摘要:

1110 a-PHENETHYLAMINE DEXTROCAMPHORSULPEONATE, LIFVO-a-PHENETHTLAMI NE WaS isolated by LOVkn (Bey., 1896, 29, 2313) in an impure state by fractionally crystallising the acid tartrates of the externally compensated base. I n the hope of finding a method of obtaining the pure active bases in quantity, we mixed the inactive base with the corresponding weight of Reychler's dex trocarnphor- sulphonic acid in hot acetone solation. On cooling, a crystalline salt separated and was purified by crystallisstion from acetone. Dext~~okt!vo-a-p?ie?tet~!/ln~t~iize L ) e . i : t ? . o c c c ) ) ~ ~ ~ ~ o 3 ' 8 ~ ~ ~ ~ ~ 0 3 2 ~ ~ t e , C,IX,* UH( CH,) *NH,,C,,H,,O*XO,,II. The salt is deposited from its cooling acetone solution in minute, melting a t 141 -1 43" ; the following analytical colourless plates results were obtained : 0.1976 gave 0.4436 CO, and 0.1353 H,O.C,,H,,O,NS requires C = 61.19 ; H- 7.64 per cent. An aqueous solution containing 0.5079 gram in 25.1 C.C. at 19' gave a,+0*5iI0 in IL 200 mm. tube, whence [all,+ 1 4 . 6 O and [MI,, + 6 1 .Tio. Since Pope and Peachey linve shown (this vol., p. 1086) that the molecular rotatory power of anirnonium dextrocamphor- sulphonate is [ IM ID + 51*7", it is evident that the salt now described belongs to the class of '' partially racemic " substances discovered by Ladenburg (Bey., 1S9S, 31, 634). The salt is very soluble in water, alcohol, or acetone, and on spontaneous evaporation the solutions become gummy and do not yield good crystals. The crystals deposited from hot acetone solutions are minute, rectangular plates having their corners replaced.They show straight extinction and the acute bisectrix of positive double refraction emerges perpendicularly throngh the large face of the plate; the optic axial angle is fairly large. After melting on a microscope slide, the liquid solidifies with great reluctance, depositing plates crystallographically identical with those obtained from the acetone solution. Inuctive Q- Phenet?~yZa?ni,~ae I'latinochloricle, (CHPhMe*NH,),,H,PtCl,, -Both the dextrocamphorsulphonate and the hydrochloride Qf the baqe C! = 61-22 ; I€ = 7.60." NON-RACEMIC " AND " RACEMIC " LIQUIDS. 111 I yield the same platinochloride ; this salt is very soluble in acetone and orystallises from a mixture of aoetone and ethylic acetate in golden- yellow scales melting at 213-214". The following analytical results were obtained : 0,1623 gave 0.04S8 Pt. Pt =li 30.06. C,,H,,NC16Pt requires Pt = 29-96 per cent. GOLDSMITIIS' INSTITUTE, NlCW CRUSS.

ISSN:0368-1645    

DOI:10.1039/CT8997501110

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

“ NON-RACEMIC ” AND “ RACEMIC )) LIQUIDS. 111 1 ALTHOUGH during the last few years Ladenburg lias persistently endeavoured to demonstrate the existence of raceinic liquids, most of the methods which he has used &ord results which have no bearing upon the question at issue. Thus he found (Anizcden, 18SS, 247, S7) that on converting a mixture of dextro- and lLevo-coniine in unequal quantities fractionally into its compound with cadmium iodide, an alteration in the specific rotatory power of the mixture of bases could be effectedj and conchded that this proved the rncemic nature of inactive coniine, but Fischer pointed out ( B e y . , 1894, 27, 3224), and it follows from recent work of Kipping and Pope (this vol., p. 1119), that this fact has nothing t o do with the racemic or non-racemic character of the liquid.Again, Ladenburg observed that on mixing dextro- and lrevo-coniine a fall in temperature occurs, and attributed this t o chemical change (Be).., 1S95, 28, 164) ; he noted fwther that, although the density is not altered thereby, the refractive index increases notably. This result involves the remarkable conclusion, which Ladenburg does not draw, that the molecular refraction of (6 racemic” coniine is about 1 per cent.. greater than that of its optically active components. Since so much depends upon the densities (compare Traube, Bey., 1S96, 29, 1396), which are not given in the paper referred to, judgment must be deferred ; Laden- burg, however, years ago ( A m d e n , 1888, 24’7, S l ) gave experimental numbers showing the density of active and inactive coniine to be the same.A criticism of his latest method (Bey., 1899, 32, 1822) is to be found in the following payer (p. 1119). Although the methods hitherto adopted in the study of externally compensated liquids are so unconvincing, yet it seems possible t o devise a trustworthy method. We owe to the labours of Ramsay and Shields (Zeit. plysikal. Chem., 1893, 12, 433) and others the know-11.12 POPE AND PEACHEY: A METHOD FOR DISCRIMINATING ledge that many liquid substances are associated, the physical mole- cules being aggregates of several chemical molecules ; some classes of compounds, such as bases, are highly associated, whilst others, like the hydrocarbons, have, in general, association factors approximating to unity.I n this question of association is to be found the cause of many facts relating to optical activity which are otherwise difficult to explain (compare also P. Frankland, this vol., p. 347). Thus, if n highly associated substance be dissolved in a solvent, it is to be expected that it will break down into simpler molecules moiw or less completely, the extent to which this occurs depending upon the solvent and the concenti-ation ; but if a liquid already consisting of chemical molecules be dissolved in a solvent, it cannot undergo further dissociation." Further, if in any case it is possible for a solvent to cause an increase in the association factor of an already associated solute as suggested by Frankland (this vol., p. 363), this is an unlikely contingency when the pure solute has an association factor approximating to unity.Since an optically active substance neces- sarily has different rotation constants according as it is associated to different degrees, we must expect to find that the specific rotatory power of substances having high association factors in the pure liquid state varies considerably with change of solvent and of concentration, whilst those substances having in the pure liquid state association factors approximating to unity would in solntion have specific rotatory powers but slightly dependent on the solvent and the concentration. An examination of tho rather meagre data available, shows this con- clusion to be appreciably i n accord Kith the facts, substances which from their nature should have high association factors exhibiting very different specific rotatory powers as the solvent is changed, whilst those which should be nearly monomolecular vary but slightly in specific rotatory power in like circutustances.Kesults are given in the present paper showing that, in the case of Isvotetrahydro- quinaldine, [ .]D varies from - 45.9" to - 11 7.9" in various solvents, whilst the specific rotatory power of lsvoyinene varies in different sol- vents between [a], - 33" atid - 42". Although we have no direct infor- mation respecting the association factors of these two substances in the pure state, yet from the fact that Traube (Bey., 1897, 30, 265) gives the association factors of aniline, pyridine, quinoline, and piperidine as 1.35, 1.75, 1.40, and 1.62 respectively at the ordinary tempera- ture, and the association factors of the aliphatic hydrocarbons and the higher homologues of benzene as unity, it may be judged that lsvopinene is monomolecular, whilst the association factor of laevo- tetrahydroquinaldine is about 1.5, * The question of electrolytic or of hydrolytic dissociation is naturally not referred to here.BETWEEN '' NON-RACEMIC " AND '' RACEMIC " LIQUIDS. 1113 I n a preceding paper (p.1066), we have elaborated a method by which at least one optically active component of an externally compensated base can be prepared in quantity, and in a state closely approaching purity. We purpose -continuing this work, supplementing it with a careful comparison of the active and inactive liquid bases; in the present paper me give the results obtained with the tetrnhydroquinaldines : results which justify us in definitely concluding that, at the ordinary temperature, dextro- and Isvo-tetrahydroquinaldine exist in the same state of molecular aggregation, whether separate or mixed, and there- fore do not combine t o form a liquid racemic compound.A considerable number of data respecting the densities of optically active and externally compensated liquids has been collected, but the only available accurate values we have been able to find are those given by Ladenburg (dmulen, 1888, 247, 81) in his classical work on coniine ; he finds that the densities of lcevo- and inactive coniine at Oo/Oo, are 0.5635 and 0.8626 respectively, numbers identical within the limits of experimental error.Density determinations of the active and inactive nlkylic glycerates have been given by Frankland and MacGregor (Trans,, 1893, 63, 511) ; these data, and also those given by Schiitz and Marckmald (Ber., 1896, 29, 52) for the valeric acids, allow of no conclusions being drawn as the experimental error is apparently large. Traube (Beis., 1896, 29, 1394) concludes from the densities of the active and inactive limonenes and carvones, that these substances are monomolecular, and that the inactive substances are merely mixtures ; the density numbers used are, however, only very approximate. Densities of , h v o - and Extewudly Coqvensated 27et~a~?l~~oqz~ii~akEine. We obtained laevotetrahydroquinaldine in B highly purified condi- tion by distilling its dextro-a- bromocamphorsulphonate (this vol., p.1067) with soda in a current of steam, extracting the distillate with purified ether, and distilling off the ether on the water-bath; the residual oil is then repeatedly distilled under about 50 mm. pressure. Highly purified samples of externally cornpensated tetrahydroquin- aldine have been prepared in a similar manner from the pure racemic hydrochloride (this vol., p. 1086). The densities were determined in a Sprengel tube holding about 5.4 c.c., with the following results : L.cevotet~.nl~?/droqui~~~ Zdilie. (1) Preparation B : d at 14*5'/4' = 1.03365. 9 9 A : ,, 18*5"/d0 = 1.03046. B : ,, 20.2'/4'= 1.01914, (2) (3) 931114 POPE AND PBACBEP : A IdETHOD POR bISCRIMINA'l'INu Extent ally Co nyiensa t ed I'e t rahy dr oquimld ine .(4) Preparation C : d at 14*5'/4'= 1,02362. ( 5 ) ,, D : ,, 16°50/40=1*02219. (6) ,, D : ,, 18*0°/4'=1~02083. (7) The density of a mixture of 3.8503 grams of lwvotetrahydro- quinaldine (preparation S) with 7.3455 grams of externally compen- sated tetrnhydroquinaldine (preparation D) was found to be 1-01 915 at 20*2'/Oo. An exa- mination of the above seven determinations shows that within the limits of experimental error the density of all the samples is given by the expression, d at t/4'= 1.01930 i- 0'00079 (20 - t ) , so that the lavo- base, the inactive base, and the mixture have the same density at the game tempernt ure, A dextrorotatory base and its Itxvorotatory antipodes necessarily have the same density under the same conditions; if both are asso- ciated and no chemical action occurs on admixture, it would be expected that no change in the association factor of either isomeride follows admixture.This latter condition can only be fulfilled if no alteration of density occurs; from the density determinations alone we must therefore conclude RS highly probable that no alteration in the state of molecular aggregation occurs on mixing dextro- and Isvo-tetrahydro- quinaldine. Four different preparations, A, B, C, and D, were used. Befraction C ' o n s t ~ ~ t s of h m o - m d h'xternally Covipenscded I'etral&*o- quinaldine. Tho refractive indices of ltevo- and externally compensated tetl.ahyclroquinalcline (preparations B and D) were determined for sodium and thallium light in a hollow glnas prism of about 60° angle j the results are given in the following table, the uioleculitr refractions, ?a' - I i V m, being calculated from the expression, ,@= - 122 f 2'2- ~ Sample.t . LXVO- B ............ ,, ,, ............ Iuactive D ............ ,, ,, ............ Light. Na TI Nll T1 71. 1.5iOSO 1'57724 1.57273 1.55184 47.50 48.07 47.57 48.19 The values for the I)-liue are probably more nearly accurate than those for the less luminous thallium flume j the molecular refractions, DlBETWEEN t r NON-RACEMIC ". AND RACEMIC " LIQUIDS. 1115 N-niethylpiperidiiie ............ N-iiieth yite traliydroquinoliiie. U- 9 , ( I ~ ~ v o - ) a- 9 7 (inactive). U- ............ 9 , ... for the D-line are identical within the limits of experimental error. With the identity in density between the active and inactive bases there goes therefore an identity in refractive index at the same temperature and an identity in molecular refraction.By applying Traube's arguments (Ber., 1897, 30, 43) on the relation between the refraction constants and the association factor to the case of the tetra- hydroquinaldines, it is seen that the association factors of the active and inactive bases are rigorously identical. A perusal of Briihl's magnificent work on the refraction constants of nitrogen compounds furnishes rnaterial for at1 interesting comparison, I n the appended table, we quote the vslues obtained by Briihl for the molecular refractions of N- and a-inethylpiperidine (Zeit. plqsiknl. Chem., 1 S95, 16, 222) and for ~~~-metliyltetrr~hydroquinoline (Zeit.physikal. Chem., 1897, 22, 395) together with the values which we now give for 31 -74 31-32 48.02 47'60 47.57 &LJ. I Snbstaiice. Preparation. A .............................. €3 .............................. t. a u. [alD. [ 5 1 3 D . 20" - 50 24" 59.12" - 85.44" 9 , - 59'32 - 5s 2 0 - 85 -56 A. 0'42 0 *52 0 *P5 Observer. ISriilil. W. J. P. :nd S. J. P. ,¶ 9 9 9 ) the active and inactive u-inethyltetrshydroquinoline and the differ- ences, A, between the molecular refrnctions for the D-line of the N- and a-isomerides of both series. Attcution should be drawn to the appre- ciable identity of the diiferences, A, between the molecular refractions of the secondary and tertiiiry polymethylenic bases. notation Coizstmtts of ~~votetrnl~;ydroqzii~LaZcli~te. The rotatory powers of the prepsmtioiis A.and B of lxvotetrahydro- qtiinsldine described above were determined in 100 mm. tubes for the D-line, and are very nearly the mine. The difference of O*OSo observed in a rotatory power of about 60° is probably mainly due t o the impossibility of obtaining a pure D-line even by the use of a long dichromate tube as a screen, It is to be noted that our value for aD a t 203, namely, 59*28O, is rather higher1116 than that given by Ladenburg (Bey,, 1894,27, 77) for the dextro-base, namely, aD + 58035~. Since it is certain that laevotetrahydroquinaldine is highly associated, we were not surprised to find that its specific rotatory power varies very considerably with the solvent. The rotations given in the following table refer to the preparation A, and the values of uD were obtained in 200 mm.tubes, except in the case of the pure base, when a 100 mm. tube was used. POPE AND PEACBEY: A METHOD FOR DISCRIhflNATIN~ Solvent, Piperidine ................... Ether ........................ None ......................... Acetone.. ..................... N-Methyl tetrahydro- yuinoline., ................ Ethylic alcohol ............. Methylic alcohol .......... Chloroform ................ tknzene ...................... Carbon tetrachloride . . , . , Acetic acid .................. t. 23 -8 21 +o 20 *o 19.5 19'0 21'5 19'5 21 *5 21.0 21 *5 21 *o 20. 1.2382 0'6333 0.6415 1 ,8957 0'6454 0*6398 0.6514 0.6465 0.6410 0.6672 - - t'. 15.00 25-34 25.24 10.10 25 '20 25.27 25-20 23.24 25 *29 25'29 - - i.58" - 2.55 - 59 2 4 - 3 '22 - 11 '91 - 3.28 - 3'50 - 4-43 - 4 *54 - 4.95 - 6-22 - 45'9" - 50.8 - 58-12 - 63'3 - 63.6 - 64.0 - 75.1 - 85.3 - 88 *6 - 97 *6 - 117'9 - 6i.5" - 74.7 - 93.1 - 93.5 - 94.1 - 110.4 - 125.4 - 130.3 - 143'5 - 173.3 - 85-44 A perusal of this table shows that as the solvent is changed the specific rotatory power of lawotetrahydroquinaldine alters from [a]= - 46.9' to [.ID - 117*9O, and is therefore nearly three times as great in one solvent as in another ; even disregarding the use of acetic acid as a solvent because of the chemical action which doubtless occurs, the fact remains that the specific rotatory power of the base in piperidine solution is less than one-half of what it is in carbon tetra- chloride solution.These large variations in specific rotatory power with change of solvent can only be attributed t o differences in the degree of association of the base in the various solutions.Corroborative evidence of this can be obtained in two ways, by making use of the highly probable supposition that if an associated substance be dissolved in a solvent of identical association factor, the association factor of the solute will remain unaltered. We see from the table that on dissolving Izvotetrahyclroquinaldine in its isomeride, N-methyltetrahydroquinoline, the specific rotatory power increases by some 9 per cent. ; although N-methyltetrahydroquinoline is isomeric with lsevotetrahydroquinaldine, the latter is a secondary and the former a tertiary base, so that, structurally, the two substances differ considerably, and are not likely to have similar association factors.Tetrahydroquinoline is, however, the next lower homologue of IEVO- tetrahydroquinaldine, and both are secondary bases in every wayBETWEEN (' NON-RACEMIC " AND " RACEMIC " LIQUIDS, 11 17 Solvent. -~ Tetrahjdroquinoline ...... closely resembling each other ; it is therefore, d p i o v i , highly probable that they have almost the same association factor. Further, it is t o be noted that tetrahydroquinoline contains no asymmetric carbon atom. The rotation constants of the optically active base were determined in the lower homologue as solvent with the following results : aD in t. ZU. v* 1 ,Icm. ------ 24.2" 1.0647 15.0 -4'18O - 58.9" - 86.6' t. W W lmo-base. inac. base. 2.8503' 7.3455 20'2" I n accordance with our expectations, the specific rotatory power of the base in this solvent ( - 58.9") is almost identical with the specific rotatory power in the pure liquid state ( - 58-12'), because the as- sociation factor remains almost unchanged.A gain, the determinations of the densities and refraction constants of laevo- and externally compensated tetrahydroquinaldine indicate with great probability that the association factor is the same in both, If any combination existed between the dextro- and laevo-isomerides in the externally compensated base this mould be impossible. If the optical antipodes are quite indifferent one to the other in the mixture, we should find the specific rotatory power of the lsvo-base, dissolved in the externally compensated mixture as solvent, absolutely identical with the specific rotation of the pure liquid laevo-base.If, however, the two antipodes are not quite mutually indifferent, the association factor mould change on admixture and hvotetrahydroquinaldine could not have the same specific rotatory power when dissolved in the externally compensated base as solvent as when solvent-free. The following determination made with the mixture used in the density determina- tions, shows in the most conclusive manner possible that the former alternative is the true one : dtw. 1.01916 The specific rotatory power of lsvotetrahydroquinaldine, peg* ue, is [ a ] D - 5S.12", whilst when dissolved in the externally compensated base the specific rotatory power has an identical value, namely, [ a ] D - 58.02O.It remains to be added that externally compensated tetrahydroquin- aldine is the best example of a physically perfect liquid solution to VOL. LXXV. 4 FI l l 8 '' NON-RACEMIC " AND '' RACEMIC '' LIQUIDB. C. 2 4 8 10 12 20 80 I which attention has yet been drawn-of a solution, namely, the physical properties of which are proportional means of those of the constituents. Although it mould appear that the variations in specific rotatory power of a substance dissolved in various chemically inert solvents are due mainly to changes in the associatiou factor of the solute, this does not preclude the solvent from exerting a specific action upon the rota- tion constants quite apart from its influenco upon the association factor. It would seem, however, that such a specific action is not exerted upon an active substance by the mixture of the two antipodes; this is evident from the fact that the specific rotatory powers of laevotetra- hydroquinaldine and of lievopinene respectively are the same in the solvent free state as in solutions in which the externally compensated substance is used as solvent.{a], a t 21 '2. C. [a], a t 21.2". - 36-85" 40 - 36 '97" - 36.87 60 - 36 '98 - 36.97 60 36-96 - 37 *oo 70 L 37.00 - 36.95 80 - 36-97 - 36 *98 90 - 3694 -36.99 100 - 36 '97 Solvent, Methylic alcohol ............ Ethylic alcohol.. ............. Ether ........................... Piperidine ..................... . Benzene ........................ Ace tone ....................... Etliylic acetate ............... Carbon tetrachloride ...... Acetic acid ................... Chloroform.. ................. - 33'3" - 34.8 - 34'9 - 35'5 - 37'5 - 38.8 - 39.2 - 39.5 - 41 *7 - 41 *5 - 37 *3" - 38.6 - 37 * 5 - 37.6 - 39.1 - 3 9 5 - 39.6 - 39.3 - 40.0 - 41.7 - 38.3" - 38.7 - 38.1 - 37 *6 - 39.2 - 39.4 - 39.4 - 40.7 - 40.4 - 42'0THE CHARAC'PERISA~ION OF " RACEMIC " LIQUIDS. 1119 aiderably affected by experimental error. The table shows that the specific rotatory power of lsvopinene varies in different solvents, but to a minute extent compared with the variation in specific rotatory power of laevotetrahydroquinaldine in different solvents. A series of determinations of the specific rotatory power of hvopinene dissolved in a carefully purified sample of externally compenmted pinene was also made, and the results, given in the last table, contrast very strongly with those obtained with solvents other than inactive pinene, The results obtained with the pinenes point to the same conclusion as do those with tetrabydroquinaldine, namely, that the two optical antipodes, when mixed together, are wholly without mutual influence, and that consequently there is no question of the two substances combining to form cz racemic compound. Our thanks are due to the Government Grant Committee of the Royal Society and to the Research Fund Committee of the Chemical Society for grants defraying the cost of apparatus and materials used in the above work. GOLDSMITHS' INSTITUTE, NEW CROSS.

ISSN:0368-1645    

DOI:10.1039/CT8997501111

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

THE CHARAC‘PERISA~ION OF “ RACEMIC ” LIQUIDS. 1119 By FREDEBIC: s r i 7 m L E Y ~ ~ I P P I N G aid \ J 7 ~ ~ ~ ~ ~ ~ f JACKSON POPE. IN a paper published early this year (this vol., p. 36), we proved that Ladenburg’s general method for distinguishing between a racemic sub- stance and a mixture of enmtiomorphously related compounds (Ber., 1894, 27, 3065) is fallacious and cannot afford the criterion desired. Shortly afterwards, in a reply communicated to this Society (this vol., p. 466), Ladenburg, after admitting the justice of our criticisms, gave what he described as a ‘‘ different form ” to his previous statement of the method in question, but, as was pointed out by one of us at the time (Proc., 1899,15, 73), the alteration in form was so profound that the new statement had no principle in common with the original one, This new method, which was also described in a German version of the paper (Bey., 1899, 32, 864)-where it appeared as a spontaneous effort on the part of its author-consists in determining the solubility of the externally compensated substance with, and without, the addition of a small proportion of one of its optically active components; if the solubilities are different, then the substance is racemic, whilst, if they are the same, it is a mere mixture of the two enantiomorphs.This method, so far as it is applied to crystalline substances, is, except 4 1’ 21120 HIPPING AND POPE: in isolated cases, perfectly valid, and is merely the logical outcome of Kenrick’s work (Ber., 1897, 30,1749) and our own (Ioc.cit.). Recently, however, Ladenburg has attempted to apply it to externally compen- sated liquids with the object of ascertaining whether they are racemic or mere mixtures (Bey., 1899, 32, 1822); and in some of these experi- ments, instead of determining the solubility of the externally com- pensated substance alone and in admixture with a small proportion of one of its optically active components, he adopts the better and more convenient plan of examining polarimetrically the solutions obtained in the two cases. H e takes, for example, an optically inactive mixture of d- and I-limonene, shakes it with dilute alcohol insufficient to dis- solve the whole, then adds a little d-limonene, and shakes again ; on subsequently examining the alcoholic solution, he finds that it is optic- ally inactive, and so he concludes that d- and I-limonene do not form a racemic liquid at the ordinary temperature.Now the results obtained by such an application of the method afford no evidence whatever of the non-racemic nature or otherwise of the externally compensated liquid, and consequently the conclusions which Ladenburg draws from them have not the slightest value. The method is valid with crystalline substances, because in the case of a non-racemic mixture of optical antipodes two solid phases in contact with the solu- tion are being dealt with; whilst, in the case of a racemic substance, t o which a small proportion of one active isomeride bas been added, there is the question only of one solid phase (a racemic one), and this is in contact with a solution saturated with respect to it and partially saturated with respect to the active component.A liquid mixture of d- and I-isomerides, whether they form a racemic liquid or not, only constitutes one phase in the system, and never two, as in the case of a crystalline non-racemic mixture. The error into which Ladenburg has fallen is the more surprising, since Bakhuis Roozeboom has recently contributed a very clear discussion of the subject from the standpoint of the theory of equilibrium (Ber., 1899,32, 637 ; Zeit. physikcd, Cheni., 1899, 28, 494). We have shown, then, by the foregoing argument, that Ladenburg’s method of dealing with liquid externally compensated substances is in disagreement with the very principles from which its author professes to deduce it, namely, the principles of equilibrium.Since, however, the examination of optically active and externally compensated sub- stances in as many directions as possible is urgently desirable at the present time, in order to make certain that the laws of equilibrium have been properly applied, we have made a fresh investigation of some substances of this kind, with results which are quite in accordance with our theoretical argument.THE CHARACTERISATION OF " RACEMIC " LfQUIDS 1121 Pseudorcccemic and Dextro-Cu~nphorsu~3~~onic Chlorides. We have previously shown that the sulphonic chloride obtained from the product of the sulphonation of d-camphor with anhydrosulphuric acid, consists of a mixture of the d- and I-isomerides, the former being present in the larger proportion.For many reasons, discussed in earlier papers (Trans., 1893, 63, 548 ; 1895, 67, 354; 1807, 71, 989), we have also concluded that the externally compensated substance is not truly racemic, but that the antipodes crystallise together, forming a pseudoracemic substance. We defined a pseudoracemic substance as one in which the enantio- morphously related components are twinned together, and we may therefore take this opportunity of pointing out that the term seems to be understood in a different sense by Roozeboom (Zeit. phpsikal, Cliem., IS99, 28, 404), who attributes to pseudoracemic substances the proper- ties of isomorphous mixtures or solid solutions. As we alone, so far, have worked with pseudoracemic substances, and have observed no marked analogy between isomorphism and pseudoraccmism, we cannot share Roozeboom's views as to the nature of such substances ; possibly, however, the pinonic acids, recently examined by Fock (Zeit.Krpt. illin., 1899, 31, 479), afford a case of pseudoracemism in the sense in which Roozeboom understands it. However, according to our views of pseudoracemism, a substance such as crystalline externally compensated camphorsulphonic chloride should behave towards solvents in a manner geometrically similar to that of a non-racemic mixture of optical antipodes, and consequently, on extracting with a solvent a sample of this substance containing a small proportion of one or other isomeride, an optically inactive solution should be obtained; this we find to be the case.A considerable quantity of crude camphorsulphonic chloride was purified by recrystallisation from ethylic acetate, and a sample was ultimately obtained having the specific rotatory power [ a ] D + 13' in chloroform solution ; since cl-camphorsulphonic chloride has the specific rotatory power [ alu + 1 2 8 O , the sample contained about 45 per cent. of I - and about 55 per cent. of the cl-sulphonic chloride. Portions of 5 grams of this mixture, when agitated for 5-7 hours at constant temperature with 30 c,c. of various mixtures of light petroleum (b. p. 40-60') and chloroform, yielded solutions devoid of optical activity when examined in 200 mm. tubes in a polarimeter reading to 0*01'. Our previous conclusion is thus confirmed; crystalline externally compensated camphorsulphonic chloride is not a racemic substapce, but is pseudoracemic in the sense of our defi- ni tion.1122 KIPPING AND POPE: But, since externally compensated camphorsulphonic chloride is not racemic in the solid state, there is no reason for expecting that it would be racemic in the pure liquid state at the same temperature, and the probability that it mould exist as a racemic substance in dilute solution is even more remote, because, so far as they have been investigated, compounds proved to be racemic in a crystalline con- dition are known to be wholly resolved into their components in solution.In order, however, to study the behaviour of mixtures of d- and I-camphorsulphonic chloride in a dissolved condition, the following experiments were made : portions of 3 gramr of the same sample as before were completely dissolved in mixtures of chloroform (10 c.c.) and light petroleum (20 c.c.) ; a mixture of alcohol (30 c.c.) and water (7 c.c.) was then added to the solution, and the whole shaken during 3-4 hours at the ordinary temperature. The liquid, which at the end, as at the commencement of the experiment, mas free from crystals, separated when left at rest into two layers; the lower one (about 32 c.c.), we may call the alcoholic, the upper one, the petroleum, solution of camyhorsulphonic chloride, Both these solutions were found to be optically active when examined in a 200 mm.tnbe, the alcoholic solution showing a rotatory power of about uD+0*6O, the petroleum about ~ ~ + 0 * 9 ~ . A repetition of these experiments with 2 grams of the same sample of sulphonic'chloride afforded similar results.Now, if Ladenburg's application of the method referred to above to liquids were valid, we should have to conclude that dissolved, externally compensated camphorsul phonic chloride is a racemic sub- stance-a conclusion which, as indicated above, is scarcely within the bounds of possibility ; there are, moreover, other arguments which lead equally to the conclusion that the sulphonic chloride in the state of solution does not show the behaviour of a racemic compound, so far as the disputed method is concerned. I n the first pl;bce, the result of shaking together the two solutions of unequal quantities of the two optically active sulphonic chlorides is quite different from that ob- tained on shaking a solid mixture of n mcemic substance and one of its optically active components with a solvent ; in the former case, both solutions (the extract and the extracted) remain optically active, whereas in the latter the optical activity is wholly confined to the liquid extract ; even granting the existence of a racemic sulphonic chloride in solution, i t seems to us that, according to Ladenburg's views, one of the solutions should become optically inactive.In the second place, or rather, putting this same argument differently-if pseudo- racemic camphorsulphonic chloride become racemic when it is dis- solved in a mixture of chloroform and petroleum, it could not possibly yield anoptically inactive solution when a mixture of unequal quantitiesTHE CHARACTERISATION OF (( RACEMIC ” LIQUIDS.1123 of the two antipodes is shaken with such a solvent, whereas our experiments have led to this result. We have therefoTe no hesitation in concluding that the experi- mental evidence which we have brought forward suffices to bear out the truth of the arguments which we have advanced, and that Ladenburg’s application to liquids (or wholly dissolved solids) of the principle used in the case of solids is theoretically unsound and in- capable of yielding practical results of the slightest value. One statement by Ladenburg, and one only, Seems to be at variance with them conclusions, namely, that a mixture of unequal quantifies of d- and I-limonene yields an optically inactive extract when shaken with dilute alcohol insufficient to dissolve the whole.So far as we can judge from the very brief description of the experiment given in his paper (Zoc. cit.), it seems more probable that the alcoholicsolution contained so much water that it dissolved too small a quantity of the mixed limonenes to afford observable optical activity. Whatever the explanation of this particulnr experiment, it seemed probable on b p’iori grounds that the results obtained on extracting an externally compensated liquid, containing a small proportion of one of the antipodes, should be subject to the ordinary law of dis- tribution, just as in the case of optically inactive compounds. This view might perhaps have been put to tho test of experiment with the aid of the sample of cnmphorsulphonic chloride employed above, but this substance does not seem a very suitable one for such a purpose; partly because it gradually hydrolyses in dilute alcoholic solution (but, as we satisfied ourselves, far too slowly to appreciably affect the qualitative results already described), partly because af the necessity for employing four different volatile liquids.For these reasons, we used the ennntioniorphously related pinenes for a series of quctn titative experiments on the distribution of the components between two liquids. Dextro- and Lavo-pinene. The pinenes which we employed mere obtained from dextrorotatory American turpentine and lmvorotntory French turpentine respectively ; both were repeatedly distilled in a current of steam with addition of a little sodium carbonate and finally fractionated twice under atmo- spheric pressure, the fractions boiling at 161-162’ being taken as pinene.Repeated distillation with steam is necessary because, after mixing the two pinenes so as to obtain an optically inactive liquid and then extracting with methylic alcohol, the alcoholic extract becomes optically active unless the purification has been carefully1124 KIPPING AND POPE: carried o u t ; in such cases, the activity is doubtless due to the presence of some oxidation product, such as sobrerol. The rotatory powers of the d- and Z-pinene thus obtained having been determined, the hydrocarbons were mixed in such proportion as to give a liquid which appeared optically inactive when examined in a 200 mm. tube. Quantities of 25 C.C. of this inactive oil were then mixed with different small proportions of Z-pinene in stoppered bottles and abont 25 C.C.of 75 per cent. ethylic alcohol added to each ; the sample of Z-pinene used had the rotatory power uD-63.33' in a 200 mm. tube at 2 1 O . The bottles were then agitated during four hours at the constant temperature of 22', by which time it was judged that equilibrium would have been attained ; the liquids were then poured into separat- ing funnels, and as soon as the separation into two layers was com- plete, samples of each layer mere run into 200 mm. tubes and examined polarimetrically. The results are given in the following table : Pinene and 75 p e ~ cent. ethplic alcol~ol. - No. 1 2 3 4 5 6 7 a - a, of oil, 3;. 0 - 2-64' - 5.53 - 7'11 - 8'25 - 11.03 - 13.75 - 58 7 3 a, of solution, Y.0 - 0.19" - 0.34 - 0.46 - 0'49 - 0.75 - 0.08 - 2.66 - 13'9 16.3 1 5 5 16'8 1473 14'0 22 *1 It will be seen that in every case both the alcoholic solution and the mixture of pinenes in equilibrium with i t are optically active; further, the ratio of the optical activity of the two liquids is approxi- mately constant. Since the pinenes are miscible in all proportions with absolute ethylic alcohol and dilution with water is necessary in order to make the miscibility imperfect, i t seemed desirable to make another series of determinations with a, solvent which is not completely miscible with the pinenes. For this purpose me employed methylic alcohol, in which the oil is only moderately soluble, and carried out the experi- ments just as before, the methylic alcohol and piaene being shaken together during about 5 hours at 20'.The values of uD in 200 mm. tubes for the oils and the alcoholic solntions are given in the following table :No. 1 2 3 4 5 6 7 8 9 10 - THE CHARACTERISATION OF '' RACEMIC " LIQUIDS. 1126 Pinene and methylic nZcohoZ. aD of oil, 0 - 0'90" - 1.81 - 5.29 - 4-23 - 4.91 - 6.17 - 6'62 - 9'46 - 10'49 a,, of solution, Y. 0 - 0.16" - 0.33 - 0'63 - 0.78 - 0'82 - 1.07 - 1.1s - 1 *73 - 1.92 X - Y' - 5.62 5-48 5 *22 5.42 5 -99 5 -77 5-61 5 '47 5 *46 The same kind of result is obtained in this as in the previous series of experiments, and strong evidence is thus obtained that the ratio of the observed rotmatory powers of the oil and of the alcoholic solution in contact with it is constant.This result proves on analysis to be of considerable interest. Let us assume in the first place that externally compensated pinene is not racemic. Then in any two determinations with the same solvent, the oils contain, in unit volume, quantities which we may call xZ1 and xZ2 of Z-pinene and quantities xd, and xd, of d-pinene; similarly, unit volumes of the alcoholic solutions in equilibrium with them contain the quantities yl, and yZ2 of Z-pinene and pd, and yd, of the d-isomeride. Then, according to the distribution law, the equalities xz, X I 2 - xd, xd, & - yd, and - & - should hold, provided that the molecular weight of the pinene is the same in the two solvents. Further, since d- and Z-pinene are enantiomorphously related and the differences between the quantities of each present are small com- pared with the actual quantities, we should expect that xtz, xd, x7, xz, ?/d, ?/d, yl, yz2 d, - zd, E - -.- -- - whence xz, - xcz, $2 - 9 4 = const. - - But the differences between the quantities of d- and Z-pinene present in unit volume are directly proportional to the algebraic sum of the rotations due to the two active components, the length of the polarimeter tube remaining constant. Hence the values of x/p i s the1126 THE CHARACTERISATION OF " RACEMIC " LIQUID6. above t,able should be constant, as they are actually found to be within the limits of experimental error. It should be pointed ont that, since the concentrations xd and X Z in the oil are very high, the ratios xd/yld and xZ/yZ would not be expected t o maintain their constancy independent of the total concentration ; nevertheless, since the quantities of dextro- and Isvo-pinene used in any experiment differ by a t most 15 per cent.and the unknown causes affecting the ratios xdlp? and xZ/yZ are therefore operative t o about the same extent on each, the difference of the two ratios x Z ~ -xd, 12: -- - - - approximately preserves constancy. Yll - Yd, 9 Again, if we assume that externally compensated pinene is racemic in both of the liquid phases, the same result is arrived at. For, replace the quantities d throughout the mithemsticnl statement given above by the qmntities 9' representing racemic material; the coin- positions of the oils in any two experiments are then ml, xZ1, and ~ 7 ' ~ and xZp, whilst the compositions of the solutes in the corresponding alcoholic solutions are yl, 9Zl, and y~~ and yZ2, and from the dis- tribution law xz, xl, 99.1 v 2 94 Yl2 - xr1 I x 2 and - - - Since the components of the first equality are inactive, the latter does not affect the rotations, and the ratios x/p in the table are pro- portional to the xZ divided by the $, &c.A third case may of course be imagined, namely, that the externally compensated pinene is racemic in one solution and not in the other ; we should then have the eqnalities involving rooh of the component terms and the ratio x/y would not be independent of the total con- centration. This eventuality, however, is excluded by the results of the experiments. We have thus shown that the behaviour of mixtures of unequal quantities of the enantiomorphously related pinenes towards solvents is quite in accordance with the ordinary distribution law and indicates that an opticnlly active pinene exists in the same st.ate of molecular aggregation when dissolved in its optical isomeride as solvent as when dissolved with this isomeride in methylic alcohol; the results of these experiments as they stand are quite independent of any assumption as to the racemic or non-racemic nature of the externally compensated hydrocarbon. Obviously then, these results, in conjunction with those obtained with the camphorsulphonic chlorides, show the futility of attempting to decide between a racernic and a non-racemic liquid by We would point out in conclusion that our use of the term racemic the method employed for t.his purpose by Ladenburg.ASYMMETRIC OPTICALLY ACTIVE NITROGEK COMPOUNDS. 1127 as applied to liquids must not be construed as an admission of the existence of such compounds; the only evidence favouring the recog- nition of racemic liquids is Ladenburg’s statement that a change of temperature occurs on mixing dextro- and laevo-coniine. We tender our thanks to the Government Grant Committee of the Royal Society for funds defrqing the expenses incurred in this investigation. UNIVERSITY COLLEGE, KOTTINGH AM. GOLDSMITHS’ INSTITUTE, NEW Cnoss.

ISSN:0368-1645    

DOI:10.1039/CT8997501119

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

ASYMMETRIC OPTICALLY ACTIVE NITROGEK COMPOUNDS. 1127 CXIV.-Asyrnwt ric OpticaUy Active Nitrogen Com- pounds. Dexts.0- uml L~~io-cL-l-renz?ll~~en~l~~nzethylammoniurrz Iodides and Bromides. By WILLIAM JACKSON POPE AND STANLEY JOHN PEACHEY. THE only direct evidence pointing t o the existence of asymmetric optically active nitrogen compounds is Le Bel’s observation (Compt. r e d . , 1891, 112, 784) that on cultivating Penicilliuna glccucunt in solutions of isobut,ylpropylethylmethylarnmonium chloride the liquid acquires a rotatory power of - 0’ 25’ or - Oo 30’ under favourable con- ditions. The value of this important observation is, however, con- siderably lessened by the fugitive nature of the opticid activity and by the failure of Marckwald and von Droste-Huelshoff (Bey., 1899, 32, 560) t o confirm Le Bel’s results.” Many futile attempts have been made to directly resolve quater- nary bases of the type N(OH)X,X,X,X, into optically active antipodes by means of optically active acids.Thus, Marckwald and von Droste-Huelshoff (loc. cit.) attempted to resolve Le Bel’s base by the aid of tartaric, camphoric, and mandelic acids whilst Wedekind (Be?..; 1899, 32, 51 7) ende:tvoured t o resolve a-benzylphenylallylmethyl- ammonium hydroxide by means of trtrtwic and camphoric acids; in no ca~e, however, was an optically active base obtsined. A consideration of the facts led us to the opinion that the failure of these and other attempts had its origin in tho facility with which tetralkylnmmonium salts are decomposed by water and converted into tertiary base and alcohol ; we therefore prepared a-benzyl- phenylallylmethylammonium iodide by M7edekind’s method (loc.c d . ) and were successful in resolving it into isomeric opticalIy active bases * Le Re1 has recently replied to IIarckwald and von Droste-Huelshoff‘s criticism (Compt. Tend,, 1899,129, 548), and has confirmed his previous results.1128 POPE AND PEACHEY: by using hydroxyl-free solvents containing only small quantities of water. A number of methods, differing in detail, were applied, but we ultimately adopted the following process as affording the best results. Carefully purified a-benzylphenylallylmethylammonium iodide was mixed with a molecular proportion of the anhydrous silver salt of Reychler's dextrocamphorsulphonic acid and boiled for an hour or so on the water-bath with a mixture of about equal parts of acetone and ethylic acetate, a few drops of water being added when necessary.After separating silver iodide from the gummy solution by filtration, the solvent was distilled off and, on cooling, the residue solidified to a crystalline mass consisting of a mixture of dextro- and laevo-benzyl- phenylallylmethylammooiuln dextrocamphorsulphonnte. Dextl.o-a-ben~~l?~en~~~il~~l~iretJ~yt(ci~z.iitoniui,t Dexlrocam~~?~o)~szc~~~?~onat~, C,H,* CH,* N(eGH,)(C,Hj)(CH,)*SO~* CloI!C150. By fractionally crystallising the mixture of dextrocamphorsulphon- ates from boiling acetone, the less soluble constituent, dextro-a-benzyl- phenylallylmethylammonium dextrocamphorsulpl~onnte wtts readily obtained in colourless, diamond-shaped plates melting a t 169-170".After drying a t looo, the salt gave the following results on analysis : 0.2005 gave 0.505s CO, and 0.1364 H,O. C,;H,,O,NS requires C = 69.0s ; 13 = 7-46. 'It is very soluble in alcohol or water, less so in acetone, and sparingly soluble in ethylic acetate. The thin, rhomboidal plates deposited from acetone shorn extinction bisecting the angles ; the bisectrix of a large optic axial angle emerges perpendicularly through the large face of the rhonib. The double refraction is positive in sign and the optic axial angle f o r blue is greater than that for red light. The rotatory power of the salt was determined in aqueous solution ; 0-5256 gram in 26 C.C. gave a,+ 1.87" in a 200 min. tube, whence [a]= + 44.4" and [ 111, + 208".As we have previously shown (this vol., p. 1086) that the molecular rotatory power of salts of destro- camphorsulphonic acid with inactive bases is [ XID + 51.7", it follows that the basic radicle in the salt now described has the molecular rotatory power of about + 150° in aqueous solution. C = 65-84 ; I3 = 7.56. ~ ; o e v o - a - 6 e l z x ? / l l ' ~ e ~ ~ l c i Z ~ Z ~ i ~ e t ~ ~ ~ t ~ ~ ~ ~ ~ i ~ ~ o n i z c n a Dextrocun~~~orsu~hoate. This salt is contained in the acetone mother liquors, and may be obtained as a granular, crystalline powder by distilling off the solvent and crystallising the residue from boiling ethylic acetate containing aASYMMETRIC OPTICALLY ACTIVE NITROGEN COMPOUNDS. 1129 little acetone ; after drying at looo, it gave the following analytical results : 0.1874 gave 0.4710 CO, and 0,1284 H,O.C = 68.55 ; H = 7.62. 0.1596 ,, 0.4016 CO, ,, 0.1099 H,O. C = 68.63 ; H = 7.64. C,7H,,0,NS requires C = 69.08 ; H = 7.46 per cent. An aqueous solution of 0.42'35 gram in 25 C.C. gave uD - 0.64" in a 200 mm. tube, whence [a],, - 18%' and [If], - 87". These numbers show that the substance still contained some of the salt of the dextro- base, because, when pure, its molecular rotatory power would be about [MIL, - 100'. Deztro-a-be~za~Z~~~~enyta~~~l~~iet~~~~~!ccl,tmoniunt Iodide, C,H,* CH,* N( C,H,)(C,H,)(CH,)I. On adding to an aqueous solution of dextro-a-benzylphenylallyl- methylammouium dextrocamphorsulplionate the equivalent quantity of potassium iodide dissolved in water, a white, crystalline precipitate immediately begins to separate.After remaining for half an hour, this is collected, well mashed with cold water, and purified by crystallising it several times from boiling 50 per cent. alcohol; it melts at 145-147'. The following analytical results mere obtained : 0.18116 gave 0.3864 CO, and 0.0962 H,O. C = 55.57 ; H = 6.63. 0.1460 ,, 0.2984 CO, ,, 0.0732 H,O. C = 55.74 ; H=5*57. 0.2561 ,, 0.1640 AgI. I = 34-61. C!,7H,,NI requires C! = 55.89 ; H = 5.48 ; I = 34.79 per cent, A solution of 0.1445 gram, made up to 15 C.C. with a mixture of equal parts of acetone and methylic alcohol, gave aD c 1*0lo in a 200 mm. tube, whence [.ID + 52.5' and [ATID + logo. This salt is much less soluble in hot ethylic alcohol than the ex- ternally compensated salt prepared by Wedekind.A hot alcoholic solution of a mixture of the dextro- and inactive iodides, when poured into a 200 mm. tube, gave uD + 0.25' whilst still warm ; on standing, however, crystals were deposited and the solution became inactive, all the dextrorotatory iodide having been deposited. These observations prove that Wedekind's externally compensated iodide is not a racemic compound but merely an ordinary or pseudoracemic mixture of the two antipodes. Corroborative evidence of this is obtained on examin- ing the small crystals of the dextro-iodide deposited from a cooling alcoholic solution ; these belong to the orthorhombic system, showing two forms of the kind (110) and (101). The microcrystallographic characters of the material are identical with those of the inactive iodide and agree with the data given for the latter by Fock (Bey.,1130 ASYMMETRIC OPTICALLY ACTIVE KITROGEN COMPOUNDS.1899, 32, 520) ; it follows that Fock actually measured crystals of the optically active iodides. Dextro-a- b e i a x ~ ~ ~ e n ~ l i t l l y l m e t 7 ~ y l ~ n z r n o l r i u l Bromide, C,H,* CH,* N( C,H,)( C,H,)( CH,) Br. On adding to an aqueous solution of dextro-a-benzylphenylallyl- methylammonium dextrocamphorsulphonate the equivalent proportion of potassium bromide dissolved in water, it precipitate of dextro-a- benzylphenylallglmethylammonium bromide was slowly formed ; after several recrystallisations from boiling alcohol, it melted at 147-1 49' and gave the following analytical results : 0.1027 gave 0.2409 CO, and 0.05SG H,O.0.1164 ,, 0.2731 CO, ,, 0.0676 H20. U=64*00 ; H=6*45. 0.3205 ,, 0,1923 AgBr. Br = 25.63. C17HJ?Br requires c1 = 64.15 ; 13 = 6-29 ; BY= 25.14 per cent. C = 63.97 ; H = 6.34. An ethylic alcoholic solution containing 0,1454 gram in 15 C.C. gave a,+1.33' in a 200 mm. tube, whence [a],+68*6 and [MID + 218O. Lcevo-a-benz?/l~~en?/~~lZ~~t~~et7~~Z([nz?iioniuna Iodide. On mixing the somewhat impure lsvo-a-benzylphenylallylmethyl- ammonium dextrocamphorsulphonate with potassium iodide as described above, a precipitate of the iodide is obtained from which Isevo-a-benzylphenylallylrnethylammonium iodide may be isolated by repeatedly crystallising the salt from boiling 50 per cent. alcohol, the active substance being less soluble than the inactive mixture. Its ordinary properties are identical with those of its dextro-isomeride ; it gave the following analytical results : 0.1335 gave 0.2'732 GO, and 0.0684 H,O.C= 55.Sl; IC=5.69. 0.1484 ,, 0,3032 UO, ,, 0.0739 H20, C=55.72; H=5.53. 0.2408 ,, 0.1539 AgI. I= 34.54. C17H,,NI requires U = 55.89 ; H = 5.48 ; I = 34.79 per cent. A solution of 0.3105 gram, made up to 15 C.C. with a mixture of equal parts of acetone and methylic alcohol, gave a,-2*13' in a 200 mm. tube, whence [ aID - 51 *4O. L ~ v o - a - ~ ~ ~ a ~ ~ Z ~ ? ~ ~ e n ? / l ( ~ l l ~ ~ ~ ~ ~ e t ~ ~ l ~ Bromide. This substance, prepared from its dextrocamphorsulphonate and purified by cry stallisation from boiling alcohol, has properties antipodal t o those of its dextro-isomeride. It gave the following results on analysis :RUHEMANN AND STAPLETON : TETRAZOLINE, 1131 0.1150 gave 0.2695 CO, and 0.0660 H,O.0.3447 ,, 0.2017 AgBr. Br= 24.90. A solution of 0.2240 gram, made up to 15 C.C. with absolute alcohol, gave aD-2*01” in a 900 mm. tube, whence [a], - 6 7 ~ 3 ~ . We have also succeeded in resolving the inactive iodide into its active components by digesting i t with the silver salt of dextro-a- bromocamphorsulphonic acid in acetone solution. C! = 63.92 ; H = 6-38, 0.1096 ,, 0.8566 CO, ,, 0.0632 H,O. C=63*85 j H ~ 6 . 4 1 , CI7H,,NBr requires C = 64.15 ; H= 6.29 ; Br = 35.14 per cent, The values of the melting points and rotatory powers given in this preliminary note are only provisional, and we shall subsequently determine them with greater accuracy, using more carefully purified materials. I n the present paper, it is proved that quaternary ammonium derivatives in which the five substituting groups are different, contain an asymmetric nitrogen atom, which gives rise to antipodal relation- ships of the same kind as those correlated with an asymmetric carbon atom. The method which has enabled UB to deal with quaternary bases is now being applied to various other types of substituted ammonium derivatives in order to ascertain the stereochemical nature of pentad nitrogen, We hope shortly to be in a position to publish results obtained with sulphonium derivatives of the type SX,X,X,T. Our thanks are due to the Government Grant Committee of the Royal Society and to the Kesearch Fund Committee of the Chemical Society for grants enabling us to purchase apparatus and materials used in this work. GOLDSMITHS’ INSTITUTE, NEW CEOSS.

ISSN:0368-1645    

DOI:10.1039/CT8997501127

出版商:RSC    

年代:1899

数据来源: RSC

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RUHEMANN AND STAPLETON : TETRAZOLINE, 1131 CXV.- Tetmzoline. By SIEGFRIED RUHEMANN and H. E. STAPLETON, Scholar of St. John’s College, Oxford. SEVERAL years ago, it was shown by one of the authors (Trans., 1889, 65, 242 ; 1890, 57, 50 ; see also Ruhemann and Elliot, Trans., 1888, 53, 850) that by the action of chloroform and alcoholic potash on phenylhydrazine a compound of the formula,1132 RUEEMANN AND STAPLETON : 'fETRAZOLINB!, resulted, which he called diphenyl tetrazi ne, Analogous substanees have been produced from ortho- and para-tolylhydrazine. The term tetrazines for this class of compounds has had to be altered to di- bydrotetrazines, since Pinner (Bey., 1894, 27, 987) obtained some members of a similar type with two hydrogen atoms less in the mole- cule. Besides these bases, the formyl derivatives of the hydrazines are also formed in the above reaction, and this fact led to the view that the latter are the first products, which in the second phase of the reaction lose water and condense to the cyclic compounds.Indeed, as shown by Pellizznri (Gaxxettcz, 1896, 26, ii, 430) and Bamberger (Bey., 1897, 30, 1263), formylphenylhydrazine, on heating, is transformed into dihydrodiphenyltetrazine, for which Pellizznri proposed the suitable name diphenyltetrazoline. The yield, however, according to these authors, is unsatisfactory, as is also the case when the base is pre- pared by the action of chloroform and alcoholic potash on phenyl- hydrazine. Lately, Pellizzari ( A t t i R. Accnd. Lincei, [v], 1899,8, 327, has found that dimethyltetrazolina and monacetyldimethyltetrizzoline me formed on heating mono- and di-acetyl hydrazine respectively, and that diformylhydrazine yields a non-crystallisable product, which, on treatment with hydrochloric acid, is transformed into tetrnzoline hydrochloride.Our attempts t o prepare tetrazoline by digesting hydrazine hydrate with chloroform and alcoholic potash have been unsuccessful, since hydr- azine seems hardly to be acted on by these substances. We find, how- ever, that it can readily be obtained by heating monoformylhydrazine, prepared by Schofer and Schwan's method (J. pr. Chem., [ii], 1895,51, 180) from hydrazine hydrate and ethylic formate. When monoformyl- hydrazine is heated for 3 hours in an oil-bath, the temperature of which is gradually raised from 150' to 210°, it loses water, and the residue, when cold, solidifies to a mass of crystals.These are fairly soluble in alcohol, but only sparingly so in chloroform or light petr- oleum. On dissolving the substance in a boiling mixture of chloroform and absolute alcohol and cooling the solution by ice-water, it separates i n exceedingly deliquescent, colourless needles which melt at 82-83'. The yield is very satisfactory. The following analytical data were obtained : 0.2003 gave 0.2085 CO, and 0.0980 H20. 0.1052 C = 25.37 ; H = 5.43. ,, 61.8 C.C. moist nitrogen a t 24' and 766 mm. N = 66.37. C,H4N, requires C = 28.57 ; H = 4.76 ; N = 66-66 per ceht. The aqueous solution of tetrazoline is not alkaline towards litmus ; itRUHEMANN AND STAPLETON : TETRAZOLINE. 1133 gives, with copper sulphate, a blue, and with ferric chloride a red coloration. Tetrazoline is very soluble in hydrochloric acid, and the hydrochloride, obtained by evaporation of the solution, crystallises from boiling ab- solute alcohol in long, transparent leaflets which melt at 151-152O (at 150°, according to Pellizzari) and are very soluble in water.On analysis, the hydrochloride gave the following numbers : 0.1 112 gave 46 C.C. moist nitrogen a t 26' and 767 mm. X = 46.30. 0*3065 ,, 0.3618 AgCl. C1=29*20. C,H,N,,HCl requires N = 46.47 ; C1= 29.46 per cent, The picrate, C,H,N,,C,H,(NO,),OH, is precipitated on mixing alcoholic solutions of the base and picric acid. It dissolves only sparingly in alcohol, and crystallises in yellow needles, which melt and decompose at 194-195'.0.1550 gave 42.5 C.C. moist nitrogen at 22' and 767 mm. N = 31.33. Tetrazoline forms, with platinic chloride, a yellow, crystalline com- CsH,0,N7 requires N = 31.50 per cent. pound which has the composition (U,H,N,)2,PtC14. 0.3680 gave 0.0945 CO, and 0.0445 H,O. 0,1642 ,, 31 C.C. moist nitrogen at 17O and 764 mm. N=22*63. C,H,N,,PtCl, requires C = 9.51 ; H = 1.58 ; N = 22.20 ; Pt = 38.53 per cent. Mercuric chloride, even in a dilute aqueous solution of tetrazoline, produces a turbidity which may disappear if the quantity of chloride is small, but is permanent if a sufficient excess is used, The com- pound, which separates in bunches of colourless needles, is sparingly soluble in water, but dissolves readily in hydrochloric acid, and has the formula 2C,H,X4,3RgC1,. 0.4127 p v e 0.2930 IlgI. H g = 61.20. 0.3550 ,, 0.2520 HgS. Hg=61*19. C4HsN,,3HgC1, requires Hg = 61-16 per cent. The aqueous solution of tetrazoline gives a yellowish, crystalline precipitate with zruric chloride, and with silver nitrate yields colourless needles of a silver compound which explodes on heating. We are engaged in the further study of tetrszoline, and shall shortly lay the results before the Society. C: = 9.61 ; H = 1.84. 0.3504 ,, 0*0960 Pt. Pt = 38.34. 0.2326 gave 0.0893 Pt. Pt = 38.35. GONVILLX ASD CAIUS COLLEGE, CAMBKIDOE. VOL. LXXV. 4 G

ISSN:0368-1645    

DOI:10.1039/CT8997501131

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

1134 LAPWORTH : ACTION OF CXVI.-Action of Hydro7ytic Agents o n a-Dibromo- C'oizstitut ion of BI.o?,aoccci~a~)7Lol.enic Acid. campho~. By ARTHUR LAPWORTH. WHEN P-dibromocamphor is warmed with strong aqueous alkalis, i t dissolves, and acid products are obtained; these do not appear to have been examined, bnt their formation indicates that hydrolysis of the dibromocamphor has occurred, and if is probable that they in- clude derivatives of a-cnmpholenic acid. This acid has been isolated from the product of the actior! of moist sodium amalgam on P-dibromo- camphor (Kachler and Spitzer, M o ~ t t s l ~ , 188.2, 3, 216 ; 1583, 4, 643), and its presence is doubtless due to the occurrence of combined reduction and hydrolysis. The formation of a-campholenic acid by two different reactions, from P-clibromocamphor on the one hand, and from camphoroxime on the other, would certainly seem to indicate that the substance is related to camphor in a simple manner.I n the present paper, how- ever, evidence is brought forward which shows that obscure changes in structure may occur under conditions which cannot be regarded as violent, and it is of especial interest that a change of this kind occurs in a reaction almost exactly analogous to that whereby P-dibromo- camphor affords a-crtmpholenic acid. Action of Silveq* Conzpounds on a-D ~bro~szocnvzpho~*. a-Dibromocamphor, unlike the P-derivative, when treated with alkalis, or with sodium amalgtm, is merely reduced, and hitherto no hydrolytic effect appears to have been observed. It mas in the hope of producing such an effect that the following experiment was made, A solution of a-dibromocamphor in alcohol was warmed on the water- bath in a reflux apparatus, and to the hot solution small quantities of finely powdered silver nitrate were added.After each addition cloudiness ensued, and was followed by a copious deposition of silver bromide, the rtddit,ion of silver salt being interrupted when this cloudiness was no longer produced. The whole was heated for about an hour, and after the addition of hydrochloric mid, in amount sufficient to precipitate the excess of silver, the liquid was filtered, . evaporated a t a low temperature, and then distilled in steam; a solid product, smelling strongly of camphor, passed over, le ving an oily residue. The solid product in the distillate was collected an carefully fractionated, when it resolved itself for the most part into camphor and monobromocamphor.The less volatile portion, on examination,HYDROLYTIC AGlENTS ON a-DIBROMOCAMPHOR. 1135 was found t o contain monobromocamphor and unaltered dibromo- camphor. The oily residue in the distilling flask could be separated into two portions by means of sodium carbonate solution ; the portion insoluble in sodium carbonate was for the most part unaltered dibromocamphor, but contained a small quantity of nitrogenous substance soluble in hot caustic potash. The portion dissolved by sodium carbonate separated on the addition of an acid as a brown, apparently amor- phous precipitate, and after purification by dissolving in sodium carbonate and reprecipitating with acid, was crystallised from alcohol.This acidic substance separated from alcohol in beautiful, white needles, and from ethylic acetate in large, transparent, monoclinic plates; it melted at 159'. It dissolved Elowly in cold dilute sodium carbonate with effervescence, and the solution a t once discharged the colour of dilute potassium permangannte. On treatment with bromine, i t evolved hydrogen bromide, and yielded a neutral substance which separated from alcohol in needles and melted at 152'. The substance obtained by the action of silver nitrate on a-dibromocamphor had therefore the properties of an unsaturated Py- or @-acid. It contained bromine, and gave the following results on analysis : 0,2073 gave 0.3701 CO, and 0.1110 H,O.C=48*7; H=6*0. CloHl,O,Br requkes C = 48.6 ; 13 = 6.1 per cent. It was finally found by direct comparison to be identical in all respects with bromocamphorenic acid, first obtained by Forster from dibromocamphor in an indirect manner (Trans., 1896, 69, 46). This action of silver nitrate appears a t first sight to be merely one of hydrolysis in accordance with the equation C,oH1,OBr, + H,O = CloHl,O,Br + I-TBr, and therefore more or less analogous to the hydrolysis of /3-dibromo- camphor by sodium amalgam, and it is now clear that the production of this substance accounts for the formation of homocamyhoronic acid when a-dibromocamphor is oxidised in presence of silver nitrate (this vol., p. 992). When, in the above experiment, acetic acid is used instead of alcohol as a solvent, nitrous fumes are rapidly evolved, and the solution on cooling frequently deposits beautiful needles of bromo- camphorenic acid.The yield of this compound, although greater than in the former case, did not in any instance greatly exceed 15 per cent. of that theoretically possible. I n order to make certain that the nitric acid or nitrous fumes disengaged during the reaction played no part in the production of bromocamphorenic acid, the experiments were repeated with silver acetate instead of nitrate, but the results only differed as regards the 4 a 21136 LAPWORTH: ACTION OF length of time required to complete the reaction, and the proportion of acid produced. a-Dibromocamphor in alcoholic solution is rapidly attacked by moist silver oxide, and, in addition to the above products, a small quantity of a yellow, oily substance is formed; this is insoluble in alkalis, and, as it gives a crystalline compound on treatment with semicarbazide acetate, is probably a ketone : it is not camphorquinone, however, as it is not volatile in steam.Action of Mei*czC?y ccnd Lead Contpounds on a-Dibroi?~occ~ni~lor. Interesting results having been obtained with silver salts, i t was thought desirable to examine the action of other met.allic com- pounds on a-dibromocamphor. Mercurous nitrate was first chosen, as it resembles silver nitrate in yielding a very sparingly soluble bromide. On adding mercurous nitrate to a hot solution of a-dibromocamphor in acetic acid, nitrous fumes were at once evolved, and a precipitate of mercurous bromide was produced.If the action was interrupted after about 15 minutes, it was found that a small quantity of bromo- camphorenic acid could be isolated, but the amount formed was considerably smaller than when silver salts were used. It is interesting that lead salts and moist lead oxide seem to have little or no effect on a-dibromocamphor under conditions similar to the above. In order to induce any marked decomposition with lead oxide, it was necessary to heat the materials with water in sealed tubes a t 120-150°, and the experiments showed that when any appreciable action occurred, the orga.nic matter was almost entirely carbonised. I n one instance, however, the aqueous solution had acquired a distinct yellow colour, and on distilling the contents of the tube with steam, i t mas found that the first few drops of the distillate were bright yellow, and deposited a few yellow needles.Although the quantity was too small for analysis, the substance was easily identified, as it melted a t 196-198°, approxiuately the melting point of camphorquinone (Claisen, Bey., 1889, 22, 530). I t sublimed with great readiness, its aqueous solution was decolorised by sodium hydrogen sulphite, the colour being restored by means of acid, and, when examined in polarised light, the crystals could not be distinguished from those of camphorqninone prepared by the ordinary method. It may Be mentioned that from the same tube a consider- able quantity of monobromocamphor was obtained by continuing the steam distillation. I n order to determine whet her broinocamphorenic acid was pro- duced in the foregoing reaction, the csrbonised contents of four tubes were united and boiled with a solution of sodium carbonate.NoHYDROLY T1C AGENTB ON a-DIBROMOCAMPEOR, 1137 appreciable quantity of bromocamphorenic acid was obtained from the filtrate after aciditication, but on extracting the acid liquid with ethylic acetate and evaporating, a small quantity of a crystalline acid was ischtcd, which, after purification, melted with some effervescence at 1 8 4 O , but when allowed to solidify, melted again a t temperatures varying between 80' and 200'. It yielded an anhydride melting at about 2 1 5 O on treatment with acetyl chloride, and its whole be- haviour suggested that it was cainphoric mid.This was confirmed by analysis. 0.1014 gave 0.8216 CO, and 0.0760 II,O. C: = 59.6 ; I3 = 8.3. CloH1604 requires C: = 60.0 ; I€ = S.0 per cent. I t is possible, of course, that the formation of cainphoric acid from dibromocamphor in this way is due to the oxidation of camphor or monobromocamphor produced a t an intermediate stage, but, it seems more probable that hydrolysis ,bas taken place, with the production of camphorquinone, which would readily yield camphoric acid under the above conditions. Oxidcct ion of Derivatives of B?.o?nocc~?~~2,~orenic Acid. I n the endeavour to obtain fairly large quantities of homocamphor- onic acid by a convenient method, a large number of experiments were made with derivatives of bromocamphorenic acid, and a brief account of the results may be given.The method used by Forster (Zoc. cit.), namely, oxidation of bromo- camphorenic acid with ice-cold permanganate, was found to give very poor yields of the desired product, and was inconvenient on account of the large quantity of liquid necessarily involved. Oxidation of bromocamphorenic acid with dilute nitric acid, even in presence of silver nitrate, also gave poor results, as it was almost impossible to avoid the formation of a stable nitro-derivative, and the substance itself is so sparingly soluble in the nitric acid that the action is excessively slow. I n every case, however, some small quantity of homocamphoronic acid was obtained. Chromic acid was found to be quite useless as an oxidising agent. Dibromocampholid was next tried, and was oxidised in various ways.With dilute nitric acid and silver nitrate, fairly good results were obtained, but the action was slow ; on evaporating the filtrate after several days treatment with tho oxidising mixture, homo- camphoronic acid was at once obtained, apparently uncontaminated with any secondary product. The yield was in each case about 15-20 per cent. of that theoretically possible. a-Monobromocampholid, the lactone obtained by treating bromo-1138 LAPWORTH: ACTION OF camphorenic acid with sulphuric acid (Forster, Zoc. cit,) was found to be the most suitable substance for the purpose. It is rapidlyattacked bya solution of silver nitrate i n dilute nitric acid (1 vol. of nitric acid of sp. gr. 1.42, and 1 i vols. of water), and if the mixture is heated on the water-bath for about 60 hours, homocamphoronic acid, sometimes amounting to more than 60 per cent.of the bromocampholid used, may be readily obtained. I n this case also, the resulting homo- camphoronic acid seems to be practically pure, and only very small quantities of any secondary products are present, A miuute quantity of an acid which did not yield an anhydride when heated at 180' was observed, but the amount was less than 1 per cent. of that of the homocamphoronic acid obtained. Constitution of Brollzoca~~t~~AoreiLiC Acid. Sufficient is now known of the properties of bromocamphorenic acid and its derivatives to warrant a discussion of the probable structural formula of this substance. It has been shown by Forster that the acid is unsaturated and that it contains one closed chain (Zoc.cit.). It is practically certain, moreover, that the grouping *CH:CBr* forms a portion of the closed cliain, as the substance, when treated with ice- cold permanganate, rapidly loses bromine, and is subsequently con- verted into hornocamphoronic acid, an open-chain tricarboxylic acid. This view represents the oxidation as resulting iu the conversion of an acid COOH. C H <EB1' into UOOH*CiH1,<COOH, 'OH and the fact l3 CH that bromine is a t once eliminated receives explanation in the circum- stance that the glycol produced as the first step in the oxidation would contain the radicle >CBr*OI-I, from which hydrogen bromide would be split off immediately with formation of the >CO group. This also supplies a simple explanation of the fact, among others, that a-mono- bromocampholid, when hydrolysed, yields an acid having the formula C,oH160, (Forster, Zoc.cit.). It was at one time thought possible that homocamphoronic acid might be formed from an intermediate &ketonic acid by hydrolysis, but a number of important considerations ha.ve led to the rejection of this view. Of the formulze containing the radicle *CH:CBr*, which can be devised to represent bromocamphorenic acid, in view of its simple relationship to homocamphoronic acid, only two, ;cI! Br YNe, f/'H QMe*COOH GH ?file* COOH, CH2*CH, CBr*CH, I. 11. $XI2* ?Ale,HYDROLYTIC AGENTS ON a-DIBROMOCAMPHOR. 1189 correspond ih ahy simple way with any possible formula for a-dibromo- camphor. These, moreover, are the only expressions containing in addition the group :CNe*COOH, which is almost certainly present in bromocamphorenic acid for the following reasons, It is now scarcely open to question that camphoric acid contains the CMe complex : C<c- d>CXe*COOH present in camphononic acid, and .... consequently there are only three expressions possible for that sub- stance, namely, the Bredt, Perkin, and Porkin-Bouvesult formulae. No matter which of these be the correct one, it must be supposed that :C-CH-CH, camphor contains the group f I , in which the trsnsposi- :C-CNe CO tion of the *CH,* and *COO groups is not possible (compare Noyes, Ber., 1899, 32, 3289 and 2290). a-Dibromocamphor must therefore contain the group i I (compare Lowry, Trans., 1898, '73, 569, 1001).I n its transformation into brouiocamphorenic acid, it is at least certain that the *CO* group is converted into *COOH, and from what has been said i t must be clear that separation of the .CO* and *CBr,* groups has occurred. Although soine curious alter- ation in the structure of the molecule occurs, consisting evidently of the absorption into a ring of the carbon t o which the bromine atoms are attached, it is altogether unnecessary t o iimgine that the change has extended to the group :Cl\le*CC), which, i t is worthy of note, is present in hoinocamphoronic acid. We have now to choose between the formulle I and 11, and there can be little doubt which of thehe is to be preferred. The latter represents a y6-unsaturated acid, atlid in all probability an acid of this formula would be readily converted into the correspondiiig @y- or ap-acid, whilst such an occurrence is impossible with an acid represented by formula I.There are, inorever, a large number of facts which, taken together, speak in favour of formula I as against formula 11. Thus in the expressions for a-inonobromocampholid and for camphononic acid derived from formula, 11, namely : : C-UH-CBr, :C-CMe*C'O C Me2 CM e-C 0 I I UH, AH2 I and I I (a) CH,-CBr-O CH,-CO ( a ) (a) C&le,* CMe*COOH I (3 there is apparently no reason why oxidation should not take place at the points marked ( b ) as well as at those marked (a), whereas in fact only one product in each case can be isoltiteci.1140 ACTION OF HYDROLYTIC AGENTS ON a-DIBROMOCAMPHOR. All these difficulties disappear when formula I is used, and this expression explains in a most satisfactory manner all the facts bearing on the qriestion whieh have been observed by Forster and by the author.It is difficult t o understand the change which a-dibromocamphor undergoes in its conversion into bromocamphorenic acid, but it does not become easier if any of the other possible formulz for the latter substance be employed. The enlargement of a ring of car- bon atoms by the inclusion of a carbon atom hitherto outside the ring is by no means a n unknown phenomenon, and an assumption very similar to the one employed here, has been recently put forward by Wagner and Brickner t o explain the conversion of pinene into derivatives of camphene (Ber., 1890,32, 2323). ' It is worthy of remark that the formula above suggested as the most suitable for bromocamphorenic acid bears t o Ereclt's formula for dibromocamphor a relationship which could not, in the circumstances, be more simple. This relationship, as well as that connecting a number of important compounds the properties OC which have neces- sarily been cousidered in eliminating the improbable formuh, is exhibited in the following scheme : 1 1 /' 1 , CH,-CMe-COOII CH,*CRIe*COOH , I 1 p e 2 1 1p~e2 CH2*c!00H COOH UOOH COOH i~oiiiocaiiiphoroiiic Caiiigliorouic acid. ncid.FORSrER : CAMPHOROXIME. PART 111. 1141 It is hoped that the investigation, which is still being carried on, may elicit further evidence bearing on the question discussed in the paper. Much of the expense incurred during the work has been defrayed by a grant from the Research Fund of the Chemical Society, and for this help the author desires to express his indebtedness. CI1EMICAL DEPAI~TMENT, SCIIOOL OF PIIAliMACY, 17, BLOOMSBU~~Y SCJUARE, V. C.

ISSN:0368-1645    

DOI:10.1039/CT8997501134

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

FORSTER : CAMPHOROXIME. PART 111. 1141 By MARTIN ONSLOW FORSTER, Ph.D., D.Sc. ON the failure of an nttenipt to prepare a-bromocamphoroxime by the direct action of bromine on camphoroxime dissolved in glacial acetic acid (Trans., 1897, 71, 1030), I was led to study the behaviour of the oxime towards an alkaline solution of potassium hypobromite. When treated with this agent, cnmphoroxime undergoes simultaneous bromination and osidation, a quantitative yield of the compound, C,oH,,BrNO,, being readily obtained if certain conditions are observed. The change is expressed by the equation Cl0Hl7NO + 2KOEr = C,oHl,BrNO, + KOH + KBr. The new derivative is not an oxime, being indifferent towards benzoic chloride, but it contains a nitroso-group, produced by removal of hydro- gen from the oximido-residue.It is remarkably indifferent towards aqueous potash, from which i t may be distilled without undergoing apparent change, mhilst hot concentrated nitric acid scarcely dissolves it, and, at first, has no perceptible action on it, On dissolving the bromonitroso-derivative in concentrated sulphuric acid, the elements of water are withdrawn, and the compound C,,H,,BrNO, is produced. Unlike the substance from which it is obtained, this compound does not give Liebermann’s reaction for nitroso- derivatives ; moreover, cold concentrated nitric acid dissolves it im- mediately, whilst hot hydrochloric acid transforms it into an isomeride which yields a benzoyl derivative by the Schotten-Baumann method. These isomeric substances are opticslly inactive, although the initial compound is strongly lsvorotatory.Under the inhence of hot caustic alkalis, the isomerides, CloH,,BrNO, break up in a remarkable manner, yielding a nitrile of the empirical1142 FORSTER : CAMPHOROXIME. PART III. BEHAVIOUR OF formula C,H,,N. The production of such a compound involves elimina- tion of carbon monoxide and hydrogen bromide in accordance with the equation, C,,,H,,BrNO = C,H,,N + CO + HBr. The nitrile, when hydrolysed with alcoholic potash, yields the corre- spoilding a u d e , which has the formula C,H,,NO, and is therefore isomeric with the amides of isolauronolic and caniphoceenic acids ; these, however., melt a t 129-130' (G. Blanc, Compt. Teizd., 1896, 123, 749) and 155' (Jagelki, BET., 1899, 32, 1506) respectively, whereas the new smide melts at 90'.Nevertheless, its relation to isolauronol- amide must of necessity be a close one, because hydrochloric acid con- verts it into that substance along with isolauronolic acid. It has been shown that when sodium orthoethylic camphorate is submitted to electrolysis, the ethylic salt of campholytic acid is formed (Walker, Trans., 1S93,63, 495) ; the acid itself is also obtained by the action of nitrous acid on dihydroaminocampholytic acid, produced on elimiuating carbon monoxide from P-camphoramic acid, NH,* CO*CSH,,*COOH, by the agency of sodium hypobromite (Noyes, Ber., 1895, 28, 547). Electrolysis of sodium orthoethylic camphorate also yields isolauronolic acid, first described by Walker, who then called it camphothetic acid (Zoc.cit.) ; the production of this compound from sulphocamphylic acid was recorded about a month later by Koenigs and Hoerlin (Be?*., 1893, 28, S l l ) , from whom it received its present name. These isomerides, isolauronolic and cainpholytic acids, are now re- garded as the cis- and c&rccns-modifications respectively of s single acid, mainly because both contain an unsaturated linking in the ap-position, and also on account of the readiness with which isolauronolic (cis-cam- pholytic) acid is produced from the labile isomeride. Mere contact with cold dilute sulyhuric acid at ordinary temperatures will suffice to convert the liquid campholytic acid into solid isolauronolic acid (Noyes, Ber., 1895,28,54S), and in a private communication, Professor Walker informs me that an impure specimen of campholytic acid which has remained in his possession for some years, has now become almost entirely transformed into isolnuronolic acid.CH,-CH Neither the formula (CH,),C<,(,,s):tl.,;dH' by which Blanc represents the structure of isolaurondic -acid (Bull. Soc. CIL'L~., 1898, [iii], IS, 634 ; compare also 1899, [iii], 21, 830), no19 the expression - - UH,-C*COOH (CH8)&<CH(CH,). dH adopted by W. H. Perkin, jun. (Trans., 1898, 73, 796), suggests any reason for supposing that one of the two possible structural isomerides which have the unsaturated linking in theCAMPHOHOXIME TOWARDS POTASSIUM HY POBROMITE. 114s up-position would be more stable than the other. There is consequently every justification for the accepted view of the relation between cam- pholytic and isolauronolic acids, and the readiness with which the new amide is converted into isoltluronolamide and isolauronolic acid renders it highly probable that the substance in hand is the hitherto unknown amide of campholytic acid, Up to tlie present, however, it has not been found possible to verify this anticipation experimentally, because the amide reeists the action of alcoholic potash, and the employment of an acid as hydrolytic agent is obviously precluded; it is noteworthy that isolauronolamide is described by Blanc as being very indifferent towards alcoholic potash.The passage from camphoroxime to isolauronolic acid is represented in the following scheme : Camphoroxime, C,,H,,ON, I Bromonitroso-compdund, C,,H1,O,N Br.I Isomeric compounds, CloH,,OXBr. I Ni trile, :C,H,,N. I Amide, C,H,,ON. 1 I Isolauronolamide, C,I3,,ON. I Isolauronolic acid, CoH1402. As regards the constitution of the bromonitroso-comyoiind and the isomerides obtained from it on withdrawing the elements of water, discussion at the present moment would be premature. Experiments on the behaviour of menthoneoxime, isoni trosocamphor, thymoquinone- oxime, and carvoxime towards alkaline hypobroniite have been carried out for purposes of comparison, but no useful information has been obtained as yet from these sources. It is clear, however, that the initial substance does not belong to the class which includes bromonitrosopropaue, obtained by Piloty from acetoxime and bromine in presence of pyridine (Ber., 1895, 31, 453), because it contains more oxygen than camphoroxime, whereas the conversion of acetoxime into bromonitrosopropane merely involves removal of hydrogen and addition of bromine.There is every probability that the substance is a true bromonitroso-derivative containing the complex >CBr*NO, the presence of the group, >C:NOBr being rendered highly improbable by the stability of the compoulid towards aqueous alkali. The disposition of the oxygen atom which has been added to the molecule can be ascer- tained only by further study, and the work is being continued from this point of view.1144 FORSTER : CAMPHOROXLhfE, PART 111. ffEHAVfOdB OF EXPERIMENTAL. Action of Potassium Hypobromite on C'mtphoroxintc. A solution of potassium hypobromite was first prepared by dissolving 600 grams of caustic potash in 1000 C.C.of water, cooling the solution with crushed ice, and adding 400 grams of bromine to the well-stirred liquid. 100 grams of finely-powdered camphoroxime were next converted into a thin paste with SO0 C.C. of water, and treated with 200 grams of caustic potash dissolved in 500 C.C. of water. The oxime, suspended and in part dissolved in the alkali, and cooled by fragmentsof ice, was finally mixed with the cold solution of hypo- bromite, which quickly transformed i t into n pale green solid having a faint, pungent odour. After 24 hours, the product had risen to the surface in a compact mass, and the clear liquid was therefore removed with the aid of a syphon ; the green solid was washed several times with water, and finally spread in thin layers on blotting paper. On exposure to air, the substance became pale yellow, but retained its pungent odour.The yield approached that required by theory. When crgstallised twice from hot alcohol, the compound mas obtained in snow-white, fern-like aggregates, and melted at 220°, forming a colourless liquid which imiueditltely began to turn red and evolve gas. The substance could not be powdered, because moderate pi'essure trans- forms it into tough, camphor-like masses; it was therefore cut- into small fragments for analysis and dried at 80". 0.2708 gave 0.4570 CO, and 0.1503 H,O. 0.4048 ,, 19.8 C.C. moist nitrogen at 23' and 769 mm. N = 5.57. 0.2376 ,, 0.1693 AgBr. Br=30*32, CloH,,O,NBr requires C = 45.80 ; H = 6-10 ; N = 5.35 ; Br = 30.53 per cent, The new derivative from camphoroxime gives Liebermann's reaction €or nitroso-compounds, It distils readily in an atmosphere of steam and is exceesively soluble in benzene or petroleum.Concentrated nitric acid has no action on the substance, which merely fuses t o a yellow oil when heated with it, and resolidifies on cooling; it is also indifferent towards boiling aqueous potash, from which it may be dis- tilled without undergoing any apparent change. A solution containing 0.34'75 gram dissolved in 25 C.C. of absolute alcohol at 23' gave uD -1" 5' in a 2-dcm. tube, whence [aID -54.7'. A solution of 0,5061 gram in 25 C.C. of benzene at 21' gave aD - 2" 39.5' in the same tube, corresponding to [a], - 65.6'. A determination of the molecular weight in benzene solution gave the following result : C = 46.02 ; H = 6.16.CAMPHOHOXIME TOWARDS POTASSIUM HYPOBROMITE.1145 Grams of Granls of benzene. suJ>stmcc. Depression of Molecular weight Grams of substRllce 'I' 'O') SOlVCll P'''s t. Of frceziiig point. deduced. 16'66 9 ) 9 9 0.292" 0'428 0.539 0.3312 1.3875 0 -3352 2.0120 0.4372 2'6242 282.8 230.3 238.5 Reduction qf the B r o n i o ~ ~ i t r 0 ~ 0 - ~ 0 ~ ~ ~ ~ ~ 0 ~ n ~ 2 . - - 5 grams wore dis- solved in glacial acetic acid and treated with 5 grams of zinc dust while the liquid was cooled with ice. On diluting the filtered solution with water, a pale yellow oil separated, and aftor several days, colourless crystals were deposited. The oil had the odour of campholenonitrile, which is generally produced when camphoroxime is heated with glacial acetic acid and zinc dust.The solid substance was dissolved in hot petroleum, which deposited the characteristic crystals of camphorouime, melting at 118'; a 3.2 per cent. solution in absolute alcohol gave [.ID - 41 *lo. Action of Concentrated ~SuZphzt~ic Acid on the 131-onionitroso-compound. A beaker coiitaiiiilig 800 C.C. of concentrated sulphuric acid was surrounded with a freezing mixture. When the temperature of the acid had fallen below Oo, the bromonitroso-compound was added i n small quantities a t a, time; meanwhile the liquid was well stirred and maintained at n temperature below 10'. A n orange coloration was developed on first adding the substance, but the liquid rapidly became dark brown, and a highly scented, viscous oil rose t o the surface.When 100 grains of material had been added, the oil was removed, and the acid allowed to flow in a thin stream on to finely crushed ice, which precipitated a pale yellow solid. The latter was collected, mashed, spread on porous earthenware, and dissolved in the minimum quantity of boiling alcohol, which was then rapidly cooled. The yield mas disappointing, as operations involving 200 grams of the bromonitroso-compound have never f urnishecl more than 75 grams of the crystallised product, and on one occasion only 50 grams were obtained ; the theoretical amount, allowing for the production of the fragrant oil, is 170 grams. I n order to secure a comparatively good yield, it is absolutely essential to maintain the sulphuric acid in con- stant agitation while the bromonitroso-compound is being added ; the latter rises t o .the surface of the acid if this remains undisturbed, where it becomes heated, and blackens, evolving gas.Even when1146 FORSTER : CAMPHOROXIME. PART 111. BEHAVIOUR OF the liquid is efficiently cooled and agitated, alcohol extracts from the crudo product a considerable quantity of tarry matter. The substance formed by dehydration of the bromonitroso-corn- pound is sparingly solrible in cold, but readily in boiling alcohol, from which i t crystallises in long, lustrous, transparent needles ; it is readily soluble in benzene. 0.2460 gave 0.4383 CO, and 0.1323 H,O. 0.2394 ,, 12.3 C.C. moist nitrogen at 21' and 756 mm. N=5*82. ,0*1977 ,, 0.1508 AgBr. Br = 32.46.C,oHI,OKBr requires C = 49.18 ; H = 5.74 ; N = 5.74 ; Br = 32.79 per cent. It has no definite melting point,, but shrinks and darkens at about 210°, becoming completely charred at 230'; it is slightly volatile on the water-bath, and sublimes in minute, transparent needles. The derivative does not give Liebermann's reaction, and is saturated towards bromine in chloroform, but a hot solution in dilute sulphuric acid quickly reduces potassium permanganate. Warm con- centrated nitric acid decomposes it, liberating gas, but hot concentrated sulphuric acid and boiling pyridine art! without action on it. As already stated, this compoiind is destitute of rotatory power. A 4 per cent. solution in benzene and a 1 per cent. solution in alcohol were examined in a 2-dcm. tube and found to be inactive.C= 48.58 ; H= 5.97, Conversion. of the Compound, CloHl,ONBr, into an Isomwide. The compound, C,oH1,ONBr, was powdered and covered with con- centrated hydrochloric acid, which was then boiled during several minutes; on dissolving the product in hot water and allowing the filtrated liquid to cool, colourless needles were deposited. This modification is also obtained by boiling an alcoholic solution of the compound with a few C.C. of concentrated hydrochloric acid, and crystallises from alcohol in large, transparent, six-sided plates ; it melts at 240' to a colourless liquid which does not decompose, and is slightly volatile a t 100'. 0.2548 gave 0.4596 CO, and 0.1347 H,O. 0.3633 ,, 18.1 C.C. moist nitrogen at 24' and 769 mm. N = 5.65. 0.2358 ,, 0.1830 AgBr.BF = 32.84. C,,H,,ONBr requires C = 49.18 ; H = 5.74 ; N = 6-74 ; BY= 32.79 per cent. The substance does not give Liebermann's reaction, and behaves like a saturated compound towards bromine dissolved in chloroform, and also towards a hot solution of potassium permanganate; it under- C = 49.19 ; H = 5.87.CAMPHOROXIME TOWARDS POTASSIUM HYPOBROMITE. 1147 goes no change when a solution in glacial acetic acid, or alcoholic hydrochloric acid, is boiled with zinc dust. It resembles the first modification in being optically inactive, but differs from it in its be- haviour towards benzoic chloride, with which it yields a benzoy1 derivative. This crystallises from alcohol in lustrous scales and melts at 174-176O. 0,2280 gave 0.1323 AgBr. €31. = 22-82.0.1998 ,, 0*10'70 AgBr. B r = 22.78. CI7H,,O,NBr repires Br = 33.00 per cent, Behavioui* of the Compounds, C,,H1,ONBr, towcwds Caustic Soda. A boiling, aqueous solution of caustic soda eliminates hydrogen bromide and carbon monoxide from the compound, C,,H1,ONBr, and from its isomeride, giving rise to a nitrile of the formula C,H13N. 100 grams of the finely powdered substance were heated with a solution of 40 grams of caustic soda in 300 C.C. of water; the operation was conducted in a reflux apparatus on the water-bath and continued during half an hour. A volatile oil soon appenred in the condenser, and the suspended solid aggregated to a pasty mass beneath the liquid. After the period specified, the condenser was rearranged for distillation, and :L current of steam was passed through the alkali until the bromo-compouiid mas completely decomposed.On extracting the distillate with ether, drying the extract with calcium chloride, and evaporating the ethereal solution, 50 grams of the nitrile were ob- tained ; the aqueous residue in the distillation flask was concentrated on the water-bath and yielded 6 grams of the solid amide described below. The nitrile is a limpid, colourless oil having an agreeable, camphor- like odour, it boils at 198-195O under 760 mm. pressure, and has a sp. gr. 0.9038 at 24". 0.2213 gave 0.6466 CO, and 0,1940 H20. C = 79.68 ; H = 9.74. 0,1560 ,, 14.1 C.C. moist nitrogen a t 20.5' and 764 mm. N = 10.37. C9H1:,N requires C = 80.00 ; H = 9-63 ; N = 10.37 per cent. The substance reduces n cold solution of potassium permanganate instantly, and also decolorises bromine dissolved in chloroform.A specimen examined in a 2-dcm. tube was feebly dextrorotatory, giving a,, +Oo 46', an angle so small, in view of the inactivity of the original compound, as to suggest the presence of some optically active impurity. In view of the fact that the elements of hydrogen bromide and carbon monoxide are withdrawn fram the compound, CloH1,ONBr, by the action of caustic soda, it became necessary to test the alkaline1148 FORSTER : CAMPHOROXIME. PART 111. residue in the distillation flask for sodium formate. The liquid was accordingly acidified with dilute sulphuric acid, and a current of steam passed through it. Formic acid mas recognised without difficulty in the distillate, which had a faint, pungent odour, and was strongly acid towards litmus ; silver nitrate gave a precipitate undergoing immediate reduction on heating, and a specimen of the characteristic lead formate was obtained. H9drolysis of the Xtvile.25 grams of the nitrile mere heated with a solution of 20 grams of caustic potash in alcohol during 30 hours in a reflux apparatus. Water was then added to the liquid, from which alcohol mas removed by evaporation ; a yellow oil floated on the surface, and rapidly crystallised as i t cooled. The product mas collected, drained on porous earthenware, and recrystalliked from boiling light petroleum. 0.2117 gave 0,5479 CO, and 0.1913 H,O. 0.2235 ,, 18.4 C.C. moist nitrogen at 24' mcl $69 i i m . N = 9.34. C,HI,ON requires cl = 70.59 ; H = 9.80 ; N = 0.15 per cent.The amide is scarcely soluble in cold, but dissolves more freely in Poiling petroleum, from which it separates in highly lustrous needlw melting a t 90"; it dissolves readily in alcohol, and is also soluble in boiling water, crystallising in flat, lustrous needles as the liquid cools, Belmviouy towards IIydrocA loric Acid .-The recrys talli sed amide dis- solved freely in cold concentrated hydrochloric acid, but on boiling the solution in a reflux apparatus it rapidly became turbid, owing to the separation of an oil ; the latter immediately crystallised on cooling the contents of the flask. On collecting the product with the aid of a filter pump, it was found that crystallisation from boiling water con- taining a' little sodium carbonate yielded a substance having the empirical formula of the original smide.C= 70.58; H= 10.04. 0*1S12 ,, 0.4663 CO, ,, 0.1613 H,O. C=70*17 ; H-9.89. 0*2000 gave 0.5145 W2 and 0.1759 H,O. Moreover, the compound crystallised in highly lustrous needles exactly resembling the substance from which it was obtained. It melted, however, at 139-1 SO3, the melting point of isolauronolamide (G. Blanc, Compt. ?*end., 1S96, 123, $49). During the conversion of the amide melting at 90' into isolauronol- amide, colourless crystals collected in the condenser. These were analysed, with the following result : cf = 70.16 ; H= 9.77. C9H,,0N requires cf = 70.59 ; H = 9.80 per cent. 0.1714 gave 0.4399 GO, and 0.1408 H,O. C = 70.00 ; H = 9.13. C,H,,O, requires cf = 70.13 ; I3 = 9.09 per cent.OPTICAL ACTIVITY OF DERIVATIVES OF RORNTLAMINE. 1149 The substance melted at 132-133' ; a solution in chloroform was in- different towards bromine, but when dissolved in sodium carbonate, the acid decolorised potassium permanganate instantly. This is the behaviour of isolauronolic acid, and i t was found that the melting point of the preparation obtained in the manner just indicated was not depressed by admixture with R specimen of isolauronolic acid sent t o me for the purpose of comparison by Prof. 'IV. H. Perkin. The action of hydrochloric acid on the amide melting at 90" pre- cludes the use of this agent for the purpose of hydrolysis. Unfortu- nately, however, alcoholic potash is almost without action on the sub- stance. In one experiment, 10 grains were heated during 50 hours with 8 concentrated solution of caustic potash iu alcohol, and practically the whole amoiint of the amicle was recovered on dilution with yater and evaporation. On heating 5 grams with 15 C.C. of a 50 per cent, aqueous solution of potash in a sealed tube at 120' during 6 hours, and removing the unaltered amide, the aqueous liquid yielded on acidifica- tion about 0.5 gram of an oily acid; f o r reasons already stated, it seems probable that this compound is campholytic acid (Walker, Trans., 1893, 63, 495), and further attempts to identify it are being made, ROYAL COLLEGE OF SCIENCE, LOKDON, SUUTH KCSSISGTOX, S.W.

ISSN:0368-1645    

DOI:10.1039/CT8997501141

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

OPTICAL ACTIVITY OF DERIVATIVES OF RORNTLAMINE. 1149 CXiTIII.--hhj21e?2Ci? Of C!I% UI2SCtt?l,lY6tCd OPb the Optical Act i d y of Certain Derivcc.t iws of Bo ~r~ylccnzirze. Ey MARTIN ONBLOW FORSTER, Ph.D., D.Sc. As a result of investigating certain alkyl derivatives of bornylamine (Forster, this vol., p. 334), it was found that, although the specific rotatory power of the monslkyl derivatives considerably exceeds t h a t of the original base, the optical activity of symmetrical clialkyl deriva- tives npproxiniates very closely to that of bornylamine itself. Ethyl- bornylnmine, for instance, has the specific rotatory power [ a ] , + 90.3O in benzene, but dimethylbornylniniue has [a]1, + 59*Go, the specific rotation of bornylnmine being [.ID + 57.1'. It appears, therefore, that the symmetrical replacement of both atoms of miinic hydrogen, in- volving comparatively slight change i n the disposition of nitrogen with regard t o asymmetric carbon, produces a correspondingly small increase in rotatory power, and i t became of interest to ascertain whether bornylamine derivatives of the type C,,H,,*N:CHR would exhibit the optical properties of didkylbornylarnines, or whether a vor,.1,x xv. 4 H1150 FORSTER : INFLUENCE OF AN UNSATURATED LINKING ON THE disturbing influence would be exerted by the presence of an unsatur- ated linking. Attempts mere niade to obtain subst.ances of the nature indicated by condensing bornylarnine with acetaldehyde and propaldehyde, but nlthough combination occurs very readily in each case, the products are ill-defined oils which boil over a range of several degrees.Atten- tion was therefore devoted to the condensation products of bornyl- amino with various aromatic aldehydes, and in the following table a corn parigon is made between the optical activity of each derivative and that of the original base : Dorny lmiiiic ............................ Heiizy lidencbnl.iiylnnliiit! ............. O r t l ~ o ~ ~ i t r o b c n z y l i ~ ~ c ~ i ~ l ~ ~ ~ ~ ~ ~ I n n ~ i ~ ~ ~ . 1'iLranit r o b e ~ ~ z ~ l i d e ~ ~ e l ~ o r ~ i ~ l a ~ l ~ i ~ i t ~ . . Ortlioliydrosyl bcnzyliileneloriiy1- niii in e .............................. Pnra'ty tl m x y lhcn zylit 1 eiirborn y 1 - aiiiiiie .................................. [ ulo in a1 coli 01. [ AllD in a1co1101. It is evident from these resnlts that no relation, similar t o that connecting bOrJlSlmhe with its dinlkyl cornpoiinds, exists between the primary base and its aromatic aldehyde deyivntives. That the difference between the types C,,I€,~*N:CRR and C,,H,:*NX, must be ascribed to the presence of an ethylenic linking, appears from the following comparison of benzylidene compounds with the corresponding benzyl derivatives : Henzylborn ylnnline .....................Bciizylidenebornyl:,~~iine ............. OrthonitrobenzylL~onlylan~ine ....... Parmlitrobenzylborn ylnnline ......... Orthoiii trobenzylidcneborliylnniinc. l'arsnitrobciizylidencbo~nylnmine . [ aID in bcnzciie. Difference. [ a ] D in nlcohol. Difference. -- 13'1" - 52 '6 - 15.1 According t o these data, a noticeable diminution in rotatory powei attends the transition from a benzyl derivative of this.series t o the corresponding benzylidene compound, and it seems highly probable that an ethylenic linking in the neighbourhood of an asymmetric carbonOPTICAL ACTIVITY OF DERIVATIVES OF BORNYLAMINE. 1151 atom is capable of exerting a perceptible influence on the optical activity t o which the asymmetry of that carbon atom gives rise (compare Haller and Muller, Coitjpt. rend., 1899, 128, 1370). It is also noteworthy that the difference in rotatory power between paranitrobenzylbornylarnine and paranitrobenzylidenebornylamine approaches closely to the corresponding difference bet ween benzyl- bornylamine and benzylidenebornylarine, but is quite unlike that between the ortho-derivatives.This is a fresh instance of closer re- semblance to the parent compound on the part of a para- than of an ortho-derivative (compare this vol., p. 930), and another case is furnished by the nitrobenzylidenebornylamines, of which the para- compound has a molecular rotation almost identical with that of benzylidenebornylarine, but differing most widely from the molecular rotation of the ortho-derivative. There is one point of chemical interest in connection with benzyl- idenebornylamine of which brief mention has been already made (Zoc. cit.). When this base is heated with methylic iodide in a sealed tube, a crystalline additive compound is produced, which, under the influence of water, is resolved into beuzaldehy do and methylbornylamine hydriodide according to the equation C'I,H,~~N(CH3)I~OH~C~H,+H,O=C1,H5*CHO+Cl,Hl~~NH*CH3,I~I. *The usual dificulty of preparing in quantity the monomethyl de- rivative of a primary base has been overcoiiie by this means in the case of bornylamine, but the reaction does not seem to be general, and is probably confined to saturated bases.Benzylidene-P-naphthylamine, for instance, when heated with methylic iodide at 130° and then extracted with ethylic .acetate, yields trimethylnaphthylammonium iodide ; benzylidenephenylhydrazone gives rise to dimethylaniline and a malachite-green. The behaviour of benzylidenebornylamine towards methylic iodide is very similar to that of benzylideneaniline towards acetic chloride, the additive compound froin which yields acetanilide, benzaldehyde, and hydrochloric acid on hydrolysis ; the description of this change (Garzarolli-Thurnlackh, Ber., 1893,32, 2277) appeared simultaneously with the brief notice of benzylidenebornylamine methiodide (this Ex P ERINENT AL.VOI., p. 936). The compound obtained by the union of boriiylamine with benz- aldehyde was described by Griepenkerl as a colourless oil (AnnuZen, 1S93, 269, 353). It has been shown, however, that the method at that time employed for preparing bornylamine gives rise to a mixture 4 ~ 21152 FORSTER : INFLUENCE OF AN UNSATURATED LINKING ON THE of two isomerides (Forster, Trans., 1898, 73, 386); i f thew are separated from one another before treatment with benzaldehyde, the benzylidene derivative of the dextrorotatory base is found to be cryst 11 line.25 grams of bornylsmine were treated with 17 grams of benz- aldehyde, which dissolved the base aid became warm, yielding ,z turbid, oily liquid ; this was heated on the water-bath during some minutes, and aftermnrds cooled with ice, when it rapidly solidified t o a hard, crystalline cake. The product was then fnsed beneath a sinall quantity of hot alcohol, and rapidly cooled, the colourless crjstnls thus obtained being collected with the aid of a piimp and finally recrystallised from alcohol, which deposits bellzylidenebornylamine iu rosettes of long, lustrous needles. It melts a t 58-59'. 0.1709 gave 0.5279 CO, and 0.1509 H,O. 0.303s ,, 16.2 C.C. moist nitrogen a t 17" and $71 mm. N = 6.28. C: = 84.34 ; H = 9.81. C17H2,N requires C = 84.64 ; H = 9.54 ; N = 5.S1 per cent.A solution containing 0.5013 gram in 25 C.C. of benzene at 30' gave a, + 1' 6' in a 2-clcm. tube, whence the specific rotatory power [ aID + 27.4'; 05127 gram dissolved in 25 C.C. of absolute alcohol at 19O, gave a, + 2' 34', corresponding to [a],, + 68.6'. Benzylidenebornylamine does not combine with hydrogon cyanide. It forms a clear solution in cold, concentmted liydrochloric acid, and is precipitated from the liquid by alkalis, but if the acid solution is boiled during a few minutes, benzaldehyde is regeneratecl, and then alkalis precipitate bornylamine. The platinochlo~itle separates almost immediately when platinic chloride, dissolved in alcohol, is added to an alcoholic solution of the base ; i t forms lustrous, transparent, six-sided plates, and decomposes at 245'.0.2029 gave 0.0446 Pt. Pt = 31.SS. (C17H2,N),,H,PtCl, requires Pt = 2 1 *SO per cent. The nLethiocZicle was prepared by heating 4.3 grams of benzylidene- bornylamine with 15 grams of methylic .iodide in a sealed tube at 120-150' during 2 hours. The contents of the tube remain liquid at 30°, below which temperature crystals slowly separate ; the product is t4reated with ether, filtered, and washed with ether, 5.7 grams of the salt being obtained in this way. The methiodide crystallises in pale yellow plates, and melts a t about 2 1 5 O , forming a, deep red liquid which evolves gas. 0.1698 gave 0.1049 AgT. I= 33.36. C,7H,3X,CH31 requires I = 33.16 per cent.OPTICAL ACTIVITY OF DERIVATIVE8 OF BORNYLAMINE. 1152 The methiodide frequently melts indefinitely, and contains proportions of iodine which differ considerably from those required by theory; a specimen decomposing at about 200' contained 30.5 per cent.of iodine, the proportion of which mas increased by recrystallisation from methylic iodide. If the methiodide is rccrystallised from solvents containing water, dissociation occurs, and meth ylbornylsmine hydriodide is produced. For instance, a solution containing 0.2527 gram in 25 C.C. of alcohol gave the specific rotatory power [.IU + 21.8" ; in the case of complete dissociation, [.IL, + 32.3". I n order to prepare metl~yl~ornylamine from benzylidenebornyl- nmine, the methiodide is heated with 5 parts by weight of ethylic acetate in a reflus apparatus during half an hour ; the solvent is for the greater part removed by distillation, and the crystalline residue, when filtered from the solution of benzaldehyde in ethylic acetate, is recrystallised from water.~letliylboimylsmine hydriodide obtained in this manner melts a t %lo, itnd has [ a ] , + 26.6' in a 1 per cent. solution in absolute alcohol. Action of I~?~ei~~Z~~llclraxilze o n ne?z~~Zide?zebos.)z~~(~~}~~ne.-Benzy lidene- bornylamine was mixed with 1 mol. of phenylhydrazine, forming a stiff pqste which rapidly became hard; when heated on the water- bath, the mixture did not melt, as would have been the case if no combination had occurred, bat became red, and smelled of bornyi- amine. After digesting with cold, dilute hydrochloric acid, the undissolved portion was collected and identified with benzylidene- phenylhydrazine, whilst the filtrate, rendered alkaline with caustic soda, yielded bornylamine.When eqna 1 quantities of born y lamine and or t honi t ro benzaldeh y de are intimately mixed, a viscous, turbid oil is produced, which rapidly becomes crystalline. Orthonitrobenzylidenebomylamine separates from dcohol in lustrous, colourless plates and melts at 71"; it becomes bright yellow, and finally dark brown, on exposure to light. 0*1891 gave 0.4946 CO, and 0.1274 H,O. C17H,,0,N, requires C = 71 *32 ; I3 = 7.68 per cent. A solution containing 0*6010 gram in 25 C.C. of benzene at 2 3 O gave aD + l o 40' in a 2-dcm. tube, whence [u],, +41*63; 0*5080 gram dissolved in 25 C.C. of absolute alcohol a t 33" gave aD +21' in a 3-dcm. tube, corresponding to [.ID + 8.6'. C= 71-33 ; H= 7-49,1154 OPTICAL ACTIVITY OF DERIVATIVBS OP kORRYLAMIl?$ Pccl.anitl.obenxyZidenebornylamine, C,,Hli *N: CH C,H;NO,.Six grams of bornylamine were mixed with the same weight of paranitrobeazaldehyde, and heated at 80" until a homogeneous product was obtained ; when cold, the turbid, viscous liqiiid rapidly solidified on being stirred with a glass rod. Pnranitrobenzylidenebornylamine separates from light petroleum in large, yellow, transparent crystals ; it melts at 75'. 0.1244 gave 0.3247 CO, and 0.0876 H,O. C = 71.18 ; H = 7.S2. 0.2266 ,, 20.5 C.C. moist nitrogen at 35" and 769 mm. N = 10.21. C17€Iz20zN2 requires C = 71-32 ; H = 7.68 ; N = 9.79 per cent. A solution containing 0.4069 gram in 25 C.C. of benzene at 15" gave aD +45' in a 2-dcm.tube, whence [ u ] ~ +23.0°; 0.4487 gram, dissolved in 25 C.C. of absolute alcohol a t 3So, gave a, + 1" 51' in a 2-cicm. tube, corresponding to [ + 51.5'. Or tholq clroxg be nxg Zidene bos.?&ntine, Cloll 17 N : C H C,H, OH. When bornylamine (4 parts) is dissolved in salicylaldehyde (3 parts), considerable rise of temperature takes place, and a turbid, bright yellow oil is produced, which solidifies after several days. Ortho- hydroxybenzylidenebornylamine crystallises from light petroleum in bright yellow, transparent prisms and melts at 63"; it dissolves very readily in alcohol, light petroleum, and ethylic acetate. 0.2369 gave 0.6894 CO, and 0.1913 H,O, A solution containing 0.4577 gram in 25 C.C. of absolute rtlcohol at C=70*36 ; H=8-97. CI7H,,ON requires C = 79.37 ; H = 8.95 per cent. 23", gave uD + 4" 23' in a 2-dcm. tube, whence [.ID + 112.3'. P ~ ~ c ~ ~ ~ ? / d r o x y b e n ~ y Z ~ ~ ~ n e b o r ~ ~ ~ Z c 6 ? ~ t ~ ? ~ e , Clo~Il,*N : CH @ C,H, * 011. Bornylamine mas intimately mixed with parnhydroxybenzaldehyde in molecular proportion, the stiff paste thus produced being heated on the water-bath until it solidified. The pnrahydroxy-compound, which is colourless, crystallises from ethylic acetate in lustrous, square, transparent plates, and melts at 162"; it dissolves in hot benzene, but is very sparingly soluble in the cold medium. 0.1510 gave 0.4376 CO, and 0.1222 H,O. C = 79.04 ; H = 8-99. C17H2,N0 requires C = 79.37 j H= 8-96 per cent,INTERACTION OF SODIUM HYDROXIDE AND BENZALDEHYDE. 1155 A solution containing 0.5054 gram in 35 C.C. of absolute alcohol at The snisylideiie and cuiuinylidene derivatives are oils, and were not 15" gave uD + 4' 30' in a 3-dcm. tube, whence [u],, + 107*1'. further investigated.

ISSN:0368-1645    

DOI:10.1039/CT8997501149

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

INTERACTION OF SODIUM HYDROXIDE AND BENZALDEHYDE. 1155 THE reaction be tween benzaldehyde and cnus tic alkdis, as employed for tlie preynrtition of benzylic alcohol, is represen ted by tlie well known eqmtt ion : ~ C ~ I ~ ~ * C H O + N a O I ~ = C ~ ~ € ~ * C H ~ ~ ~ ~ +C,IC,*COONa. Caustic potash is generally employed in the preparation in preference t o c:tiistic soda, according to the inethod detailed by E. Ileyer (Ber,, 1851, 14, 339-1). In the course of soiiie experiments on condensation products of benzaldehyde in pmsence of siunll quantities of alkali, i t wits observed t h a t a n immecliate flocculeiit xiicl bulky precipitate is produced on tile addition of .z concentrated caustic soch solution t o benzttlcleliycle. 'J'he sudden nature of the change, which is accoiiipaiiied by a distinct rise in ternperat&e, indicated the p o d b i l i t y of an intermediate stage in the reaction, and a series of eq)erinients were accordingly carried out with the view of isolatiug, or otherwise provi~ig the presence of :in intermediate compound.The results Ixtve not led to tlie isolation of such a compound, but we have obtained satisfactory indirect evidence of the formation of a n intermecliate ortho-derivative, analogous to t h a t described by Claisen (Be?*., lSS7, 20, 646) as tlie product of the action of sodium methoside on benzaldeliycle. When sodium methoside reacts with benzaldehyde, a white, bulky solid is formed which, when decomposed by water, yields sodium benzoate and benzylic alcoliol, just as benznldehyde does with caustic alkali.If, however, the solid product is first treated with glacial acetic acid and then with water, benzylic benzoate, benzylic alcohol, and methylic benzoate, with only a trace of benzoic acid, are obtained. This1156 KOHN AND TRANTOM: THE INTERACTION 05' result is attributed by Claisen to the formation and decomposition of an intermediate ortho-compound, /ON% \O* CH,* CGH, CGH,* C-0. CH, Such cz compound would be immediately decomposed by water into sodium benzoate, benzylic alcohol, 'and inethylic alcohol, whilst of itself it can brexk down either into beuzylic benzoate and sodium methoxids, or into sodium benxyhte tinil methylic benzoat,e. It is on the formation of an analogous benxylic compound tliilt Cllnisen has based his excellent mekhod for the preparation of benzylic beiizoate (Zoc.cit., p. G-19). The results of the following experiments prove that, in the absence of water, or in the presence of an excess of benzaldehyde, benzylic benzoate is EL product of the action of sodium hydroside on beimildehyde. Its formation may be due t o the action of benzylic alcohol on sodium benzoate in presence of the glacid acetic acid used for decomposing the first product of the reaction, o r to benzylic benzo:ite itaself being the initial producl of the reaction, or finally to the decomposition of an intermediate ortho-compound. To test the first possibility, sodium benzoate and benzylic nlcohol weve heated together in g1aci:tl acetic acid solution for 4 hours, hut the whole of the original products mere recovered without the formation of any benzylic benzoate.When benzylic benzoate itself is treated w i t h caustic soda under the condi- tions employed in the action of the alkali on benzaldehyde with subse- quent decomposition by water, tlie hydrolysis of the ester is incom- plete, whilst benzaldehyde is coinpletely converted into the alcohol and acid by the theoretical quantity of cnustic so& a t the orclinary temperature. Further, if the estcr be the original product, it should be present, irrespective of wliether the presence of an escess of aldehyde or the absence of water is a condition of the reaction, and this is not the case. The formation OF an intermediate ortho-com- pound is the remaining possibility to explain the production of the ester, and the experimental evidence is ~vholly in favour of this view.From this standpoint, the action of cnustic soda on Lenzaldehyde takes the following form : In presence. of water, decomposition into benzylic alcohol and sodium benzoate, the ordinary products of the reaction, will occur : H C,H,*COOPu'a + C,H,*CH,OH + o - + H,O. C,jH,* C-ONn /OH \O*CI-I,* C,H, HSODIUM HYDROXIDE AND BENZALDEHYDE. 1157 I n the absence of water, two decompositions a r e possible : ONa / -...~. I, C,H,*C;iOjLI = O,,H,* COONa + C,H,* C€€,OH, CH, C,;H, . . . . . . . . , /iO EL- Ir, c,~,. c.-o:N~ = c,H~* COO+CH,*U,~I~, + N~OH. \\ ... . O*CH,* Cf,I$', The first decomposition takes place far more readily thnn the second; it is favoured by ail excess of alkali, wliilst an escess of aldehyde favours the latter : facts which corroborate this view of t h e reaction." The experimental results shorn that Nef's suppositions (AwnnZen, 1597, 298, 301) in regard t o the course of the reaction between benz- aldehyde and c:~ustic alkalis are iiniiecessary, and they bring t h e change into line with the analogous reactions studied by Chisen.There are two ways in which the aldehyde gronps of 2 molecules OF benzaldehyde can give rise t o the formation of condensatiou products. One of these is t h e well known benzoin condensabion, the other should lead to tlie formation of benzylic benzoate, thus : Eoi y l i c I/cth:oc& condc:iioccficn. The latter change, however, as shown in the following esperiments, takes place only as the result of the formation of a n intermediate compound, and it is probable that the production of an additive com- pound also precedes the benzoin condensation. This point is under investigation, especially with respect t o the use of dry materials i n the reaction.* In a reccnt paper by Hallcr 011 compoiinds of cainplior with alcichycles (Con@. m i d . , 1S99, 128, l2i0), the forniation of piperonylic piperonnte by the action of piperonaldehyde on sodium camphor is attribnted to the l~rcsence of sodiiiin borneol in the niixtnre ; since, however, caustic soda is liberated in the forination of the condensation product, piperonylidcnccniii~~lior, which is the chief product of the remtioii, i t appears extremely probable that tlie formatioii of piperonylic piperonate, which is accoinpanid by some piperonylic nlcoliol, is redly clrie to the action of the liberated alkali on tlie piperonaldehyde.If so, the formation of the ester is an interesting coiifirinntioii of the above vie\\ of the i l l teractioii of aldehydes and caustic alkali. In a lirevious paper (Cutript. rc)2(2., 1S91, 113, 22) on the sanie subject, caniphylic salts of the acids corresl~onding with the aldchycles employed are described as secondary products of the reaction and their formation is accounted for on the lines of the reitctions studied by Claisen.1158 KOaN ANb TRANTOM: THE INTERACTION OF There is one other possible course for the reaction between benz- aldehyde and caustic soda, namely, that the two molecules of aldehyde condense directly to an unsaturated glycol : ‘(iHb* $*OH This repre- C,I-I,* C*OH’ sents a tautomeric form of benzoin, the dibenzoyl and dincetyl deriva- tives of which are known, but no indication of the foriiiation of such a compound or of its derivatives wns obtained. It could yield benzoic acid and benzylic alcohol very simply, thus :- C,H,*C*OI-I + ff2 = C,H j* CI€,Ol-I C0HG C 0 H 0 C,H,* CO*OII but the formation of benzylic benzoate from it would not depend on the absence of water, or the presence of an excess of aldehyde.EX P E 11 111 EN TATA. A c t i o n of Ccczcstic Soda O?L L’e?azxakleAp2e i ~ b Prescizce of TVuter. 9 number of esperiments were first tried in wliicli an aqueous solutiou of sodium hydroxide was added to benznldehyde in the pro- portion of one molecule of the former to two of the htter. The precipitate that is formed immediately, iiicrettses in bulk rapidly on standing, and the reactioii may he completed eitliev by heating the mixture on the water-bath for 3 hours, or by allowing it to stand, with repeated shaking, for a day.To 53 grams of benzaldehyde, 10 grams of caustic soda dissolved in 15 grams of water were added. The fiual product consisted of a hard cake, which was dissolved in 75 C.C. of ~varm glacial acetic acid, and the solution diluted with mnter, made alkaline, and extracted with ether ; the oil oltained by evapor ation of the ethereal solution was then fractionated. The alkaline solution mas acidified and the precipitated benzoic acid collected, Under these conditions, beiizylic alcohol and sodium benzoate proved to be the sole products; it is a matter of indifference, therefore, whether water or glacial acetic acid is used in the decomposition of the final product of the reaction.The yield of benzylic alcohol under these conditions is extremely good, 90 per cent. of the theoretical yield being obtained, and by in- creasing the proportion of sodiuiu hydroxide to 30 grains, ti theoretical yield (0s per cent.) resulted. This is consequently n better, as well as EL cheaper, methsd for the preparation of benzylic alcohol thnn that usually employed. Action of Solid Ccczcst ic S‘ocla OIL Bema Idel@. 10 grams of caustic soda were ground to a fine powder undei benzene, washed into a flask with benzene, and a solution of 53 gramsYODIUhl HYDROXIDE AND BENZALDEHYDE. 1159 of benzaldehyde in 100 C.C. of benzene added.During the addition, the mixture was well shaken; after a short time, the whole set to a hard mass. This was heated in a reflux apparatus on the water-bath for 2 hours, the mass being broken up and shaken several times during the heating. Tho solid residue was ground up in one case with ether, and in another with benzene, the extracts filtered, and the residues fractionated after distilling off the solvent, but iu both cases only benzylic alcohol together with some unchanged benzaldehyde was left, the yield of the former amounting to 76 per cent. of the theoretical. , In these experiments, no special care had been taken to render the materials anhydrous, lout the necessity of this condition became ob- vious when the structure of a possible intermediate product was taken into account.As shown on p. 1157, a inolecu1:tr proportion of water ie regenerated in the action ; this, therefore, will suttice to effect the complete breaking down of the compound into benzylic alcohol and sodium benzoate. I n the subsequent experitnents, the caustic soda was first ground up under benzene to prevent undue absorption of moisture during the grinding, the greater part of the benzene drained off, and the rest removed by drying in an cxsiccatoi*. The final drying was effected in a vacuum over phosphoric oxide repeatedly renewed. Only small quantities of caustic soda, spread over a large surface, were dried at a time. The benzene employed as solvent was distilled over sulphuric acid and phosphoric oxide successively. Two ex- periments were made with materials thus prepared.In both cases, the mixture became solid very soon, athough in one (No. 11) the aldehyde was added very gradually, and the temperature kept down by means of ice previous t o the heating on the water-bath. The product of the reaction mas first dissolved in glacial acetic acid, the solution diluted with water, and then extracted with ether aftor the addition of alkali. The following are the details of these two ex- periments, 200 C.C. of benzene being used in each : 11 *5 10.01160 KOHN AND ~ R A N ~ O M : THE INTERACTION oli’ The presence of unchanged benzaldehyde in both cases is due to the difficulty of effecting a complete reaction in the solid mass, although it was broken up and thoroughly mixed several times during each experiment, Claisen obtained from 10 to 40 grams of benzylic benzoate from 106 grams of benzaldehyde by the action of sodium methoxide.It therefore appears that tlie methylic ether of the ortho-compound breaks up somewhat less readily than the simpler derivative into the alcohol and acid (methylic ester), The benzylic ether is still more stable in this respect. The benzylic benzoate boiled at 280-320°, and was therefore accompanied by some benzylic alcohol. &ref idly fractionated, it yielded a product boiling at 310-330°, which gave the following results on analysis : 0.2089 gave 0.6074 CO, and 0.1 132 H,O. Pure benzylic benzoate was found to boil at 316*S”, as determined by an Anschiitz thermometer with its stein immersed in the vapour (Claisen gives 323-324O).That the product was benzylic benzoate was confirmed by hydrolysis with alcoholic potash, when benzylic alcohol and potassium benzoate were obtained. c! = 7930 ; H = 6.09. C,,H,,O, requires C = 79.35 ; H = 5.66 per cent. Action OJ Caustic ) b d a on an Excess of Benxdclelyde. 111 the above experiments, the theoretical quantity of caustic soda required by the equation was emploFed. I n order to obtain a condition more favourable to the decomposition of the ortho-compound into benzylic benzoate and caustic soda, an excess of benznldehyde was used with which the liberated alkali might react until tlie decomposi- tion mas complete, The results and conditions of this series of ex- periments are tabulated below. The formation of benzylic benzoate when an aqueous solation of caustic soda was used, is ;I most satis- factory proof of the formation of the intermediate ortho-compound.With dry solid caustic soda, it mas found estremely difficult to complete the reaction, since the mass cakes together mid the excess of aldehyde thus largely escapes further action. This is doubtless the reason mhy the extent of the decomposition as well as the quantity of ester found as the product of tho decomposition is not greater. The alkali was not always added at once, being sometimes introduced in portions at intervals of several hours. I n all cases, the mixtures were heated on the water-bath for t,he times stated, and the products of decomposition worked up as described above.SODIUM HYDROXIDE AND BENZALDEHYDE. experirnent,s I 6 22 20 31 27 and 11, the total decomposition cori esponds approximately to the maximum for the quantity of caustic soda employed, but in experiments 111, .CV, and V? carried out with dry materials and solid caustic soda, only from 30-50 per cent.of the total decomposition lins been effected. Action of Caustic Soda O I L 13e1~x~lic Bemoate. If the supposition is correct that an intermediate ortho-compound is formed in the action of caustic Bocla 011 Lenzddehyde, the same pro- duct should result when benzylic benzoate is treated with caustic soda. 26 grams of benzylic benzoate, dissolved in 100 C.C. of benzene, were treated with 5 grains of dry solid caustic sod:L. No appreciable action took place until the injxture was heated on the wltter-bath, when, after 6 hours, the whole became nearly solid. The product was dissolved i n water and examined, with the result that altogether 20 grams of sodium beiizoute and benzylic alcohol mere isol:tted, 10 grams of the ester remaining unchanged, thus proving that benzylic benzoate is not the initial product of the action of caustic socla on benzaldehyde.Action of lSoclizcni Benz&zitle on Be~izctkdekyle. 4.6 grams of sodium were dissolved in 21.6 grams of benzylic alcohol in 125 C.C. of benzene, and 43.8 grams of benzaldehyde were added graclually. After shaking, the mixture was heated on the water-bat11 for 16 hours, the solid residue dissolved in water, estracted with ether, and the residue froin tho ethereal solution fractionated. benzoic acid was separated from the alkaline solution by the addition of hydrochloric acid. The following products were obtained : Unchanged aldehyde ............... nil. Benzylic alcohol ................... 18 grams. Benzoic acid ........................ 8.5 ,, Beiizylic benzoate .................. 29 ,,1162 BLYTH : TXE ULTRA-VIOLET ABSORPTION SPECTRUM OF I n this case, therefore, despite the direct addition of water, decompo- sition into the ester proceeds to the extent of 54 per cent., and that int.0 benzylic alcohol and benzoic acid only to the extent of 46 per cent. of the theoretical ; the forination of these products, however, is a satisfactory confirmation of the correctness of Claisen's view. Also the relative staldity of the met,hyl and benzyl ethers of the ortho-compound, as regards their decomposition into esters, is quite in accord with the influence of these siibstituting groups. The decomposition of this benzyl ether by water into benzylic alcohol stid sodium benzoate is represented by the equation : The foregoing results lead naturally to the study of the influence of water in several reactions involving the use of alkalis, such as the two decompositioiis of ethylic aoetoacetate and allied changes ; also t o the complex action of alkalis upon aliphatic aldehydes. These sub- jects, as also the action of alkalis on other aromatic aldehydes, are now under investigation, LIVERPOOL. UNIVEMITP COIITJEOR,

ISSN:0368-1645    

DOI:10.1039/CT8997501155

出版商:RSC    

年代:1899

数据来源: RSC

摘要:

1162 BLYTH : TXE ULTRA-VIOLET ABSORPTION SPECTRUM OF CXX.-Thc Ultrcc-violct rlbsoiptiou SpectrwL of Protez'ds in Relcction to Tyrosiiie, By A. JvYNTEIl BLYTH. T m apparatus employed in the investigation of the ultra-violet absorption spectrum of proteids consists of a large quartz prism made of two halves of right and left hand rotation respectively. A double quartz slit is used, as it possesses the advantage that two spectra are taken one above the other, one with a wide, the other with a narrow slit, so that when it is necessary to use a slit wide enough to blur the lines, the narrower slit will give the metallic lines sharply defined, and thus enable the position of any absorption bands to be measured. The source of light is a powerful spark produced by a large coil charged either from storage batteries or from the main, the coil is provided with a Wehnelt's brea.k, and one Leyden jar is used as a condenser.The optical train is quartz, and the image is thrown by a lens of 12 inches focal length on to a photographic film placed at aPROTEIDS IN RELATION TO TYROSINE. 1163 proper angle. The tube bearing the slit is passed through a hole in the door of a dark room in which the instrument is placed. The poles used have been various : cadmium, cadmium and nickel, nickel and iron, nickel and copper. To obtain an interpolation curve, poles made of an alloy of mercury, zinc, mdmium, and tin were em- ployed, n photograph being taken of the metal under examination with tho centre of the slit blotted out by a screen; on the same film, the spectrum of the alloy was nest taken, using a second screen so nrrnnged that the spectrum would occupy the blank space left by the first.Since all the wave-lengths of cadmium, mercury, zinc, and tin in the ultra-violet are well known, the spectrum of the alloy with its very numerous lines acted as a nntural scale. The liquids under examination have been ex- amined in ordinary cells closed 1)y quartz plates, but as the cleansing of these cells was found to be troublesome and tedious, the author devised a special absoiaption cell which promises to furnish important aid in researches of this kind. The cell consists of a block of quartz (a) cut into suc- cessive steps, the faces of the steps and the back are perfectly parallel and highly polished, the cell is completed by a quartz plate in front (b), the sides being of ground glass, a metal frame pro- vided with screws acting on small plates of instal, ,securely presses the plates of glass and quartz together, the top is closed with a glass plate, b J which is kept in place by a screw.The steps in the preseut cell are cut so as to give successive thicknesses of 1, 2, 4, 8, and 16 mm. The cell is supported on a stand capable of moving by rack-work. The photographic slide is similarly moved by rack-work. Five photographs on the same film can thus be taken in less than 5 minutes. If other thicknesses are required, they can be obtained in the ordinary way. According to Soret, diluted eggalbumin gives a single absorption band of wave-lengths 2880-2650. Hartley (Trans., 1887, 51, 69) confirms this statement, giving the band in wave-lengths as 2948-2572.The author has investigated the absorption spectrum of egg-albumin, ~erum-albumin, animal casein, and vegetable casein, as well as. of Witte's peptone, and also finds a single band. * The cell was constructed by Mr. Hilger, of Stanhope Street.1164 BLYTH : THE ULTRA-VIOLET ABSORPTION SPECTRUM OF 3439-3766 3509-3784 3509 -3766 3509-3766 The egg-albumin, purified by frequent precipitation, was diluted and filtered through several hardened filter papers, and ultimately an almost limpid solution obtained. A fractional part of the solution was evaporated on a platinum dish until i t ceased to lose weight, and the residue ignited and weighed; the solution was then diluted until it attained the strength desired. A similar process was adopted with both vegetable casein, legurnin, and sernm-albumin.It mas found that the absorption bands of these substances differed quantitatively rather than essentially in character. The following are the measurements obtained with solutions of egg-albumin and Witte's peptone, it being understood that, although mave-lengths in four 29SO- 2655 28 50-26 13 2850-2655 2850-2655 0 figures are given, the wave-length is taken from a definite metallic line bordering the absorption band ; in point of fact, the bands are never so definite, being diffuse a t the edges, Solution of egg-albumin in wcctei. (1 C.C. = 1.52 nzilligrccm of nlbzcmin). Oscillation Absorption Spcc trulll lmud. ellds. I in mm. 20 15 10 5 2415 2405 2385 2360PROTEIDS IN RELATION TO TYROSINE.1165 Solution of Witte's peptone in water (1 C.C. = 3.14 nzilligrccrns of p@one). Thickness of film i n mm. 20 35 10 5 ~ ~~ Oscillation fr equc n cie s . l / A . ~~ Absorption band. A. 3478-3783 3478-3538 3478-3538 34n-353a 2875-2643 2875-2826 2875-2826 2875-2826 ~~ Spectrum ends. A. 2260 2260 2258 2256 There are, however, quantitative differences between the different absorption spectra. Solutions containing equal amounts of nitrogen give absorption spectra of unequal length, Witte's peptone extending farthest into the ultra-violet, then come, in succession, legumin, egg- albumin, serum-albumin, and an alkaline solution of casein. Each of these substances may be made to yield tyrosine by appro- priate treatment.Solution of tplrosine ivt water (1 C.C. = 0.256 9?ziUiqmm of tyrosine). Thickness of film in n i m 16 8 4 2 1 Oscillation frequencies. 1/A. 3471-3na 3551-3731 Absorption band. A. Spectrnm ends. A. 2405 2360 2305 2272 2272 Solution of tyrosine in watw (I c,c. = 0.126 nailligrana of tglrosine). Thickness of film in nim. 16 10 8 5 4 2 1 Oscillation frequencies. 1 /A. Absorption band. A. 3470-3784 3509-3571 3558-3676 3558-3676 2882-2643 2850-2680 2810-2720 2810-2750 Faint baud Spectrum ends. A. 2377 2345 2335 2335 2315 2315 2305 The chief features of these absorption bands are indicated in the VOL LXXV. 4 1 curves on p. 1164.1166 THE ULTRA-VIOLET ABSORPTION SPECTRUM OF PROTEIDS. It is thus seen that the absorption spectrum of tyrosine is practically identical with that of the proteids enumerated.The author has little doubt that the single absorption band given by the various vegetable and animal albumins is due to the fact that tyrosine enters into their structure. Albumoses and Gelatin. Schrotter (Monatsh., 1893, 14, 612) has described an albumose possessing very definite properties, Briefly, it is prepared by acting on an acidified solution of Witte’s peptone with zinc dust, filtering, evaporating to dryness in a vacuum at the ordinary temperature, taking up with methylic alcohol, in which it is soluble, and reprecipi- tating with ether. The albumose may be obtained pure by precipi- tating several times. It contains C = 51.0, N = 16.8, H = 6.4, S = 1.1 per cent., and gives all the ordinary reactions of an albumin. This substance was dissolved in water, diluted, and a series of absorp- tion spectra taken from extinction of most of the ultra-violet to almost perfect transparency, but no selective absorption could be discovered. A pathogenic toxalbumin from diphtheria, submitted to the author by Prof. Sidney Martin, gave the usual absorption band of albumin. A toxalbumin from a case of ulcerative endocarditis, also strongly poisonous, and submitted by Prof. Martin, gave a continuous spectrum. Gelatin from various sources also failed to show selective absorption. It therefore seems to the author that proteids might be divided conveniently, from a chemical standpoint, into those which show the tyrosine absorption band and those in which the band is absent-a division which is correlated with a profound difference in molecular composition.

ISSN:0368-1645    

DOI:10.1039/CT8997501162

出版商:RSC    

年代:1899

数据来源: RSC