The Hyclrides of the Halogens. Dry hydrogen chloride or bromide, when mixed with nickel carbongl over mercury, a t once increases in volume owing t o the vapour pres- sure of the carbonyl, the increase being exactly that amount which would be expected from the known value of the vapour pressure. Practically no further change could be observed on allowing the mixture to remain for several days. A minute amount of solid was deposited in some case@, but there was obviously no extensive reaction.The reaction between hydrogen iodide and nickel carbonyl was in- vestigated as follows, the use of mercury being inadmissible on account of it8 action on the acid gas. A glass bulb was carefully exhausted and then filled with hydrogen iodide a t a slightly reduced pressure, a little nickel carbonyl was then admitted, excess being avoided at first. The gases soon reacted with the deposition of a black solid, the gaseous products were examined by passing through a U-tube im- mersed in liquid air and collecting the uncondensable gas and after- wards fractionating the condensed portions. The uncondensed gasesNICKEL CARBONYL. PART I. 211 consisted of bydrogen and carbon monoxide, the condensable part being hydrogen iodide and nickel carbonyl. No formaldehyde could be detected.The solid produced was pure nickel iodide and contained no free iodine. A solution of hydrogen iodide in chloroform rewts very rapidly with a similar solution of nickel carbonyl, producing carbon monoxide and a mixture of solids containing nickel iodide and free iodine, which has not yet been fully examined. Sulphur, A solution of sulphur in carbon disulphide reacts slowly with nickel carbonyl in the absence of air, evolving a gas and forming a black solid. The gas evolved is not immediately absorbed by an alcoholio potash solution and therefore contains no carbon oxysulphide, it is, however, taken up by a solution of cuprous chloride in hydrochlorio acid and is therefore practically pure carbon monoxide. The solid contains nickel and sulphur.A similar reaction occurs with a solution of sulphur in xylene, but in both cases i t takes place very slowly. With 1.5 C.C. of a normal solution of nickel carbonyl and an excess of a solution of sulphur in carbon disulphide, gas was steadily evolved for four days until about 7s C.C. had been collected, this being approximately the amount to be expected. The heat of the reaction (Ni,S,nK,O) is given by Thomsen (loc. cit.) as 19.4 Cal., so that the reaction [NJ(CO),,S] might therefore be strongly endothermic. However, there is no marked fall of tempera- ture during the reaction, no energy can be obtained from radiant light since the black deposit rapidly renders the walls of the vessel quite opaque, and moreover, the reaction proceeds in the dark. The solid, on examination, was found to be a higher sulphide than NiS, having, in fact, a composition closely corresponding to Ni,S,.Found Ni= 54.8. Ni,S, requires Ni = 54.5 per cent. Hence the necessary energy may be derived from the formation of this more aomplex compound, Hydrogen Su Zph ide , Hydrogen sulphide mixad with excess OF nickel carbonyl reacts very slowly, depositing a black solid and liberating hydrogen and carbon monoxide. I n about a week only about 40 per cent. of the sulphide had reacted. In alcoholic solution, the reaction proceeds more quickly, and the black precipitate first formed acquires a bronze lustre. On analysis, this solid proved to be the monosulphide, NiS. Found Ni = 64.4. NiS requires Ni = 64.7 per cent.212 DEWAR AND JONES: THE CHEMICAL REACTIONS OF The gases evolved contained hydrogen and carbon monoxide, and no formaldehyde could be identified with certainty among the products of reaction. Sulphuric Acid. Berthelot (Compt. rend., 1891, 112, 1343) states that nickel carbonyl i n contact with concentrated sulphuric acid detonates alter a few minutes. This is quite contrary to our experience, for even when slightly moist nickel carbonyl was used, the reaction always took place slowly without any great evolution of heat. Some nickel carbonyl and sulphuric acid were sealed up in a tube, a reaction went on very slowly during several weeks. The tube was opened from time to time and examined. Considerable pressure was developed and a yellow precipitate was formed. The gas evolved mas a mixture of carbon monoxide and hydrogen, a little hydrogen sulphide was observed later, and the yellow solid proved to be nickel sulphate, so that the reaction seems to proceed according t o the equation : Ni(CO), + H,SO, = NiSO, + 4CO + H,. Pi~osphorus. Nickel carbonyl, when mixed with a solution of phosphorus in carbon disulphide and left out of contact with air, undergoes no change after several weeks. If, however, dry air has access t o the mixture, a reaction slowly occurs with the evolution of gas and the formation of a black solid which contains nickel and phosphorus, but which has not yet been fully examined. UNIVERSITY CHEMICAL LABORATORY, CAMBRIDGE,

ISSN:0368-1645    

DOI:10.1039/CT9048500203

出版商:RSC    

年代:1904

数据来源: RSC

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212 DEWAR AND JONES: THE CHEMICAL REACTIONS OF XXVI1.- The Chemical Reactions of A%cEeZ Caybonyl. Reaction with Aromatic Hydrocarbons Syathesis of Part II. i a prese.iLcc of Alumi.iliicm Chloride. Aldehydes arm! Anthmcene Dwivati/ues. By JAMES DEWAH. and HUMPHREY OWEN JONES. NICKEL carbonyl does not react with aluminium chloride or most of the other metallic chlorides, nor has it by itself any action on aromatic hydrocarbons. If, however, a mixture of nickel csrbonyl and a hydro- carbon, such as benzene or toluene, is treated with aluminium chlorideNICKEL CARBONYL. PAliT 11. 213 in the cold, a rapid evolution of hydrogen chloride a t once occurs, while the mixture darkens in colour and becomes viscid. It is remarkable that during this apparently violent reaction there is no perceptible rise of temperature.The reaction was allowed to proceed in the cold and also a t looo, and the products investigated. In the former case, an aldehyde was produced, the reaction being very similar to that effected by a mixture of carbon monoxide and hydrogen chloride in the presence of aluminium chloride (Gattermann and Koch, Ber., 1897,30, 1622 ; 1898, 31, 1149), and little or no nickel chloride could be detected. I n the latter case, the aldehyde had almost entirely disappeared ; an anthracene derivative was found to have been produced whenever possible, and a consider- able quantity of nickel chloride appeared among the reaction products. The mechanism of this reaction is obscure, and although it is probable that the anthracene is formed by the condensation of two molecules cf the aldehyde with the elimination of the elements of hydrogen per- oxide, a change which may be effected by the metallic nickel present, yet numerous experiments made with the view of throwing further light on the process have given negative results.The aldehyde produced from toluene is p-tolualdehyde, and the dimethylanthracene formed must then be 2 : 6-dirnethylanthracene. m-Xylene gives 2 : 4-dimethylbenzaldehyde, and the tetramethyl- anthracene is therefore the 2 : 4 : 6 : %derivative, since the aldehyde can only condense in one way so as to give an anthracene compound. This tetramethylanthracene is identical with that produced by Anschutz from m-xylene. Consequently the other produced from m-xylem by Friedel and Crafts must be the 1 : 3 : 6 : 8-isomeride, since there are only two such compounds which can be derived from m-xylene.Mesitylene gives the aldehyde and no condensation product, the formation of an anthracene derivative being impossible in this case. Naphthalene behaves in an entirely different manner from the above benzene derivatives; no aldehyde could be detected, and the product contains a hydrocarbon, Cl6HI2, apparently identical with that obtained from ruficoccin by distillatior, with zinc dust and also by the action of methyl chloride and aluminium chloride on naphthalene. I n this case, it would appear that carbon rings have been formed directly from carbon monoxide. Benseihe. A mixture of benzene (4 mols.), aluminium chloride (4 mols.), and nickel carbonyl (1 mol.) was allowed to react in the cold either in a flask provided with a calcium chloride tube with a very small orifice as outlet for the gas, or in a sealed tube, which was opened from time to time to relieve the pressure.After a few days, the dark mass was214 DEWAR AND JONES : THE CEIEMrCAL REACTIONS OF decomposed by means of ice-water (the aqueous layer contained only mere traoes of nickel in solution), and after the addition of hydrochloric acid was submitted to distillation in a current of steam. The distil- late and residue were extracted with benzene, dried over calcium chloride, and distilled. The distillate in steam was found to consist almost entirely of benzaldehyde, which was further identified by oxidation to benzoic acid and by the formation of its phenylhydrazone. The yield obtainable is not large, not exceeding 25 per cent.of the weight of the benzene used. The residue not volatile in steam was found to contain only a small quantity of viscid oil, which was not further examined. On heating a mixture of the reagents, in the same proportions as above, at looo in a sealed tube for periods varying from half an hour t o several hours, the result was invariably the same, a dark mass was formed, considerable pressure developed, and a certain amount of the three reagents was found to be &till present. The product of the reaction was mixed with ice-water and treated as already described ; the aqueous layer now contained considerable quantities of nickel in solution. The distillate in steam yielded a small quantity of benzaldehyde and a trace of a crystalline solid, which was afterwards found to be identical with the substance isolated from the part not volatile in steam.The dark, tarry solid left in the flask after the distillation in steam was taken up in hot benzene and the solution dried over calcium chloride and distilled under reduced pres- sure. A crystalline solid having a pale yellow colour distilled over between 250° and 260° under 10 mm. pressure, leaving behind a small amount of tarry residue, which was not further investigated. In one experiment, 12 grams of the solid were obtained, together with a small amount of benzaldehyde, from 17 grams of nickel carbonyl and 31.2 grams of benzene. The solid, which was repeatedly crystallised from hot alcohol or benzene, was finally obtained in colourless, lustrous plates melting at 211' (uncorr.), and showing a beautiful violet fluorescence; it was identified as anthracene by ultimate analysis and vapour density deter- minations, and was further characterised by the formation of its picrate (m.p. 136-137') and anthraquinone. Xoreover, it was found that both this product and pure anthracene dissolved in pure sulphuric acid to a pale yellow solution, but if a trace of nitric acid were present-as is always the case with the ordinary ' pure ' acid-a brilliant, dark green coloration was produced, and on adding potassium dichromate or a larger amount of nitric acid, the colour changed to a brilliant, reddish-purple, and finally t o brown. This reaction, which we have never seen described, constitutes an ex-NICKEL CARBONYL.PART 11. 215 ceedingIy delicate test for anthracene and its homologuea, and serves to distinguish this series from allied substances. Anthracene is therefore the principal product of the action of nickel carbonyl on benzene in the presence of aluminium chloride a t loo", and it seems that benzaldehyde is certainly an intermediate product. The mechanism of this reaction, if benzaldehyde is assumed to be the intermediate product, consists in the elimination of the elements of hydrogen peroxide. H H This change is of considerable interest, and several experiments have been made with the object of elucidating it ; but, unfortunately, little information has been gained. The metallic nickel, produced by the decomposition of its carbony1 derivative, is very probably the reducing agent which effeots the cbange, since it is only dissolved in any quantity when anthracene is produced.(1) Benzaldehyde, when heated with aluminium chloride alone or with benzene and aluminium chloride, produced no anthracene, but only benzoic acid and a solid melting at 90'. (2) On heating with aluminium chloride and zinc dust, benzaldehyde yielded a solid not volatile in steam; this product dissolved in hot alcohol and crystallised in needles melting at 1343. 0.1223 gave 0.366 CO, and 0.0625 H,O. C = 78.8 ; H = 5.6. (C,H,*CHO), requires C = 79.2 ; H = 5-6 per cent. The substance is identified as being benzoin by the foregoing analysis and by a comparison of its melting point with that of the pure substance.(3) A mixture of benzaldehyde, aluminium chloride, and finely- divided metallic nickel (reduced a t a low temperature), when left in the cold became hot, and R small quantity of gas was produced. The product was heated at 100° for 5 hours and then examined in the manner already described. There was a slight pressure in the tube, and the aqueous solution contained nickel chloride. The steam distil- late contained benzaldehyde and benzoic acid, but no anthracene could be obtained. Hydrogen chloride, in benzene solution, mas found to have only a very slight action on nickel carbonyl. Zinc chloride and anhydrous ferric chloride cause the production of a small amount of hydrogen218 DEWAR AND JONES: THE CHEMICAL REACTIONS OF chloride, but the action is very slight and the liquid remains clear and colourless even after prolonged heating.Toluene. On mixing nickel carbonyl (1 mol.) with toluene (4 mols.) and aluminium chloride (4 mols.), torrents of hydrochloric acid were im- mediately evolved, and the evolution of gas from the mixture continued slowly for several days. The reaction product was treated successively with &-water and hydrochloric acid, being then submitted to steam distillation and worked up as already described. The aqueous solution contained only a trace of nickel chloride. Toluene distilled over first, and then a small quantity of oil boiling a t 204' was obtained, the yield being about 16 per cent. of the toluene used. This product was identified as p-tolualdehyde by the preparation of methyl tere- phthalate from the product of i t s oxidation.The phenylhydrazone of this aldehyde was prepared; it separated from alcoholic solution in almost colourless plates which melt at 114-115' and readily turn pink on exposure to sunlight. There was a small amount of non-crys- tallisable oil with a high boiling point, which was not further examined. The product of the reaction at loo*, worked up in a similar way, gave about 9 per cent. of the aldehyde, and then the residue gave a solid, which, on crystallising from hot alcohol, separated in plates melting a t 215-216'. 0.1566 gave 0.5330 CO, and 0.099 H,O. C = 92.9 ; H= 7-02. C,,H,, requires C = 93.2 ; H = 6.8 per cent. The substance is therefore a di~net?iylanthl.ucene. This hydrocarbon gives the same colour reactions as anthracene with sulphuric and nitric acids, the colour being a little more intense, On oxidation with an acetic acid solution of chromic acid, it gave a quinone which melted at 159-160'.Elbs and Wittich (Beg.., 1885, 18, 348), by the action of chloroform and aluminium chloride on toluene in carbon disulphide solution, ob- tained a dimethylanthracene melting at 2 15-2 16O, and producing a quinone melting at 16 1-1 62O. This hydrocarbon is probably iden- tical with that described above. A similar hydrocarbon melting at 331--232O, usnally assumed to be identical with t h a t of Elbs and Wittich, has been prepared by Friedel and Crafts (Arzm. Chim. Phys., 1884, [vi], 1, 482) by tho action of benzyl chloride and alumin- ium chloride on toluene, and also by the action of methylene chloride and aluminium chloride on toluene (Zoc.cit., 11, 266). The constitution of the dimethylanthracene prepared by these methods has not been determined.NICKEL CARRONYL. PART 11. 217 If, as is probable, p-tolualdehyde is an intermediate product in the formation of the anthracene derivative, then the constitution of the dimethylanthracene thus produced, and consequently that of Elbs and Wit tich, is at once fixed, since y-tolualdehyde can only condense in one way giving 2 : 6-dimethylanthracene, K H H H H &\,,/ \/yq \A/\/H I 1 : H;//\CH 0 H /\C1T3 -+ 1 I c H,' H H H CH3i)JS H U H C \P H This dimethylanthracene is therefore probably not the same as that obtained by Louise ( A m , . Chim. Phys,, 1885, [vi], 6, IS) ; this sub- stance, which melted at 218-219O and yielded a quinone melting at 170°, was prepared by passing benzplmesitylene through a red hot tube.These two hydrocarbons could not, however, be identical unless some profouud molecular rearrangement had taken place. rn-Xylene. A mixture of m-xylene, nickel carbonyl, and aluminium chloride in the proportions employed in the preceding examples at once darkened and a rapid evolution of hydrogen chloride occurred. The reaction product was allowed to remain for several days and then worked up in the manner already described. The distillate in steam gave an approxi- mately 20 per cent. yield of an aldehyde boiling at 215--220", and a very small quantity of a n oil with a high boiling point; there was a small amount of tarry residue left in toe distillation flask.The aldehyde, on oxidation with chromic or nitric acids or when left exposed to the air, gave an acid which, after recrystallisation from hot water, was obtained as long, lustrous prisms melting a t 1269 0.1355 gave 0.3560 CO, and 0.0838 H,O. C6H,(CH,),*C0,H requires C = 72.0 ; H = 6.7 per cent. The acid is therefore 2 : 4.dimethylbenzoic acid (xylic acid), identical with that produced by the action of carbonyl chloride and aluminium chloride on m-xylene (Ador and Meier, Ber., 1879, 12, 1968). Accordingly the aldehyde is 2 : 4-dimethylbenzaldehyde, identical with that produced by the action of carbon monoxide, hydro- gen chloride, and aluminium chloride on m-xylene by Gitttermann and Koch (ZOO. cit.). The phenylhydrazone of this aldehyde crystallises from alcohol in pale yellow, rhombic plates melting at 82-84O.It has a great tendency t o separato as an oil, and decomposes rapidly in sunlight, becoming coloured and gummy. C = 71.66 ; H = 6.87.218 DEWAR AND JONES: THE CHEMICAL REACTIONS OF The mixture was also heated at 100' for several hours in a sealed tube and the products worked up as beFore. The part which volatilised in steam gave an approximately 20 per cent. yield of the aldehyde, just a8 if the reaction had proceeded in the cold. The residue in the distilling flak yielded a quantity of a solid boiling above 280' under 20 mm. pressure and a non-crystallisable oil with a higher boiling point. The solid mas crystallised successively from hot benzene and from hot acetic acid, and was obtained in beautiful, lustrous plates melting at 280' and having a slight yellow tinge with a brilliant green fluorescence.This hydrocarbon is sparingly soluble in cold ether, alcohol, benzene and acetic acid, but more soluble in the hot solvents; it is fairly soluble in cold chloroform. 0,2698 gave 0.9097 CO, and 0.1875 H,O. C,,H,, requires C = 92.3 ; H = 7.7 per cent. The compound gives a yellowish-brown coloration when dissolved in sulphuric acid with a trace of nitric acid; the solution, on further addition of the latter acid, assumes a claret, or an intense reddish- purple colour. On oxidation with chromic acid dissolved in acetic acid, a quinone was obtained, whicb, on recrystallisation from hot alcohol or acetic acid, formed pale yellow prisms melting a t 228-230'.The hydrocarbon is therefore a tetmmethylanthracene, and appears to be identical with that prepared by Anschiitz (Annulen, 1886, 235, 174) by the action of acetylene tetrabromide and aluminium chloride on m-xylene. Since the aldehyde C = 91.9 ; H = 7.72. can only condense in one way, the compound produced must be 2 : 4 : 6 : 8-tetramethylanthracene having this constitution : CH,H H unless, during the reaction, a considerable transformation has taken place resulting in the change of position of the methyl groups. The quinone described above is therefore 2 : 4 : 6 : S-tetramethyl- ant hraquinone. Friedel and Crafts (Ann. Chim. Phys., 1887, [vi], 11, 268) obtained a tetramethylanthracene by the action of methylene chloride andNICKEL CARBONYL.PART 11. 219 aluminium chloride on nz-xylene, which is certainly diiferent from that obtained by the authors and by Anschutz, since i t melts at 162-163' and gives a quinone melting at 235". This hydrocarbon must be 1 : 3 : 6 : €l-tetrarnethylanthracene, since this is the only other possible derivative obtainable from nz-xylene. MesityZene. Mixtures of mesitylene (4 mols.), aluminium chloride (4 mols.), and nickel carbonyl (1 mol.) were either allowed to remain in the cold or heated in sealed tubes for several hours at 100'. The result in both cases was the same, On opening the tubes, there was but little pres- sure due t o hydrogen chloride as compared t o that observed with benzene and toluene, and on treating wit8h water only a comparatively small quantity of nickel went into solution.After acidification, the liquid was submitted to distillation in steam, when the whole of the oil passed over leaving only a very small quantity of tarry matter in the distilling flask. The distillate was extrwted with ether, dried over calcium chloride, and submitted to fractional distillation. The main portion OF the liquid was found to be unchanged mesitglene, the remainder was an oil boiling at 234-240' and having the character- istics of an aldehyde. This oil, when oxidised with the calculated quantity of potassium permanganate in an a1 kaline solution, yielded an acid which was sparingly soluble in cold water and, on crystal- lisation from hot water, melted at 152'. 0.1072 gave 0.2865 CO, and 0.0725 H,O. C,H2(CH,),*C02H requires C = 73.17 ; H = 7.32 per cent.The substance is therefore mesitylenecarboxylic acid (m. p. 152O), the aldehyde being 2 : 4 : 6-trimethylbenzaldehyde, the boiling point of which is given as 235-240' by Feith (Ber., 1891, 24, 3544) ; this compound cannot condense to form an anthracene derivative. I n the present instance, the reaction is very incomplete, thus, after heating at 100' for 6 hours, only 2 grams of the aldehyde were ob- tained from 24 grams of mesitglene. I n a similar experiment, in which the heating lasted 16 hours, only a small quantity of aldehyde was obtained, but a little mesityleaecarboxylic acid was also produced (compare the formation of benzoic acid, page 215). C=72*89 ; Hx7.51. iVGp?&cclene, Mixtures of naphthalene, nickel carbouyl, and aluminium chloride in the proportions indicated in the preceding experiments, when allowed t o remain in the cold, gradually became very dark and slowly220 DEWAR AND JONES: THE CHEMICAL REACTIONS OF evolved hydrogen chloride.After about:a week, the mass was worked up in the manner already described. The distillate in steam which solidified was found to be practically pure naphthalene, and no product of an aldehydic nature was found. The black solid left in the distill- ing flask was dissolved in benzene, dried over calcium chloride, and, after evaporating off the benzene, was distilled under diminished pressure. At first a smdl amount of naphthalene distilled over, at about 280' under 17 mm. pressure an oil distilled which afterwards solidified, then above 300° the oily fraction, which had an orange colour, only partially solidified, and a small amount of black residue was left in the distilling flask. When the same mixture had been heated at looo f o r n few hours in a sealed tube and worked up as before, the same products were ob- tained, but in different proportions.There was now only a small quantity of naphthalene, together with a certain amount of the solid distillate and more of the oily fraction, but the main product remained in the distilling flask as a hard, black, resinous residue decomposing at the temperature at which the glass began to soften. The two last- mentioned substances still await further investigation. The principal solid product obtained when the reaction was carried out in the cold or when the heating only continued for a very short time, was purified by repeated crystallisation from hot benzene, and was then isolated in lustrous plates having a yellow tinge and melting at 180-1 81'.This substance is very sparingly soluble in cold alcohol, benzene and acetic acid, much more so in the hot solvents, and especi- ally in benzene or ethylene dibromide ; its solutions are fluorescent. The colour of the hydrocarbon was diminished by crystallisation from hot alcohol with the addition of animal charcoal, but the melting point remained unchanged, From its solution in ethylene dibromide, the compound was obtained in colourless plates melting a t 180-181', the fluorescence of which still persists. 0.1203 gave 0.4100 CO, and 0*0610 H,O. C = 93.7 ; H = 5.63.0.1371 ,, 0.4722 CO, ,? 0.0711 H,O. C= 93.9 ; H 4 - 7 6 . (C,H,), requires C = 93.75 ; H = 6.25. (C,H,), ,, C=94*11 ; Hn5.89. (C,H,), ,, C-92.7 j H=7*3 per cent. A determination of the vapour density was made by V. Meyer'g 0.0712 gave 8.4 C.C. at 12' and '774 mm. After cooling the apparatus, it was found that the hydrocarbon bad Several determinations of the molecular weight were made by the method, using a lead bath heated to a high temperature. M. W. = 196.4. aublimed in lustrous plates without charring.NICKEL CARBONYL. PART 11. 221 cryoscopic method with carefully purified ethylene dibromide as solvent. Test experiments with naphthalene and ant hracene served to show that the solvent was pure and gave very Satisfactory numbers. The experimental errors in the determination of the depression are necessarily large, since with solutions nearly saturated, as, for example, with 0.11 gram of the substance in 41 grams of solvent, the depression wa8 only 0*16', so that accurate results could not be expected. The following values mere obtained : M.W. = 193. 198. 214. 227. Attempts were made to use acetic acid or benzene for the cryoscopic method, but the hydrocarbon was too sparingly soluble in these solvents. With phenol, the valw 215 was obtained, but the depres- sion observed with a nearly saturated solution was only O.OSo. By the ebullioscopic method with alcohol as solvent, the elevation was too small to give reliable results, but in benzene the values 263 and 334 were obtained. Mr. G. Barger, B.A., of King's College, kindly determined the molecular weight; of the hydrocarbon by means of his microscopic method (this vol, p.286). The sparing solubility again makes the determinations difficult, and largely increases the experimental error. A solution in benzene containing 9.07 grams to the litre mas found t o be isotonic with a benzil solution containing 0.0345 gram-molecule per litre, hence the molecular weight is 263. A solution in ethylene dibromide containing 11 -5 grams per litre mas isotonic with a solution containing between 0.057 and 0,064 gram- molecule of triphenylmethane per litre. Hence molecular weight is 180-202, giviog 191 as a mean value. A solution containing 12.7 grams per litre was isotonic with a scjlution containing between 0.055 and 0.066 gram-molecule of benzil per litre, hence the molecular weight is 192-231, the mean being 211.The analyses and molecular weight determinations correspond best with the formula C16H,2, and the properties of the hydrocarbon corre- spond fairly well with those of a hydrocarbon having this formula, which had already been prepared by several chemists. Liebermann and Dorp (AnnaZsn, 1873, 163, 112), by the distillation of ruficoccin with zinc dust, obtained a hydrocarbon, C16H12, melting at 183-18S0, and giving a quinone melting at 250". The constitution Cl,H,<8z is suggested by these authors for this hydrocarbon. By distilling either coccinin or carmine with zinc dust, Fiirth (Bey., 1883, 16, 2169) obtained a hydrocarban having this formula and melting at Bischoff (Ber., 1890, 23, 1905 and 3200), by the action of methyl chloride on naphthalene in the presence of aluminium chloride, obtained, VOL LXXXV, Q 186-1 87'.228 THE CHEMICAL REACTIONS OF NICKEL CARBONYL. among other products, a hydrocarbon, boiling at about 36O0, from which a crystalline substance was isolated having the empirical formula C,H, and melting at 179-181O.The melting point and solubility of Bischoff’s compound correspond exactly with those of the compound prepared by the authors. It may or may not be identical with the compound from ruficoccin. BischoE put forward the following formula : for his hydrocarbon, suggesting that it might be derived from 1 : 4 : 5 : 8-tetramethylnaphthalene. Whatever the formula of the hjdrocarbon may be, it is clear t h a t unless the highly improbable assumption is made that some of the naphthalene molecules are partially broken down, and the hydrocarbon then built up from intact naphthalene molecules and the degradation products, it must be coicluded that a carbon ring bas been synthekised from carbon monoxide. The only other case in which this has been shown to occur is in tho production of potassium hexaoxybenzene by the action of carbon monoxide on potassium. Reaetion of Nickel CarboPqZ with BeTazlene in the Pressnee of Aluminium Bromide. In this case, a reaction readily takes place, and the product was treated in the manner already described for aluminium chloride. No benzaldehyde and no anthracene could be detected, but a crystalline product distilling at 300’ under 30 mm. pressure, and an uncrystaliis- able oil with a higher boiling point were obtained. The crystalline product, on repeated crystallisation from hot alcohol, was obtained in lustrous plates melting a t 181-181.5O, and appeared to be identical in every respect with that obtained from naphthalene, a mixture of the two substances melting a t 181-181.5°. The authors desire to express their thanks t o Dr. Mond for his aid in supplying the means for the conduct of these investigations. U N I v E R s I T Y C H E MI c A I, LA BO I: AT o RY , CAMBRIDGE.

ISSN:0368-1645    

DOI:10.1039/CT9048500212

出版商:RSC    

年代:1904

数据来源: RSC

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OPTICALLY ACTIVE NITROGEN COMPOUNDS, 223 XXVII1.-Optically Active Nitrogen Compounds. d-. and 1-Phenylbenzylmethylethyla-mmonium Salts, By HUMPHREY OWEN JONES. THE first definite proof of the existence of optically active compounds in which the optical activity is due to asymmetric atoms other than carbon atoms was given by Pope and Peachey (Trans., 1899, ’75,1127), when they resolved Wetiekind’s a-phenyl benzylmethylallylammoniurn iodide into dextro- and {avo-rotatory forms in which the activity is caused by the asymmetzy of the quinqrievalent nitrogen atom. Up to the present time, the salts then described, together with those described later by Pope and Harvey (TIans., 1901, 79, S%), derived from the Same sub-tance, are the only active nitrogen compounds known. The a- and P-phenylbenzylmet hylally lamrnonium salts are also unique i n that they are the only ones which have been shown to exist in definite stable isorrieric foi ms.The phenomena observed iq the phenyl trrethylett-iylHllylnmmonium iodides by Wedekind (Bey., 1903, 36, 3791), if they can be considered as due t o isomerism a t all, are of quite a different order, since the differences vanish when the compounds separate from solution and the amorphous product becomes crystalline. It becomes therefore a matter of importance to determine whether the existence of optical activity is in any way connected with the existeoce of isomerides or whether it is dependent on the presence of any special radicles. The resolution of one of these compounds was undertaken by the author i n order to show that the negative result of the attempts to prepare active forms of salcs of the type NR’R’R,”’X was not due t o the absence of ordinary isomerides or to the particular radicles used.A preliminary notice of the partial resolution of phenylbenzyl- methylethylammonium compounds has already been published (Trans,, 1903, 83, 1419). This subject acquired additional interest after the publication of a paper by Wedekind (Zed. physikal. Chem., 1903, 46, 235), in which unsuccessful attempts to resolve two salts, namely, p-tolyl- benzylmethylallylammonium and p-tolylmethylethylallylammonium d-camphorsulphonates, are described. The question of the existence of isomerides of phenylbenzylethyl- methylammonium iodide was first investigated by preparing this compound in the three possible ways and carefully comparing the properties of the products.2 2 4 JONES : OPTICALLY ACTIVE NITROGEN COMPOUNDS.Pherqlbenna: ylmethy Zethylammoniunz Iodide. (1) A mixture of methylethylaniline (27 grams) and benzyl iodide (43 grams) in molecuIar proportion set almost completely to a solid gum in the course of about two hours. The gummy mass, when dis- solved in rectified spirit, crystallised slowly ; the crystals which aeparated were short, almost colourless prisms melting at 139--140°, the melting point being slightly raised by repeatedly crystallising the substance from alcohol. Unfortunately, with this compound, as with some of the other substituted ammonium salts pi-eviously investigated, the melting point is not a constant, but depends on the rate of heat- ing, and was sometimes found to have been lowered a degree or two when the substance was left for some time in a, stoppered tube, although in this case no visible change had taken place.The carefully purified salt, when slowly heated, becomes slightly brown a t 140°, and melts either at, or just below, 144-145'. If, however, the tube con- taining the salt is not introduced until the bath is at about 140°, the salt may not melt below 146-148'. These differences are apparently due to partial decomposition below the melting point. Hence, in the comparison of melting points described below, two tubes containing the substances to be compared were always heated side by side in the same bath. (2) Benzylethylaniline, which was prepared as described by Fried- lander (Bey., 1889, 22, 58s) by the action of ethyl iodide on benzyl- aniline at looo, boiled at 2S6-288' under 750 mm, and at 190' under 20 mm.pressure. A mixture of this base (14.4 grams) with methyl iodide (10 grams) in molecular proportion gradually deposited the ammonium iodide in a crystalline form, yielding about 1.6 per cent. after three days. The cold alcoholic solution, when diluted with ether, slowly deposited prismatic crystals which melted a t 145' when slowly heated and at 147-148* when quickly heated, or a little higher than the compound produced by method (1). A mixture of the two preparations melted at the same temperature as the product of the second method ; more. over, the crystalline form of the t w o products is the same, go that the two are apparently identical.(3) A mixture of benzylmethylaniline ( I 9.6 grams) and ethyl iodide (15-6 grams) in molecular proportion deposited, with extreme sIowness, a crystalline solid and a little gummy matter, not more than about 2 per cent. of the salt being obtained after ahout a fortnight. The melting pointof the cruEe substance was 135-137', and on recrystallisatlon from alcohol the melting point rose t o 143-144', being identical with that of the product from the first method; a mixture of the two Qelted atD- AND L-PHENYLBENZYLMETHYLETHYLAMMONlUM SALTS. 225 the same temperature, so that they are evidently the same. The quantity of material available was insufficient to furnish crystals large enough for crystallographic examination.Hence no definite stable isomerides can be produced in this way. It is possible that the gummy product produced at first by method (1) and also the amorphous phenylmethylethylallylammonium iodide of Wedekind (Bey., 1903, 36, 379 I ) may represent the untransformed, and, in these cases, the unstable addition product, which, when deposited from solution, undergoes transformation into the more stable form, but which is stable under special conditions, as in the case of certain compounds investigated by Kipping, and the a- and P-phenylbenzylmethylallylammonium compounds of Wedekind (com- pare Trans., 1903, 83, 1405). A specimen dried in a vacuum desiccator was employed in the following analysis : 0,1350 gave 0.2695 CO, and 0.0691 H,O. (2-54.4; H=5*60. C,,H,,NI requires C = 54.4 ; H = 5-66 per cent.Resolution of the d- und l-Cal?z,~horszcZpho.Izutes. The camphorsulphonates were made in the usual manner by boiling the silver salt of the acid with the calculated quantity of the ammon- ium iodide prepared by method (l), and a mixture of ethyl acetate and a little alcohol. I-Camphorsulphonic acid was prepared from I-borneol as described by Pope and Harvey (Trans., 1901, 79, 76) and was found to melt a t 193'; its ammonium salt in aqueous solu- tion gave [MI, = 51.5". The I-camphorsulphonate of the I-base was prepared both from the inactive iodide and from crude 2-iodide obtained from the most soluble portions of the d-camphorsulphonate. The camphorsulphonates crystallise readily, are very sparingly soluble in acetone and ethyl acetate, even when hot, but dissolve quite readily in methylene diethyl ether (ethylal) ; a mixture of this with ethyl acetate was therefore used as solvent.The crystallisation was carried out at a comparatively low temperature, as it was found that prolonged heating induced a distinct reti*ogression in the rotatory power of the salt, most probably due to racemisation. Several crystallisations (6-8) were found to be necessary before the rotatory power of the salts became constant ; the resolution therefore proceeds somewhat slowly and is not effected quite so readily as in the case of the phenyl benzylmethylallylammonium salts resolved by Pope and Peachey (Zoc. cit.). The rotatory power of the salts is small compared with that of the last-mentioned compounds, so that on this account a much larger quantity of material must be worked up (about 30-40 grams of the226 JONES : OPTICALLY ACTIVE NITROGEN COMPOUNDS.camphorsulphonates were employed), so that for this reason, and on account of the slight solubility of the salts and the necessity for keeping down the temperature, the process is somewhat tedious. The amount of the rotation observed was in all cases small even with comparatively concentrated solutions, consequently the experimental error is necessarily large, and great care had t o be exercised in order t o secure the highest degree of accuracy. d-PlienylbenxyZmetl~yZethyZaminorzium d-Cnmpho~*suZphonctte. This salt formed lustrous, prismatic crystals melting sharply at 180-181°; its rotatory power in aqueoussolution wasdetermined several times during the process of fractional crystallisation, and [MID was found to approach a constant value of about 71".A specimen mas then dissolved in a mixture of ethyl acetate and ethylal, the solution allowed to evaporate slowly in a desiccator, and the successive fractions examined. The identity of the two results given below shows, within the limits of experimental error, that the compound is pure. First fraction : 1.086 in 25 C.C. gave aD = 1 ~ 3 5 ~ in a 200 mm. tube," Third fraction : 1.063 in 25 C.C. gave uD= 1-32', hence [a],= 15.52' hence 15.54' and [MJD=714'. and [MI, = 70.94O. 0,1355 gave 0.3385 CO, and 0.0935 H,O. C = 68.1 ; H = 7.7. C,,H,,O,NS requires C = 68.2 ; H = 7.6 per cent. 1-Phenylbenxylmet~yleth~larnmoni.um 1-Campliorsulphonacte.The salt has exactly the same properties as the corresponding dd-salt, crystallising in similar lustrous prisms and melting a t 180-181O ; its molecular rotatory power in aqueoas solution gradually became constant at about 71'. A specimen was then dissolved in a mixture of ethyl acetate and ethylal, the solution allowed to evaporate slowly in a desiccator, and the rotatory power of the successive fractions examined. The practical identity of the numbers obtained with one another and with those already given for the dextrorotatory isomeride shows t h a t the salt is homogeneous. First fraction: 0.583 in 25 C.C. gave aD = -0*73O, hence [aID = Second fraction : 1.027 in 25 C.C. gave aD = - 1*27O, hence [ alD = - 15 6' and [ MID = - 71.5". - 15.46' and [MID = - 7 0 - 7 O .* All the following determinations of a, were carried out in a 200 111111. tube.D- AND L-PHENYLBENZYLMETHYLETHYLAMMONIUM SALTS. 227 Third fraction : 1.076 in 25 C.C. gave a,, = - 1-33', hence [ u ] D = Fourth fraction : 1.002 in 35 C.C. gave a, = -1*27', hence [ a ] ~ - 15.45' and [MI, = -70.6'. - 15.8' and [MID = - 7 2 . 3 O . 0.1930 gave 0.4829 CO, and 0-1330 H,O. C26E,,0,NS requires C: = 68.2 ; H = 7.6 per cent. The molecular rotatory power of the d-phenylbenzylmethylethyl- ammonium d-camphorsulphonate is therefore + 71.0' (mean), and t h a t of the corresponding Zl-salt is -71.2' (mean). Since the molecular rotatory powers of the d- and I-camphorsulphonate ions are respectively +51.7' and -51*6O, the molecular rotatory powers of the a?- and 2-phenylbenzylmethglethylarnmonium ions are + 1 9 .3 O and - 19.6' respectively. The value for the d-phenylbenzylmethylethyl- ammonium d-camphorsulphonate agrees fairly well with that already given, namely, + 6 9 O (20~. cit., 1419). The molecular rotatory powers of the d- and I-phenylbenzylmethylallylammonium ions are + 166.4' and - 159' respectively (Pope and Harvey, Zoc. cit.). The remarkably low value obtained for these compounds, which only differ from those last mentioned by the introduction of an ethyl instead of an ally1 radicle, is therefore very surprising. It is dificult to see why such a small difference as this could produce such an enormou8 change in the rotatory powers were it not that it has been repeatedly shown that an ethylene linking exerts a very marked influence in increasing the rotatory power.An attempt was made t o confirm these values by the examination of the bromocamphor- sulphonates, but unfortunately these have not been obtained crys- talline. Even when the d-iodide of the base, obtained from the d-cam- phorsulphonate, was converted into the d-bromocamphorsulphonate, the salt still remained a gum and could not be induced to crystallise. C = 68-2 ; H = 7'66. d-PhenyZbenzylnzethylet~~~Za~n~onizLnz Iodide. The d-iodide of the base was obtained in a crystalline form by add- ing the calculated quantity of a concentrated aqueous solution of potassium iodide to fin aqueous solution of the d-camphorsulphonate. The crystalline salt thus obtained, dried in a vacuum desiccator, was found to melt at practically the same temperature as the inactive iodide, admixture with which did not appreciably change the melting point.The specimen for analysis was crystallised from cold alcohol in the dark, 0.1334 gave 0.2655 CO, and 0.0700 H,O. C = 54.28 : H = 5-82, C,,H,,NI requires C = 54.39 ; H = 5.66 per cent.228 JONES : OPTICALLY ACTIVE NITROGEN COMPOUNDS. The determinations of the rotatory power of the iodide offer con- siderable difficulties. The salt has a very small rotatory power and is very sparingly soluble in alcohol, so that, even with practically saturated solutions, the rotations observed were very small, for example, 0*3-0*4*, and hence the experimental error is very large. Chloroform dissolves a little more of the salt, but the solution shows a peculiar supersaturation phenomenon, the salt first dissolves and then partly crystallises out, in most cases rapidly, but sometimes more slowly, leaving a solution which gives a rotation of about the same magnitude as that of an alcoholic solution. Racemisation also occurs slowly in a chloroform solution, and consequently its use was abandoned.Several determinations were made in alcoholic solution at a concen- tration of about 2 per cent., which represents a nearly saturated solution at the ordinary temperature, The following data represent three of these determinations : 0.5620 in 25 C.C. absolute alcohol gave (XD = 0~37', hence [a], = 8023~ and [MID = 29.0'. 0.5455 in 25 C.C. gave aD = 0*36O, hence [a]D = 895' and [MI, = 29.1'. 0.5560 in 25 C.C.gave aD = 0.38', hence [aID = 8.5" and [MID = 30-1°, It may therefore be concluded that thevalue of [a], for the d-iodide is about 8*3O, although no very great reliance can be placed on these numbers owing to the very large experimental error. I- Phenylbcnxybnaeth yleth ybanznzonium Iodide. This iodide was prepared from the corresponding camphorsulphonate in the manner already described for the biodide. The salt, after re- crystallisation from cold alcohol in the dark, was found to melt, when slowly heated, at the same temperature as the I- and d-iodides, and mixtures of the I- and inactive iodides also meltad a t the same temperature. The following analysis was made on a specimen dried in a vacuum desiccator. 0.1862 gave 0.3701 CO, and 0-0975 H,O. The rotatory power was determined in alcoholic solution in the same 0.547 in 25 C.C.absolute alcohol gave (XD = -0*38', hence [ a ] , , = C =54.2 ; H = 5.81. C1,,H2,NI requires C = 54-39 ; H = 5-66 per cent. way as that of the d-iodide, with the following results : - 6-68' and [MAD = - 30.8'.D- AND L-PHENYLBENZTLMETHYLETKYLAMMONIUM SALTS. 229 0.514 in 35 C.C. absolute alcohol gave all = - 0*34', hence [u]D = - 8.27" and [MID = - 29.2'. 0.526 in 25 C.C. absolute alcohol gave uD = - 0.35', hence [ a ] D = - 8-33" and [MI,, = - 29.4'. The specific rotatory power of the 2-iodide in alcoholic solution is therefore numerically identical, within the limits of experimental error, with that of the corresponding d-salt, namely, about - 8.4'. Automcenaiaation of the Phern ylbenxy Imeth ylet hybammonium Xn Its.The camphorsulphonates retain their rotatory power practically unchanged for weeks in aqueous solution and also in cold alcoholic or ethylal solutions. If, however, the solutions are heated, the aqueous solution becomes turbid, the rotatory power of the other solutions diminishes, and the salt deposited from them has a distinctly low rotatory power. I n one experiment, a specimen of d-phengl benzyl- methylethylammonium d-camphorsulphonate,.having [ MID = 71*4', was recrystallised from a hot mixture of ethyl acetate and acetone, the solution being heated for about 10 minutes in order to bring all the salt into solution; the salt which was deposited on cooling had a much lower rotatory power, namely, [MI,= 56.0'. Boiling in ethyl acetate solution had therefore caused almost complete racemisation of the basic part of the molecule.In the fractional crystallisation of these salts, it is consequently necessary to avoid heating the solutions, and in practice the tempera- ture was usually not rjisecl above about 40'. The solutions of the iodides in alcohol retain their rotatory power in the cold for a long time, especially when left in the dark, On heating, however, the rotatory power diminishes, so that when recrystallising theso com - poands from alcohol the process must be carried out at as low a tetuperature as possible. I n chloroform solution, racemisation takes place slowly in the cold and in absence of light. On one occasion, a fairly strong chloroform solution of the d-iodide(not quite pure), when put into the tube, did not deposit the excess of iodide as all other chloroform solutions did, and was observed to be in the supersaturated state for about a week.The rest of the solution in the flask soon deposited crystals just as the other chloroform solutions had done. 0.859 in 25 C.C. chloroform gave ~,=0*64", hence [a],= 9-31' ; The rotatory power diminished gradually at first a t the rate of about Onlo per day, until it became practically inactive after a little more than a week. These salts therefore behave much in the same way as [M ]D= 33*8'.230 JONES : OPTICALLY ACTIVE NITROGEN COMPOtJNDS. the a-phenyl benzylme thylallglammonium salts investigated by Pope and Harvey (ZOC. cit.). The effect of chloroform in causing racemisation may be due, as suggested by these authors, to a dissociation of the ammonium salt into the tertiary amine and alkyl iodide and subsequent recom- bination to form the quaternary compound.This hypothesis is sup- ported by an experiment made by the authors, which showed that the rate of formation of the salt in chloroform solution is large compared with that in alcohol or ether. Wedekind (Zeit. physikal. Chem., 1900, 6, 23), ondetermining the molecular weight of the iodide in chloro- form solution by the ebullioscopic method, obtained values about one- third of the calculated value indicating dissociation of the salt into its constituents. It is difficult to see how the iodide could dissociate into three sub- stances, the results therefore seem t o indicate that the ebullioscopia method is inapplicable here.Moreover, the slow rate of racemisation indicates dissociation to a slight extent only ; were the dissociation complete, the racemisation ought to be instantaneous. The molecular weights of phenylbenzylmethylallylammonium iodide a n d phenylbenzylmethylethylammonium iodide in chloroform solution were determined by Mr. G. Barger, B.A.., of King’s College, who used his microscopic method. The author is glad t o take the opportunity of expressing his thanks t o Mr. Barger for the care and trouble which he expended on these determinations (compare this vol., p. 286). Phenylberte yZniet?~yZet?~y Zanimoniuna Iodide. A solution containing 23.9 grams per litre was found t o be isotonic with a solution of triphenylmethane containing 0.075 gram-molecule per litre, whence the molecular weight is 319.A solution containing 25.1 grams per litre was found to be isotonic with a solution of azo- benzene containing 0.0725 gram-molecule per litre, which gives a molecular weight 346. The calculated molecular weight is 353, so that at the ordinary temperature the molecular weight is approximately normal. a- PhenyZ6enxyZmeth~ZaZZ~Za~~mmcnium Iodzde. This salt, being much more soluble in chloroform than the fore- going compound, gives better results. A solution containing 59.0 grams per litre was foiind t o be isotonic with a solution of triphenyl- methane containing 0.1 6-0.17 gram-molecule per litre. Hence the molecular weight of the iodide lies between 335 and 381 (mean 358). The calculated value for CI7H,,,NI is 365. So that the molecularD- AND L-PHENYLBENZTLMETHILETHYLAMMONIUM SALTS. 231 weight at the ordinary temperature gives no indication of extensive dissociation. A peculiar phenomenon was observed in t h e case of both salts, which was, however, more marked with the phenylbenzylmethylallyl- ammoniurri iodide than with the other.I n the freshly prepared solution, the molecular weight always appeared slightly too high ; it then gradually diminished, became normal, and went on diminishing until it was somewhat too low. The rate of diminution was much increased by raising the temperature. This behaviour is being investigated, as it may throw light on the cause of the racemisation, and is probably the cause of the anomalous results obtained by the ebullioscopic method.The above results, which show that in both cases there is only a very slight dissociation of the salts in chloroform solution at the ordinary temperature, thus account for the slow rate of race- misa tion. i-P~cnyZ~enxyZmetl~yZethyZammonium Bromide.-This salt was prepared from the iodide by digesting an alcoholic solution with silver bromide. It crystallises from alcohol in prisms closely resembling those of the iodide, which melt sharply a t 155-156'. The rneltiug point of the bromide does not depend on the rate of heating in the same way as the iodide. l-PhenyZ6enzyEmetl~yEethyZammonizLm bromide is not precipitated from the aqueous solution of the camphorsulphonnte by the addition of a concentrated aqueous solution of potassium bromide, and consequently had t o be prepared by the same method as the inactive compound.It crystnllises from alcohol in long prisms melting at 155-156'. A mixture of the I- and i-bromides also melts sharply at the same temperature. A determination of the rotatory power in alcoholic solution was made with the following result : 0.634 in 25 C.C. gave a, = -0668O; hence [.ID = -1304' and The rotatory power is greater than that of tbe corresponding iodide, just as the rotatory power of the active a-phenylbenzylmethylallyl- ammonium bromide is greater than that of the iodide. The rotatory power of the bromide diminishes on recrystallising from alcohol. C = 62.36 ; H- 6.4. [MI, = - 4101~. 0.212 gave 0.4850 CO, and 0.1200 H,O. C,,H,,NBr requires C = 62.7 ; H = 6.53 per cent.232 JONES : OPTICALLY ACTIVE NITROGEN COMPOUNDS.CrystaEZine Form of the d-, 1-, and i - P ? ~ e n y l b e n , y ? / l i , a e t h y l e t ~ ~ l a ~ ~ ~ Iodides. The crystallographic examination was undertaken in order to decide whether the inactive form was a racemic compound or merely an inactive mixture. These salts crystallise from alcoholic solutions in beautiful, lustrous prisms, the faces of which, although appearing quite bright, nevertheless give bad reflections on a goniometer, so that i t was found difficult t o get good measurements. The crystals could only be obtained of very small size, 1-2 mm. i n length, and were therefore troublesome to measure. The dominant form mas always the prism nz(llO), the pinacoid FIG. 1. I u5- ~(100) was sometimes present as a very narrow face, but b(010) was never observed.Two distinct types of crystals mere observed, see Figs. 1 and 2, one sort exhibited the domes e(011) and n(012) with the basal plane c(OOl), often as a mere line, arid o( 11 2) was sometimes present; the other kind showed a well-developed basal plane and no domes, but o(112) was always present, and cc{lOO) was occasionally observed. No general forms were present, 80 that the question of hemi- hedrism could not be definitely settled. From analogy with the a-phenyl- benzylmethylallylammonium salts and the phenylmethylethylallyl- ammonium salts which belong t o the sphenoidal class of the prismatic system, it is probable that this salt also belongs to the same class;D- AND L-PHENYLBENZYLMETHYLEF€iYLAMMONIUM SALTS.233 this is supported by the scanty evidence which was obtained by examining the etched figures produced on the faces m(110) and m”’(lT0) by dilute alcohol. The few definite figures observed were devoid of a plane of symmetry, and those on rn and m”’ were inter- changeable by rotation about the dyad axis. The crystals of the d-, I-, and i-salts are similar in habit and appearance and have identical angles, so that the inactive salt is either an inactive mixture or a pseudoracemic compound. The fact F I G . 2. of the melting points of mixtures of d- or h a l t with the i-salt being the same as that of any one of the salts also supports this conclusion. Crystalline system. Prismatic. Sphenoidal Class (1). a : b :~=0*7456 : 1 : 1.1409. Forms observed : a(100), mfllO>, cfOOl), e(011), 4 0 1 2 ) , and 01112). The following angular measurements were made : ! Number of observations.Angle. I--___ ; -- m. m’”= 110 : i i o ’ 20 rnm’ = i i o : i i o 19 a m =100:110 I 4 c c =001:1)11 1 10 c 7a = 0 0 1 : 0 ~ 2 10 c e’ =011:011 6 n V! =012 : oi.2 4 F n. =011:012 1 8 c ‘)tf =Oil :012 I 7 m n =110:012 1 3 m”n = i i o : o i 2 I 3 c 0 =001:112 1 9 na 0 =110:112 I 10 Limits. - 0 13 0’- 73”55’ 106 0-10850 36 20-- 36 55 48 35 - 48 56 29 1s - 29 56 97 14- 97 46 58 50- 59 50 18 25- 19 20 72 40 - 73 30 106 39 -107 20 20 20 - 21 19 69 0 - 69 30 78 10- 78 56 hi e m . 106 34 1 36 40 48 46 ~ 29 37 1 97 32 1 59 12 19 0 78 28 78 13 / 106 56 20 56 i 69 14 I 1 Calculated. I 106’35‘ ! 36 37 I 97 32 ’ 59 34 19 4 ~ 78 28 78 3 ‘ 106 57 1 6 9 8 20 58234 SUDBOROUGH AND ROBERTS : The author desires to express his thanks t o Mr. A. Hutchinson for kindly placing at his disposal the goniometer with which the above measurements were made. It may therefore be concluded that (1) the ammonium compounds of the type NR’R”RR””X can be resolved into enan tiomorphously related optically active forms, although the resolution may often be difficult owing to the feeble rotatory power of the salts aud the ease with which racemisation takes place, and that (2) the existence of optical activity is in’dependent of the existence of ordiuary isomerides of the salt. Racemisation of the active salt,s takes place very readily on heating or on allowing Folutions in chloroform to remain in the cold ; the cause of the racemisation is probably dissociation into tertiary amine and alkyl iodide, followed rapidly by recombination, as suggested by Pope and Harvey. The expenses of this invest,igation have been met by a grant from the Government Grant Committee of the Royal Society, for whtch the author is glad to make this acknowledgment. UNIVERSITY CHEMICAL LABORATORY, CAMBEIDGE.

ISSN:0368-1645    

DOI:10.1039/CT9048500223

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

234 SUDBOROUGH AND ROBERTS : XXIX. -Diortho-substituted Benxoic Acids. Part V. Formation of Xults from Dio1.tho-substituted Benxoic Acids agd Orgnnic Bases. By JOHN JOSEPH SUDBOROUGR and WILLIAM ROBERTS. IN a previous communication on this subject (Lloyd and Sudborough, Trans., 1899, 75,580), it has been shown that stereochemical influences only slightly affect the reactions between substituted benzoic acids and organic bases, these influences being completely masked by the effect of the comparative strengths of the acids and bases. Since the publication of this earlier paper, E m i l Fischer (Bey., 1900, 33, 345, 1967) has drawn attention to the fact that diortho-substituted tertiary bases are incapable of combining with an alkyl iodide to yield quatern- ary ammonium compounds.As the earlier experiments were not carried out with bases of this type, we have tried to prepare salts from diortho-substituted alkylated arylamines of the type of dimethyl-DIORTHO-SUBSTITUTED BENZOIC ACIDS. PART v. 235 mesidine and various substituted benzoic acids, including those with two ortho-substituents. We have also attempted to combine the same acids with diethyl-a- and P-naphthylamines. s-Trinitrobenzoic acid forms salts with all the bases examined ; 2 : 4 : 6-tribromo-3-aminobenzoic acid also forms salts with a number of the bases, but not many have been obtained in a crystalline form. It would thus appear that the introduction of ortho-substituents into the acid and basic molecules does not prevent the formation of saltp, provided that the acid is very strong and the base not too weak.In addition, we have attempted to settle a point raised in the earlier paper (ibid., p. 583), namely, the behaviour of various organic bases towards a weak diortho-substituted acid of the type of s-trimethyl- benzoic acid. The acid forms a well-defined, crystalline salt with a strong base such as benzplamine, and also dissolves readily in 33 per cent. aqueous trimethylamine solution, but all attempts to combine it with tertiary bases such as dimethylmesidine, dimethyl-$-cumidine, bromodimethyl-nz-xylidine, and diethy laniline have given negative results; in each case, the unaltered acid crystallised out from the different solvents, even when two or three times the theoretical amount of base was employed. It is clear that the loss of the function of salt formation is not due to the presence of ortho-substitu- ents in the basic molecules, because a simple base like diethylaniline is incapable of forming a salt with this acid.I n order t o determine whether it is due to ortho-substituents in the acid molecule, we have endeavoured t o prepare salts from the same bases and mono-substituted benzoiu acids containing substituent methyl, bromo-, and nitro-groups. The fact that no salts are formed from either nz-toluic acid and dimethylaniline, or p-toluic acid and dimethylaniline or +-cumidine indicate that the presence of ortho-substituents in the acid molecule is not necessary in order to inhibit salt formation. In addition t o the normal salts formed by the unionof one molecule of acid with one of the base, we have obtained a number of acid salts formed by the union of two molecules of acid with one of the base, ag, for example, the acid salts derived from $-cumidhe and o-toluic acid, dimethyl-q-cumidine and fimitrobenzoic acid, $-cumidine and fit-nitro- benzoic acid, dimethyl-$-cumidine and tribromoaminobenzoic acid, and dimethyl-$-cumidhe and o-nitrobonzoic acid.These compounds are similar to the acid potassium and ammonium salts derived from sub- stituted benzoic acids, which have been recently described by Farmer (Trans,, 1903, 83, 1440). According to this investigator, the probable constitution of these acid salts is represented by the formula R-co>O<g, and the molecule contains a quadrivalent oxygen R-CO.0 atm. With such a formula, it is quite possible t h a t inhibition236 SUDBOROUGH AND ROBERTS : through stereochemical influences should occur.If ortho-substituents retard or prevent the formation of additive compounds involving the carbonyl residue of the substituted benzoic acid (compare Trans., 1899, '75, 581), it is quite possible that ortho-substituents would also prevent the conversion of the bivalent oxygen atom of the hydroxyl group into a quadrivalent oxygen. We might therefore expect that diortho-substituted benzoic acids mould not give rise to acid salts. Although we have not particularly investigated this question, we have met with only one such salt derived from dimethyl-q-cumidine and tribromoamiaobenxoic acid. The salts were usually analysed by determining the amount of acid present according to the method previously described (Zoc.cit., 584). We have found that the majority of the salts can also be analysed by titrating their alcoholic solutions with standard baryta when phenol- phthalein is used as indicator. The presence of the organic base does not interfere with the titration, and good results are obtained. For example, 20 C.C. of N/20 oxalic acid required 15.4 C.C. of baryta solution, and 20 C.C. of N/20 oxalic acid mixed with 6 drops of dimethyl- +ximidine also required 15.4 C.C. of the same alkali solution. EXPERIMENTAL. A. Prepavation of Bases. C,H,Me,*NMe, [Me, : NMe, = 2 : 4 : 5 : 1 3, was obtained by a method somewhat similar to that employed by Noelting in the preparation of dimethyl-m-xylidine (Bey., 1891, 24, 563); 20 grams of +-cumidbe melting at 6S0, 70 grams of methyl iodide, 47 grams of sodium carbonate, and 500 grams of water were heated in a reflux apparatus until all the iodide had disappeared; caustic potash solution was added and the base extracted with ether. The ethereal solution, when dry, gave 17 grams of a colourless oil distilling a t 219q which was characterised by the formation of its pkatinichloride.Dimetbyl-+-cumidine, 0.3808 gave 0.1008 Pt = 26.4'7. (C,H2Me,*NMe,),,H1PtCI, requires 26.47 per cent. Dimethylmesidine [Me, : NMe, = 2 : 4 : 6 : 11, obtained in a similar manner from mesidioe, was freed from secondary base by heating in a sealed tube with methyl iodide and dry magnesia a t 100' (Fischer, Ber., 1900, 33, 1968). Bromo-m-xylidine [Me, : NH, : Br = 2 : 4 : 1 : 61, melting at 46--47O, was obtained by Fischer's method (ibid., 1971) and transformed into the tertiary base by the method employed in the case of mesidine.Diethyl a- and /3-nsphthylamines were prepared by Morgan'sDIORTHO-SUBSTITUTED BENZOIC ACIDS. PART V. 237 process (Trans., 1900, 77, 823). OF the acids employed, the 2 : 4 : 6-tribromo-3-aminobenzoic acid was prepared by the method already described (Trans., 1899, 75, 589), the s-trinitrobenzoic acid was kindly presented by the Chemische-Fabrik Griesheim, and the 8-trimethylbenzoic acid was prepared from mesitylglyoxylic acid (Meyer, AnnaZen, 1888, 246, 139). Van Scherperizeil (Bee. traw. chim., 1900, 19, 380) recommends heating the glyoxylic acid with concentrated sulphuric acid until no more carbon monoxide is evolved, but we find that in order to obtain a good yield the temperature should be carefully regulated, the best yields being obtained when the temperature is kept about 40"; above 50°, carbon dioxide begins to be evolved, and the trimethylbenzoic acid itself is destroyed.I n one experiment, we obtained 2.05 grams of trimethylbenzoic acid from 2.5 grams of the glyoxylic acid (m. p. 152'). The magenta coloration produced when glyoxy lic acid is dissolved in concentrated sulphuric acid is extremely characteristic. 33. S a l t s f r o m s - T r i n i t p . o b e n , x o i c A c i d . (~02),C6H,~C02*~HMe20C6H,Me3, slowly separated in the form of snow-white, small needles on mixing alcoholio solutions of the acid and base ; it crystallises from benzene in small needles, dissolves in hot water, alcohol, or chloroform, but is insoluble in carbon disulphide or light petroleum.Like the salts of trinitrobenzoic acid already described, it has no definite melting point ; on heating, it melts and decomposes, yielding a dark red oil ; the temperature at which this occurs varies considerably with the rate of heating. When heated fairly rapidly, it begins to turn dark at 1 1 6 O and melts at 120°. DirnethyZ-$-cumidine 2 : 4 : 6-T~initrobenxoate.--The salt, 0,7179 gave 0.438 trinitrobenzoic acid = 61.0. C,8H200,N, requires 6 1-2 per cent. Dimethylmeoidine Trinitrobenxoate, (NO,),C,H,* CO, NHMe,*C,H,Me,. -The salt, obtained in the form of small needles when alcoholic solu- tions of the two components were mixed, begins to darken at 105O, and is completely decomposed a t 116-117'; it dissolves in the ordinary solvents on heating, but is decomposed by some of these, more especially water or alcohol.When boiled for a short time with alcohol, it yields crystals melting a t 122"; these proved to be s-trinitro- benzene, as with diethyl-P-aaphthylamine they furnished purplish- black needles melting a t 125-1 16". 0.8867 gave 0.5392 trinitrobenzoic acid = 60% VOL. LXXXV. R C,,H,008N4 requires 61.2 per cent.238 SUDBOROITGH AND ROBERTS : Bromo-m-aylidine ~rinil~~~berf~~oate,(NO,),~C~H,*CO,~NH,*C,H,Me~-This salt, which was prepared by mixing alcoholic solutions of the acid and base, slowly separated in yellow, prismatic crystals which begin t o change colour at 1 30°, are completely decomposed at 150° ; it is soluble in warm alcohol. 0.7154 gave 073986 trinitrobenzoic acid = 55.6.C15H1308N4Br requires 56.2 per cent. When the alcoholic solution was boiled for a short time, it acquired a red colour, and small, red needles melting at 104-105° were obtained on cooling. This substance, which is the additive compound, C6H2Me,Br*NH,,C,H,( NO,) 3, was a1 so obtained by mixing alcoholic solutions of bromo-m-xylidine and trinitrobenzene. 0.3824 gave 0.1955 trinitrobenzene = 51.1. It dissolves readily in ether, benzene, chloroform, and warm alcohol, Bromodimethyl-m-xylidine T&nitrobenzoccte, C,,H,,O,N,Br requires 51.5 per cent. (NO,),-C,H,* C02*NHMe,* C,H,Me,Br. -The salt, which was obtained from alcoholic solutions, begins to change colour a t 1 0 5 O , and is completely decomposed at 10s'.0.6506 gave 0.3435 trinitrobenzoic acid = 52.8. C,7H,p0,N,Br requires 53.0 per cent. D i e t ~ y l - a - . n ~ ~ h t r y Z ~ ~ i n ~ s-TrinitroEerfLzoate.-This salt separated in the form of flat, slightly yellow plates when warm alcoholic solu- tions of the acid and base were mixed. The mother liquor, when kept for several days, deposited bright red needles melting at 95O. These consist of diethyl-a-naphthylamine-trinitrobenzene (Trans., 1903, 83, 1338), and if the alcoholic solution of the salt is boiled, it is completely converted into this compound. The salt decomposes at 117-118° and dissolves in alcohol, benzene, or chloroform. 0.5420 gave 0,3024 trinitrobenzoic acid = 55.S. C,lH,,O,N, requires 56.3 per cent.D iethyLP-naphth y lamine s- Frinitrobmzoate. -T h i s salt, which was also obtained from alcoholic solutions of the acid and base, begins to darken at 1 2 5 O and is completely decomposed at 132'; it dissolves in hot water, alcohol, benzene, and chloroform, and, like its isomeride, shows a tendency to lose carbon dioxide and to form diethyl-p-naphthyl- amine-trinitrobenzene melting at 116' (Trans., 1903, 83, 1340). This transformation is practically quantitative when an alcoholic solution of the salt is boiled for a short time.DIORTHO-SUBSTITUTED BENZOIC ACIDS. PART v. 239 0.4736 gave 0.2641 trinitrobenzoic acid = 65.7. C,,H,,O,N, requires 56.3 per cent. The changes which these salts undergo when their alcoholic solutions are boiled, illustrate remarkably well the difference in stability between the additive compounds of s-trinitrobenzene with aniline derivatives and those produced with naphthylamine derivatives. Dimethyl-+-cumidine and dimethylmesidine, when boiled in alcoholic solution, yield the free base and s-trinitrobenzene, whereas diethyl-a- or -P-naphthylamine trinitrobenzoate yields the corresponding coloured additive compound of the base with s-trinitrobenzene.I n order t o determine whether dimethyl-$-cumidine forms a definite compound with s-trinitrobenzene, we have made a number of experi- ments with different solutions, but in all cases, even when excess oE the base was employed, crystals of unaltered s-trinitrobenoene were deposited. A coloured compound, obtained by crystallising s-trinitro- benzene from the base and allowing the crystals to dry in a desiccator containing a little of the free base, separated in small, bright red needles with no definite melting point, as when warmed they readily give up the base, leaving a colourless residue.When exposed to the air, the substance readily leaves a colourless residue of s-trinitrobenzene. 0.5 gave 0.2831 trinitrobenzene (m. p. 122') = 56.62. C,7H2,06N, requires 56.6 per cent. An additive compound of trinitrobenzene and ybcumidine, obtained by mixing together alcoholic solutions of the constituents, crystallises in long, slender, purple-brown needles melting at llS0, and is much more stable than the compound of aniline with trinitrobenzene. NE 15.9. 0.3036 gave 41.3 C.C. moist nitrogen at 17" and 765 mm.C,,HI,O,N, requires 16.09 per cent. C. S a l t s f3-om 2 : 4 ; 6-T~1~ibromo-3-aminobenxoic A c i d . Biinethylrnesidine 2 ; 4 : 6-Trib~omo-3 -aminobenxoate, NH,*C,HBr,* C02-N HMe, C, €&Me,. -The salt was obtained by dissolving the acid in ether, adding a slight excess of dimethylmesidine, and allowing the greater part of the ether to evaporate; it crystallised from water in small needles, softening at 147" and melting at 163-165'. 0-8002 gave 0,5677 tribromonminobenzoic acid = 70 9. C,8H210,N2Br, requires 69.6 per cent. The salt readily dissolves in alcohol, and also t o a less extent in ether, benzene, chloroform, or hot water, but is very sparingly soluble in light petroleum. R 2240 SUDBOROUGH AND ROBERTS : DimethyE-11/-cumidilze Hydrogen ~ribromoaminobentzoate, 2(NH,*CBHBr,*C02H),C,,H,Me3*NMe2. -When the acid and base were mixed in moleuulap proportion, the mixture did not set t o a solid mass, but remained pasty, and when the mixture was crystallised from benzene, in which it is only moderately soluble, nodular aggregates of small, colourless needles melting at 145.5-1 46' were obtained.When titrated in alcoholic solution with standard baryta, using phenol- phthalein as indicator, 0.4062 required 17-85 C.C. of N/20 Ba(OH),. The amount required for the normal and acid salts, NH,*C,HBr,* CO,H, C,H,Me,- NMe, and 2(NH,*C,HBr,*C0,H),C,H,Me3*NMe,, are 15 -48 and 17.84 C.C. respectively. When decomposed with dilute hydrochloric acid and extracted with ether, 0.6024 gave 0.505 tribromoaminobenzoic acid = 83.8 per cent.NH2*C6HBr3* C02H,C6H2Me,*NMe2 and 2( NH20C,HBr,*C02H),C6H,Me,oNMe2 require 69.6 and 82.1 per cent. respectively. The same compound, obtained in the form of glistening, well- developed prisms by dissolving molecular quantities of the acid and base in alcohol, adding water, and allowing the solvent to evaporate slowly, melted a t 146". 0.3 required 13.24 C.C. of N/20 Ba(OH), for neutralisation ; 2 mols. acid + 1 mol. base requires 13.17 C.C. The melting point was not affected by crystallisation from benzene. We have attempted t o prepare the normal salt (1 mol. acid + 1 mol. base) by dissolving a mixture of the acid with twice its weight of base in hot benzene and allowing the solution to crystallise and also by dissolving the acid (1 mol.) in dry ether, and adding an ethereal solution of the base (4 mols.), but the same acid salt melting at 1 4 6 O was obtained in both cases.Attempts to obtain salts with diethyl-a- and -P-naphthylamines led to the formation of gummy, uncrystallisable masses. D. SaEts f r o m 2 : 4 :6-TrimethyZbe~nxoic Acid. Benxpkamine 2 : 4 : 6-t?.in.zet?~yEbenxoate is obtained by separately dissolving equivalent amounts of the acid and base in light petroleum and mixing the solutions; it crystallises from benzene in small, feathery, colourless needles melting at 1 6B0. 0,3052 gave 0.1868 trimethylbenzoic acid = 61.2. Salts could not be obtained with this acid and any of the following C17H2,02N requires 60.5 per cent.DIORTHO-SUBSTITUTED BENZOIC ACIDS. PART v. 24 1 bases : dimethylmesidine, dimethyl-+-cumidine, bromodimethyl-m- xylidine, diethylaniline.E. S a l t s of t h e T h r e e Toluic Acids. BenzyZamine o-toluate, obtained from light petroleum solutions of the acid and base, crystallises from benzene in small prisms melting at 146'. It dissolves readily in water, and to a moderate extent in light petroleum. 0.4'716 gave 0.2668 o-toluic acid = 56.5. C,H,Me*CO,*NH,*CH,Pb requires 55-9 per cent. $-Cumidine hydrogen o-toluate, 2 (C,H,Me*CO,H), C,H,Me,* NH,, pro- duced by mixing together ethereal or light petroleum solutions of the acid and base, crystallised from water in long, snow-white, silky needles, softening somewhat at 80' and melting at 82.5'. The same compound is obtained when an excess of the baee is employed. 0.5 gave 0.3315 o-toluic acid (m.p. 105) = 66.3. One mol. acid + 1 mol. base requires 50.18. Two $ 9 ,? ? ) ,, 66.8 per cent. 0.70 gram, when dissolved in sodium carbonate and extracted with ether, gave 0.236 gram of solid base =33*7. The acid salt requires 33.2 per cent. 0.25 gram of the salt, when dissolved in ethyl alcohol, required 24.8 C.C. of 21'/20 baryta solution for complete neutralisation, using phenolphtbalein as indicator. Salts of o-toluic acid with dimethylaniline, dimethyl-$-cumidhe and dimethylmesidine could not be obtained. Definite salts could not be obtained either from m-toluic acid and q-cumidine or dimethylaniline, or from p-toluic acid and the same bases. The acid salt requires 24.6 C.C. F. XaZts fi*ona t h e T h r e e N i t r o b e n x o i c A c i d s .J/-Cumidine o-Nitrobenxoate,-This salt; was obtained in the form of silky needles when ethereal or benzene solutions of the constituents were mixed; when crystallised from water, it formed long, silky, prismatic needles melting a t 133-1 34'. 0.4137 gave 0.2260 o-nitrobenzoic acid = 54.6. 0.3 required 20.1 C.C. of N/20 baryta solution for neutralisation. C16H180,N, requires 55.3 per cent. The normal salt requires 19.9.242 DIORTHO-SUBSTITUTED BENZOIC ACIDS. PART V. Dimethyl-+-cumidine hydvogen o-ruitrobenxoccte, 2( NO,. C,H,*CO,H),C,H,Me,NMe,, obtained by mixing equal weights of the acid and base in benzene solution and crystallising from this solvent, forms small, colourless crystals melting at 1245. 0.50 required 40.6 C.C. N/20 baryta solution. The acid salt requires 40.2 C.C.t,!d?umidine m-nitro6enzoate was obtained in . the form of long, colourless, feathery needles melting at 129fj-l3O0, when the acid was mixed with twice its weight of +-cumidhe and crystallised from benzene. 0.3 required 20.05 C.C. N/20 alkali. The normal salt requires 19.9 C.C. 0.5 requires 33.4 C.C. The normal salt requires 33.16. The ucid salt, 2(N0,~C6H,*C0,H),C6H,Me,*NH,, was obtained when a mixture of the acid (2 mols,) and base (1 mol.) was dis- solved in benzene and allowed to cool; it crystallises from water in pale yellowish needles melting at 144O." 0.40 required 34.3 C.C. of N/20 alkali. The acid salt requires 34.12 C.C. A mixture of the two salts was obtained when equal weights of the acid and base were crystallised together from benzene or water.The normal salt, when boiled with water, is partially transformed into the acid salt. BirnethyE~-cumidine hydrogen m-niti*obenxoate, obtained when mole- cular quantities of the acid and base are mixed in ethereal solutions, crystallises from benzene in small, colourless prisms melting at 119 * 5 O , dissolves readily in alcohol, ether, or chloroform, but is only sparingly soluble in carbon disulphide or light petroleum, and crystallises from hot water in colourless, flat plates. 0.3566 gave 0.2362 m-nitrobenzoic acid = 66.2. 0.255 required 20.77 C.C. of ~ i / 2 0 alkali. The acid salt The acid salt requires requires 67.2 per cent. 20.52 C.C. q-Cumidine p-nitrobemoate, obtained by mixing ethereal solutions of the acid and base, separates from water in small, feathery crystals melting at 160O. * The salt mentioned previously (Trans., 1899, 75, 595) as melting a t 140-141" must have been the acid salt, but the specimen actually analysed must have been the normal salt melting a t 129*5-130".STUDIES ON THE ELECTROLYTIC OXIDATION OF PHEKOLS. 243 0 3246 gave 0.1872 p-nitrobenzoic acid 1: 57.6. No definite salts could be obtained from dimethylaniline and the ~ 0 2 ~ C , H , ~ C 0 2 ~ ~ H , ~ c 6 ~ , M e 3 requires 55.3 per cent. three nitrobenzoic acids. G. S a l t s f y o m the Three Bromobefixoic Acids. +!I -Cumidine o ~ bromo benzoate, C6H,Br* CO;NH,. C6H,Me3, slowly separates in the form of fine needles from an ethereal solution of the acid and base; i t dissolves readily in benzene, alcohol, or hot water, and crystallises from either light petroleum or hot water i n colourless needles melting a t 106-106*5°. 0.555 gave 0.32863 o-bromobenzoic acid = 59.2. The normal salt requires 59.8 per cent. Ob5O required 29-87 C.C. of A720 alkali. The normal salt requires 29.76 C.C. $-Cumidine m -6romobenxoute crystallises from benzene in long, felted needles, melts at 98*5", and is readily soluble in chlorolorm, alcohol, warm ether, or benzene, 0.50 required 29.7 C.C. of N/20 alkali, The normal salt require8 29.76 C.C. No definite salts could be obtained from dimethylaniline and the three bromobenzoic acids, and an ethereal solution of t,b-cumidine and the pbromo-acid slowly deposited crystals of the free acid melt- ing at 251O. CHEMICAL LABORATORIES, UNIVERSITY COLLEGE OF WALES, ABERPSTWYTH.

ISSN:0368-1645    

DOI:10.1039/CT9048500234

出版商:RSC    

年代:1904

数据来源: RSC

摘要:

STUDIES ON THE ELECTROLYTIC OXIDATION OF PHEKOLS. 243 XXX.-Studies on the Electrolytic Oxidatioja of Phenols. Part I. By ARTHUR GEORGE PERKIN and FREDERICK MOLLWO PERKIN. OF the numerous substances which can be obtained by the oxidation of pyrogallol and its derivations, one of the most interesting is purpuro- gallin, a compound possessing well-marked tinctorial properties. Originally prepared by Gerard from pyrogallol (Bey., 1869, 2, 562) by the action of potassium permanganate and sulphuric acid, it has been244 PERKIN AND PERKIN: STUDIES ON THE subsequently obtained from the same phenol by means of a most varied series of oxidising agents. I n a recent communication, certain deriva- tives and decomposition products of this substance were described (Trans., 1903, 83, 192), from which i t appears t o have t h e formula C,,H,O,, and t o be a derivative of naphthalene, as was first indicated by Nietzki and Steinmann (Bey.., 1887, 20, 1277).The formation of a naphthalene compound from pyrogallol, although very remarkable, is not unique, for a somewhat similar reaction is described by Zincke and Branke (Annalen, 1896,293,l ZO), who prepared dibromo-/3-naphtha- quinonecarboxylic acid by the action of nitric acid on bromoproto- cntechuic acid. During the formation of these substances, it appears likely t h a t a certain quantity of the phenol is converted by oxidation into an open chain compound, which then condenses with the phenyl residues. Further work on the constitution of purpurogallin is in active progress, and it appeared possible that by a study of the electrolytic oxidation of pyrogallol some intermediate or secondary product might thus be prepared, and, moreover, it was anticipated also that if the colouring matter could be produced by this method, a considerably increased yield might be obtained.The following experiments indicate without doubt that by employing certain precautions the electrolytic method is the most suitable for the production of purpurogallin, for not only can the yield be thus augmented, but an almost chemically pure product is at once isolated. On the other hand,it has not as yet been found possible to prepare any intermediate compound which would be of service in elucidating the course of the reaction. EXPERIMENTAL. In selecting a suitable electrolyte, numerous substances were ex- amined, and although purpurogallin was obtained in all instances, it was frequently contaminated with a brownish-black impurity, which rendered the method of little service.The employment of a 15 per cent. solution of sodium sulphxte has been eventually adopted, and by this means a very pure bright orange-coloured product has been obtained. Solutions of sodium and ammonium acetates do not give satisfactory results, because when they are employed a somewhat poor yield of the impure alkali salt of purpurogallin is produced. In the earlier experiments, the anode and cathode compartments were divided by means of a porous cell, but i t subsequently appeared t h a t better results could be obtained if the anode and cathode were not separated.Satisfactory results are obtained only when the anode is made of platinum and caused t o rotate rapidly during the electro- lysis. When a stationary anode is employed, the colouring matter isELECTROLYTlC OXIDATION OF PHENOLS. PART I. 245 apt to settle on the electrode, and is thus subjected to further oxida- tion. A rotating anode of lead, even when previously peroxidised, was very unsatisfactory, for in this case from 10 to 16 per cent. only of very impure purpurogallin could be obtained." I n carrying out the oxidation, 28 grams of pprogallol dissolved in 500 C.C. of a 15 per cent, solution of sodium sulphate were placed in a rectangular glass jar, at two opposite corners of which were fixed two thin pieces of composition piping. On t o each of tbe pipes a copper wire was soldered, and these were connected with each other by means of a screw connection and formed the cathode.The iridio- platinum anode had a surface of 1.5 square decimetres and was rotated rapidly by means of a water turbine or electromotor. During the electrolysis, the current density was kept at 2 amperes and the E.H.F. was 4.3-4-5 volts. To avoid a rise in temperature, the cell was surrounded with cold water. As soon as the current commenced to flow, the solution became yellow and a yellow precipitate gradually separated. When the electrolysis had continued for 8 hours, the product was left overnight, then collected, washed with water, and dried on a porous plate, Satisfactory results mere also obtained when, instead of rotating the anode, a rapid stream of air was blown through tbe mixture.In this case, the cakhode consisted of a perforated 1ea.den tube placed between two anodes of platinum foil, having a total surface of 4 square decimetres. The air, which was blown through the cathode during the operation, appears to help in the oxidation of the pyrogallol. Thus 446 grams of pyrogallol dissolved in a solution of 1 kilogram of sodium sulphate (Na,SO,,lOH,O in six litres of water gave, after 35 hours' electrolysis, current density 9-10 amperes, X.M.F. 9.5-10.3 volts) 165 grams of purpurogallin or 37 per cent. The average yield was 10.2 grams or 36.4 per cent., although on two occasions 13 grams (or 46.4 per cent,) were obtained. Nitrous acid yields only 25 per cent. of the crtide product. That the substance thus obtained was practically pure is indicated by the analysis ( A ) ; the second estimation (B) was made on the product obtained with a lead anode, but this specimen was, however, first purified by crystal- lisation from acetic acid.In the preparation of periodic acid by the electrolytic oxidation of iodic acid, with smooth platinum electrodes as anode, the yield is extremely small. But when peroxidised lead anodes are employed a very much better yield is obtained. The explanation being that the potential at which the oxygen is yielded up at the anode is higher with a lead peroxide anode than with one of polished platinum (Ber., 1902, 35, 2662). In the case of pyrogallol, the probability is that when lead electrodes are used, the higher potential at which the oxygen is yielded causes the oxidation to be too vigorous.246 PERKIN AND PERRIN: STUDIES ON THE Found ( A ) C = 60*03 ; H = 3.60.C,,H,O, requires C = 60.00 ; H = 3.63 per cent. The colouring matter was further characterised by conversion into the acetyl derivative, which was obtained in the form of yellow needles melting a t 184-186O. Found C = 58.87 ; H = 4.04. After one crystallisation from acetic acid, this product was found to be chemically pure. Experiments were also tried with an alternating current, but although small quantities of purpurogallin were obtained, the method was not found satisfactory. (B) C = 60.19 ; H = 3.60. C,,H,O,(C,H,O), requires C = 58-77 ; H = 4.12 per cent. The Electrolytic Oxidation of Gallic Acid. It was previously shown that by the oxidation of gallic acid with potassium ferricyanide in the presence of sodium acetate a new substance, probab1y:a purpurogallincarboxylic acid, is formed.As the yield by this method was extremely poor (3 per cent.) and the compound difficult to isolate, the electrolytic oxidation of gallic acid was studied in the hope that as in the case of pgrogallol a larger yield of a purer product mould thus be obtained. Experiment showed that the purpurogallincarboxylic acid is rapidly obtained in this manner, and although the yield has up to the present been some- what disappointing, it is evident that sufficient can be obtained by this process for a complete study of its constitution. After numerous trials, the following method was adopted. It was found necessary to sepa- rate the anode and cathode com- partments. A rectangular glass vessel was employed as before, on two sides of which were fitted two porous cells.These cells contained a piece of sheet lead, to which was soldered a stout copper wire, In order to keep the cells in position, the wire was bent over against the side of the glass jar as shown in the figure. The anodes consisted of a platinum stirrer and a stout wire bent up at each side against the bottom of the porous cells. To this wire was also welded a piece of platinum foil nearly large enough to cover the bottom ofELECTROLYTIC OXIDATION OF PHENOLS. PART I. 247 the glass jar. The total active anode surface was about 1-75 square decimetres. Various electrolytes were tried, but the only one which gave satisfactory results was a 15 per cent.solution of sodium or ammonium acetate acidified with acetic acid. I n carrying out an electrolysis, 10-15 grams of gallic acid were dissolved in 600 C.C. of a 15 per cent. solution of ammonium or sodium acetate, 10 C.C. of glacial acetic acid were then added, and the mixture electrolysed. The cathode cells contained a similar solution, During the electrolysis, the cathode cells become too full and are apt to overflow ; as the solution in these cells becomes strongly alkaline, it is necessary to remove a portion every now and then by means of a pipette in order to prevent it flowing over into the anode compartment. As soon as the current passes, the solution commences to turn brown and finally become3 almost black. After about 6 hours, the current is stopped, the electrodes and porous cells removed, the mixture left overnight, and then filtered, when a dark bronze-coloured product is obtained. This consists chiefly of the alkali salt of the acid in a somewhat crude condition. The yield varies very greatly, from 10 grams of gallic acid usually about 2 grams (or 20 per cent.) of the crude product are isolated, but we have obtained as much as 5 grams, or 50 per cent. The product of the reaction was purified as follows : The substance ground into a thin cream with alcohol was diluted with some quantity of this solvent, a little hydrochloric acid added, and the mixture boiled for a minute or two ; the solution obtained was then poured into ether, the ethereal extract washed with water, boiled with a little animal charcoal, filtered, and then evaporated to dryness. The orange-yellow, crystal1ine:residue was collected, washed with water, then with ether, and dried. Found C = 54-64 ; H = 3.52. C,,H,07 requires C = 54.54 ; H = 3-03 per cent, It was found to be identical in all respects with the purpurogallin- carboxylic acid previously obtained from gallic acid by means of potassium ferricyanide.

ISSN:0368-1645    

DOI:10.1039/CT9048500243

出版商:RSC    

年代:1904

数据来源: RSC