摘要:

2156 FORSTER AND ZJMMERLI !CCXXV.-Studies in the Camphane Se.ries. PartStereoisomeric Hydrazones and Semi- X X VIII.cai-baxones of Carnphorquinone.By MARTIN ONSLOW FORSTER and ADOLF ZIMMERLI.THE expectation of stereoisomerism among semicarbazones is anatural corollary of the Hantzsch-Werner hypothesis, Up to thepresent time, however, it does not appear that any systematicattempt has been made to place the question of semicarbazone-isomerism on the basis occupied by that of the oximes, Apart fromthe distrust with which the hypothesis in question is stiIl viewed insome quarters, the principal reason for this omission to bring thesemicarbazones into Iine with oximes is the scattered and ill-definednature of the evidence relating to the occurrence of isomerism inthe former class.The cases of isothujone, carvenone, and tetra-hydrocarvone appear to have been established by Wallach (Ber.,1895, 28, 1955), but the isomeric semicarbazones of citral and ofionone owe their formation to the existence of each ketonein two isomeric forms. Wallach has also shown that syn-thetical pulegone, obtained by condensation of methylhexanonewith acetone, yields two semicarbazonea (Ber., 1896, 29, 2955 ;also AnnaEen, 1898, 300, 269), from both of which the ketone isregenerated by acid, but a claim for the production of isomeridesfrom phenyl-l-methyl-A6-cycZohexen-5-one (Knoevenagel and GoldSTUDlES IN THE CAMPHANE SERIES. PART XXVIII. 2151smith, Ber., 1898, 31, 2465) is not based on strong evidence.Benzoylmethylthiodiazole, on the other hand, gives rise t o twoderivatives (Wolff, Annulert, 1902, 325, 173), but the supposedexistence of two benzilnionosemicarbazones (Posner, Ber., 1901, 34,3979) was shown to be fallacious by Biltz and Arnd (Ber., 1902,35, 344; compare also Biltz, Annulen, 1905, 339, 243), the secondsubstance being 5 : 6-diphenyl-3-oxy-1 : 2 : 4-triazineY prepared byThiele and Stange (Annalen, 1894, 283, 27).Nef has recordedthe production of two semicarbazones from propaldehyde (Annulen,1904, 335, 202), whilst Knoevenagel and Same1 (Ber., 1906, 39,681), and later Rupe and Dorschky ( B e y . , 1906, 39, 2112),found that when semicarbazide acts on carvone in the cold, theproduct is distinct from that described by von Baeyer, into which,however, it is convertible at raised temperatures.I n reviewing the foregoing evidence relating to the existence ofisomeric semicarbazones, we have not encountered any systematicattempt to explain the phenomenon, but the experiments describedin this paper lead us to express the opinion that stereoisomerism ofthe type displayed by oximes must now be regarded as existing inthis class also.Our attention was drawn to the subject by an observation madein connexion with camphorquinonesemicarbazone (Lapworth andChapman, Trans., 1901, 79, 381), and our thanks are due toDr.Lapworth for his consent t o our using this material. I npreparing it by the slightly modified process of Diels and vom Dorp(Ber., 1903, 36, 3190), we noticed that the mother liquor containeda more soluble isomeride melting a t a lower temperature thanthe modification already described, and calling the latter thea-derivative, we refer to the new compound as the 8-semicarbazone.When this is heated above its melting point, it is converted intothe a-semicarbazone, and the latter, under the influence of hotaniline, undergoes the change described by Borsche ( B e y ., 1901,34, 4297 ; 1904, 37, 3177), giving rise to camphorquinonephenyl-carbamylhydrazone, with liberation of ammonia :The product, however, is an equilibrium mixture of two isomerides,related to one another in a manner similar t o the connexionbetween the semicarbazones. Both camphorquinonephenylcarbamyl-hydrazones are produced, also, when the B-semicarbltzone is heate2158 FORSTER AND ZIMMERLI :with aniline, and by the condensation of camphorquinone withphenylcarbamylhydrazide :and they may be obtained separately by the action of phenyl-carbimide on two new hydrazones of camphorquinone.The action of hydrazine on camphorquinone is stated by Odd0(Gazzetta, 1897, 27, ii, 117) to yield " biscamphanonazine," identicalwith Angeli's azocamphanone (Gazzetta, 1894, 24, ii, 44), producedin association with camphenone by heating diazocamphor.Asrepresented by Angeli, the formation of azocamphanone :CsH,,<?:N":(?>C H co oc 14'obviousIy depends on the condensation of hydrazine with twomolecules of the diketone, but we find that if the substances interactin molecular proportion, two new derivatives of ca.mphorquinone areproduced; these, being isomeric, are referred to as the a- andP-hydrazones, and it is by the action of phenylcarbirnide on thesetwo substances that the above-mentioned a- and P-phenylcarbamyl-hydrazones are respectively obtainable :Thus, the isomeric hydrazones (m.p. 206O and 1 0 2 O ) are con-nected through the isomeric phenylcarbamylhydrazones (m. p. 21 loand 161O) with the isomeric semicarbazones (m. p. 2 3 6 O and 147O)respectively, and the members of each pair bear to one another thesame relation in respect of solubility, fusibility, and inter-convertibility by heat, A further connexion between the hydrazonesand semicarbazones is established by the fact that whilst aceticanhydride converts the hydrazones into acetyl derivatives (m.p.239O and 150°), of which the 8-compound is transformed into thea-modification by heat, an equilibrium mixture of these isomericace.tyl derivatives follows the action of hot acetic anhydride onthe isomeric semicarbazones :+ CH,*CO*NH, + CO,. C:N*NH-CO*CH, cs %<b*These reactions are summarised in the diagram on p. 2159.It now becomes necessary to explain our grounds for ascribingthe present case of isomerism to stereochemical rather than strucHea2160 FORSTER A N D ZIMMERLI :tural considerations, a.nd since the only justification for a stereo-chemical explanation is the exclusion of structural differences, weproceed to deal with the possible causes of the foregoing relation-ships. These are:1. Dimorphism, condemned by the distinct differences in opticalactivity which solutions of the respective pairs display undercomparable conditions.2.Polymerism, which might be suspected from the higher meltingpoint and sparing solubility of the a-compounds. The latterproperty has precluded application of the freezing-point method ofmolecular-weight determination except in the case of the a-phenyl-carbamylhydrazone ; this is normal, and so is the a-semicarbazonein boiling chloroform, whilst for other reasons which becomeapparent later in this paper it is difficult to believe that theIess fusible member of each pair is merely a polymeride of thecorresponding &modification.3. The structural difference which, depending on the asymmetryof the camphane molecule, renders the types,C , H , , < ~ ~ 2 and C,H,,<?’ cx,’distinct from one another.The principal objection to thisexplanation is one which is familiar to all workers with camphorderivatives, namely, the immensely superior reactivity of thea-position. But it is excluded also by the formation of thehydrazones on reducing diazocamphor, supported by the improba-bility of the above types undergoing interconversion by merelyheating the substances at 100-200°.4. cis-trans-Isomerism, also depending on the asymmetry of thecamphane nucleus, as represented by the formulae:NX NHC8€Xl,(C<hH and C8Hl,(Y<kx ,‘co ‘cothe possibility of which has been indicated by Armstrong andRobertson (Trans., 1905, 87, 1278). This point would be difficultto argue in the case of the semicarbazones and phenylcarbamyl-hydrazones if these had the constitution :respectively, but is simplified by their experimental relation to thehydrazones, because it is obvious that cis-trans-isomerism of theorder shown above could not occur in the case of the lattersubstancesSTUDIES IN THE CAMPHANE SERIES.PART XXVIII. 21615. The structural difference arising from enolisation, namely :as suggested by Betti in connexion with the phenylhydrazones( B e y . , 1899, 32, 1995). Here again the test is furnished by thesimple hydrazones, which would be represented as :But this enolic formula represents the nitrogen in a conditionhopelessly unprotected and quite incompatible with stability, whilstthe alternative cycloid could not reasonably be expected to displaychemical behaviour practically identical with the azethenoid com-pound represented by the first of the above expressions.The latterremark applies also to the formula:suggested by analogy to Hantzsch's representation of the alkaliderivatives from oximinoketones. Thus the keystone of thediscussion is the constitutdon of the simple hydrazones.6. The structural difference of compounds derived from theazethenoid and cyclic hydrazones :respectively. The discussion of this possibility involves a referenceto the early work of Curtius on the interaction of hydrazine hydrateand ketonic substances. I n dealing with the constitution ofhydrazine derivatives from benzil and benzophenone, Curtius andThun (J.pr. Chem., 1891, [ii], 44, 161) and, later, Curtius andRauterberg (Zoc. cit., p. 192) distinguish the products by theformulz :N €3'GH5' and (C6H5\,C: N *NH,,C,H5-C0respectively. Their principal reasons for doing so were the superiorreactivity of the benzophenone derivative towards benzaldehyde,although the benzilhydrazone also condenses with that substance,and the oxidation of the benzilhydrazone to the correspondingderivative of diazomethane by the actsion of mercuric oxide :NH N C6H5*CO*CPh<hH -+ C,H,*CO*CPh<#2168 FORSTER AND ZLMMERLI :the benzophenonehydrazone being stated to yield a tetrazone bythis treatment :(C,H,),C:N*NH, --+ (C,H,),C: N*N:N*N : C( C61T5),.The evidence of tetrazone-formation will be found on examination,however, to be noticeably slender, and in the light of our ownexperiments we suggest that the “ tetrazones ” derived from benzo-phenonehydrazone (Curtius and Rauterberg, Zoc.cit.), benzylidene-hydrazone (Curtius and Pflug, Zoc. cit., p. 535), and acetophenone-hydrazone (Curtius and Pflug, Zoc. cit.) are unstable derivatives ofdiazomethane, corresponding with that obtained from benzil-hydrazone.I f this suggestion is justified it would, a t first sight, appear toconfirm the cyclic representation of the hydrazones. But it hasbeen already pointed out that cis-trans-isomerism of an unsub-stituted cyclic hydrazone does not seem possible, and the directconsequence of revealing isomerism in a simple hydrazone istherefore to discredit the cyclic structure for at least one member ofthe pair in favour of the azethenoid representation.How, then,is the formation of a diazomethane derivative from an szethenoidhydrazone to be explained ? We suggest the following inter-pretation, first pointing out that it is probably the self-evidence ofthe conclusion that a hydrazone, convertible into a diazomethanederivative by mercuric oxide, must be derived from a cyclic type,which has obscured the possibility of an alternative explanation.It seems to us most likely that the cause of this change is to befound in the Hofmann-Curtius reaction, which, without quotingother examples (Trans., 1909, 95, 433; Schroeter, Ber., 1909, 42,2336) may be summarised in the equations:X*@O*NHBr - HBr =X*N:C:O.X*CO*N,- N,=X*N:C:O.Applying this t o the present question, we have to deal with acase of arrested transformation :X,C:N*NH, - H, = X,C:N*N --+ X,C<n ”it being impracticable for the denuded atom of nitrogen to displacecarbon from its position in the molecule, with the result that theazethenoid linking incurs a redistribution of valency.Although a superficial criticism of this explanation might dismissit as forced, and less probable than the one at present accepted, itis strongly supported by the following circumstances. As alreadypointed out, the isomeric camphorquinonehydraones cannot bothhave the cyclic structure; if, on the other hand, one were cyclicand the other azethenoid, some difference in bebaviour towards anoxidising agent should evince itself.But there is none. ThSTUDIES IN THE CAMPHAKE SERIES. P m r XXVIII. 2163a- and /3-hydrazones, dissolved in cold pyridine, have been oxidisedwith aqueous mercury acetamide to diazocamphor, and the pre-cipitation of mercury takes place instantaneously in both cases.Moreover, by reducing diazocamphor in cold alcohol with ammoniumsulphide, both hydrazones have been regenerated. It appears tous that these experiments point incontestably t o stereoisomerismof the Hantzsch-Werner type. Theoretical considerations make itclear that at least one of the hydrazones must be azethenoid, andsince oxidation of both leads to diazocamphor, the production of adiazomethane derivative from a hydrazone by this step cannot beaccepted any longer as evidence of the cyclic structure.Further-more, the fact that diazocamphor yields both hydrazones onreduction vitiates the conclusion that because diazomethane iscycloid, a hydrogenised diazocamphor must be a cyclic hydrazone.On the other hand, formation of both hydrazones on reducing diazo-camphor gives colour to our hypothesis, because if it be admittedthat ring-scission occurs on reduction, anti- and syn-modificationswould be produced simultaneously :Moreover, from relationships developed recently between structureand optical activity in the camphane series (Trans., 1909, 95, 942),it is to be exjected that a substance derived from diazocamphor inthe manner indicated by the formuls:would display lower rotatory power than diazocamphor itself,whereas the a- and B-hydrazones of camphorquinone both havedistinctly higher molecular rotation.Furthermore, they do notdiffer greatly from one another in respect of this property, althougha, considerable difference might be anticipated between an azethenoidand a. cyclic hydrazone.The second chemical distinction which has been mentioned asleading Curtius to differentiate between cyclic and azethenoidhydrazones, namely, condensation with benzaldehyde, corroboratesthe evidence from oxidation. When suspended in cold water andshaken with this agent, both hydrazones undergo immediate con-densation, indicated by a change of colour, since the benzylidenederivative is deep yellow. The final product is the same whetherthe a- or the 8-hydrazone is employed as starting-material, but th2164 FORSTEB AND ZIMMERLI :deeper colour generated by the latter substance, and the delay insolidification shown by the product, suggest the preliminaryformation of an unstable P-benzylidene compound.Before concluding, we ought to mention that there is one dis-tinction existing between the members of each pair which willdoubtless be quoted as evidence in conflict with our explanation.Itis a fact that whilst the a-hydrazone, a-semicarbazone, and a-phenyl-carbamylhydrazone are colourless, the P-modifications are faintlyyellow. It was by a distinction of this order that Armstrong andRobertson (Zoc. c i t . ) attempted to justify their representation of thephenylmethylhydrazone and phenylbenzylhydrazone of camphor-quinone as " phanes," whilst retaining the azethenoid structure forthe diphenylhydrazone, and if the same principle were applied tothe substances described herein, the colourless a-hydrazone and itsderivatives would be represented as cycloid, whilst the yellowfl-compounds would be labelled azethenoid.I n the foregoingremarks we have endeavoured to show that this cannot be accepted,but even if that evidence could be swept aside, we still hold thatthe conclusion from colour is in support of our hypothesis, whichregards the a- and /3-derivatives as anti- and syn-carbonylic respec-tively :FHXa-Hydrazone, a-semicarbazone, &Hydrazone, B-semicarbazone,For it cannot be denied that from the conflict of views as to therelation between colour and constitution there does emerge thisprinciple, that colour appears to be associated with a concentrationof unsaturated atoms.Clearly there is a more intimate massing ofsuch atoms in the P-compounds as represented above than in theirisomerides, and it is fair t o claim this point as favouring the stereo-chemical hypothesis. I n further support of the latter, it may bestated that the only chemical distinction between the members ofeach pair which has yet come to light is to be found in the behaviourof the semicarbazones towards aqueous alkali. Whilst the a-semi-carbazone forms a yellow solution which does not undergo spon-taneous alteration, the dissolved 8-semicarbazone quickly loses itsand a-phenylcarbamylhydrazone.and 8-ph enylcarbamy lhy drazone.colour, and on acidifying the liquid there is liberatedoxyt,riazine :thSTUDIES IN THE CAMPHANE SERIES. PART XXVIlI. 2165production of which is obviously more favoured by the s y ~carbonylic configuration than by the alternative one.These, then, are our principal reasons for inclining to the stereo-chemical representation of the camphorquiponehydrazones and theirderivatives described in this paper. If this interpretation findsacceptance, it carries with it fresh evidence in support of theHan tzsc h-Werner hypothesis ,EXPERIMENTAL.A ction of Hydraaine Hydrate on Camphorpinone.A zocamphanone.-Twelve grams of hydrazine hydrochloride, dis-solved in 100 c . ~ . of water, were treated with 12 grams of potassiumhydroxide, and, when cold, mixed with 33 grams of camphor-quinone in 100 C.C.of hot alcohol. During one hour at 40° theappearance of the liquid had completely changed, owing to theseparation of a bulky, pale yellow precipitate; this was collected,washed with 50 per cent. alcohol, and found to weigh 29 grams.The product was dissolved in 400 C.C. of boiling alcohol, whichdeposited lustrous, six-sided, transparent plates, almost rhombo-hedral in form; becoming deep yellow at 195O, it melted anddecomposed at 218O. (Found, N = 8.75 ; C,,H,,0,N2 requiresN =8.53 per cent.) This compound is the ‘‘ azocamphanone ” ofAngeli (Zoc. cit.), who records 222O as the melting point, whilstOdd0 gives 217-218O. It does not reduce hot Fehling’s solution,and is not hydrolysed by a hot 20 per cent;.solution of alcoholicpotassium hydroxide ; concentrated hydrochloric acid, however,when mixed with an alcoholic solution and boiled, eliminateshydrazine, but cold concentrated sulphuric acid, although forminga deep yellow solution, does not resolve azwamphanone int’ohydrazine and camphorquinone. An alcoholic solution does notchange when heated with an aqueous solution of mercury acetamide.When powdered or in separate crystals, azocamphanone appearscolourless, but when viewed in bulk it has a, yellow tinge, andsolutions are deep yellow ; 0-3104 gram, dissolved in chloroformand made up t o 25 c.c., gave a, 4O20’ in a 2-dcm. tube, whence[a]D 174’5O and [MI, 571°J not 790°J as previously stated in error(Trans., 1909,95, 948).C‘:N*NH,Cc)T h e Isomeric Camphorquinonehydrazones, C,H,,< I .-Anaqueous solution of hydrazine hydrate prepared from 30 gramsof hydrazine sulphate and 24 grams of potassium hydroxide in150 C.C.of water was mixed with 33 grams of camphorquinone,dissolved in 150 C.C. of hot alcohol. After three hours at 40°2166 FORSTER AND ZTMMERLI :23 grams of pale brown crystals had separated, quite distinct irlappearance from the bulky precipitate of azocamphanone, and acurrent of steam having been passed through the filtrate until allvolatile matter was removed, a further 2 grams crystallised fromthe hot liquid, so that under these conditions the yield ofa-hydrazone amounted to 75 per cent. There was not any azo-camphanone or camphorquinone, and after recrystallisation fromabout 400 C.C.of boiling alcohol, the a-hydrazone separated in long,lustrous, transparent prisms, melting and evolving gas at 206O :0-2538 gave 0.6189 CO, and 0.2037 H20. C = 66.51 ; H = 8.98.0.1418C,,H,,ON, requires C = 66-66 ; H = 8.88 ; N = 15.55 per cent.The a-hydrazone and its solutions are colourless, but large crystdsfrequently have a brown tinge; 0.3110 gram, dissolved in chloroformand made up to 25 c.c., gave a, 7 O 9 ’ in a 2-dcm. tube, whence[a]= 287-4O. The compound is insoluble in petroleum, and is notreadily soluble in other media even when these are boiled; acetoneor benzene is a convenient solvent from which to obtain it incolourless crystals, but upwards of 100 C.C. of the latter solvent atthe boiling point are required to dissolve 1 gram of the substance.It is readily soluble, however, in warm phenol, and sparingly so incold pyridine.A solution in chloroform decolorises bromine immediately, andammoniacal silver oxide is reduced when warmed with the alcoholicsolution. On adding solid sodium nitrite to a cold suspension of thea-hydrazone in glacial acetic acid, the salt assumed a transientpurple tint, whilst the liquid became yellow and evolved gas; ondiluting the acetic acid with water, azocamphanone was precipitated,On passing a current of steam through the filtrate from thea-hydrazone as prepared under the foregoing conditions, 3 gramsof a straw-yellow, crystalline material were carried over.The yieldof this compound, however, was trebled by adding 40 grams ofhydrazine hydrate to 50 grams of camphorquinone dissolved in75 C.C. of alcohol, when the deep yellow colour changed immediatelyto pale brown; copious precipitation of the a-hydrazone took placeafter a very short interval, and at the end of half an hour theliquid was filtered and subjected to a current of steam, The soliddistillate, consisting of P-hydrazone, weighed 12.5 grams, whilst2 grams more were obtained by extracting the distilled water(1200 c.c.) with ether ; the yield of accompanying a-hydrazone wm66.6 per cent., and if both compounds are required, the aboveconditions of procedure are the most economical. The P-hydrazonewas recrystallised twice from boiling petroleum (b.p. 60--80°),12 grams requiring 120 C.C. of the solvent, which deposited long,,, 18.9 C.C. N, at 1 5 O and 751.5 mm. N=15*43STUDIES IN THE CAMPHANE SERIES. PART XXVIII. 2167lustrous, straw-yellow needles or transparent prisms, melting at102O :0.2038 gave 0.4975 CO, and 0.1632 H,O.0.1864The substance has a faint odour suggesting that of bornylamine;it is readily soluble in organic media, excepting petroleum. Asolution containing 0.3134 gram, made up to 25 C.C. with chloroform,gave a, 5O48' in a 2-dcm. tube, whence [a], 231'3O. An alcoholicsolution reduces cold ammoniacal silver oxide, and a solution inchloroform decolorises bromine immediately.C = 66.59 ; H = 8.96.C,,H,,ON, requires C = 66.66 ; H= 8.88 ; N= 15.55 per cent.?, 26.6 C.C.N, a t 25O and 754 mm. N=15.79.Interconversion of the Hydrazones.On melting the &hydrazone, it was noticed that if the temperatureof the bath is raised to 150-160° the liquid solidifies, and thischange was found to be due to conversion into the isomeride, whichis readily isolated by recrystallisation from hot alcohol. Theconverse transformation cannot be brought about by merely meltingthe a-hydrazone, because this modification slowly loses nitrogen at205-210°, yielding camphor :If, however, the a-hydrazone is dissolved in molten paraffin wax,and maintained at 180° during a few minutes, it is a simple matterto demonstrate the formation of the P-hydrazone by suspendingthe product in hot water, and passing a current of steam throughthe liquid, when the volatile modification is carried into thecondenser.Action of Sulphuric Acid on the Hydrazones.The hydrazonss behave exactly alike towards sulphuric acid.When covered with the warm agent of 30 per cent.strength, aclear solution is formed almost immediately, and this a t oncebecomes turbid, setting to a paste of azocamphanone in the courseof a few minutes; on extracting the filtered product with boilingalcohol, crystals of hydrazine sulphate remain undissolved. With10 per cent. acid, a clear solution is not produced, because thedissolution of the hydrazone is overtaken by the separation ofazocamphanone2168 FORSTER AND ZIMMERLI :Acyt Derivativee of the HydrazonesC: N *NH*CHO The a-Formyl .Derivative, CsH,,<&O .-On dissolving1 gram of the a-hydrazone in 10 gra.ms of formic acid (D 1*2),the pale yellow solution remained clear during a few seconds,when a shower of crystals separated; the derivative wasrecrystallised from boiling alcohol, of which about 70 C.C.wererequired by 1 gram, and was deposited in colourless, lustrous, six-sided plates, which displayed frequent twinning. It melts at 234O :0.1240 gave 14.6 C.C. N, at 18O and 757 mm. N=13*54.CI,HIBO,N, requires N = 13.45 per cent.The formyl derivative is insoluble in boiling petroleum, anddissolves sparingly in methyl alcohol, benzene, acetone, and chloro-form unless these solvents are heated, 15 C.C. of the lasbnamed,for example, dissolving about one decigram until warmed; it ismore readily soluble in pyridine and glacial acetic acid.A solutioncontaining 0.1720 gram, made up to 25 C.C. with chloroform, gavea, 3O33’ in a 2-dcm. tube, whence [a], 258.0°. On adding ferricchloride to an alcoholic solution, a pale brown coloration isdeveloped, whilst that with copper acetate is grass-green. Aqueousalkalis dissolve the substance readily, producing a bright yellowsolution, and on adding ferrous sulphate to the diluted liquid adark bluish-green precipitate is formed ; when the alkaline solutionis left a t the laboratory temperature, the colour quickly fades, andthe a-hydrazone separates.The same formyl derivative was also produced by the action ofthe acid on the P-hydrazone. An attempt to prepare a benzoylderivative by the action of benzoyl chloride on the formyl compounddissolved in pyridine was not successful.C: N*NH*CO*CH, The a-Acety2 Deiiuatiue, C8H,,<),0 .-Althoughdissolving readily in cold formic acid, the a-hydrazone is onlymoderately soluble in cold glacial acetic acid ; it dissolves on warm-ing the liquid, but does not crystallise readily even on dilution,owing to partial acetylation.The substance was therefore warmedwith five parts of acetic anhydride, when the acetyl derivativeseparated as a paste of crystals at the moment of complete dis-solution in the hot liquid ; recrystallisation from a considerableproportion of boiling alcohol gave long, lustrous, snow-whiteneedles, melting and decomposing at 239O :0-1047 gave 11.8 C.C. N, at 17O and 760 mm.N=13*07.C12H1802Ng requires N = 12.61 per centSTUDIES IN THE CAMPHANE SERIES. PART xxvm. 2169A solution containing 0.2226 gram, made up to 20 C.C. withchloroform, gave a, 5O54' in a 2-dcm. tube, whence [a]= 265'5O.The compound dissolves freely in dilute aqueous alkali, developinga, bright yellow coloration, and the solution yields an intense bluish-green precipitate with ferrous sulphate; 0.2083 gram, dissolved in5 C.C. of 10 per cent. sodium hydroxide and diluted to 25 C.C. withwater, gave aD 4O121 in a 2-dcm. tube, whence [aJD 252*0°. I nprocess of time, the colour of the alkaline solution fades, and thea-hydrazone separates from the liquid.The B-A cetyl Derivative,--On dissolving the P-hydrazone in fiveparts of cold acetic anhydride, the temperature rose slightly, andlong, fiat, transparent prisms began to separate in the course of afew minutes; after recrystallisation from boiling petroleum, thesubstance was found to be pale yellow, and melted at 150O:0.1297 gave 14-5 C.C.N, at 1 8 O and 760 mm.C,,H,,O,N, requires N = 12.61 per cent.A solution containing 0.3890 gram, made up to 25 C.C. withchloroform, gave aD 6O58' in a 2-dcm. tube, whence [a], 223'8O.The solution in aqueous alkali has the same appearance as that ofthe a-acetyl derivative, developing a similar precipitate withferrous sulphate; in the course of some hours, the yellow colourfades, and the liquid deposits crystals of the a-hydrazone.When the P-acetyl derivative is heated at temperatures aboveits melting point, varying proportions of the a-acetyl compound areproduced, but the conversion is not complete; moreover, on heatingthe a-acetylhydrazone in acet'ic anhydride, a certain amount of theB-isomeride may be isolated from the product.The a-Benzoyl Derivative, C,H,,<CO .-Thea-hydrazone requires about 25 parts of pyridine to maintain a clearsolution at zero, and on adding the calculated amount of benzoylchloride, also dissolved in ice-cold pyridine, the hydrochloride ofthe base separated, the benzoyl derivative being precipitated ondilution with water j recrystallisation from boiling alcohol, inwhich it is sparingly soluble, gave tough, lustrous, snow-whiteneedles, becoming yellow above 200°, and melting at 219-222O,according t o the rate at which the temperature is raised:N = 10.01.N=12.91.7 : N N H*CO*C,H,0.1322 gave 11.4 C.C.N2 at 16O and 757 mm.CI7H2,O2N, requires N = 9-86 per cent.The substance is not readily soluble in chloroform, and a solutioncontaining 0.2135 gram, made up to 50 C.C. with this solvent, gaveU, 1°45/ in a, 2-dcm. tube, whence [a], 204.9O. Although in partdissolved by 2 per cent. aqueous sodium hydroxide, the benzoylderivative did not form a clear solution; 0.1904 pam, suspendedVOL. XCVJI. 7 2170 FORSTER AND ZIMMERLI :in about 20 C.C. of the agent, was made up to 50 C.C. with absolutealcohol, the clear, deep yellow liquid giving a, 1°50/ in a, 2-dcm.tube, whence [aID 240'7O.On attempting to prepare a benzoyl derivative of the B-hydrazone,the principal product wm found to consist of the substance justdescribed, but the residue from the mother liquor remained oilyduring many nionths, suggesting that both isomerides are formed.The a-benzoyl derivative was obtained also by mixing equalquantities of camphorquinone and benzoylhydrazine in dilutealcohol, crystals separating after two hours at 40°; in this case,also, the filtrate deposited an oil, indicating the presence of a,mixture.Benzytidene Derivative of Ca,mpF.orpuinonehydrazone,The a-hydrazme was finely powdered, mixed with the calculatedamount of benzaldehyde, and heated with a few C.C.of alcoholduring two or three minutes; crystals did not separate on cooling,but water precipitated a, yellow oil, which quickly became solid, andwas recrystallised from boiling petroleum (b.p. 60--80°). Themassive, yellow crystals melted at 109'5O :0.1253 gave 12.0 C.C. N, at 20-5O and 758 mm.C,,H,,ON, requires N = 10.44 per cent.The substance is freely soluble in chloroform, benzene, acetone,alcohol, and ethyl acetate, but only moderately so in warmpetroleum; a solution containing 0.3035 gram, made up to 20 C.C.with chloroform, gave a, 4O50' in a 2-dcm. tube, whence [a], 159'2O.It is also produced immediately on shaking the finely powderedhydrazone with water and benzaldehyde, but the method is notconvenient, as a portion of the hydrazone remains mechanicallyprotected.The same benzylidene derivative is produced on agitating theP-hydrazone suspended in water with the aldehyde, the deep yellowcolour of the condensation product becoming noticeable imme-diately. Owing to the solubility of the P-hydrazone in water, noneescapes combination, but the product remains liquid during manydays, although rapidly becoming solid when heated t o looo andscratched.Another example of the capacity of the hydrazones for takingpart in condensation changes was given by heating an alcoholicsolution of the a-hydrazone and camphorquinone in molecular pro-N = 10.90STUDIES IN THE CAMPHANE SEHIES.PART XXVlII. 21'71portion during twelve hours under reflux, when azocamphanonewas produced :Oxidation of the Hydrazones t o Diazocamphor.Since i t was desirable to study the oxidation of the hydrazonesunder conditions precluding the likelihood of preliminary inter-conversion, it occurred to us that mercury acetamide, owing to itssolubility in cold water, might be a more suitable agent thanmercuric oxide, a study of the acetamide compound having shownthat it acts rapidly on primary hydrazines with precipitation ofmercury (Trans., 1898, 73, 783).Experiment showed that thebehaviour of the isomeric hydrazones of camphorquinone towardsthis agent distinguishes itself sharply from the indifference of azo-camphanone. It having been first ascertained that the P-hydrazoneis not transformed into the isomeride by dissolution in pyridine,1 gram dissolved in 3 C.C. of the cold solvent was treated with2 grams of mercury acetamide in 3 C.C. of cold water, the meta.1being precipitated immediately.The production of the diazo-compound was indicated on extracting with ether, which becamedeep yellow, and, after evaporation, the pyridine residue yielded0.8 gram of diazocamphor on dilution with water; recrystallisationfrom petroleum (b. p. 40°) gave long, striated, yellow prisms,melting at 73-74O.Procedure in the case of the a-hydrazone was modified by thesparing solubility of the substance, 5 grams of which were dissolvedin 80 C.C. of hot pyridine, cooled to 50-60°, and treated with 10grams of mercury acetamide in 30 C.C. of warm water; mercury wasprecipitated immediately, and 4 grams of diazocamphor obtained.A solution containing 0.4605 gram of the diazo-compound, madeup to 25 C.C. with chloroform, gave a, 4 O 5 8 ' in a, 2-dcm.tube,whence [a'JD 134.8O.Reduction of Uiaxocamphor to the Hydrazones.A 20 per cent. solution of diazocamphor in absolute alcohol wassaturated with hydrogen sulphide without undergoing any changein appearance, but on adding a few drops of dilute ammonia andagain passing the gas, the liquid became pale brown, and gradualseparation of the a-hydrazone took place; on subjecting the filtrateto steam distillation, a small proportion of the P-hydrazone wascarried over. As it is a matter of importance to establish theproduction of both compounds without question, the experiment7 c 2172 FORSTER AND ZIMMERLI !was repeated at zero, when it was found that the precipitation ofthe a-hydrazone was diminished, and the yield of P-hydrazone wasproportiona.tely increased.Reduction of t h e a-Hydrazone to a-Aminocamphor.Owing to the readiness with which the hydrazones undergoacetylation, a certain amount of the a-acetyl derivative is formedon attempting to reduce the a-hydrazone with zinc dust and aceticacid; it is precipitated, however, when the acid is neutralised.Onadding a further quantity of alkali to the filtrate, ammonia is setfree, and ether extracts aminocamphor, which may be identifiedby conversion into the oxime; a specimen of aminocamphoroximeobtained in this way melted a t 144-145O.T h e Isom,em'c Camphorquinonesemical.bazones,The discovery of a second camphorquinonesemicarbazone arosefrom the observation that on evaporating the filtrate from thesubstance described by Lapworth and Chapman, there is depositedan oil which, by treatment with very dilute aqueous alkali, isdivisible into two solids; one passes into solution, and consists ofthe derivative already known, whilst the new semicarbazone remainssuspended.A solution containing 33.2 grams of camphorquinone in 150 C.C.of alcohol was mixed with semicarbazide acetate prepared from22.2 grams of the hydrochloride and 27 grams of crystallisedsodium acetate in 100 C.C.of water; the liquid, from which crystalsof the a-semicarbazone quickly separated, was transferred to astoppered filtering flask connected with a water-pump, the alcoholbeing evaporated at the laboratory temperature during six to eighthours, when drops of oil became noticeable among the crystals.From the resulting sludge about 16 grams of the less soluble a-semi-carbazone were filtered, the mother liquor being poured into waterand treated with alkali hydroxide until a faint yellow colourpersisted ; the suspended oil became solid when stirred, and con-sisted of the more soluble P-semicarbazone mixed with a smallproportion of the isomeride. I n order to remove the latter, thefiltered product was ground three or four times with 10 C.C.of2 per cent. aqueous sodium hydroxide, the filtration necessary aftereach extraction being carried out as quickly as possible, becausealthough the a-semicarbazone dissolves in weak alkali without delay,the 8-modification is also soluble, but very slowly. The pale yellowpowder was then extracted twice with 300 C.C.of boiling water, thSTUDIES IN THE CAMPHAXE SERlES PART XXVIII. 2173crystalline deposit (6 grams) from this being recrystallised from25 C.C. of warm benzene, to which the same volume of petroleumwas added. A t this stage the purification was complicated by thefact that following closely on the slender, yellow crystals of theP-semicarbazona there appeared opaque nodules containing theisomeride.Camplzorquino~ze-a-semicarbazone is the substance described byLapworth and Chapman (loc. cit.). It crystallises from alcohol inlustrous, colourless prisms, melting and evolving gas at 236O, aftersintering and becoming yellow at about 230O; it is much lessreadily soluble in organic niedia than the isomeride, and is insolublein petroleum.A solution containing 0.3152 gram, made up to20 C.C. with methyl alcohol, gave a, 8O45’ in a 2-dcm. tube, whence[a],, 277.6O. As distinguished from the P-compound, it dissolvesimmediately in dilute alkali, and 0.3344 gram in sufficient potassiumhydroxide, made up to 25 C.C. with water, gave a, 8O55‘ in a 2-dcm.tube, whence [aJD 333.3O ; this remained constant during six days,and the semicarbazone precipitated from the solution by aceticacid was unchanged material. Nevertheless, on heating with 10 percent. potassium hydroxide during three to four days, camphor wasgradually produced. Cold concentrated sulphuric acid dissolvesthe a-semicarbazone, and gradually changes it to azocamphanone,which is precipitated on pouring the liquid into water ; if, however,the hot acid is used, a certain amount of camphorquinone isproduced.An estimation of the molecular weight in boilingchloroform gave 236 instead of 223.Camp?borq uinone-P-semicar b azone cryst allises in pale yellowprisms, melts at 1 4 7 O , and is readily soluble in alcohol, acetone,ethyl acetate, chloroform, ether, or benzene, but dissolves onlysparingly in hot water or boiling petroleum :0.2328 gave 0.5037 CO, and 0.1539 HiO. C = 59.03 ; H = 7.66.0.3225 N=18*79.C,,H,,O,N, requires C = 59.19 ; €I = 7.62 ; N= 18.83 per cent.A solution containing 0.3152 gram, made up to 20 C.C. withmethyl alcohol, gave a, 6O20’ in a 2-dcm. tube, whence [a], 200-9O.When covered with aqueous alkali hydroxide, the P-semicarbazonedoes not appear to dissolve; if, however, the solid substance isthrown into hot 10 per cent.sodium hydroxide, there is producedimmediately a deep yellow solution, the colour of which graduallyfades, owing to the formation of the oxytriazine (see below), Onraising the temperature of the fused P-semicarbazone to about 190°,the substance became solid, and the a-semicarbazone wits found tohave been produced.,, 54.8 C.C. N, at 25O and 754 mm2174 FORSTER AND ZIMMERLI :Conversion of the Semicarbazones into the A cetylhydrazones.The semicarbazones were separately heated with boiling aceticanhydride during one hour, the solid product obtained in eachcase, on pouring the liquid into water, being found fa consist of amixture of the a- and P-acetyl derivatives of the hydrazones.Thetransformation was not easy to establish experimentally, becausethe relative solubility of the acetyl derivatives in alkali exactlyresembles that of the semicarbazones themselves, and as the meltingpoints of the latter differ from those of the respective acetylhydrazones by 3O only in each case, the preliminary experiments ledt o the supposition that the semicarbaxones are directly inter-convertible by tohe action of the agent in question.The Tsomeric Campho~~.uinonephenylcar6amylhydrazones,These derivatives were prepared by three different methods.(1) Action of hot aniline on the a- and P-semicarbazones, eachof which gave both phenylcarbamylhydrazones.(2) Condensation of camphorquinone with phenylcarbamyl-hydrazide, also yielding a mixture.(3) Interaction of phenylcarbimide and the a- and P-hydrazones,which led to the individual phenylcarbamylhydrazones, respectively.Camphorquinone-a-phenyl car6 amylh ydrazone.-Four grams ofthe a-semicarbazone were dissolved in 20 C.C.of aniline, and heatedten minutes a t the boiling point of the solvent, ammonia beingliberated freely before this temperature was reached ; the cooledliquid was diluted with its volume of alcohol, and poured into200 C.C. of 10 per cent, acetic acid at zero. The precipitated oilquickly hardened when scratched, and on dissolving the productin 80 C.C. of hot methyl alcohol, the a-phenylcarbamylhydrazonecrystallised in thick, colourless plates, melting at 21 lo, whilst theisomeride remained dissolved :0.2494 gave 0.6096 CO, and 0.1656 H,O.0-1660C,,H2,102N3,~CH,0 requires C = 66.64 ; H = 7.30 ; N = 13.33 per cent.The transparent crystals became opaque in the steam-oven, owingt o loss of crystal-alcohol :0.2462 gave 0.6158 CO, and 0.1546 H,O.C=68*23; H-7.03.C17H2102N3 requires C = 68.23 ; H = 7-03 per cent.Ordinary solvents, excepting petroleum, dissolve the substancereadily, but, unlike the a-semicarbazone, it is insoluble in coldC = 66.67 ; H= 7.43.N=13*75. ,, 20.3 C.C. N, at 24O and 761.5 mmSTUDIES I N THE CAMPHANE SERIES. PART XXVIII. 2175aqueous alkali hydroxide, although dissolving when heated, withdevelopment of a yellow coloration. A solution containing 0.2207gram, made up t o 25 C.C.with chloroform, gave a, 4’3‘ in a 2-dcm.tube, whence [a], 229’3O. An estimation of the molecular weightby depression of the melting point of benzene gave 327 insteadof 299.Camphorquinone-/3-p h e n ylcar b amylhydraaone.-From the motherliquor of the foregoing substance there gradually separated long,slender, silky needles, in which a few small crystals of thea-compound were embedded, and as the latter remained undissolvedon rapidly warming the liquid, it was possible to isolate theP-modification without much difficulty, the final recrysfallisationbeing effected by adding petroleum to a solution of the needles inbenzene. The substance is very pale yellow, and melts at 161O:0.2142 gave 0.5346 CO, and 0.1372 H,O. C = 68.10 ; H = 7.17.0.1062 ,, 13.9 C.C.N2 a t 24O and 754 mm.C,,H,,0,N3 requires C = 68.23 ; H = 7.03 ; N = 14-09 per cent.I n all common media the solubility of the P-phenylcarbamyl-hydrazone scarcely differs from that of the isomeride, but thetendency to form supersaturated solutions is much greater. Asolution containing 0.2128 gram, made up to 25 C.C. with chloro-form, gave a, 3O16’ in the 2-dcm. tube, whence [a], 191.9O.As in the case of the P-semicarbazone, transformation into thea-modification was readily accomplished by heating the P-phenyl-carbamylhydrazone above its melting point ; the clear liquid whichhad been carried to 200° remained vitreous on cooling, but imme-diately became crystalline on being scratched in presence of a smallquantity of methyl alcohol.In preparing the phenylcarbamylhydrazones by the foregoingmethod, it was noticed that the proportion of the two modificationsdepends on the duration of heating and on the temperaturereached.This is explained by the fact that either is convertibleinto the other isomeride by the action of hot aniline, eachindividual yielding an equilibrium mixture when a solution in thatbase is heated until the solvent boils; roughly speaking, the relationbetween the constituents of this mixture is a: B =2 : 1.The second process for obtaining the phenylcarbamylhydrazoneswas practised by mixing solutions containing 5 grams ofcamphorquinone and 4.5 grams of phenylcarbamylhydrazide,C,H5*NH*CO*NR*NH2, each in 15 C.C. of hot methyl alcohol, andheating the iiquid on the water-bath during a few minutaa;2.8 grams of the a-phenylcarbamylhydrazone separated on coolin:,whilst the mother liquor deposited a mixture of this with thecharacteristic, silky needles of the @modification,“~14.552176 FORSTER AND ZIMMERLI :The third method is the most convenient when the hydrazonesare available, because it leads to the individuals, and thus obviatesthe necessity of a tedious separation.The finely powdereda-hydrazone (1.8 gram), suspended in 250 C.C. of boiling benzene,in which it was not completely soluble, was heated with 3 gramsof phenylcarbimide on the water-bath during two hours, when theliquid did not deposit crystals on cooling. After distilling off thesolvent until only 30 C.C. remained, twice this volume of petroleumwas added, precipitating 2.7 grams of a crystalline powder, readilyidentified with the a-phenylcarbamylhydrazone on recrystallisation.I n preparing the &modification by this process, 0.9 gram of theP-hydrazone, dissolved in 10 C.C.of benzene, was treated with 0.7gram of phenylcarbimide, the mixture being left at the laboratorytemperature, and after the lapse of twelve hours diluted withpetroleum until pale yellow needles appeared ; after recrystallisationit melted at 161°, and did not depress the melting-point of theP-phenylcarbamylhydrazone prepared by the other methods.Camphane-oxytriuzine,Whilst the a-semicarbazone is dissolved immediately by aqueousalkali hydroxide, forming a permanent yellow solution, the&modification is transformed into the anhydride represented above,the conversion taking place at rates depending on the temperature.Camphorquinone-B-semicarbazone was covered with 10 parts of10 per cent.aqueous sodium hydroxide, and shaken at intervalsduring five hours, when the solid substance, at first coloured yellowby the agent, had passed into a colourless solution. After extractionwith ether, dilute sulphuric acid was added until the initial pre-cipitate was redissolved, when the liquid was shaken eight timeswith ether; the solvent deposited 85 per cent. of viscous residue,which quickly solidified. Recrystallisation from warm benzene, towhich petroleum was added, gave colourless, transparent pyramids,melting at 166-167O :0.2183 gave 0.5137 GO2 and 0.1406 H,O. C = 64.18 ; H = 7.21.0.1950 N=20.75.C,,H,,ON, requires C = 64-39 ; H = 7-31 ; N = 20.49 per cent.The substance is somewhat readily soluble in warm water, anddoes not crystallise completely on cooling ; alcohol, ether, chloroformand benzene dissolve it readily, but it is insoluble in petroleum. It,, 35.6 C.C. N, at 21° and 759 mmSTUDIES IN THE CAMPHBNE SERIES. PART XXVIII. 2177does not reduce Fehling’s solution, and when heated withammoniacal silver oxide yields a voluminous, white precipitate,freely soluble in ammonia,. A solution in sodium carbonate isstrongly alkaline, and gives a transient violet precipitate withferrous sulphate, becoming bright green when excess is added ;copper salts produce an apple-green precipitate, also formed bynickel sulphate, excess of which yields a clear solution. The opticalactivity of the oxytriazine and its derivatives is very much lowerthan that of the foregoing compounds of camphorquinone; a solutioncontaining 0.2855 gram, made up t o 25 C.C. with chloroform, gavea, 0°31/ in a, 2-dcm. tube, whence [aID 22*G0.The ucetyl derivative was readily formed on heating the oxy-triazine with a.cetic anhydride ; after recrystallisation from a,mixture of benzene and petroleum, it melted at 168-169O :0.1765 gave 0.4096 CO, and 0.1127 H,O.C,,H,,O,N, requires C = 63.16 ; H = 6-88 per cent.The substance dissolves freely in cold benzene, chloroform,acetone, or methyl alcohol, but is less readily soluble in ethylalcohol or ethyl acetate, from which it crystallises in lustrous,colourless needles. A solution containing 0.2444 gram, made up to20 C.C. with chloroform, gave a, 1°2/ in a 2-dcm. tube, whence[a], 42.2O.The benzoyl derivative, prepared by the action of benzoyl chloridein pyridine solution and purified by precipitation from acetic acid,followed by recrystallisation froin a mixture of benzene andpetroleum, melted at 193-194O :C=63*30; H=7.14.0.2021 gave 0.5150 CO, and 0.1108 H,O.C,8Hl,0,N, requires C = 69.90 ; H = 6-15 per cent.The compound is freely soluble in cold acetone or chloroform,but ethyl acetate, methyl alcohol, benzene, or ethyl alcohol dissolveit less readily, and it is very sparingly soluble in boiling petroleum.A solution containing 0.2808 gram, made up to 20 C.C. with chloro-form, gave only a, 0°13’ in a 2-dcm. tube, whence [a],, 7 ~ 7 ~ .C = 69.51 ; H=G.13.ROYAL COLLEGE OF SCIENCE, LONDON.SOUTH KENSINGTON, S.W

ISSN:0368-1645    

DOI:10.1039/CT9109702156

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2178 RHEAD AND WHEELER: THE EFFECT OFCCXXVL-The Eflect of Temperature on theEquilibrium 2CO CO,+C.By THOMAS FRED ERIC RHEAD and RICHARD VERNON WHEELER.THE fact that carbon monoxide dissociates under the influence ofheat, yielding carbon dioxide and carbon, or, in other words, thefact that the reaction:is reversible, was discovered by H. Sainte-Claire Deville in 1864(Gompt. rend., 1864, 59, 873; 1865, 60, 317) by means of hisI' hot-cold " tube. He was able to observe only a small degree ofdissociation a t a temperature a little lower than the melting pointof silver, whilst at temperatures above 1000° none at all couldbe detected.Since i t was assumed that the degree of dissociation of carbonmonoxide, like that of carbon dioxide and steam, should increasewith increased temperature, doubt was cast on Deville's first experi-ments, and it was suggested that the formation of carbon dioxideand the deposition of carbon were due to the chemical action ofthe glaze of the porcelain tubes he employed.I n 1869 Sir Lothian Bell (Journ.Chem. SOC., 22, 203), whilestudying the reactions taking place in the blast-furnace, found thatsuch portions of the iron ore as had been subjected to the actionof carlon monoxide at comparatively low temperatures in the upperpart of the furnace were impregnated with carbon, presumablyarising from the dissociation of the gas. He thereupon institutedlaboratory experiments to determine the action of carbon monoxideon different oxides at different temperatures.As a result of these experiments, Bell was able to state that thereduced metal was as effective as the oxide ip determining thedecomposition of carbon monoxide, and he gave the equation of thereaction as being:GO, + c = 2c"o2co = co, + c.He also showed that the oxides of nickel and cobalt and thereduced metals acted in a similar manner to iron oxide and reducediron.The influence of temperature on the amount of decomposition ina given time was also studied by Bell, comparative figures beingobtained from the quantities of carbon deposited.This is wellshown in the following series of experiments, in which carboTEMPERATURE ON THE EQUIL~BR~UM 2co ;~r CO,+C. 2179monoxide was passed slowly over reduced iron at different tem-peratures during six hours :Tem1)erature ,.. , . , ,. . , , . , , , . . . . . . ... . ,. . , , .. . . . . . . . . . , , . .Carbon deposited. Grams per 100 grams of iron 4.7 181 95 6 0.3It is thus apparent that a low temperature favours the decom-position, a result which explains the failure of Deville and otherst o obtain evidence of dissocia.tion a t 1000°, and is in accordance withthe fact that the reaction 2C?O=CO,+C is exothermic. The heatof reaction is shown by the following eqmtions:250" 400" 500" 600" 800"(1). CO + 0 = CO, + 6s-0 Kg.C. units.(2). C + 0 = CO + 29.0 ,, 3 9whence 2CO = GO, + C + 39.0 ,, 9 )_____Since the reaction is reversible, an equilibrium must be establishedbetween the quantities of carbon dioxide and monoxide that canexist together in the presence of carbon; and, in accordance withvan't Hoff's principle of mobile equilibrium, the quantity of carbonmonoxide will be increased by lowering the temperature.The equilibrium a t different temperatures has been studied by0. Boudouard (Ann.C'hirn. Phys., 1901, [vii], 24, 5 ) , who has givenfigures for 650°, 800°, and 925O.I n studying the reaction 2CO-+CO, + C, Boudouard made useof iron, nickel, and cobalt as catalysts. The finely divided metalswere obtained by impregnating broken pumice with the nitrates andigniting, the oxides thus formed being afterwards heated in astream of carbon monoxide until reduction was considered to becomplete.For the experiments a t temperatures below 700°, glass tubes,6 to 7 cm. long and 1-5 cm.in diameter, were used, the total volumeof gas being from 12 t o 15 C.C. Above 700°, a porcelain tube,40 cm. long and of 2.4 cm. internal diameter, was employed, thepumice containing the catalyst occupying the middle 10 cm. of thetube, and the remainder being packed with broken porcelain.The main results were as follow:Carbon dioxide,Temperature. Catalyst. Duration of heating. per cent.44 5" iron 6 horns 100445 nickel 1 hour 100445 cobalt 1 7 9 100650 cobalt 7 Y , 61800 nickel 4 ,Y 6.7800 cobalt 4 9 ) 6 -5I n one experiment at 4 4 5 O , using a very small quantity of ironoxide (reduced by carbon monoxide) as catalyst, Boudouardobtained 52.3 per cent. of carbon dioxide and 47-7 per cent. ofcarbon monoxide remaining after six hours' heating2180 RHEAD AND WHEELER: THE EFFECT OFThe reverse reaction, CO2+C-+2C0, was studied in a similarmanner, but without the use of catalysts, purified wood charcoalbeing employed.The carbon was heated in an atmosphere ofcarbon dioxide in tubes sealed at one end, with the other end openand bent so as to dip under mercury, the object being to avoidbursting of the tubes due to increased pressure as the reactionproceeded.The results were as follow :Duration of heating, Carbon dioxide,Temperature. hours. per cent.650" 9 62'4650 12 61 *5800 6 6 -7800 6 6-3I n addition to the above, two experiments were made at 925O, inwhich a measured volume of carbon dioxide was passed in a, slowstream through the heated charcoal, and the resulting gases bubbledthrough baryta water, the barium carbonate that was precipitatedbeing afterwards weighed. Assuming that a single passage of thecarbon dioxide over the heated charcoal was sufficient to establishequilibrium, Boudouard calculated from one experiment 3.3 percent., and from the other 4.5 per cent., of carbon dioxide remainingin equilibrium with carbon monoxide over carbon at 925O.Boudouard's experiments prove that the equilibrium ratioCO/C'O, in contact with carbon is a function of temperature, andthe results are in general agreement with the laws respectingequilibria in gaseous systems.R.Schenck and F. Zimmermann (Ber., 1903,36, l), while studyingmore particularly the order of the reactions taking place, have beenable to prove that the oxides of iron, nickel, and cobalt are quiteineffective in determining the dissociation of carbon monoxide, andthat it is only the reduced metals that act catalytically.This is indirect opposition to the views advanced by Boudouard. A t thesame time Schenck and Zimmermann give results for the equilibriumat low temperatures (445O and SOSO) that are entirely at variancewith those of Boudouard. At 445O Boudouard regards the dis-sociation of carbon monoxide as complete ; while Schenck andZimmermann, using reduced iron as catalyst, obtained 52.8 percent. of carbon monoxide as the quantity remaining in equilibriumat that temperature. It is interesting to note that this figureagrees fairly well with that obtained by Boudouard when usingonly a small quantity of iron as catalyst (a result which he discards),and it seems probable that in those experiments, otherwiseinexplicable, in which he obtained complete decomposition of carbonmonoxide, the oxides of the metals used as catalysts were incomTEMPERATURE ON THE EQUILIBRIUM 2co co,+c.2181pletely reduced before the tubes were sealed, and that oxidation ofthe carbon monoxide took place.We considered it desirable to determine the equilibrium ratiomore accurately and for a greater number of temperatures, avoidingthe use of catalysts, for Boudouard's method of experiment did notappear to us to be calculated to give very accurate results, andhis figures were not in agreement with those obtained by us duringthe course of an investigation on the mcde of burning of carbonon which we are still engaged.The method we have adopted has been to circulate carbondioxide continuously over purified wood charcoal packed in aporcelain tube, and heated in an electric resistance furnace.We have obtained in this manner the following figures for thepercentages of carbon dioxide and monoxide that are in equilibriumin the presence of excess of carbon at different temperatures:Temperature.850"9009501000105011001200C:trbon dioxide. Carbon monoxide.Per cent.by volnme.r6-232.221 *320.590 '370'150.0693.779 i . 7 898.6899.4199.6399.8599 9 1The percentages are calculated as those of the nitrogen-free gases.The gases usually contained from 1 to 2 per cent.of nitrogen.I n Le Chatelier's general formula for equilibrium in gaseoussystems :L = the total heat of the reaction at absolute temperature Y'.P = the prcssure in atmospheres.N and N'= the Lumber of molecules on the left- and on the right-hand side of the equation.ml, ~ 2 ' ~ , , .. and n2, nf2, ... = the number of molecules of the differentsubstances taking part in the reaction, index 1 meaning the initial andindex 2 the final system.cl, c ' ~ , ... and c2, c'~, ... 5 the concentrations of the different sub-stances, icdices as above.I n the system:2co = CO, i- cnl&= 2 ; n2= 1 ; n',=O ; c',=O.and the expressionIf the system is in equilibrium at atmospheric pressure, Y = l ,( N - N)lo.g.,P=O2182 KHEAD AND WHEELER: THE EFFECT OFAssuming with Le Chatelier that the heat of reaction is constant,and introducing its value (39.0 Kg.C.units), the equation thenbecomes :i- log, !i! = k. 19,500I' c2The values for Ic calculated from our resulk are as follow:T.11 23"117312231273132313731473c1-0.93770.97780.98680'99410,99630*99850.9994c,.0.06230.02220.01320.00590-00370.00150.0006k.20.0120'3920 '2420'4420'3220.7020'65EXPERIMENTAL,The Epuilib rium Furnace.-In designing the equilibrium furnace,the two chief considerations were (a) the obtaining of a uniformtemperature, and ( b ) the attainment of rapid cooling of the gasesafter they had left the zone of reaction, in order to "fix" theequilibrium. We had, moreover, to recognise the fact that a ttemperatures above 1000° both porcelain and fused silica or quartztubes, such as we intended to employ for the reaction vessel, becomeslightly porous to gases.The construction of the furnace, which was made for us byMessrs.C. W. Cook and Co., at the University Engineering Works,Manchester, is shown in Fig. 1. It consists essentially of a glazedBerlin porcelain tube, 51 cm. long and of 28 mm. external and20 mm. internal diameter, wound with platinum wire, through whichan electric current can be passed. The winding is arranged so asto give a uniform temperature throughout the central portion of12 cm., and is carried on either side close up to the gunmetal water-jackets, J, being insulated from them by thin disks of porcelain.By winding the coils closer near each end than along the rest ofthe tube, we are able, when a fairly rapid stream of water is passingthrough the jackets, to obtain a sudden reduction in the temperatureof the tube from 1000° in the central uniform portion to 400° orless within a distance of 1.5 cm., while the temperature falls to below150° within a distance of 5 cm.This result is not attained solely as the effect of water-coolingand increasing the length of resistance wire a t the ends, but is inpart due to the double-jacketing arrangement, A , which is intendedprimarily to avoid any error due to porosity of the porcelain tubeat high temperatures. A nickel tube, 22 cm.long and of 7.1 cm.external and 5'7 cm.internal diameter, is fixed coaxially with thTEMPERATURE ON TEE EQUILIBRIUM 2 0 ) C0,t-C. 2183'2.f ar"Rcf-mat- - 2184 RHEAD AND WHEELER: THE EFFECT OFporcelain tube, and through the annular space a slow stream ofdry nitrogen is passed. The nitrogen, prepared by Harcourt’smethod, enters under a slight pressure through the central tube B,and issues at C, C through wash-bottles containing concentratedsulphuric acid. The passing of this stream of dry nitrogen, inaddition to ensuring that no oxygen or water vapour enters theporcelain tube if it becomes porous a t high temperatures, causes amore uniform distribution of heat throughout the length of thefurnace, an effect which is enhanced by the position of entrance ofthe gas.The furnace tubes are surrounded by a thick layer of kieselguhrto prevent loss of heat by radiation, and the whole is encased ina jacket of sheet iron.The carbon used throughout this research has been wood charcoalpurified by first digesting with concentrated hydrochloric acid (ina bolt-head flask fitted with a reflex condenser) to remove the ash;washing with distilled water ; and subsequently heating at 1000°in a stream of dry chlorine, washing, heating in a stream ofhydrogen, and finally in a vacuum at 1000° for forty-eight hours.It is crushed and sieved so as to pass through a 10-mesh sieve andremain on a 10-mesh, and about 6 grams are then loosely packedinto a thin tube of quartz, 12 cm.long and open at both ends, whichslides easily into the porcelain tube.After the insertion of the quartz sheath containing the carbon,a plug of silica, 16.5 cm.long and 1.9 cm. in diameter with a hole3 mm. in diameter drilled through the centre, is introduced a t eachend. These plugs serve to keep the carbon surface in position inthe zone of constant temperature, but they are intended moreespecially to cause the stream of gases, after passing over the heatedcarbon, to pass rapidly out of the tube, and thus ensure that theequilibrium determined shall be that of the experimental tem-perature recorded.The Measurement of Temperature.-The temperatures aremeasured by means of a platinum and platinum-rhodium thermcFcouple, and recorded by one of the Cambridge Scientific InstrumentCompany’s ‘‘ Thread-Recorders.” The couple is embedded in themiddle of the carbon, the leads being insulated by thin quill tubingof quartz, and the whole enclosed in a sheath of thin quartz, whichpasses easily through the bore of the plug P.Some little difficulty was at first experienced in maintaining aconstant t,emperature, owing to fluctuations in the voltage of theelectric current supplied to the furnace.Since the experimentsextended continuously over several days, or, in some cases, severalweeks, personal attentioL was found to be impossible, and a meanTEMPERATURE ON THE EQUlLlRRlUM 2CO C0,fC. 2185had to be devised of autoniaiically regulating the voltage. Themethod finally employed, for the suggestion of which we are indebtedto Mr. E.Muller, of the Cambridge Scientific Instrument Company,is as follows.The voltage of the main current is first cut down by the largeresistance, R (Pig. Z), t o within a small margin of that required toobtain the experimental temperature in the furnace. It then passesthrough the Nernst lamp steadying resist~ances, N , of which asufficient number are arranged in parallel to allow the requisitequantity of current to pass round the circuit. These steadyingresistances take as their normal current 1 ampere at 15 volts, whilstthe furnace, when hot, takes about 3 amperes. The exact numberthat are required to ensure perfect regulation and automatic adjust-ment of the voltage across the furnace terminals depends on theexperimental temperature employed ; there must be a sufficientFIG.2.It A 1number to ensure that the spirals of fine iron wire within theexhausted globes of each shall glow a dull red without becomingoverheated; for they depend for their action on the change inelectrical resistance that occurs in iron wire at a temperature ofabout 775O.After passing through the Nernst lamp resistances, the currentis divided, part going through the furnace, and part through theshunt, S, containing a rheostat. About equal quantities of currentp a s through the furnace and the shunt. The final adjustment ofthe voltage across the furnace to that required to obtain a giventemperature is made by means of the rheostat in the shunt, thealteration of which does not interfere with the main current, sincethe whole of it passes through the Nernst lamp resistances.This method has proved eminently satisfactory, the experimentaltemperature being maintained without any serious fluctuationscontinuously auring several weeks,VOL.XCVII. 7 2186 RHEAD AND WHEELER: THE EFFPCT OFGeneral Arrangement of A ppuratus.-The reacting gases arecirculated without interruption over the heated carbon untilequilibrium is attained. The general form of the circulationapparatus is that designed by one of us in conjunction withW. A. Bone for the investigation of the slow combustion of hydro-carbons (Trans., 1903, 83, 1074).The porcelain tube containing the carbon carries a ground glassjoint at each end held firmly in position by strong springs. Thesejoints make connexion on either side, through the mercury-cuptaps T, T' (Fig.l), with the cylindrical vessels C, C', each of200 C.C. capacity. These vessels mainly determine the capacity ofthe apparatus, and are cylindrical in form in order to allow ofbeing heated to drive off any traces of gas that may have a tendencyto stick to the glass.On the rightrhand side, connexion is made, through the calciumchloride drying-tube D, to the head of the Sprengel pump S. Onthe left is fused a long tube of wide bore, which passes horizontallyacross the front of the furnace and is then bent downwards at rightangles, forming a manometric tube, which stands over the delivery-tube of the Sprengel pump in the mercury trough M . A shortT-piece near the left-hand cylinder, closed by a mercury-cup tap,serves f o r the introduction of the gas.With the exception of the ground joint connexions to the porcelaintube, the apparatus is of fused glass throughout:The gases are drawn, by means of the automatic Sprengel pump,through the furnace, and delivered under mercury in the trough Minto the manometric tube B, whence they return along the horizontaltube H to the cylinder C, and are again drawn forward through thefurnace.The automatic Sprengel pump, the general constructionof which is described in the paper referred to above (Zoc. cit.,p. 1079), is actuated by suction produced by a doubleacting Gerykpump driven by an electric motor, and is so arranged that the headof mercury in the reservoir R allows of the gases being circulated atatmospheric pressure.The total volume of the apparatus, measured at Oo, is 570 c.c.;that of the packed porcelain tube 96 C.C.The Gus Analyses.-The carbon dioxide was prepared by droppingboiled concentrated sulphuric acid from a separating funnel into aboiled solution of sodium carbonate contained in an Erlenmeyerflask.The gas evolved waa passed through two sulphuric acidworms, and collected in a glass gas-holder containing concentratedsulphuric acid, over which it wa.s stored for two weeks before beingused for an experiment.The carbon monoxide was prepared from sodium formate, madTEMPERATURE ON THE EQUILIBRIUM 2CO CO,+C. 2187into a stiff paste with distilled water, by the action of concentratedsulphuric acid. It was washed through two worms containingpotassium hydroxide solution, and stored over sulphuric acid inthe same manner as the carbon dioxide.The gases remaining after an experiment were analysed volu-metrically in a, Bone and Wheeler gas analysis apparatus overmercury, from 200 to 300 measure of gas being taken for ananalysis.Carbon dioxide was estimated by absorption with as smalla quantity of aqueous potassium hydroxide as possible, or whenonly small quantities were present, by absorption with a concentratedsolution of barium hydroxide. Carbon monoxide was absorbed byam ammoniacal solution of cuprous chloride, prepared by passingammonia gas into distilled water containing the freshly precipitatedcuprous chloride in suspension until the latter was dissolved.Alittle ammonium chloride was added to the solution as thus preparedto reduce the tension of ammonia vapour. The gas was treatedtwice with small quantities of this solution, and afterwards washedwith dilute sulphuric acid.Any residue (which never amounted to more than 2 per cent.of the total gas) was afterwards exploded with a measured volumeof air and oxygen, to which a few C.C. of pure electrolytic gas wereadded. Any contraction in volume after explosion, or afterabsorption with potassium hydroxide, wits then determined. Atrace of hydrogen due to insufficient drying of the gases, or tomoisture in the circulation apparatus, was detected in severalexperiments the results of which were discarded.dlethod of Conducting am Expem’ment.-The apparatus havingbeen thoroughly exhausted, the glass being heated in a large blow-pipe flame to drive off the last traces of air, the carbon dioxide(or monoxide) is introduced in such quantity that when the reactionis complete the gases shall be as nearly its possible at atmosphericpressure. As a preliminary to a series of experiments, a, certainquantity of carbon dioxide is introduced to the carbon heated to1000° and allowed to circulate for several days.The resulting gasesare then pumped out, and the furnace brought to the experimentaltemperature. This preliminary treatment serves to remove anytraces of water-vapour that still remain in the apparatus; it wasin the gases resulting from such experiments that we were able todetect traces of hydrogen.In the experiments proper the gases are allowed to circulate fortwenty-four hours after the volume, ag indicated by a scale fixedbehind the manometric tube, has ceased to change.The reactiontube is then shut off from the rest of the apparatus, and samplesare withdrawn for analysis.7 D 2188 RHEAD AND WHEELER: THE EFFECT OFResults of Experiments.The results of our experiments can bestform aa follow :Experimentnumber.E 14E 9E 16E 4E 18E 5E 6Duration of heating,Temperature. hours.850" 240900 180950 1441000 481050 481100 481200 48be expressed in tabularCoiiiposition of resultinggases (calculated asnitrogen-free mixture). - co,. co.6.23 93.772 '22 97.781'32 98-680.59 99.410 -37 93.630.15 99.850.06 99 94In addition, w e have made two attempts to attain equilibrium a ta temperature of 800° with the circulation apparatus, but haveabandoned the experiments after they had continued for six weekswithout showing signs of coming to a conclusion, 20 per cent.ofcarbon dioxide still remaining after that time.Boudouard, in the reduction of carbon dioxide by wood charcoalwithout the presence of a catalyst, states that equilibrium wasattained in his experiments after six hours' heating at SOOO andafter twelve hours' heating at 650°, the percentages of carbondioxide remaining in equilibrium being 6.3 and 61.5 per cent.respectively at the two temperatures. The volume of his apparatuswas only from 12 to 15 C.C.as against our 570 c.c., but we do notthink that this fact is sufficient to explain the marked discrepancybetween our results, since we used a correspondingly larger quantityof carbon surface. I n another series of experiments that we aremaking on the rate of reduction of carbon dioxide by wood charcoalat different temperatures, we have been unable to obtain a dis-appearance of carbon dioxide of more than 0.7 per cent. after122 hours' heating a t 700O.All our experiments recorded above have been made startingwith an initial concentration of 100 per cent. carbon dioxide; forthe rate at which the reverse reaction proceeds was too slow toenable us to attain equilibrium in a reasonable time without thepresence of a catalyst, the use of which we wished to avoid.The relative rates of the two reactions during the initial stagesare well shown in the experiments recorded below.A temperatureof S50° was chosen as being that at which the reduction of carbondioxide by carbon was fairly rapid, and the dissociation oE carbonmonoxide readily appreciable.The rates of the reactions are calculated, by means of the relationZ C - log -2 = k,t CTEMPERATURE ON THE EQUILIBRIUM 2CO Z= CO,+C. 2189from the partial pressures (concentrations) of the carbon dioxide atdifferent time intervals in experiment R 13, and from the partialpressures of the carbon monoxide in experiment R 15 :Experiment R 13.co, -I- c = 2co.Time.( U n i t = l hour). P. at 0".0 258'61 292.32 317-84 356.36 389-08 415.812 439.5Temperature 8 5 0 O .pcoz.257'6224.9199*4160.9128'2101.477.7kCop -0.05900.05550'05110-05050'05060'0434Experiment R 15.2co = co, 3. c.Time.(Unit=I hour). P. a t 0".0 463'024 459.248 453.972 452'196 448'0120 447-2Temperature 850O.Pco. kco.453.7 --446'1 0*00030435-5 0.00037431.9 0.00030423'7 0-00031422.1 0'00026It will thus be seen that the reduction of carbon dioxide bycarbon takes place at 850° at a speed 166 times as great as thedissociation of carbon monoxide at the same temperature.We may incidentally draw attention to the fact that the goodt ctfor a unimolecular reaction, points to both reactions beingessentially surface phenomena; the rate of reduction of carbondioxide and the rate of dissociation of carbon monoxide both varyingdirectly with the partial pressure of the gas. It is our intentionto discuss this question more fully when we have concluded aresearch, on which we are at present engaged, on the relative ratesof reaction between carbon dioxide, carbon monoxide, oxygen, andcarbon at different temperatures.agreement of the constant k, calculated from the expression 1 -1og- CfJThis work has been undertaken in connexion with the experimentsnow being carried out by the Mining Association of Great Britainon coal-dust explosions. We are extending it to the investigationof the influence of pressure on the equilibrium ratio,ALTOFTS

ISSN:0368-1645    

DOI:10.1039/CT9109702178

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2190 JERUSALEM : THE MOlWHOTROPIC RELATIONSHIPSCCXXVI1.-The Morphotropic Relutionships betweerLSilicon and Carbon Cornpouds of Corr-espondinyCompositiorhs.By GEORGE JERUSALEM.CARBON occupies an altogether unique position amongst the elementsin crystallographio as well as in chemical respects; although largenumbers of compounds of the elements of group I V of the periodicclassification have been crystallographically examined, no case hasbeen yet observed in which a carbon atom is isomorphously replacedby one atom of any other element. It is true that both carbontetraiodide and silicon tetraiodide crystallise in the cubic system,but, since the crystal class is known in neither case, the informationrequisite for deciding as to whether these two compounds are is*morphous is lacking.Isomorphism might be expected as betweenthe metallic carbonates and metasilicates, but although comparisonis possible in a number of cases, no instance is on record in whichsilicon replaces carbon without profound modification of thecrystalline form ; thus lithium carbonate, Li,CO,, is monosymmetricwith a : b : c = 1.672 : 1 : 1.244, p= 114O25’ (Mallard, Zeitsch.Rryst. Mh., 1894, 2 3 , 483), whilst lithium metasilicate, Li,SiO,,is rhombohedra1 with a: c= 1 : 0.6681 (Friedel, Zeitsch. lilryst.Min., 1903,37, 204). Comparison of the crystalline forms exhibitedby the carbonates of the bivalent metals with those of thecompounds CaSiO,, MgCa( SiO,),, MgSiO,, MnSi’Os, MgTiO,,MnTiO,, and FeTiO,, fails to reveal any isomorphous relationshipbetween the carbonates and the latter compounds.Further, theobservation that carborundum, CSi, is a stable substance dissimilarin crystalline form from either component element does not favourthe view that the two elements are isomorphous.Whilst a considerable amount of evidence, such as the above,indicates that carbon is crystallographically quite unique, it isnoteworthy that ample evidence is available to show that silicon isdisplaceable by many bivalent elements without considerable changein crystalline form.From a discussion of the crystal data available for carbon andsilicon compounds, Barlow and Pope have been led to attributethe crystallographic-and also chemical-dissimilarity to a differencein the fundamental valencies of these two elements (Trans., 1908,93, 1554); carbon thus stands alone as the only element exhibitingthe fundamental valency of four, whilst silicon and many otherelements are fundamentally bivalent.Owing to the comparativBETWEEN SILICON AND CARBON COMPOUNDS. 2191ease with which, during the last few years, it has become possibleto exhibit the relation between chemical constitution and crystallineform, the question of the relative fundamental valencies of siliconand carbon has become one of great importance; the work describedin the present paper was undertaken as a step towards the solutionof the problem involved.A study of the crystal data already available for correspondingsilicon and carbon compounds indicates clearly that the two elementsexercise such different morphotropic effects that few positive resulhcould be hopefully anticipated unless some condition, hithertounconsidered, were introduced for the purpose of accentuating suchcrystallographic similarity of function as may exist between siliconand carbon.The directing condition, thus indicated as desira.ble,is found in the rule discovered empirically by Tscbermak (Tsch.Hin. Mitt., 1903, 22, 393; Ann. Reports, 1908, 5, 263) that, inthe crystalline form of a compound substance, the principal axes ofsymmetry tend to express numerically the atomic composition ofthe molecule; thus, if three similar atoms are present with othersin the molecule of a particular substance, the crystalline form ofthe compound will, in the majority of cases, include a threefoldaxis of symmetry.Since crystal structures are now regarded asclose-packed assemblages of atomic domains, a compound containingidentically located atoms, or groups of atoms, in the moleculewould tend to exhibit it particular element of symmetry displayingan n-fold repetition; Tschermak’s empirical rule has thus nowacquired theoretlcal significance and, simultaneously, a concretemeaning. The rule may be conveniently applied to the purpose ofaccentuating any possible morphotropic relationship between twoelements a and b, by preparing two substances containing in themolecule three large atomic groups or radicles associated with ana and b atom, respectively, of a unique kind; any morphotropyexhibited as between a and b should then be easily traced bygoniometric examination.This particular development of the new mode of regarding crystalstructure is applied in the present paper to the examination oftribenzyl and triphenyl derivatives of silicol and carbinol; theintroduction of three benzyl or phenyl groups into the molecule is,of course, intended to secure t.he presence of a trigonal axis ofsymmetry and to ensure that the silicon and carbon analogues shallto a very great ext.ent exhibit identical marshalling of their com-ponent atoms.Trib enzylsilicol, (C,H,*CH,),Si*OH.A supply of this substance was kindly provided by Prof.F. S.Kipping, and melted at 1 0 6 O , as stated by Dilthey (Ber., 19052192 JERUSALEM : THE MOHPIIOI'ROPIC RELATIONSHIPS38, 4136).On slow evaporation of its solution in a mixture ofchloroform and petroleum boiling at 70°, it was obtained in smaI1,lustrous crystals suitable for measurement; the form (001) is thelargest, and {loo}, {101}, and { l l l } , although smaller, are welldeveloped. The pyramid, (122}, is always very small but quitebrilliant; no distinct cleavage was observed, but, as the faces of{ 111) are always much larger at one end of the c-axis, and its thefaces of { 122) are only observed at the same end of this axis, thesubstance is probably hemimorphous. No confirmation of the hemi-morphism was obtained by the study of the etch-figures producedby the action of alcohol on faces of the form (001).Crystalline form : Orthorhombic.a : b : c=1'7214: 1 : 2.1384.Forms observed: { l o o ) , {OOl), {101}, { l l l } , and (122).The following angular measurements were obtained :Angles.111 : Ti1111 : 111111 : 100101 : 001001 : 122122 : 122111 : 001101 : 111100 : 1221.01 : 100Number ofobservations.161433134919410Limits.55" 2'-55'49'43 46 -44 1561 31 -62 5450 59 -51 3565 31 -66 638 26-39 667 43 -68 1753 16 -53 2774 51 -75 2048 23Mean.55'30'20"44 1506213 051 13 3065 53 038 47 048 23 053 19 1075 7 5068 150Calculated.-62"14 50"51 10 038 50 048 22 2067 59 053 17 1075 15 3065 48 50It is very interesting to note that, although the substance doesnot exhibit a, trigonal axis of symmetry as would be anticipatedfrom Tschermak's empirical rule, it possesses a pseudetrigonal axis,as would be expected from the interpretation of the rule and themolecular composition in accordance with Barlow and Pope'smethod.Thus, a crystal presenting trigonal symmetry, referred torectangular axes, would exhibit as one axial ratio the value1 : d 3 = 1 : 1.7321, whilst an almost identical ratio, b : a = l : 1'7214,is actually observed on the crystals of tribenzylsilicol ; the pseudo-trigonal nature of the crystal structure is thus apparent. It willbe seen later that all the substances described below, in whichthree large groups are present in the molecular complex, conformt o the same rule, and betray the presence of a trigonal or a pseudo-trigonal axis, with the possible exception of triphenylsilicol, ofwhich the low crystal symmetry would naturally obscure the pseudo-trigonal character.Taking the valency volume of silicon as two, that of tribenzyl-silicol is W=110, and the equivalence parameters are obtained its:x : y : z=5.3418 : 3.1032 : 6.6358BETWEEN SILICON AND CARBON COMPOUNDS.21 93The density of the crystalline substance wits determined byRetgers' floating method in barium mercuri-iodide solution asd = 1.1772, whence the molecular volume, V = 270.66 ; the quotient,R = V / W = 2.4605, and the molecular distance ratios are calculatedas:x : J/ : w = 7 2116 : 4.1894 : 8.9586.Trib enzylcarbinol, (C,H,*CH,),C*OH.This substance was prepared by the method given by Klages andHeilmann (Ber., 1904, 37, 1456), and was obtained in crystalssuitable for goniometric measurement by spontaneous evaporationof its solution in a mixture of chloroform and petroleum.Thecrystals so closely resemble those of the preceding compound thatno separate description is necessary.Crystalline system : Orthorhombic.a : b : c=1*7166 : 1 : 2.1574.Forms observed: {loo}, {OOl}, {101}, { l l l } , and (122).The following angular measurements were obtained :Angles.1QO : 111001 : 111001 : 101100 : LO1111 : 111111 : 111.111 : T i 1100 : 122001 : 122Number ofobservations.26231018121316126Limits.6V52 '-62"20'68 0 -68 1751 18 -51 3738 21 -38 4455 32 -55 5143 31 -44 153 9 -53 3674 51 -75 2665 57 -66 7Mean.62" 8'50"68 9 2051 26 5038 32 5055 37 1043 40 2053 20 5075 9 4066 2 10Calculated - -51"28 '10"38 31 5055 42 2043 41 2053 19 3075 12 065 59 20The development of the faces indicates hemimorphous develop-ment as in the case of the corresponding silicol; the etch-figuresobtained do not reveal hemimorphism.The axial ratios calculatedshow that the substance is very closely related morphotropicallyto the corresponding silicol, and the present observations constitutethe first published evidence of morphotropy as between these twoelements.x : y : z =5*3482 : 3.1156 : 6.7215, with W = 112.The equivalent parameters are calculated ~ t s :The density of the crystals was determined as d = 1-1869, whencethe molecular volume, V = 258.99, and the quotient, I2 = V / TV =2.3124.The molecular distance ratios are therefore :x : $ : w * 7.0724 : 4.1200 : 8 8885.Tribensylmethyl Chloride, (C,H,*CH,),CCl.This substance was prepared by the method given by Schmerda(Monatsh., 1909, 30, 390), and exhibited the properties describe2194 JERUSALEM : THE MORPHOTROPIC RELATIONSHIPSby him; it separates from its acetone solution in very small butquite brilliant rhombohedron-shaped crystals.Crystalline system : Rhombohedral. Trapezohedral-tetatohedralclass.a : c = l : 0.3700.Forms observed : { 2fiO} and { lOil}.The following angular measurements were obtained :Number ofAngles, Observations. Limito. Mean. Calculated.2iTo : 1011 41 70” 0’-70”22’ 70” 6’20’’ -ioii : o i i i 18 39 34 -40 0 39 49 20 3 9 ‘4 7 ’2 0”The evidence that the crystals belong to the trapezohedral-tetartohedral class represented by quartz and cinnabar is, first, thatthe alternate faces of the form (2110) are very different in size,and, secondly, that the etch-figures produced on these faces by theaction of benzene are asymmetric with respect to the hexagonalplanes of symmetry normal to the faces.A good cleavage isobserved parallel to the form (2110).In order that the crystal form may be compared with those ofthe preceding compounds, it must first be stated with respect to thealternative hexagonal system and then ref erred to rectangular axesand the value, c / a , multiplied by five; the axial ratios are thusobtained in the form:a : b : c = 1.7321 : 1 : 2.1364, and the equivalence parameters as :x : y : z = 5*3,656 : 3.0977 : 6.6180, with W= 110.The use of the factor five in the multiplication of the ratio c / ais naturally just,ified by the very close similarity which theequivalence parameters of the three above substances exhibit afterthe multiplication has been performed in the case of tribenzylmethylchloride.Triphemjls&col, (C6H,)3Si*OH.Triphenylsilicol was prepared by Dilthey and Eduardoff’s method(Ber., 1904, 37, 1140), and showed the properties described bythese authors; the best crystals were obtained from solutions inmixtures of chloroform and petroleum, but even these were poor,and scarcely suitable for goniometric examination.The forms{loo}, {OlO}, and (001) show the largest faces, and are aboutequally well developed ; { 11 1 } and { 111 } are very poorly developed,and unsatisfactory in character.Crystalline system : Anorthic.a : b : c = 2,144 : 1 : 1.331, a = 5g030f, B = 113O291, y = 84O11’.Forms observed: {loo}, {OlO}, {OOl), ( l l l } , and (111)BETWEEN SILlCON AND CARBON COMPOUNDS.2195The following angular measurements were obtained :Angles.100 : 010 o_oi : 010100 : 111111 - : 001111 : 010111 : 001111 : 010111 : 100LOO : 001Number ofobservations.16810997542Limits.58" 1'--58'48'67 5 -67 4652 50 -53 2964 10 -54 4790 38 -91 1841 0 -41 5861 56 -62 3868 22 -68 5358 57 -59 24Mean. Calculated.58"20'50" -67 25 0 -53 6 10 -64 29 30 -90 57 40 _-41 39 10 42'10'20''6219 0 62 19 4068 36 30 69 2 2059 10 30 59 46 30The density of the crystals was observed as d = 1.1777, so that themolecular volume, V = 234.83 ; the quotient, R = V / W'= 2.5525No morphotropic relationship is immediately obvious between thisand the previously described substances, and, since triphenylsilicolbelongs t o the anorthic system, the symmetry affords no indicationas to the way in which a morphotropic relationship is to be sought;further, the ratio, V / W , is considerably larger than in the othercases referred to.It is consequently t,o be concluded that thissilicol does not fall into line with the series now under discussion.TriphenylcarbkoZ, (C,H,),C*OH.This substance has already been crystallographically examinedby Groth (Zeitsch.Kryst. .&fin., 1881, 5, 479), who found it to berhombohedra1 with a : c = 1 : 0.6984. Measurable crystals wereobtained from benzene solution, and these showed only the forms{lOTl} and { l l z O ) .Crystalline system : Rhombohedral.The following angular measurements were obtained :a : c = 1 : 0.6975.Number ofAngles, Observations. Limits. Mean. Calculated.2120 : lgll 13 56'46'-57"19' 57" 5'40" -1011 : 0111 5 65 35 -66 5 65 47 20 65O48'40''In order to render the crystal form comparable with those of thetribenzyl compounds described above, the ratio cia must be multi-plied by three and referred to a rectangular system of axes. Thefollowing ratios are thus obtained :a : b : c=1'7321: 1 : 2.0925.X : 9: ~=5*1271: 2'9601: 6.1939; W=94.The density of t'he crystals was determined as d = 1.1884, so thatthe molecular volume, V = 218.92, and t.he quotient, R = V / W =2.3289. The moIecular distance ratios are :x : $ : o = 6.7960 : 3.9236 : 8*2100.The value for R is slightly greater than that for tribenzylcarbinol2 196 JERUSALEM : THE MORPKOTROPIC RELATIONSHIPSnamely, 2.3124 ; this is in accordance with the indications obtainedin the case of the picrates and styphnates. Aniline picrate givesan R value of 2.464, slightly greater than 2.433, the value forbenzylamine picrate (Jerusalem, Trans., 1909, 95, 1290).For comparison with the above substances the following crystallineforms may be quoted.Triphenylmethane is described as ortho-rhombic by Hintze with a: b : c=0*5716 : 1 : 0.5867 (Zeitsch.Kryst.Min., 1884, 9, 546); on interchanging a and 6, and multiply-ing the resulting value of c / b by two, the axial ratios become:a : b : c =1*7495: 1 : 2.0528.o-Bromotriphenylmetliane, Ph,CBr, was found to be hexagonalby Hintze (Zoc. cit.) with the value (1; : G = 1 : 0.7843 ; on stating thisratio in the alternative hexagonal form as a : c = 1 : 0.6792, multiply-ing c / a by three, and referring the ratio to rectangular axes, thevalues are obtained as :a: b : c=1.7321: 1 : 2’0376.Triphenylacetic acid is monosymmetric (Groth, Zeitsch. Kryst.Min., 1881, 5, 483), and the axial ratios can be stated in the forma: b : c=0*5646: 1 : 0.6161, P=9O012’30’’ (Barlow and Pope,Trans., 1906, 89, 1719).On treating these axial ratios in themanner adopted with triphenylmethane, namely, multiplying c bby two, and then interchanging a and b, the values become:a : b : c=1*7712 : 1 : 2.1824, a=90°12’30”.The additive compound of triphenylmethane and benzene,(C,H,),CH,C,H,, is rhombohedra1 with a : c = 1 : 2.5565 (Hintze,Zoc. cit.) ; by referring this ratio to rectangular axes it becomes :a : b : c=1*7321: 1 : 2.5565.A consideration of the axial ratios, molecular distance ratios, andequivalence parameters for the above substances shows, first, thatalthough the morphotropic relationships are distinctly evident inthe axial ratios, they axe much more completely expressed by theequivalence parameters. Secondly, it is obvious that the moleculardistance ratios, although not greatly dissimilar in the instances inwhich they have been determined, differ much more amongst them-selves than do the equivalence parameters; the degree with whichthey correspond is, in fact, measured in the main by the degreeof approximation of the respective values of R = V / W .I n this,as in the majority of other cases, the molecular distance ratios lendthemselves less fruitfully to the discussion of morphotropic relation-ships than do the equivalence parameters ; the morphotropy musttherefore be considered merely in the light of the equivalenceparameters, and the axial ratios and molecular distance ratios maybe disregardedBETWEEN SILICON AND CARBON COMPOUNDS. 2197The following table states the equivalence parameters of all thesubstances dealt with above, calculated from the sets of axial ratiosfinally adopted.In the case of tribenzylsilicol, it is convenient tostate the equivalence parameters in accordance with the alternativesthat Si=2 and 4:1. (O,H,*CH,),Si*OH ......2. (CGH5'CH,)3Si'OH .. ...3. (CGH5*CH2)JC*OH ......4. (C,H;CH,),CCl .........5. (C, H,),C*OH . . . . . . . . . .6. (C,H,),CH . . . . . . . -. . . . . . .7. (C,H,)& Br , . . . . . . . , . . . . . ,8. (C,H,),C*C02H .........9. (CGH,),CH,C6HG ... ......5. Y. 6. 5'3418 : 3.1032 : 6.63585.3740 : 3'1219 : 6.67585,3482 : 3.1156 : 6.72155'3666 : 3.0977 : 6.61805,1271 : 2.9601 : 6.19355'1572 : 2'9479 : 6.05155.1359 : 2.9651 : 6.04165.2384 : 2.9576 : 6.45435.2314 : 3.0203 : 7.7213W=110 Si=2W=112 S i = 4 w= 112 w= 110lV= 94IV= 92lV= 92lt'= 100TI.'= 122Considering the parameters 2 and 3, calculated on the basis thatsilicon and carbon both exhibit the fundamental valency 4, it isnoticed that in passing from the silicol to the carbinol, the x-valuediminishes by about one-half per cent,., whilst the z-value increasesby rather a larger fraction.If crystal structure is to be regardedas a question of close-packing, it is difficult to conceive that inthe large tribenzylsilicol molecule the displacement of the siliconby a carbon atom of approximately the same valency volume fourcan lead, without change of symmetry, t o such it notable changein dimensions of the packed structure; it seems thus indicated thatcarbon and silicon have not the same fundamental valency of four.On considering next the values 1 and 3, calculated on the basisof Si=2 and C=4, it is seen that the differences for x and y aresmall, and that practically the whole weight of the displacement of2.2 and 3 Differences 0.02581 , 9 3 ,, 0.00643 7 9 4 ,, 0'01743 9' 5 ,) 0'22115 9' 6 ,) 0'03015 ,, 7 ,, 0.00875 Y , 8 ,, 0.11136 1 , 9 ,, 0'0742!I* x.0-0063 0'04570.0121 0-08570*0179 0.10350.1555 0'52800'0122 0'14200-0050 0'15190.0025 0.15190'0524 0.6698silicon by carbon falls on the z-parameter, which thus changes bynearly 2 per cent..; this is in complete agreement with what wouldbe anticipated by an increase of volume of one constituent atomicdomain from 2 to 4.Such a substitution, provided that themechanical operation of Tschermak's rule conserves the marshalling,could well lead to the expansion of the assemblage in one of thethree rectangular directions of principal symmetry. An identicaleffect is, in fact, observed in operation in other cases, notably inthe passage from tribenzylcarbinol to tribenzylmethyl chloride,where a similar change of valency volume by two units occurs a2 198 JERUSALEM : THE MORPIIOTROPIC RELATIONSHIPS, ETC.the result of the displacement of the hydroxyl group by the chlorineatom; here again small changes occur in the values of two dimen-sions, x and y, and most of the weight of the substitution is thrownon to the third or z-parameter, which alters by about 1.5 per cent.These considerations suggest that silicon and carbon have notthe same fundamental valency, but that, whilst that of carbon isfour, that of silicon is two.The available evidence is, however,not sufficient in amount to enable such a decision to be arrived atwith certainty, but it must be concluded that the quantitativeevidence, just i ~ s in the case of the humite series, points to thevalue of 2 rather than 4 as representing the fundamental valencyof silicon.The table of differences quoted makes it clear that the passagefrom tribenzylcarbinol to triphenylcarbinol, differences 3 and 5, isaccompanied by a marked contraction of the structure in all threerectangular directions, but that this effect is much more markedin the direction of the z-dimension than in those of x and y. Fromdifferences 5 and 6, and 6 and 7, it is seen that the substitutionof the hydroxyl group in triphenylcarbinol by hydrogen or bromineaffects the crystal Structure almost entirely in the direction of thez-axis; this is precisely what takes place in the correspondingoperation of passing from tribenzylcarbinol to tribenzylsilicol, inwhich the valency volume was diminished by two units on the viewthat Si=2, The differences 5 and 8 show that the displacementof the hydroxyl group in triphenylcarbinol by carboxyl also producesa maximum effect in the z-dimension, although the dimension of xis also appreciably affected. The differences 6 aad 9 indicateclearly that, in the passage from triphenylmethane to its additioncompound with benzene, the dimensions of LG and y are increasedto an equal and small extent, whilst the main change in dimensionsfalls on the z-axis.It is proposed to extend the application of Tschermak’s rule tothe investigation of morphotropy in later communications.I desire to express my heartiest thanks to Prof. W. J. Pope,F.R.S., for having suggested this work, and for his kind help duringits elaboration.UNIVERSITY CHEMICAL LABORATORY,CAMBRIDQE

ISSN:0368-1645    

DOI:10.1039/CT9109702190

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

EXTERNALLY COMPENSATED TETRAHYDROQUINALDINE. 21 99CCXXVIII.-Extenzally Compensated Tetrahydroquin-aldine (Tctrahydro - 2 - methylqzcinolirbe) uncl itsOptically Active Components.By WILLIAM JACKSON POPE and JOHN READ.THE resolution of externally compensated tetrahydroquinaldine(tetrahydre2-methylquinoline) into its opti.cally a t i v e componentswas effected by Pope and Peachey (Trans., 1899, 75, 1066) bycrystallising its hydrochloride (two equivalents) with ammoniumd-a-bromocamphor-?r-sulphonate (one equivalent) in aqueous solu-tion ; the deposit consists of practically pure I-tetrahydroquinaldined-a-bromocamphor-n-sulphonate. The d-tetrahydroquinaldine wasisolated from the mother liquors by fractional crysta-llisation of thebenzoyl derivative prepared from the separated crude d-base andsubsequent hydrolysis of the pure benzoyl-d-tetrahydroquinaldine.The method thus briefly described affords an easy method for thepreparation of I-tetrahydroquinaldine, but the isolation of theenantiomorphously related base is lengthy and difficult; in thepresent paper a method is described by means of which the twoenantiomorphously related bases can be readily prepared in a state ofhigh purity.bExternally Compensated Tetrahydroquinaldine.This base was prepared, in the manner previously described, asa colourless oil, boiling at 196O/207*5 mm.; at the ordinary tem-perature it is a mobile liquid which shows no tendency to crystallise,and, on cooling in boiling liquid air, it solidifies to a hard, resinousmaterial, which does not crystallise even after long exposure t o thelow temperature thus obtained.When, however, a few drops ofthe base are dissolved in ten times their volume of light petroleum,and the solution cooled in boiling liquid air, tetrahydroquinaldinecrystallises out as a mass of white needles; on inoculating carefullypurified externally compensated tetrahydroquinaldine with thesecrystals at the ordinary temperature, crystallisation at once sets in,and after the lapse of some hours the whole of the base becomesconverted into ilr hard, crystalline mass.It is thus evident that at the ordinary laboratory temperatureexternally compensated tetrahydroquinaldine is a supercooled liquid ;no other method than the one above described has get been foundfor causing the crystallisation.In all probability, the fact thatcrystallisation can only be started by such an uncommon methodas that just described is responsible for the observation not havin2200 POPE AND READ : EXTERNAT,LY COMPENSATED TETRAHYDRO-been previously made that the modification of tetrahydroquinaldinestable at the ordinary temperature is a crystalline one.A specimen of externally compensated tetrahydroquinaldine,prepared from a sample of the hydrochloride which had beenrepeatedly crystallised from acetone, after having been caused tocryshllise in the manner indicated, melted at 20'75O ; after meltingthe crystalline mass, cooling it to 15O, and inoculating the liquidwith the crystalline base, a standard thermometer immersed in thesolidifying substance showed that the temperature rose to 20'75Oduring crystallisation.This may therefore be taken as the meltingpoint of externally compensated tetxahydroquinaldine. It isinteresting to note that on preserving a quantity of the crystallinematerial in contact with the liquefied substance at the laboratorytemperature, the mass of minute crystals gradually becomes con-verted into several large rhombohedra; the latter grow to a diameterof four or five centimetres, and are very transparent, with highlyplane faces. A good example is thus afforded of the well-knownfact that the larger crystals present in contact with a solution tendto grow a t the expense of the smaller ones (Curie, Bull. SOC. Min.franc., 1885, 8, 145).Preparation of Ammonium d- and 1-a-Bromocamphor-n-sulphonat es.For the preparation of the large qua.ntities of ammonium cl- andI-a-bromocamphor-7r-sulphonates required in this and similar work,the sulphonation with chlorosulphonic acid (Kipping and Pope,Trans., 1895, 67, 356) is inconvenient, and may be replaced by aslight modification of t.he method first used by these authors(Trans., 1893, 63, 577).A mixture of fuming and 100 per cent.sulphuric acids is made of such concentration that a-bromocamphordissolves in it to a deep amber-coloured solution, and is not pre-cipitated by pouring on to ice; the concentration of the acid usedrequires careful adjustment, and a suitable concentration was foundto have the density 1.865 at 15O, and to consist of 200 C.C. of100 per cent.sulphuric acid with 75 C.C. of 65 per cent. sulphurtrioxide. This quantity of acid, cooled to the ordinary temperature,readily dissolves 95 grams of d-a-bromocamphor, and simultaneouslythe temperature rises to about 50°. After agitation for half aminute, the mixture is poured through a large funnel filled withcrushed ice, when an insignificant separation of unchanged bromo-camphor occurs; if the acid used is too concentrated, thesulphonation product suddenly carbonises with evolution of torrentsof sulphur dioxide. It is convenient to sulphonate a kilogram ofd-a-bromocamphor in quantities of 100 grams at a time, and almostto neutralise the diluted solution with milk of lime, completinQUINALDINE AND ITS OPTICALLY ACTIVE COMPONENTS. 2201Anamoniumd-a- Bromocamphor-n-su Zphoncite.2.0439 grams in 50 C.C.NWD line).Hg(ye1low). Hg(green).a $13.94" +14*72" +17*30"[u] +85.25 $90.02 -!-105*SOAmmonium1 -a- horn ocnmphor- rr-sulphonate.2.0150 grams in 50 C.C.Na(o line). Hg(ye1low). Hg(green).- 13.62" - 14'47" - 16-97" - 84 '58 - 89-85 - 105.38Resolution of Externully Compensated Tetraliydro~uiizaldine.On treating racemic tetrahydroquinaldine hydrochloride withrather less than half an equivalent of ammonium d-a-bromocamphor-Ir-sulphonate, as already described (Trans., 1899, 75, 1066), thegreater part of the Z-base separates as the sparingly soluble Z-tetra-hydroquinaldine d-a-bromocamphor-n-sulphonate ; the latter salt isobtained in a state of high purity by crystallisation from alcohol.The mother liquors, containing the whole of the d-base, are thentreated with sodium hydroxide, the base separa.ted, and distilled ;VOL. XCVII.7 2202 POPE AND READ : EXTERNALLY COMPENSATED TETRAHYDRO-I-Base, d-Acid.0,2118 gram in 30 C.C.h ' q ~ line). Hg(ye11ow). Hg(green).a +0*91" +0*96" +1*14"[a] +32'22 333.99 +40*37the rotatory power of the distillate is then determined, and the per-centage of d-base calculated; in general, about 80 per cent. of d-baseis present. This base is next dissolved in the requisite amount ofdilute hydrochloric acid, and to the hot solution is added ammoniumI-a-bromocamphor-r-sulphonate ; the proportion of the latter usedis about 2 per cent. less than the quantity equivalent to thed-tetrahydroquinaldine present, Crystallisation does not ordinarilyoccur spontaneously, but may be induced by inoculation with a littlecrystalline .d-tetrahydroquinaldine I-a-bromocamphor-lr-sulphonate ;the la,tter is readily obtained by evaporating a few drops of thesolution to dryness, and rubbing the residue with ether. Afterinoculation, crystallisation takes place with considerable rise intemperature, and almost the whole of the d-base separates as thesalt of the optically active acid ; the salt is purified by crystallisationfrom boiling alcohol, and its physical properties correspond withthose of the enantiorvorphously related salt.The base extracted from the final mother liquors consists mainlyof I-tetrahydroquinaldine, which may be separated by again treatingwith ammonium d-a-bromocamphor-crr-sulphonate in hydrochloricacid solution. The practically quantitative separation of theexternally compensated tetrahydroquinaldine into its optically activecomponents is thus effected.d-Base, 1-Acid.0.2034 gram in 30 C.C.H g(p el lo w) .Na ( D I in e). Hg( green 1.- 0.87" - 0 '92" - 1.05" - 32 '08 - 33 '92 - 40 '1QUINALDINE AND ITS OPTICALLY ACTIVE COMPONENTS. 2203d- Tetrahydroquinaldinne at 16'.NaD (line). Hg(ye1low). Hg(green).u +61'13" +63'66" +71*85"[u] +59+79 +62'26 +70*271- Tetiuhydroquimldine at 20'.Na(o line). Hg(yel1ow). Hg (green).- 61 '20" - 63-80" - 71.97"-60.04 -62.59 70.61d-(1-> T e t rah y dro qwinaldine d-(l-> a-Bromo carnphor-n-sulphonat e.On dissolving pure d-tetrahydroquinaldine in the equivalentquantity of d-a-bromocamphor-?r-sulphonic acid solution and7 3 2204 POPE AND READ : EXTERNA1,LY COMPENSATED TETRAHYDRO-d-Base, d-Acid.0'2143 gram in 30 C.C.1-Base, 1-Acid.0.2082 gram in 30 C.C.d- and l-Tetrahydropuinaldine Hydrochloiide, CloH~3N,HCl,H20.For comparison with the salts wit,h optically active acids, it seemeddesirable to determine the rotatory powers of the hydrochloridesprepared from pure d- and Ltetrahydroquinaldine; these salts wereprepared as already described, and recrystallised from acetone.Thefollowing determinations were made in aqueous solution in 4-dcm.tubes at 1 7 O :Hydrochloride of d-Base.Weight in 30 C.C. Na(o line).Hg(ye11ow).0*1111 gram a + 0.99" + 1-02"66-83 68.860'2004 ,, a 1 7 8 1 '8466-62 68'86a 3.64 3-78 [.I 66.33 68'88[a1r.10'4116 ,,Hg(green>. + 1 - l i "78.982'1078 -594-3178'5QUINALDINE AND ITS OPTICALLY ACTIVE COMPONENTS. 2205Eydrochloride of l-Base.Weight in 30 C.C. N ~ D line). Hg(yel1ow). Hg(green1.0'1136 grain a - 1 *01" - 1.05" - 1 *20"0.2062 ,, a 1-83 1 -90 2'18a 3 *56 3.70 4 *2366'68 69-32 79.2s66.56 69.11 79-29[a1 66.47 69.80 78.98[a11.10.4017 ,,Mean molecular rotatory powers : [MI,, 134.24" ; [M]Hg (yellow) 139.15" ;The mean rotatory dispersions are, for Hg(green)/Na(yellow) = 1.1 86,It will be seen that the values for the two hydrochlorides agreevery closely, and that the specific rotatory power decreases slowlyas the concentration increases.The mean values are appreciablyhigher than were obtained by Pope and Peachey, who found thevalue [MI, - 121-7O for Z-tetrahydroquinaldine hydrochloride indilute aqueous solution.From the values now recorded, the molecular rotatory powers ofthe optically active basic and acidic ions can be calculated for com-parison with those directly observed with the tetrahydroquinaldinehydrochlorides and the ammonium a-bromocamphor-a-sulphonatesby means of the formuh:[MI of dBdA + [MI of ZBdA =Twice [MI of dA ion.[MI of dBdA-[MI of lBdA=Twice [MI of dB ion.[M]Hg (green) 159'14".and for Hg(yelIow)/Na(J'ellow) = 1 -03 7-The following values are t h u s calculated :Basic ion. Acidic ion.Nap line).Hg(ye1low). Hg (green). Na(D line). Hg(ye11ow). Hg(:(sraen).[MI 126'4" 131.7" 152.2" I 273.8" 287.3" 337'8"Dispersions : Hg(green)/Na(yellow) = 1.203 ; Hg(green)/Nt~(ye~ow) = 1 '230 ;Hg(;(sellow)/Na(Sello\r) -- 1 '041 ; Hg(yellow)/Na(yeUow)= 1 '049.The appended values are those deduced from the examination ofthe hydrochlorides of the base and the ammonium salts of theoptically acfhe acids ;N a ( o line). Hg(:(selIow). Hggreen). Na(D he). Hg(ye1Iow). Hg(green).Dispersions : Hg(green)/Na(yellow) = 1'186 ; Hg(green)/Na(ye~ow) = 1.243 ;[MI 134.2" 139.1" 159.1" I 278.7" 295'2" 346'6"Hg(yel~ow)/Na(;(sellow)= 1 -037 ; Hg(yellow)/Nqyellow) = 1 *059.It is noteworthy that, although the molecular rotatory powersand dispersions calculated in the two different ways respectively areof the same order, the differences are much greater t'han could beattributed t o experimental errot .The discrepancies are scarcelytraceable to the disregard of the concentration of the solution2206 EXTERNALLY COMPENSATED TETRAHYDROQUINALDINE.examined, and are possibly due t,o the operation of isomeric change(compare Kipping, Trans., 1905, 87, 628); the whole question isnow being further studied.The Opticdly Active Benzoyltetrahydroq~~nald~ne~.With the aid of the pure optically active tetrahydroquinaldineswhich have been now prepared, it is possible to obtain the benzoylderivatives in a greater state of purity than previously, and to makestandard measurements of their rotation constants ; these are ofinterest because the sign of rotation of the base changes duringpreparation of the benzoyl derivative. The benzoyl derivativeswere prepared in the manner already described, and the followingdeterminations made in absolute alcoholic solution in 4-dcm.tubes :Benzoyl-d-t etrahydroquinale.Weight in 30 C.C. t. N ~ D line). Hg(yel1ow). Hg(green).0.1602 gram ......... 17" a - 7'03" - 7-40" - 8'59"0.5031 gram ......... 18 a 21.93 23-00 26 '68[a] 329.1 346-4 402.1[u] 326.9 342.9 3 9 i *7B enzo yl-1-t e t rah y dro quinaldin e .0.1751 gram ......... 17" a + 7.70" -f- 8'08" + 9'40"[u] 329.8 346.1 402.60.5067 gram ......... 18 a 22-07 23'12 26'84The agreement between the specific rotatory powers of the d- andZ-isomerides for similar concentration and identical wavelength isvery close. The mean specific rotatory powers are, for the lowerconcentration at 17O :[u] 326.7 342.2 397'3[ a l D 32 9-46' ; [a]Hg (yellow) 346.26' ; [a]Hg (green) 402.38'.The rotatory dispersions are, for Hg(green)/Na(yellow) = 1.221, andFor the higher concentration at 18O, the mean values are :The rotatory dispersions are, for Hg(green)/NZt(yellow) = 1.21 7, andfor Hg(yellow)/Na(yellow) ,= 1 '048-I n view of the obvious high order of accuracy of the above deter-minations, it can be safely concluded that the rotatory dispersionsof the benzoyl derivatives diminish slightly as the concentrationincreases, and that the rotakory dispersions of the benzoyl derivativesand those of the parent bases are not identical.for Hg(yellow)/Na(yel~ow) = 1.051.[a], 326.79' ; [a]Hg (yellow) 342.54' [a]Hg (green) 397.50'-THE CHEMICAL LABORATORY,UNIVERSITY OF CAMBRIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702199

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

RESOLUTION OF EXTERNALLY COMPENSATED PAVINE, ETC, 2207CCXXIX.-T/ze Resolution of Externnlly CompensatedPavine and a- B? -0 rnocarnphor-r-sulp ho ?a ic A cid.By WILLIAM JACKSON POPE and CHARLES STANLEY GIBSON.PYMAN has recently demonstrated the probability (Trans., 1909,95, 1610) that the tetrahydropapaverine ” described by Gold-schmiedt (Morzutsh., 1886, 7,485; 1898, 19, 324) is the 1 : 2-dihydro-papaverine; some little uncertainty still remains as to theconstitution of Goldschmiedt’s base, and Pyman and Reynolds (thisvol., p. 1320) consequently prefer to call the substance pavine. Thepresence of an asymmetric carbon atom in the molecule of “tetra,-hydropapaverine,” or pavine, was demonstrated by the resolutionof the ba-se into its optically active components (Pope and Peachey,Trans., 1898, 73, 893), but in view of the interest which nowattaches to pavine it seemed desirable to apply to its resolution themethods which have been developed since that date.Preparation.of Ext ern&& Compensated Pavine.The method of reducing papaverine described by Pyman yieldsthe true tetrahydropapaverine as the chief product ; the followingprocess furnishes good yields of pavine. Papaverine (35 grams),hydrochloric acid (480 c.c.), and water (800 c.c.) are heated togetherunder reflux, powdered tin (95 grams) being added in smallportdons ; the tin becomes completely dissolved after about twentyhours’ boiling, and, on coding, a white, crystalline double saltseparates. The latter is crystallised once from boiling water, andfreed from tin by precipitation with hydrogen sulphide in boilingaqueous solution ; the filtered solution, on evaporation, yields pavinehydrochloride, which is purified by crystallisation from hot water.About onsquarter of the papaverine used is thus obtained aspavine, whilst the mother liquors contain both the latter base andtetrahydropapaverine.This considerable yield of pavine is ofinterest in connexion with the suggestion, made and rejected byPyman and Reynolds (loc. cit.), that this base is formed from someimpurity present in the papaverine used.Resolution of Externally Compensated Pavine.The resolution of pavine into its optically active components, bycrystallising the externally compensated base with one equivalentof d-bromocamphor-n-sulphonic acid, as described by Pope andPeachey, proceeds slowly, because the sparingly soluble crystallinesalt of the laevo-component and the resinous salt of the dextro2208 POPE AND GIBSON: THE RESOLUTION OFcomponent separate together ; the former salt is with difficultypurified from the latter by crystallisation.The following appli-cation of Pope and Peachey's method (Trans., 1899, 75, 1066)leads to a more satisfactory resolution of the base into its opticallyactive components.Externally compensated pavine hydrochloride is treated withone-half an equivalent proportion of ammonium d-a-bromocamphor-n-sulphonate in hot aqueous solution ; on cooling, I-pavine d-a-bromo-camphor-n-sulphonate separates in long needles not contaminatedby the resinous salt of the d-base.That the salt ZBdAthus obtained contained none of the salt dBdA was shown bytreating it, without recrystallisation, with ammonia, and deter-mining the specific rotatory power of the liberated base; in an8 per cent. chloroform solution the value [a],, - 152*0° was obtained,which agrees well with the more accurately determined constantgiven below. It is clear that the resolution proceeds in accordancewith the first type distinguished by Pope and Read (this vol.,p. 989).Although the separation of a pure I-pavine salt is rendered easyby the above method, yet the yield is not large, because on workingin concentrated solutions, or on concentrating the mother liquors,hydrochloride of the base crystallises together with the salt ZBdA;the following modification of the original pocess, which is applicablein other cases, was therefore adopted.The salts formed by pavinewith inorganic acids are in general sparingly soluble in water, butPope and Peachey found that the d-camphor-B-sulphonates of thebase are readily soluble in water (Trans., 1898, 73, 902); theexternally compensated pavine was therefore dissolved in one equi-valent proportion of d-camphor-P-sulphonic acid, and to the solutionwas added half an equivalent of ammonium d-a-bromocamphor-n-sulphonate, water being used as the solvent, and the solutionbeing kept as concentrated as conveniently possible. Of the numberof salts which might be formed in the mixed solution, Lpavined-a-bromocamphor-n-sulphonate is the least soluble, and, as onlysufficient ammonium salt was added fo allow of the formation ofthis salt, it was to be expected that practically the whole of theE-pavine would separate as the pure salt.In accordance with thisanticipation, the solution, prepared as described above, depositedalmost all of the I-pavine as the sparingly soluble d-a-bromocamphor-r-sulphonate, and the deposit'ed salt, after once recrystallising fromboiling aqueous alcohol, has the properties previously ascribed t o it.After the I-pavine d-a-bromocamphor-n-sulphonate has beenobtained in a pure state, the residual base-consisting almost entirelyof d-pavineis precipitated from the mother liquors by addition oEXTERNALLY COMPENSATED PAVINE, ETC.2209ammonia, and its actual content of d-pavine determined from itsrotatory power in chloroform solution; the base is then dissolvedin the requisite amount of d-camphor-P-sulphonic acid solution, andammonium Z-a-bromocamphor-?r-sulphonate added in just sufficientquantity to precipitate all the d-pavine as the salt dBZA, which,being enant.iomorphously related to the crystalline. salt ZBdA dealtwith above, exhibits ordinary physical properties identical with thoseof the latter.d-Pa& e l-a-Bromocamphor-?r-sulphonat e,C,,H,304N,C,oH,40Br* SO,H.This new salt separates immediately in long, colourless needleswhen the above operation is performed; after cooling, the salt iscollected and recrystallised from boiling aqueous alcohol.Thesubstance decomposes at 290-300°, and gave the following r e d t son analysis:0.0933 gave 0.1888 CO, and 0-0482 H,O. C=55-19; H=5-78.C3,H3,08NBrs requires c = 55.19 ; = 5-87 per cent.d- and l-Pavine.These substances separate on cooling a, hot dilute alcoholic solu-tion of the corresponding bromocamphorsulphonates after additionof ammonia; after recrystallisation from benzene, the bases meltedat 224O. The following determinations of rotatory power were madewith the recrystallised substances after drying at llOo :1- Pavine.0'1983 gram, made up to 20 C.C. withNa(o line). Hg(ye11ow). Hg(green).Chloroform, in a 2-dcm. tube a t 23":u -2.990" -3.119" -3.500"[u] - 150'8 - 157'3 - 176.50,7316 gram, made up to 20 C.C. withchloroform, in a l-dcm.tube at 22":u -5'445" -5T30" -6-500"[a] - 148'8 - 156'6 - 177.7d -Pa vine.0.1970 gram, made up to 20 C.C. withchloroform, in a 2-dcm. tube at 23":N;~(D line). Hg(ye1low). Hg(green).a +2'960" +3*093" +3*470"[u] + 150.3 + 157.0 + 176.1chloroform, in a l-dcm. tube at 22":a +5'241" +5-520" +6*250"0'7033 gram, made up to 20 C.C. with[a] + 149'0 + 157.0 + 177.7The values obtained under similar conditions for the twoenantiomorphously related bases are in good agreement, and areslightly higher than those previously recorded ; the specific rotatorypower diminishes slowly with increasing concentration, and thenumbers afford some indication that the rotatory dispersion isdependent on the concentration of the solution22 10 RESOLUTION OF EXTERNALT,Y COMPENSATED PAVINE, ETC.dl-Pavine dl-a-Bromocamphor-n-suZphonat e,2C20H2,0,N,2C,oH1,0Br*S0,H,H,0.In view of the sparing solubility of the two crystalline salts dealtwith above, nam:ly, ZBdA and dBZA, and of the fact that the saltsdBdA and ZBZA are resinous and also sparingly soluble, it seemeddesirable t o examine the salt formed by externally compensatedpavine with the externally compensated a-bromocamphor-7r-sulphonicacid. This substance was easily prepared by dissolving dl-pavinein an aqueous solution of the requisite amount of &-a-bromo-camphor-n-sulphonic acid, and evaporating to a gummy consistency ;the residue crystallises on keeping, and after several recrys-tallisations from strong alcohol the salt is obtained in radiate clustersof soft, white, silky needles.The salt is optically inactive inaqueous solution, and the following analyses were made on theair-dried material :0.1111 gave 0.2204 CO, and 0.0595 H20.0.3233, heated at l l O o for three hours, lost 0.0044.C=54.11; H=5*97.H,O=1*35.C,oH76016N2Br2S2,H20 requires C = 54.44 ; H = 5-94 ;H20 = 1-36 per cent.This fully racemic salt thus differs from the active ones previouslydescribed, which crystallise without water, in containing water ofcrystallisation; it is a h very soluble in water, and melts withoutblackening at 248-250°, whilst the active salts are sparingly solubleand decompose at 290--3OOO.The Resolution of Externally Compensat ed a-Bromocamphor-a-szclphonic A cid.The ease with which the resolution of externally compensatedpavine can be effected with the aid of d- and Z-a-bromocamphor-7r-sulphonic acid suggests that the optically active bases could beused in effecting the resolution of the externally compensated acidin accordance with the method of Pope and Peachey.With this object, an aqueous solution was prepared containingd-pavine (one equivalent), ammonia (one equivalent), and dZ-a-bromo-camphor-n-sulphonic acid ; a clear solution is obtained on boilingwith addition of a little alcohol, and, on cooling, the greater partof the alkaloid separates as the crystalline d-pavine I-a-bromo-camphor-n-sulphonate.After recrystallisation from water, thelatter salt was treated with ammonia, and the resulting ammoniumI-a-bromocamphor-n-sulphonate separated by crystallisation ; 0-1080gram 09 this ammonium salt, made up t o 20 C.C. with water, gaveaD - 0.915O in a 2-dcm. tube at 22O, whence [aID - 84.7O. The lattePOPE AND GIBSON: ROTATORY POWERS, ETC. 2211value is identical with that observed with ammonium I-a-bromo-camphor-?r-suIphonate prepared from I-camphor, so that theresolution of the externally compensated acid has been effected.The mother liquors from which the d-pavine salt had beenseparated were next treated with ammonia, filtered, and evaporateduntil crystallisation occurred ; on recrystallising the residue fromaqueous alcohol, pure ammonium &a-bromocamphor-n-sulphonatewas obtained. 0.1082 gram, made up to 20 C.C. with water, gavea, +0*915O in a 2-dcm. tube at 22O, whence [a], +84*6*, whichis the value ordinarily assigned to pure ammonium d-a-brorno-camphor-n-sulphonate.THE CHEMICAL LARORATOKY,UNIYERSITY OF CANBILIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702207

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

POPE AND GIBSON: ROTATORY POWERS, ETC. 2211CCXXX.-The Rotatoqy Powers of the Sulta of cl- ccnd1- Carnphor-t3-sutphonic Acid with d- and LPavine.By WILLIAM JACKSON POPE and CHARLES STANLEY GIBSON.IT has been repeatedly shown that a, knowledge of molecularrotatory power in aqueous solution renders great service in con-nexion with the resolution of externally compensated bases (oracids) by crystallisation with a powerful optically active acid (orbase); the theoretical scheme which leads to the indicated useof rotatory power determinations is too well known to requirerecapitulation (see preceding paper). A t the same time, theexperimental data on which the scheme is based are not veryextensive, and it is of importance to collect further evidence injustification of the extended use now so frequently made of deter-minations of molecular rotatory powers in aqueous solutions, Forthis reason, we have made a careful polarimetric examination ofthe d- and I-pavine d- and I-camphor-P-sulphonates, and haveappended thereto a description of a number of metallic salts of thelatter acids.d-Pavine d-Camphor-/3-subph ona t e and 1-Pavine 1-Cam phor-P-sdphonate, C,oH,,O,N,C,,,II,;O*SO,H.These salts are obtained by boiling equivalent quantities of thesilver salt of the corresponding acid with the hydrochloride of thecorresponding base in aqueous solution ; after filtration and con-centration, they are obtained crystalline, and, on recrystallisatio2212 POPE AND UIBSON : ROTATORY POWERS OF THE SALTS OF D-from hot alcohol, separate in glistening clusters of colourless,transparent prisms. They are very soluble in water or hot alcohol,less so in acetone or cold alcohol, and almost insoluble in benzeneor ether, and do not melt on heating:c'=62.67;C=62*39;0.1156 of d-salt gave 0.2656 CO, and 0.0708 H,O.0.1175 of Z-salt gave 0.2694 CO, and 0.0726 H20.H = 6.85.H = 6.93.C,,H,,O,NS requires C = 62.78 ; H = 6.86 per cent.The following det,erminations of rotatory power were made in2-dcm.tubes at 21°, water being used as the solvent:dBdA.0.1094 gram in 20 C.C.Na(o line). Hg(yelIos 1. Hg(green).a +1*3?2" 4-1'454" +1%63"[a] +125'4 +132-9 +l52'0[M]t718.7 +761.5 4-871.0lBlA.0.1142 gram in 20 C . C .Na(o line). Hg(ye11on). Hg(green).- 1 '438" - 1 *510" - 1 *733"- 125.9 - 132.2 - 151.7- 721 '5 - 757 *5 - 869.3From the above values the mean molecular rotatory powers of thesalts dBdA and ZBZA in dilute aqueous solution are calculated as[MI, +_ 720.1°, [MIHg +_ 759-5", and [MIHg +_ 870-lo.The mole-cular rotatory dispersions are for Hg(green)/Na(yellow) = 1.208, and forHg(yellow)/ Na(ye11ow) = 1.055-d-Pa vin e I-Ca?nphor-&xdph ona t e an d 1- Pa vin e d-Cam pho r-P-sulphonate, dBlA and ZBdA.These s a h were prepared and crystallised in the same way asthe two preceding ones, from which they differ but little in solu-bilities and general physical properties ; they crystallise in small,colourless needles :0.1189 dBZA gave 0.2726 CO, and 0-0716 H,O. C = 62-53 ; H = 6-74.0.1033 ZBdA ,, 0.2370 (20, ,, 0.0645 H20.C=62.57; H=6*98.CNH,,O,NS requires C = 62.78 ; H = 6.86 per cent.The following determinations of rotatory power were made in2-dcm. tubes at 20°, water being the solvent:dBlA.0'1200 gram in 20 C.C.Na Hi? HR(D line). (yellow). (green).a +1'315" +1*365" +1.540"[a] +109.6 +113-8 +128'3[MI + 628.1 + 652.1 t 735.1I ZSdA.0.1226 gram in 20 C.C.( D line). (1 ellow). (green). Na Hg Hg- 1.340" - 1 -380" - 1.580"- 109'3 -113 6 - 128'9- 626'3 - 651 '0 - 738.6The mean molecular rot'atory dispersions of the salts CEBZA andZBdA in dilute aqueous soIution are hence calculated as:[MI, +_ 627.2O9 [MI, (yel.) +, 651.5', and CMItI.4 (grell) +_ 736.8'AND L-CAMPHOR-P-SULPHONIC ACID WITH D- AND L-PAVINE.2213The molecular rotatory dispersions are for Hg(green)lNa(yellow) ==1.175, and f o r Hg(gellow)/NB(yellow] = 1.039 ; t1ieL.e values differconsiderably from the corresponding rotatory dispersions for thesalts dBdA and ZBZA, and this, as will be shown below, is to betraced to the differences in molecular rotatory dispersion betweenthe basic and the acid ions.It has been shown by Pope and Peachey (Trans., 1899, 75,1084)that the molecular rotatory powers of the basic and acidic ionsmay be calculated in the following manner from the molecularrotatory powers of the salts 6BdA and dBZA in dilute aqueoussolutions :[MI of dBdA+ [MI of dBZA=Twice [MI of dB ion.[MI of dBdA-[MI of dBZA=Twice [MI of dA ion.Applying these formulze to the values given above, the followingare obtained :Molecular rotations.Rotatory dispersions,Ka Hg Hg I H g ( P e d ITg(yellaw)/( D line). (yellow). (green). i Na(yel1ow). Na(pi1ow).&Base ion +673-6" +705*5" +803'4" 1.193 1047d-Acid ion +46*4 +54*0 +66*6 1 1'435 1-163ConsideratJon of the above table indicates that the discrepanciesbetween the rotatory dispersions of the two pairs of enantio-morphously related salts are due to the existence of considerabledifferences between the rotatory dispersions of the basic and acidicions produced from the salts in aqueous solution. Whilst theoptical behaviour of the salts in question is up to this point entirelyin accordance with what would be expected, it is at least remarkablethat the molecular rotatory power of the acidic ion is considerablysmaller t'han the value hitherto accepted; the examination of theammonium salt of d-camphor-P-sulphonic acid and of the salts whichthe latter forms with d- and I-tetrahydroquinaldine (Pope andPeachey, Trans., 1899, 75, 1085) leads to the conclusion that theacidic ion has the molecular rotatory power [MID +51-7O, whilstthe results stated above indicate that the value should be takenas [MI, +46*4@ It thus seemed important to obtain furtherexperimental data to supplement the small amount.of informationnow available concerning the rotatary powers of the &camphor-B-sulphonates, and Mr. P. V. Delahunty, M.Sc.Tech., has examinedcarefully purified samples of a number of such salts and of theparent acid; the results of his determinations are now given.d-Camphor-P-sulphonic A cid.This acid was prepared by the method described by Reychler(Bud,? SOC.chim., 1898, [iii], 19, la()), and, after separation fro2214 POPE AND GIBSON : ROTATORY POWERS OF THE SALTS OF D-the acetic acid solution, was recryst'allised repeatedly from ethylacetate ; during the crystallisation it was several times exposedover alkali hydroxide in a vacuum to free it from acetic acid, whichit retains with some tenacity. Solutions of the purified acid dissolvemagnesium freely in the cold and zinc on slight warming, but donot act on copper at the boiling point; the crystalline acid wassubsequently exposed to the air, and the following determinationsmade with two separate preparations :1.0012 required 0.15624 Na*OH for neutralisation.2.1170 required 0.33006 Na-OH for neutralisation.CloHl5O*SO3H = 90.51.C,oH,50*S03H = 90.41.2C,,Hl,0*803H,3H20 requires C,,H,,O*SO,H = 89.58.The above sample of the acid, which thus contains 90.45 per cent.of camphorsulphonic acid, gave the following results on deter-mination of rotatory power in aqueous solution in 2-dcm.tubesat 16O:Weight in 25 C.C. QD. [a],.1.1713 grams ...... +1*82" + 21 -44" + 49.7"1'0430 ,, . . . . . . + 1.65 + 21-86 -t-50.71'0431 ,, . . . . . , + 1'63 + 21.59 + 50.1The mean molecular rotatory power in the dilute aqueous solutionis thus [MI, +50-2O.Ammonium d-Camphor-P-sulphonate.This salt was prepared in the usud manner, and was obtainedas a mass of white needles; three separate prepara'tions indicated,on distillation with soda and titration with acid, the presence of7.59, 7-69, and 7.64 per cent.of ammonium, NH,, respectively, inplace of the theoretical percentage of 7.23. The cause of this slightdiscrepancy was not t'raced. The following determinations weremade in aqueous solutions at 16O, 2-dcm. tubes being used:Grams i n 25 C.C. a,. [ a l D * [ M I D .1-1726 + 1-92" + 20 46" + 50 *go1.0536 1'72 20.40 50'81.1295 1-85 2047 50.8The mean molecular rotatory power in dilute aqueous solutionis thus [MID +50*8O.Po t a ssium d-Cam p h o r-/3-suJp h ona t e .This salt was prepared in the usual manner, and when purifiedby crystallisation from alcohol, is obtained in colourless needles,which contain no solvent of crystallisation AND L-CAMPHOR-P-SULPHONTC ACID WITH D- AND L-PAVINE, 22 150-7860 gave 0.7150 K2PtC1,.The following determinations of rotatory power were made inK= 14.60.C1,H,,O,SK requires K = 14.44 per cent.aqueous solutions at 1 6 O in 2-dcm.tubes:Grams in 25 C.C. a D * [a],. [MI,.1.1190 4- 1 $4" -t. 18'32" + 49 '5"1.0956 1-61 18.37 49 -61 *0910 1 *60 18 *33 49 -5Calcium d-Gamphor-j3-sulphonate.On treating a solution of the acid with lime, precipitating theexcess of the latter with carbon dioxide, filtering, and Concentrating,the calcium salt is obtained in large, colourless prisms:1.0685 gave 0.2540 CaSO,.2'0298 lost 0.2613 at 105O.(C,oH,,0,S)2Ca,4H20 requires Ca= 6.97 ; H20 = 12-54 per cent.The following determinations were made in aqueous solutions atGrams in 26 C.C.a,. La1D. [MI,.1 '0042 -?- 1-39" + 17'30" + 49 '6"1.0184 1 -40 17-18 49.31'2048 1.65 17.12 49 '1Ca= 6.99.H20 =12*87.16O in 2-dcm. tubes :The mean molecular rotatory power in dilute aqueous solution isthus [MI, +49*3O.Barium d-Camphor-P-szclphoIznte, (CloH,50*S03)2Ba,3H20.This salt wm prepared by treating the ammonium salt -withbaryta, separating the excess of the latter in the usual way, andconcentrating the filtered solution until crystallisation occurred ;it was purified by recrystallisation from water, and finally obtainedin colourless needles. The solvent of crystallisation is only lostcompletely at 120-130°, and the anhydrous salt is hygroscopic :1-0124 gave 0.3600 BaSO,.Ba= 20.90.1.7860 lost 0.1473 at 130O. HzO=8.25.(C,,H,,04S),Ba,3H,0 requires Ba=20*98; HzO = 8.27 per cent.The following determinations were made in aqueous solutions atGrams in 25 C.C. QD. [ulD* [MID.1-1760 -I- 1 -43" + 15.30" + 49'6"10136 1 *23 15.16 49.51'0422 1.27 15-23 49 *71 6 O in 2-dcm. tubes :The mean molecular rotatory power in dilute aqueous solution isthus [MID + 49*6O2216 POPE AND GIBSON: ROTA'I'OKT POWERS OF THE SALTS OF D-Zinc d-Carnphor-~-sulphonate, (C,,H,,04S),Zn,6H20.The zinc salt, prepared by double decomposition between thebarium salt and zinc sulphate, crystallises in lustrous, six-sidedprisms, which melt at 167O:0.9052 lost 0-1540 at 130O.1.0136 gave 0.1300 ZnO. Zn=10-29.The following determinations were made in aqueous solutions atGrams in 25 C.C.a,. [a],IT,0=17.01.(C,,HI,04S),Zn,6H20 requires H,O = 17.01 ; Zn = 10.33 per cent.16O in 2-dcm. tubes:1 -0001 + 1 *24" + 15-49' 4- 49 '2"1'0130 1-26 15.55 4 9 41.0132 1.25 15.42 49'0The mean molecular rotatory power in aqueous solution is thus[MI, +49*2O.Silver d-Cam& o r-p-s ulph onat e, C1,H 150 S0,Ag.This salt, prepared by dissolving silver hydroxide in the aqueousacid, crystallises in colourless needles, and is readily soluble in waterand alcohol:1.0506 gave 0.4466 AgC1.The following determinations were made in aqueous solutions atAg = 31.97.CloHl,O,SAg requires Ag = 31-86 per cent.16O in 2-dcm. tubes:Grains in 25 C.C. a,. [alD. [ bf]D-1*0010 + 1-17" + 14.61" + 49 .5°1.0730 1 *25 14 56 49'41'1008 1-28 14-54 49.2The mean molecular rotatory power in dilute aqueous solution isthus [MI, +49*4O.I n addition to the salts described above, the cupric salt,crystallising with 5.5 molecules of water in pale blue rhombs, andt h e ferric salt, crystallising in yellowish-green leaflets, have alsobeen prepared.It is noteworthy that in the concentrations used, all the abovecompounds, with the exception of the free acid and its ammoniumsalt, give molecular rotatory powers less than [MID + 50°; this valueis notably lkss than was obtained by Pope and Peachey fromexamination of the ammonium salt.The still smaller value of[MI, +46.4O obtained for the acidic ion by the examination of thepavine salts described above possibly result from the greater degreeof molecular dilution in which the latter salts were examined; iASD J,-CAMPHC~R-,8-SULPHONIC ACID WITH D- AND L-PAVINE. 2217this connexion, it is worthy of note that Walden (Zeitsch.pihysikat.Chem., 1894, 15, 196) found that the molecular rotatory powersof the d-a-bromocamphor-n-sulphonates decreased slightly as thedilution increased in aqueous solution.d- and 1-Pauine d-Tartratea.Since externally compensated pavine cannot be resolved bycrystallisation with d-tartaric acid, owing to the formation of awell-characterised partly racemic dl-pavine d-tartrate (Goldschmiedt,Nonatsh., 1898, 19,321; Pope and Peachey, Trans., 1898, 73, 902),it appeared of interest to prepare and examine the d-tartrates ofboth d- and I-pavine.The salts were prepared by dissolvingequivalent quantities of the base and acid in aqueous alcvhol andevaporating to dryness ; the partly crystalline residues were thendissolved in dry acetone and precipitated as microcrystalline, whitepowders by the gradual addition of dry ether. Both salts absorbmoisture from the air, and are extremely soluble in water and mostorganic solvents ; they thus contrast strongly with dI-pavined-tartrate, which is stable in the air, and dissolves sparingly inwater and alcohol.d-Pavine d-Tartrat e, 2C~o'EE,04N,C4H606,6H~0.This salt readily absorbs moisture after drying in a vacuumdesiccator, and, for purposes of analysis, was exposed to the airuntil constant in weight :0-1170 gave 02401 CO, and 0.0682 H20.0.4364 lost 0.0394 at 1 0 5 O . H,O=9.03.C44H,,0,0N, requires C = 56.14 ; H = 6-86 ; H,O = 11.50 per cent.An accurate determination of the water of crystallisation couldnot be made, because decomposition sets in before the salt becomesanhydrous; the above analyses merely show that the salt is thenormal tartrate.0.2260 gram, dried at 105O, and made up to 20.0 C.C. with watera t 2 2 O , gave a, +3*56O in a 2-dcm. tube, whence [ulD +157-5O.C=55*97; H=6*52.It melts and decomposes at 156-158O :1-Pavine d-Tar t mt e, 2 C,,H,,0,W2,C4Hg06,H,0.After drying at 105O, this salt was found by the followinganalyses to retain one molecule of water of crystallisation; like thecorresponding salt of d-pavine, it, melts and decomposes at156-158' :VOL. XCVlI. 7 2218 CROSSLEY AND GITLTNQ : SYNTHESIS OE'0.1658 gave 0.3759 C02 and 0.0950 H,O. C = 61.81 ; H = 6.40.0.1694 ,) 0.3862 CO, 77 0.0968 H20. C = 62-16 ; H= 6.39.C,,H,,0,,N2 requires C = 62-10 ; H = 6-40 per cent.0.2810 gram, made up to 20.0 C.C. with water at 22O, gavea, - 4 . 2 3 O in a 2-dcm. tube, whence [aID - 150.5O.UNIVERSITY CHEMICAL LABORATORY,CAMBRIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702211

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

2218 CROSSLEY AND GITLTNQ : SYNTHESIS OE'CCXXX1.-Synthesis of 1 : 1 : 3- Trimethylcyclohexene(cyclo Geraniolene).By ARTHUR WILLIAM CROS SLEY and CHARLES GILLING (Salters'Fellow).SOME years ago Tiemann and Semmler (Ber., 1893, 26, 2708)prepared from the aldehyde citral (geranial) an open-chain hydro-carbon, C9HI6, named by them geraniolene. The constitution ofthis substance (I) follows from that of citral, which was establishedby Barbier and BouveauIt in 1896 (Compt. rend., 122, 393).When geraniolene is shaken with a 60 per cent. solution ofsulphuric acid, an isomeric change takes place, the open-chainhydrocarbon being converted into a mixture of two cyclic hydro-carbons, a- and P-cyclogeraniolene (I1 and 111), in which mixturethe a-variety is present in larger quantity:CMe,: CH*CH,*CH,*CMe: CH, -+ CMe2<E2: :>OH and(1.1 ~ (11.)-CHzCNe(111.)CMe2&,.CQ2>CH2The constitutional formuh of these hydrocarbons were ultimatelydetermined by Tiemann (Ber., 1898, 31, 816, 881; 1900, 33, 3711)from a study of their oxidation with potassium permanganate, theproducts isolated being two ketonic acids, isogeronic (IV) andgeronic (V) acids, together with as-dimethylsuccinic acid and BB-di-methylglutaric acidI : 1 : 3-TRIMETHYLCYCLOHEXENE (CYCLOGERANIOLENE). 2219The formation of the two modifications of cyclogeraniolene wasascribed to the addition of two molecules of water to the moleculeof geraniolene which were subsequently eliminated. According toTiemann, hydroxyl groups became attached to the carbon atomsbearing methyl groups, so that the first stage in the reaction consistsin the formation of a compound of formula VI; this is succeededby ring-formation due to elimination of a molecule of water andsubsequent union of the two carbon atoms marked *:It is obvious that the second molecule of water may be eliminatedfrom the compound (VII) in two different ways, and the formationof the two modifications of cyclogeraniolene is thus explained :A third hydrocarbon having the formula :is a possibility, but no evidence of its presence is recorded.Tiemann did not actually isolate either of the hydroxy-compoundsV I or VII, but a synthesis of 1: 1: 3-trimethylcyclohexan-3-01(VII) has now been effected by a method which leaves no doubtas to its constitution, and it is found that this alcohol can be readilyconverted into cy clogeraniolene, thus affording confirmation ofTiemann's supposition.The starting point was 1 : 1-dimethylcyclohexan-3-one (VIII),prepared by the action of reducing agenh on 5-chloro-1 : l-dimethyl-A~cyclohexen-3-one (Trans., 1907, 91, 81).When this ketone istreated with an ethered solution of magnesium methyl iodide andthe product decomposed with water, trimethylcyclohexanol (IX) isobtained as a well-defined, crystalline substance, melting at 72'5O(X- 1Fuming hydrobromic acid converts the alcohol into 3-broms3 : 1 : 3-t.rimethylcycZohexane (X), which, when treated withalcoholic potassium hydroxide, losses the elements of hydrogen7 F 2220 CROSSLEY AND QILLING : SYNTHESIS OFbromide in two ways, giving rise to the same mixture of hydro-carbons as described by Tiemann.The work of Tiemann on the preparation of cyctogeraniolene wasrepeated by Wallach (Annalen, 1902, 324, 97), who prepared thenitrosate of a-cyclogeraniolene, and proved that it was transformedby the action of alkalis into the oxime of 1 : 1 : 3-trimethyl-A2-cycZo-hexen4-one. The identity of the hydrocarbons described in thepresent communication with cyclogeraniolene has been establishedby preparing this crystalline nitrosate, and from it the above-mentioned oxime ; further, by oxidising the hydrocarbons withpotassium permanganate, when the products isolated were as-di-rnethylsuccinic acid, isogeronic and geronic acids, the two latterbeing identified as their semicarbazones, melting at 195O and 164Orespectively .EXPERIMENTAL.>CH,.I : 1 : 3-Trimethytcyclohexan-3-oZ, CMe,<CI12 CH,*CMe(OH) CH2Thirty grams of 1 : l-dime~hylcycZohexan-3-one (Trans., 1907, 91,Sl), dissolved in an equal volume of ether, were gradually added toa Grignard reagent prepared from 33 grams of methyl iodide and5.7 grams of magnesium turnings in 100 C.C.of dry ether. Theethereal solution was gently boiled on a water-bath for one hour,cooled, and poured into a concentrated solution of ammoniumchloride, t o which ice had been added. The ethereal layer wasseparated, the saline solution extracted three times with ether, themixed ethereal liquids washed, dried over potassium carbonate, andevaporated, when a solid residue (23 grams=70 per cent.of thetheoretical amount) was obtained, which, after drying on porousplate, was recrystallised from dilute alcohol and analysed :0.1061 gave 0.2965 CO, and 0.1209 H,O.C,H,iO requires C = 76-06 ; H = 12.67 per cent.1 : 1 : 3-Tm'methyZcyclohexan-3-ol is readily soluble in the cold inall the ordinary organic solvents, and may be crystallised fromdilute alcohol or dilute acetone, from which it separates in beautifulfour-sided, elongated prisms, having a characteristic, stronglycamphoraceous odour, and melting at 72'5O.C=76*21; H=12-66.3-Bromo-I : 1 : 3-trimethylcyclohexane.Trimethylcyctohexanol, in quantities of 10 grams at one time,were sealed up with 50 C.C. of a solution of hydrogen bromide(saturated at Oo) in small soda-water bottles, which were heatedin a boiling-water bath for one hour.The mixture was poureI : 1 : 3-TItIMETHYLCYCI.OHEXENE (CYCLOGERANIOLENE). 2221into water, extracted three times with ether, the ethereal solutionwashed with a solution of sodium hydrogen carbonate, then withwater, dried, evaporated, and the residue distilled under diminishedpressure, when, after two distillations, 11.5 grams passed overconstantly at SS0/20 mm.:0.1527 gave 0.1375 AgBr.C,H,,Br requires Br = 39-02 per cent.Bromotrimethylcyclohexane is, when freshly prepared, a faintlyyellow liquid boiling at 8 8 O / 20 mm., which, especially on exposureto air, evolves fumes of hydrogen bromide and rapidly decomposes,becoming green, and finally black.The rapidity with which thisdecomposition takes place accounts, no doubt, €or the low result forbromine quoted above.Br = 38-31.1 : 1 : 3-Trimetliyl43- and 42-cyclohexenes. a- and /3-cyclo-Geranwlene,Thirty grams of potassium hydroxide were dissolved in a littlewater, and added to 35 grams of bromotrimethylcyclohexane dis-solved in 150 c . ~ . of absolute alcohol. The whole was heated on thewaterrbath for one hour, cooled, poured into water, and extractedfour times with ether; the ethereal solution was washed, dried, andevaporated, and the residue distilled, when the following fractionswere collected : 110-136O = 2 grams; 136-142O= 13 grams ;142-150° = 3 grams. m e fraction 136-142O was twice redistilledover sodium and analysed:0.1244 gave 0.3971 CO, and 0.1430 H,O.C9H,, requires C= 87.10 ; H= 12.90 per cent.Trimethylcyclohexeme (cyclogeruniolene) is a colourless, refractiveliquid, possessing a pronounced terpene-like odour.It boils at137-140°/760 mm., and has a density of 0.8085 at 15O/15*.This hydrocarbon has also been prepared by the action ofdehydrating agents on trimethylcyclohexanol (potassium hydrogensulphate at 130-140°, and zinc chloride at 160-170°) and byshaking trimethylcyclohexanol with dilute sulphuric acid (D 1-67)for several hours at the laboratory temperature. If this latteraction is prolonged for several days, the principal product is apolymeric modification of the hydrocarbon boiling at 165-170°/30 mm.When dissolved in glacial acetic acid and treated with amylnitrite and nitric acid according to the directions of WallachC = 87.06 ; H = 12.772.222 SYNTHESIS OF 1 : 1 : 3-TKIMETHYLCYCLOHEXENE.(Zoc.cit.), _the mixture of trimethylcydohexenes, prepared by any ofthese methods, yielded the crystalline nitrosate of 1 : 1 : 3-trimethyl-A3-cycZohexene, melting at 103-104°, which by the action of sodiummethoxide was transformed into the oxime of 1: 1 : 3-trimethyl-A%yclohexen-4-one, melting at 128O.The hydrocarbon was oxidised with potassium permanganate asdescribed by Tiemann (Ber., 1900, 33, 3711), when the residueobtained on working up the product partly solidified on keeping.It was spread on plate, and the residue crystallised from water,when it melted at 140O.The identity of this substance with as-di-methylsuccinic acid was proved by the mixed melting-point method,and by preparing from it an anilic acid, which melted at 186O.The porous plate (see above), on extraction with ether, yieldedan oil which was dissolved in alcohol and treated with a solutionof semicarbazide acetate. After some time a solid wils deposited,melting at 185-192O, which crystallised from alcohol, in whichsolvent it is only sparingly soluble, in feathery needles, melting anddecomposing at 198O. (Found, N = 18.46. Cl,Hl,03N3 requiresN=18.34 per cent.) These data prove the substance to be thesemicarbazone of isogeronic acid.On concentrat.ing the mother liquor from the above semicarbazone,a further quantity of crystals was obtained in glistening lamellae,melting, after recrystallisation, at 163O.(Found, N = 18.37.Cl,H,,03N, requires N = 18.34 per cent.) The substance was therefore the semicarbazone of geronic acid (compare Tiemann).It appeared to be of interest, in connexion with other work whichis in hand, to try the action of Grignard reagents, other thanmagnesium methyl bromide, on dimethylcyclohexanone, but theresults are most disappointing, as with increase in the molecularweight of the alkyl group, the yields of the products decreaserapidly, and further work in this direction has been abandoned forthe present.1 : l-DimethyZ-3-ethiyZcyclohexan-3-oZ, prepared by the action ofmagnesium ethyl bromide on 1 : l-dimethylcycZohexan-3-one, is acolourless, refractive liquid, boiling at 94O/ 30 mm., and possessing apenetrating, camphoraceous d o u r :0.1363 gave 0.3851 CO, and 0'1552 H20.C,,H2,0 requires C = 76.93 ; H = 12.82 per cent.The alcohol is readily converted by the action of fuming hydro-bromic acid into 3-bromo-l : 1-dimethyl-3-ethylcyclohexane (b. p.105-106O/ 22 mm.), from which substance hydrogen bromide iseliminated by potassium hydroxide to give a mixture of isomeric1 : I-dimethyl-3-ethylcyclohexenes :C = 77.05 ; H = 12.65MOORE : THE cmsrI'rumn OF GELSEMIUM. 22230.1210 gave 0.3848 CO, and 0.1425 H,O.Dim,ethyZethyZcyclohexene is a colourless, refractive liquid,, boilingC = 86.73 ; H = 13.09.CIoHl8 requires C = 86.95 ; H = 13.04 per cent.at 156O/760 mm.RESEARCH LABORATORY, PHARMACEUTICAL SOCIETY,17, BLOOMSBURY SQUARE, W.C

ISSN:0368-1645    

DOI:10.1039/CT9109702218

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

MOORE : THE cmsrI‘rumn OF GELSEMIUM. 2223CCXXXI1.-The Constituents o f Gelserniuna.By CHARLES WATSON MOORE.UNDER the title of “gelsemium” several of the pharmacopaeiasrecognise the dried rhizome and roots of Gelsemiurn sempervirens,Aiton, commonly known as the “ yellow jessamine.”The medicinal value of the plant is due to the presence of certainalkaloids, only one of which, however, has been obtained in a crystal-line condition.Among the earlier investigations of gelsemiurn there may be notedthat of Wormley (Amer. J. Pharm., 1870, 42, l), who isolated animpure alkaloidal product to which he gave the name of “ gelseminine.”This base was afterwards investigated by Sonnenschein ( B e y . , 1876,9, 1182) and Gerrard (Pharm. J., 1883, 13, [iii], 641), who assignedto it the formulse C,,H,,O,N, and C2,H,,0,N2 respectively.The last-mentioned investigator was the first to obtain gelsernine and its saltsi n a crystalline state. Thompson (Jahresbey., 2887,2218), who ascribedto gelsemine the formula C,,H,,O,,N,, showed that i t was accompaniedin the plant by a second alkaloid, which he obtained in an amorphouscondition, and which he designated as ‘‘ gelseminine.” Both gelsemineand gelseminine have more recently been examined by Cushny(Bey., 1893, 26, 1725), who proposed the formulae C,,H,,O,,N, andC,,H470,4N, respectively for the two bases. Spiegel (Be?*., 1893, 26,1045) suggested the formula C,,H,,O,N, for the crystalline base, whichwas confirmed by Gceldner (Ber. deut. pharm. Ges., 1895, 5, 330), whoobtained it in colourless crystals, melting at 160’.Some confusion has arisen as to the nomenclature of the two basesisolated from gelsemium; thus in the English literature the crystal-line base is referred to as gelsemine, and the amorphous product asgelseminine, whilst most of the German investigators, for example,Spiegel (Zoc.cit.) and Gceldner (Zoc. cit.), use these names in the oppositesense. I n this communication the English nomenclature is adhered to.The present investigation has resulted in the isolation of the tzlkaloidgelsemine in a pure crystalline condition. The base is found to meltconsiderably higher than has hitherto been recorded (m. p. 178”, instea2224 MOORE : THE CONSTITUENTS OF GELSEMIUM.of 160°), and it has been conclusively shown to possess the formulaC2,,H2,0,N2.Besides gelsernine and gelseminine, the presence of athird alkaloidal substance in gelsemiurn has been established. Thissubstance is weakly basic and amorphous, but possesses strongly toxicproperties.It was shown by Wormley (Zoc. cit.) that gelsemine was accompaniedin the plant by an acidic substance, which he called I‘ gelseminic acid,”an observation which has been confirmed by the present author.Gelseminic or “gelsemic ” acid has been shown by Schmidt (Arcii.Phurm., 1898, 236, 236) to be a monomethyl ether of t-esculetin(4 : 5-dihydroxycoumarin). Two sesculetin monomethyl ethers areknown, which have been incorrectly termed a- and P-methylmculetinrespectively (compare Beilstein’s Handbuch, III., 5 68), the compoundfrom gelsemiurn having been given by Schmidt the latter designation.It is evident, however, that the names a- a.nd P-methylsesculetin canonly be correctly applied t o substances possessing the following formulsrespectively (Pechmann and Kraft, Ber., 1901, 34, 423) :CH C*CH,Gelseminic acid is, therefore, xsculetin 4-(or-5)monomethyl ether,and it is considered desirable to retain for this substance the name‘( scopoletin,” as proposed by Eykman (Rac.trccv. chirn., 1884, 3, 171),who first obtained it from the rhizome of Xcopolicc japonica. Thefluorescent substance, known as P-methyl~esculetin, which is containedin the bark of Prztnus serotina and in jalap (Trans,, 1909, 95, 243;J. Amer. Chem. ~ o c . , 1910, 32, 93) would accordingly be moreappropriately termed scopoletin.A summary of the results of the complete investigation of gelsemiurn,is given a t the end of this paper.E XPE R I MEN TAL.The material employed in this investigation consisted of the driedrhizome and roots of Gelsemiurn senapemipcens, Aiton.A portion (20 grams) of the crushed drug was extracted successivelyin a Soxhlet apparatus with various solvents, when the followingamounts of extract, dried a t looo, were obtained :Petroleum (b.p. 35-50”) extracted 0.39 gram = 1’95 per cent.Ether ,, 0.16 y y 0.80 ,)Chloroform ), 0.34 ,, 1-70 y yEthyl acetate ,, 0.16 ,, 0’80 ,)Alcohol ?, 1’63 $ 7 8.15 ,,- -Total ,........... 2‘68 grams=13.4MOORE : THE COXSTITVENTS OF OELSEMIUM. 2225For the purpose of a complete examination, 49.44 kilograms of theground material were completely extracted with hot alcohol, Afterthe removal of the greater portion of the alcohol, a viscid, dark-coloured extract was obtained, amounting to 9.20 kilograms.Distillation of the Extract with Steam.A quantity (2 kilograms) of the above-mentioned extract, represent-ing about 10.75 kilograms of the drug, was mixed with water, andsteam passed through the mixture for some hours.The distillate,which amounted to 5 litres, contained some drops of oil floating on thesurface. It was extracted with ether, the ethereal liquid being driedand the solvent removed, when a small quantity of an essential oil masobtained, This was a very pale yellow liquid, and amounted to about2 grams, being thus equivalent to about 0.019 per cent.of the weightof the drug.Non-volatile Constituents of the Extract.After the distillation of the extract with steam, as described above,there remained in the distillation flask a quantity of a brown resin(A) and a dark-coloured aqueous liquid (B). The resin was collected,and repeatedly washed with water until nothing further was removed,the washings being added to the a bove-mentioned aqueous liquid.This resin was a brown, viscid solid, and amounted to 412 grams. Itwas dissolved in alcohol and mixed with purified sawdust, thethoroughly dried mixture being then successively extracted in aSoxhlet apparatus with petroleum (b. p. 35-50"}, ether, chloroform,ethyl acetate, and alcohol.Petroleum Extract of the Resin (A).Isokation of Pentatriacontane, C35K72, and Emodim Monomethyl Ether.The petroleum extract, which formed a brown, semi-liquid mass andamounted to 224 grams, was dissolved in 2 litres of warm ether andthe solution kept for some days, when a small quantity of an almostcolourless substance separated, This was collected and washed with alittle ether, after which it was dihtilled under diminished pressure.The distillate, which rapidly solidified, was crystallised from ethylacetate, when it was obtained in small, colourless, glistening leaflets,melting at 75'.(Found, C = 84.9 ; H = 14.5. Calc., C = 85.4 ; H = 14.6per cent.)This substance was therefore pentatriacontane.The ethereal liquid, from which the pentatriacontane had beenremoved as above described, was extracted with successive portions ofan aqueous solution of sodium carbonate, and finally washed wit2226 MOORE : THE CONSTITUENTS OF GELSEMLUM.water. The alkaline liquids and washings were united, acidified, andextracted with ether, when 15 grams of a viscid, oily liquid wereobtained.On distilling this liquid under diminished pressure, i tpassed over between 245Oand 255"/25 mm., and then became almostsolid. It consisted of a mixture of fatty acids, which were examinedin connexion with a similar product obtained from the non-acidicportion of. the petroleum extract after its hydrolysis.The ethereal liquid, from which the pentatriacontane and free fattyacids had been removed, as above described, was subsequently shakenwith a solution of sodium hydroxide.The alkaline extracts, whichhad assumed a red colour, were acidified and extracted with ether, whena very small quantity of an orange-yellow substance was obtained.This when crystallised from ethyl acetate formed orange-red prisms,which melted a t about 190°, and when mixed with a little ernodinmonomethyl ether, fusion occurred at the same temperature. Thequantity so obtained was too small for analysis, but the substanceappeared to be emodin monomethyl ether (m. p. 195O), since on heatingfor a short time with concentrated sulphuric acid it gave a substancesoluble in aqueous sodium carbonate and agreeing in its propertieswith emodin.Isolation of GL Phytosterol, C,lH,,O.The ethereal liquid which had been extracted with alkalis, as abovedepcribed, was evaporated, when a quantity of an oily product wasobtained. This was hydrolysed by heating with an alcoholic solutionof potassium hydroxide, the alcohol removed, water added, and thealkaline liquid extracted with ether.The ethereal solution waswashed, dried, and the solvent removed, when a quantity of brownresinous material was obtained. This was extracted with cold absolutealcohol, in which only a small portion dissolved. The alcoholic solu-tion was concentrated, and a little water added, when, on keeping, asubstance separated in flat needles, which after recrystallisation froma mixture of dilute alcohol and ethyl acetate formed glistening,flat needles, melting at 136".The amount of this substance was1.5 grams :0.1600, on heating at 1 loo, lost 0.0072 H,O.0*1336* gave 0.4110 CO, and 0;1455 H,O.H,O = 4.5.C = 83.9 ; H = 12.1.C,7H,60,H,0 requires H,O = 4.5 per cent.C,7H,60 requires C = 83.9 ; H = 11.9 per cent.This subst.ance thus agrees in composition with a phytosterol, and i tyielded the colour reaction of that class of compounds. A determinationof its rotatory power gave the following result :* Anliydrous substanceMOORE : TEE CONSTITIJENTS OF GELSEAHUM. 22270.2393, made up t o 20 C.C. with chloroform, gave aD -0'58' in a2-dcm. tube, whence [a]D -40.4'.The acetyl derivative, when crystallised from acetic anhydride,separated in needles melting at 125-127'.The brown resinous material, from which the phytosterol had beenremoved by extraction with alcohol, as above described, was thoroughlyexamined, but nothing definite could be isolated from it.I t appearedto consist of a mixture of hydrocarbons.IdentiJication of t?k Fatty Acids.The alkaline aqueous solution of potassium salts, from which thephytosterol had been removed by extraction with ether, as abovedescribed, was acidified and again extracted with ether, the etherealsolution being washed, dried, and the solvent removed. A quantity(10 grams) of fatty acids was thus obtained, which, when distilledunder diminished pressure, passed over between 240" and 260'/25 mm.As these acids distilled within the same range of temperature as thosepreviously obtained, which existed in the drug in the free state, for thepurpose of their examination the two portions were mixed.Twenty grams of the mixed acids were converted into their Ieadsalts, and the latter digested with ether, when a portion dissolved.Both the soluble and insoluble portions were decomposed by hydro-chloric acid, and the regenerated fatty acids purified by distillationunder diminished pressure. The soluble portion of the lead saltsyielded 11 grams of liquid acids, while the insoluble portion gave8 grams of solid acids.The Liquid Acids.-These acids, when distilled under diminishedpressure, passed over at about 225'/15 mm.An analysis and adetermination of the iodine value gave the following results :0.1430 gave 0,4030 GO, and 0.1518 H,O.0.4224 absorbed 0,6783 iodine.C= 76.8 ; H = 11.8.Iodine value = 160.C18H3402 requires C = 76.6 ; H = 12.1 per cent.Iodine value = 90.1.C16H3202 ,, C=77*1 ; H.= 11.4 ,, ,) ,) =181.4.In order to obtain more definite information respecting the natureof the above mixture, a quantity of it was oxidised according to themethod described by Lewkowitsch (Chemiccd Technology and Analysisof Oils, Fats, and Waxes, 1904, Vol. I,, p. 360). This resulted in theformation of tetrahydroxystearic acid (m. p. 157-160') and a smallquantity of dihydroxystearic acid (m. p. 125-127'). It may thus beconcluded that the liquid acids consisted chiefly of a mixture of oleicand linolic acids, the latter in predominating amount.The Solid Acids.-These acids melted at about 55', and on analysisgave the following result 2228 MOORE : THE CONSTITUENTS OF GELSEMIUM.0.1383 gave 0,3842 CO, and 0.1590 H20.C = 75.8 ; H = 12.7.ClsH,,02 requires C = 75.0 ; H = 12.5 per cent.C18H3602 ,, C== 76.1 ; H= 12.7 ,,From this result it would appear that the solid acids consisted of amixture of palmitic and stearic acids, the latter predominating.Ethereal ExtructIof the Resin.Ierolation of Ipurunol, C23H3802(OH)2.This extract was a brown, amorphous mass, and amounted to10 grams. It was redissolved in about 500 C.C. of warm ether andkept for some days, when a small quantity of an almost colourless,amorphous substance separated. This was collected and crystallisedfrom a mixture of pyridine and dilute alcohol, when it formedmicroscopic needles, melting a t 290'.(Found, C = 72.3 ; H = 10.5.Calc., C = 72.6 ; H = 10.5 per cent.)This substance was thus identified as ipuranol, and when treatedwith sulphuric acid and acetic anhydride it yielded the colour reactionshown by this coqpound. From it was also prepared diacetylipuranol,which separated from acetic anhydride in glistening leaflets, meltingat 162'.The ethereal solution from which the ipuranol had been separated,as above described, was examined, but nothing definite was isolatedfrom it.The chloroform, ethyl acetate, and alcohol extracts of the resinamounted to 35, 36, and 95 grams respectively, and consisted entirelyof amorphous products.Examination of the Aqueous Liquid (B).Isolation of Scopoletin.This liquid, as already indicated, represented that portion of theoriginal alcoholic extract of the drug which was soluble in cold water,and from which the previously-described resin (A) had been removed.It was thoroughly extracted with chloroform, these extracts beingwashed, dried, and the solvent removed.A quantity (about 5 grams)of a crystalline compound was thus obtained, which, after recrystallisa-tion from alcohol, formed long, almost colourless needles, melting at204'. Its alkaline solution showed a fine blue fluorescence,0.1430 gave 0.3286 CO, and 0.0550 H20. C = 62.6 ; H = 4.2.CIoH,O, requires C = 62.5 j H = 4.2 per centMOORE : TEE CONSTITUENTS OF GELSEMIUM. 2229A methoxyl determination by means of Perkin's modification of the0.2132 gave 0.2584 AgT.The substance is thus identi6ed as scopoletin, a methyl ether ofasculetin.Its acetyl derivative separates from acetic anhydride in colourlessleaflets, melting at 177".Dibromoscopoletin, C,,R,O,Br,.-Five grams (six atoms) of brominewere added t o a solution of scopoletin (2 grams) in about 50 C.C.ofchloroform. Hydrogen bromide was slowly evolved, but the liquid did notbecome colourless. After keeping some hours, a crystalline substanceseparated, which was removed and recrystallised from alcohol, when i tformed yellow, glistening plates, melting a t 249' :Zeisel method gave the following result :OMe= 16.0.C,HBO,*OMe requires OMe = 16*1 per cent.0,1682 gave 0.1800 AgBr. Br=45.5.This substance is therefore a dibromoscopoletin.Dibromoscopoletin is sparingly soluble in ether, chloroform, oralcohol, and its solution in alkalis shows a very intense green fluores-cence.The two bromine atoms in dibromoscopoletin appear to be in thebenzene nucleus, as this Substance instantly decolorises a cold alkalinesolution of potassium permanganate, and, therefore, still contains adouble linking.I n this respect it resembles the dibromocoumarindescribed by Perkin (Trans., 1870, 23, 371).On heating dibromoscopoletin with acetic anhydride, it is readilyacetylated. The acetyl derivative forms colourless prisms, meltinga t 224O.Isolation of Gelsemine, C2-,H2202NpC,,H,0,Br2 requires Br = 45.7 per cent.The aqueous liquid from which the scopoletin had been removed, asabove deFcribed, was extracted with successive portions of amylalcohol. This, however, only removed small quantities of an amorphousnitrogenous product, which was non-basic, and from which nothingdefinite could be isolated.The liquid was accordingly renderedalkaline with sodium carbonate and thoroughly extracted with ether,the combined ethereal extracts being washed, dried, and the solventremoved. A quantity of a pale yellow product was thus obtained,which crystallised very readily from acetone in handsome, glis teniogprisms, melting a t 175-178? After recrystallisation from the samesolvent, its melting point was constant a t 1'78'. The quantity isolatedamounted to 12 grams. It gave all the usual reactions characteristicof alkaloids 2230 MOORE : THE CONSTITURNTS OP GELSEMIOM.1.1448, when heated at 120°, lost 0.1774 acetone.0.1594" gave 0.4353 CO, and 0.0980 H,O.0*345S* ,, 27*5 C.C.N, at 27' and 764 mm. N=S*7.C3H60= 15.5.C = 74.5 ; H = 6.8.C,,H,,O,N, requires C = 74.5 ; H = 6.8 ; N = 8.7 per cent.C,,H,,0,N,,C3H60 requires C,H,O = 15.3 per cent.This substance, therefore, corresponds with the crystalline alkaloid,gelsemine, which has previously been isolated from gelsemium, and forwhich, as already mentioned, several empirical formula? have beensuggested, The fact that gelsemino crystallises from acetone with onemolecule of this solvent (see above) was con6rmed by mixing 1 gramof the air-dried preparation with 20 C.C. of water and distilling theliquid. On adding p-bromophenylhydrazine t o the distillate, a crystal-line precipitate was formed, melting a t 03', which corresponded in allrespects with acetone-p-bromophenglhydrazono.The molecular weight of gelsemine was determined by the cryoscopicmethod in acetic acid solution :0*5250*, in 24.90 acetic acid, gave At = - 0*270°.C,,H2,0,N, requires M.W. = 322.In benzene solution association occurs, and numbers corresponding0*6340*, in 20.70 benzene, gave At= - 0*248O.(C2,H,,02N2), requires M.W. = 644.In order to ascertain whether gelsemine is homogeneous, a quantitywas converted into its hydrochloride, and this salt recrystal-lised, first from dilute alcohol and then from water. The base wasthen regenerated, and, after crystallisation from acetone, againanalysed :M.W.= 305.with twice this molecular weight are obtained :M.W. = 605.0.1414" gave 0.3866 CO, and 0.0880 H,O.For further confirmation of the purity of the material, the base wasconverted into its nitrate. This salt, which forms glistening prisms,melting above 280", was recrystallised from water, and .the baseregenerated from it. The product so obtained, after crystallisationfrom acetone, gave the following results on analysis :C= 74.5; H=6*9.C,,H2,0,N2 requires C = 74.5 ; H = 6.8 per cent.0.1462" gave 0.3980 GO, and 0.0906 H,O.The formula of the base deduced from these analyses is in harmonyGelsemine forms a monohydrochloride cry stallising in small0.5614 gave 0*2310 AgCI.C = 74.2 ; H= 6%C,,H,,O,N, requires C = 74.5 ; H = 6.8 per cent.with the result ohtained from the analysis of the hydrochloride.prisms, melting indefinitely at about 300° :C1= 10.1.C,,H,,O,N,,HCl requires C1- 9.9 per cent,* Constant at 120"MOORE : THE CONSTITUENTS OF CIELSEMIUM.2231A determination of its specific rotatory power gave the following0.3100, made up to 20 C.C. with water, gave [.ID + 0'5' in a 2-dcmThe close agreement of these results shows conclusively that theA determination of its specific rotatory power gave the following0.4066*, made up to 20 C.C. with chloroform, gave [a]D +Oo39' in aresult :tube, whence [a], + 2.6'.empirical formula of gelsemine is C,,H,,O,N,.result :2-dcm. tube, whence [a]. + 15.9'.Examination of the Amorphous Alkaloidal Products.The alkaline, aqueous liquid from which the gelsemine had beenremoved by extraction with ether, as above described, was repeatedlyextracted by means of amyl alcohol, when a relatively small quantityof an amorphous, basic product was obtained.This appeared toconsist of a mixture, and two alkaloidal products were found to bepresent, one of which was much more strongly basic than the other.It was dissolved in chloroform, and extracted several tinies with1 per cent. aqueous hydrochloric acid, which removed the more stronglybasic product. The material obtained on rendering the acid extractsalkaline was isolated by means of chloroform, when it formed anamorphous, brown-coloured product. Neither the free base nor any ofits salts could be obtained in a crystalline condition.This morestrongly basic product appears to correspond with the amorphousalkaloid to which the name '( gelseminine " has been given.The chloroform solution from which the '( gelseminine " had beenremoved by means of 1 per cent. acid, as above described, was shakenmany times with 10 per cent. aqueous sulphuric acid, which slowlyremoved a small quantity of (L. very weakly basic substance. As inthe case of (' gelseminine," neither the free base nor its salts could beobtained in a crystalline condition. This substance responds to theusual alkaloid reagents, but appears to be stable only in the form of itssalts, as on keeping a chloroform solution of the base for some timethe product becomes insoluble in acids.The alkaline aqueous liquid from which the alkaloidal products hadbeen removed, as above described, was neutralised by means of aceticacid and treated with a solution of basic lead acetate.This produceda voluminous yellow precipitate, which was collected, washed, andthen suspended in water and decomposed by hydrogen sulphide. Onfiltering the mixture, a liquid was obtained which gave a bluish-black* Constant at 120"2232 MOORE : THE CONSTITUENTS OF GELSEMIUM,coloration with ferric chloride, and evidently contained a quantityof tannin, but no definite products could be isolated from it.The filtrate from the basic lead acetate precipitate was treated withhydrogen sulphide for the removal of the excess of lead, and thefiltered liquid concentrated under diminished pressure to a volume ofabout 2 litres. The Concentrated liquid contained a considerablequantity of a sngar, as i t readily reduced Fehling's solution, andyielded d phenylglucosazone, melting at 808-21 0'.One-fifth of the total liquid was diluted with water to 1 litre, about60 grams of concentrated sulphuric acid, diluted with a n equal weightof water, added, and the liquid repeatedly extracted with chloroformwith the object of isolating any organic acids present.As thisoperation removed only a small quantity of acetic acid, the acidaqueous liquid was boiled for an hour and again extracted with chloro;form, when nearly a gram of scopoletin was obtained. It thus appearsprobable that a glucoside of scopoletin was present in the originalaqueous liquid, but all attempts t o isolate this substance wereunauccessf ul.Pl~ysiological Teats.The following physiological tests were conducted in the WellcomePhysiological Research Laboratories by Dr.H, H. Dale, t o whom theauthor now wishes to express his thanks :A quantity (0.1 gram) of gelsemine hydrochloride, when injectedintravenously into a rabbit, caused practically no effect, a resultwhich is in agreement with an observation by Cushny.One milligram of the hydrochlorides of both the amorphous bases,when injected intravenously into rabbits, caused death from respiratoryfailure in about twenty-five minutes, preceded by convulsions.fluntmnry .The results of this investigation may be summarised as follows :The material employed consisted of the dried rhizome ,and roots ofGelsemiurn sempervirena, Ai ton.An alcoholic extract of the drug, when distilled with steam, yieldeda small amount of an essential oil. The nonLvolatile constituents, asobtained after treating the alcoholic extract with steam, consisted of abrown resin insoluble in water, and material which remained dissolvedin the cold aqueous liquid. The resin, amounting to about 3.8per cent. of the weight of the drug, yielded pentatriacontane ; traces ofemodin monomethyl ether; a phytosterol, C,7H,,0 (m. p. 136';[a], -40.4'); a small amount of ipuranol, C,,H,,O,(OH),; and amixture of fatty acids, consisting of palmitic, stearic, oleic, and linolicacids. The portion of the alcoholic extract of the drug which waEVANS: THE DISTILLATION OF MIXTURES, ETC. 2233soluble in water, and from which the above-described resin had beenremoved, contained scopoletin (admonomethyl ether of asculetin), whichwas present in the free state, and also in the form of a glucoside,together with a quantity ,of sugar, It yielded, furthermore, threealkaloidal products, one of which, gelsemine, has been obtained ina pure crystalline state, melting considerably higher than has hithertobeen recorded (1789 instead of 160°), and which has been conclusivelyshown to possess the formula C2,H,,0,N,. The other alkaloidalproducts, one of which corresponds with the so-called ‘( gelseminine ” ofThompson (Zoc. cit.) and Cushny (Zoc. cit.), were amorphous, andno crystalline derivative could be obtained from them.THE WELLCOME CHEMICAL RESEARUH LABORATORIES,LONDON

ISSN:0368-1645    

DOI:10.1039/CT9109702223

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

EVANS: THE DISTILLATION OF MIXTURES, ETC. 2233CCXXXII1.-The Distillation of Mixtures o f Enantio-morphously Related Substances.By WILLIAM CHARLES EVBNS.ALTHOUGH most of the possible types of behaviour which can ariseduring the distillation of mixtures have been experimentally studied,one of the simplest appears hitherto to have escaped investigation.This type is the one in which the two components of the liquidmixture have the same boiling point under all the pressures dealtwith, and in which the boiling points of mixtures of all com-positions are identical with those of the components under thesame pressure. Under these conditions it would be expectedthat all mixtures of the two components should behave on dis-tillation like a single substance; the composition of the vapourshould be the same as that of the liquid even when the pressureis varied, and no separation by fractional distillation should bepossible .Probably the only instances in which conditions of this highlyspecialised character can be experimentally realised are to be foundamongst mixtures of enantiomorphously related substances, and inthe study of such cases the delicate nature of the method availablefor determining the composition of the mixtures greatly facilitatesthe practical examination.It is, of course, well known that noseparation of the optically active components of an externally com-pensated substance can be effected by fractional distillation; but ithaa not previously been shown and is not immediately evidentVOL. XCVII.7 2234 EVANS: THE DISTILLATION OF MIXTURES OFthat mixtures of two enantiomorphously related isomerides in anycasual proportion would resist separation by fractional distillation.The following observations of the behaviour of optically activemixtures of d- and I-camphor and also of d- and I-tetrahydro-quinaldine were made at the suggestion of Professor Pope for thepurpose of obtaining the lacking experimental data.A. Distillation of Mixtures of d- and 1-Camphor.The mixtures were prepared from natural d-camphor and arti-ficially prepared externally compensated camphor in suitableproportions. In the following series of experiments, the camphorwas distilled from a retort heated by a naked flame, care beingtaken to prevent the distillate from solidifying in the neck of theretort; the distillate was collected in a number of fractions, and thespecific rotatory power of each determined in benzene solution,(1) d-Camphor alone was distilled, and the specific rotatorypowers of the first and last fractions of the distillate, in 10 per cent.solutions, found to be [a], + 40'85O and + 40-95O respectively; thesevalues are ident,ical within the limits of experimental error.(2) On distilling externally compensated camphor in the samemanner, the first and last fractions were found to be opticallyinactive.(3) A mixture consisting approximately of one part of Z-camphorand two parts of d-camphor was separated into five fractions bydistillation as above described under atmospheric pressure ; thespecific rotatory powers of the five fractions in 8 per cent.benzenesolution were [a], + 27*15O, + 27*02O, + 27.37O, + 26*66O, and+ 26'14O respectively. A similar distillation was performed withanother mixture, and yielded five fractions with the specific rotatorypowers [a], + 21.40°, + 20'09O, + 19*75O, + 20*21°, and + 20s050respectively. It will be noted that the rotatory powers of the fivefractions composing either series are not identical within the limitsof experimental error, so that some slight degree of separation isindicated. I n these determinations, however, no special precautionswere taken to ensure thorough admixture of the two componentsbefore distillation; it therefore seemed possible that, owing to thereadiness with which camphor sublimes, the two components, presentin the solid state in different quantities, might have sublimed atdifferent rates determined by the surface exposed and the tem-perature attained by the solid.(4) The contingency just indicated waa obviated by meltingtogether the mixturea of d- and I-camphor before introducing theminto the retort; after taking this precaution, one mixture, similarto those examined in (3), gave five fractions, of which the specifiENANTIOMORPHOUSLY RELATED SUBSTANCES.2235rotatory powers in 8 per cent. solutions were [a], + 20*24O, + 20*66O,+ 20*55O, + 20.60°, and + 20-56O respectively. These five values areidentical within the limits of experimental error, and it is thusindicated that intimate mixtures of d- and Z-camphor cannot bealtered in composition by distillation under atmospheric pressure.B.Distillation of Mixtwres of d- and l-Camphor in Steam.(5) A mixture prepared from d-camphor and externally com-pensated camphor, and consisting of about two parts of d-camphorand one of Z-camphor, was distilled in a current of steam, threefractions being collected; these, and the residue left in the distillingflask, were collected and dried in the air. The three fractions andthe residue gave the specific rotatory powers, in 4 per cent. benzenesolution, of [a],, + 16'44O, + 15*24O, + 14'55O, and + 27*90° respec-tively ; repetition of the operation with another similar mixtureyielded four fractions and a residue, which gave the specific rotatorypowers of [u],, + 1 5 * 9 5 O , + 14*28O, + 1 4 * 1 5 O , + 14*49O, and + 27015~respectively.No precautions were taken to ensure intimate admix-ture of the CE- and dl-camphor previous to the steam distillation, andthe variations in the specific rotatory power of the distillate andthe large difference between these values and those referring to theresidues left in the distilling flask might, it was anticipated, bedue to differences in the rate of sublimation in steam of the solidactive and externally compensated substances.(6) That the cause just suggested of the variable rotatory powersof the distillate and residue is the true one was demonstrated by thefollowing trials. A mixture of approximately one part of d-camphorand two parts of externally compensated camphor WBS melted andallowed to solidify, then roughly ground, and subjected to steamdistillation as described under (5).The three fractions of camphorwhich distilled and the residue which remained in the still, examinedin 5 per cent. benzene solution, gave the specific rotatory powers[ u ] ~ + 21*54O, + 21*26O, + 21'62O, and + 21'55O respectively.The close approximation to constancy of these numbers shows thatmixtures of d- and Z-camphor, if care is take to ensure intimateadmixture, behave like a single substance on distillation in acurrent of steam.C. Dietillatioolc of Mixtures of d- and l-Tetra~ydroqwircaldine.As indicated in the previous pages, the investigation of theproblem under consideration with the aid of mixtures of d- andLcamphor is complicated by the fact that these substances are solidat the ordinary temperatures, and that their melting and boilingpoints do not differ greatly.Further information ww therefore7 ~ 2236 EVANS: TEE DISTILLATION OF MIXTURES7 ETC.sought from the study of mixtures of d- and I-tetrahydro-quinaldine.Externally compensated tetrahydroquinaldine wa8 treated withd-a-bromocamphor-wsulphonic acid, and the laevo-component of thebase in large measure separated by Pope and Peachey's method(Trans., 1899, 75, 1068); the mixture of the d-base with a smallproportion of the I-isomeride remaining after the separation of theI-tetrahydroquinaldine d-a-bromocamphorsulphonate was isolated bydistilling the mother liquors in a current of steam after additionof lime.Such mixtures were used in the following series ofexperiments.(7) Two specimens of the mixed d- and I-tetrahydr~uinaldine,containing (a) about 75 per cent. of d- and 25 per cent. of I-tetr*hydroquinaldine, and ( b ) about 56 per cent, of d- and 44 per cent.of I-tetrahydroquinaldine, were distilled from Wurtz flasks undera pressure of 300 mm. of mercury. The rotatory powers, a,, ofthe several fractions collected were determined in 100 mm. tubesat 16O:(a. ) (a. 1Fractions. QD. an.1 + 28-39' + 6 *85'2 28'47 6.873 28-48 6-874 28.46 6-895 28-41 6.876 28'44 6 '887 28'43 6.878 28'479 28'49(8) Two specimens of the mixed bases containing ( c ) about 65 percent. of d- and 35 per cent. of I-tetrahydroquinaldine, and (d) and(e) about 78 per cent.of d- and 22 per cent. of I-tetrahydroquinaldine,were distilled from a Wurtz flask over a naked flame, ( c ) underpressures increased gradually from 55 to 415 mm. of mercury, (d)under atmospheric pressure, and (e) under pressures which werecaused to rise and fall during distillation between 140 and 600 mm.of mercury. The rotatory powers observed in 100 mm. tubes ofthe various fractions collected are stated in the appended table:Fractions.12345678910(c. 1a,.3- 11.34"11'3911 '4011.3811.4011.3811'3911-3611-3911 *39(d. 1an.+ 33-42'33.4333'4633-4533 '4233'46(e. 1a,. + 33-40"33-3833'3933.4533.3933'4TERTIARY ACIDIC, ETC., DERIVATIVES OF D-CAMPHORIMIDE. 2237From the above results, it is to be concluded that on distillingmixtures of enantiomorphously related compounds under varyingconditions of pressure, no difference in composition is to be observedbetween the various fractions of the distillate by determination ofthe rotatory powers, and that< therefore no separation of suchmixtures into their optically active components is possible bydistillation. The fact that no change in rotatory power can bedetected in partly compensated mixtures of either d- and E-camphoror d- and I-tetrahydroquinaldine on fractional distillation maydoubtless be regarded as a demonstration that under the conditionsprevailing during distillation no combination of a racemic characterexists between the enantiomorphously related isomerides.The above are the first recorded instances of the theoreticallysimplest case arising in the distillatmion of mixtures, but no doubtsuch instances could be easily multiplied amongst other mixtures ofenantiomorphously related compounds.THE CHEMICAL LABORATORY,UNIVERSITY OF CAMBRIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702233

出版商:RSC    

年代:1910

数据来源: RSC

摘要:

TERTIARY ACIDIC, ETC., DERIVATIVES OF D-CAMPHORIMIDE. 2237CCXXX1V.-The Tertiary Acidic and Alkyl Deriu-atiz'es of d- Carnphorimide.By WILLIAM C'HARLES EVANS.ALTHOUGH it is generally recognised that phthalic acid and cam-phoric acid exhibit striking analogies in chemical behaviour, thesimilarities existing between the two acids have not previously beentraced in the reactions of their imides. At the suggestion ofProfessor W. J. Pope, I have therefore endeavoured to ascertainto what extent the reactions by means of which the imidogenhydrogen atom in pht.halimide can be replaced by halogen atomsand by alkyl groups are capable of effecting similar substitutions ind-camphorimide ; that a very deep-rooted analogy in chemicalbehaviour exists between the two acid imides will be evident fromthe description of the modes of preparation of the compoundsdescribed below.Preparation of d-Camphorimide.A comparison of the various methods which have been describedfor the preparation of d-camphorimide showed that a methodidentical in principle with that given by Bredt (Amden, 1903,528, 344) is the most convenient for use in the preparation of thi2238 EVANS: THE TERTIARY ACIDIC AND ALKYLsubstance.d-Camphoric acid is gently boiled in a retort providedwith a long and wide-necked retort heated in a metal-bath; at thesame time a brisk current of dry ammonia gas is passed throughthe boiling acid from a steel storage cylinder. After the evolutionof water vapour has completely ceased, the material is distilled,and, in order to ensure that-no camphoric anhydride has escaped.conversion, the distillate is once more distilled in a current ofammonia gas.The d-camphorimide thus obtained is practicallypure, and, after crystallisation from dilute alcohol, melts at 243O.d-Camphorb romoimide, C,H1,<CO>N co Br ,To a cold solution of 12.3 grams of d-camphorimide and 2.7 gramsof sodium hydroxide in 125 C.C. of water is gradually added a well-cooled solution of 11 grams of bromine in 250 C.C. of water; awhite, crystalline substance immediately separates, which, aftercollection and crystallisation from benzene, is obtained in minute,white crystals, melting at 154O. The compound thus obtaineddissolves readily in chloroform, acetone, ether, or ethyl acetate, andis less soluble in alcohol or benzene.It is decomposed by hydriodicacid in accordance witrh the equation :@,,H,,02:NBr + 2HI = C,,H,40,:NH + HBr + I,,and, in accordance with this reaction, its analysis was effected bydissolving a weighed quantity in chloroform, to which a littlepotassium iodide and acetic acid had been added, and titrating theliberated iodine with thiosulphate solution :0.1856 required 15.4 C.C. thiosulphate (1 C.C. = 0.022690.1822 gave 0.3086 CO, and 0.0930 H,O.G,,H,,O,NBr requires Br=30*77; C=40*16; H=5.39 per cent.The following determinations of rotatory power were made inSolvent. Wejght in 25 C.C. a,. [ale.Benzene ............... 0.4853 gram + 051" + 12-0"), ............... 0.5960 ), 0.587 11'2 * ,, ...............0.7707 ,, 0.81 12-0Chloroforni ......... 0 '4 16 1 , , 0.512 13'69 , 0.6843 ,, 0-785 13'0$ 9 0.7lGO ,, 1 *29 12.8The substance is not completely stable in moist air, and to thismust be attributed the slight variations in specific rotatory powerobvious above.Na.&3,0,,5H20). Br = 30.36.C = 40.20 ; H = 5'67.2.2-dcm. tubes at 18O :.................DERIVATIVES OF D-CAMPHORIMIDE. 2239co d-Camphoriodoimide, C, A,,<cO>NI.d-Camphorimide (5 grams, 1 mol.) and sodium hydroxide (1.3grams, 1 mol.) are dissolved in water (350 c.c.), and the resultingsolution added slowly and with vigorous stirring to a well-cooledsolution of iodine (3-5 grams, 1 mol.), sodium bromide (5 grams),and bromine (2.3 grams, 1 mol.) in water (50 c.c.).A greyish-blacksolid immediately separates, which, on stirring, becomes brown ;after collection, washing, and drying in a vacuum, the substanceis crystallised from hot benzene, from which it separates in minute,light yellow crystals, melting and decomposing at 207O. The iodn-derivative thus obtained is readily soluble in acetone, chloroform,or ether, but less soluble in alcohol or benzene. It reacts withhydriodic acid in accordance with the following equation :CloH,,02:NI + HI = C,,H,,02:NH + I,,and, in accordance therewith, the iodine was determined by dis-solving a weighed quantity in chloroform, adding potassium iodideand acetic acid, and titrating with thiosulphate :0.2458 required 17-25 C.C. thiosulphate (1 C.C. =0*022690.1632 gave 0.2330 CO, and 0.0717 H,O.The following determinations of rotatory power were made :N~S20.$H2O.I =40'76.C=38*94; H=4-88.CloH,,02NI requires I = 41.37 ; C = 39.09 ; H = 4.56 per cent.Solvell t , Weight in 25 C.C. QD. i.1 D. Chloroform ......... 0-3852 gram + 0.514" in 2.2-dcm. tube. + 15.2' v ,. ......... 0.5130 , , 0.690 ,, 2-2 ,,9 , ......... 0.6448 , , 0'406 ,, 1 ,,,> 0.7468 ,, 0.470 ,, 1 ,, .........Benzene ............. 0.4055 ,, 0.260 ,, 1 ,,,, ............... 0.4383 ,, 0'280 ,, 1 ,,The solutions in chloroform rapidly undergo decompositionbecome deep violet in colour.dCamphorme t hqlimide, CsH,,<cO>NMe. coThe method of preparation of this substance described15.315.715-716.016.0andbyHoogewerff and van Dorp (Rec.trav. chim., 1893, 12, 13) may beconveniently replaced by the following simpler one. Camphorimide(5 grams) is dissolved in a mixture of 1*125N-potassium hydroxide(27.2 c.c., 1 mol.) and methyl iodide (4 grams); potassium iodidecommences to separate in the cold, and the reaction is completed byheating for two hours on the water-bath. After separation of thepotassium iodide and evaporation of the alcohol, the residue isdissolved in benzene ; the benzene solution, an evaporation, yield2240 EVANS: THE TERTIARY ACIDIC AND ALKYLa crystalline residue of d-camphormethylimide, which, when crys-tallised from aqueous alcohol, melts at 46O. Hoogewerff and vanDorp give the melting point as 4 0 4 2 O . The substance is verysoluble in most organic solvents.This compound may be alsoconveniently isolated from the mixture obtained by heatingd-camphorimide, potassium hydroxide, and methyl iodide, by treat-ment with dilute sodium hydroxide solution in order to removeunchanged camphorimide, and crystallising the residue from dilutealcohol. The following determinations of rotatory power were made :Solvent. Weight in 25 C.C. a, in 2-dcm. tube. [ale.Alcohol ............ 0.6088 gram +0'54 " +11'1"), .............. 0.7843 ,) 0.69 11 -0 ,, ............... 0.8887 ), 0-81 11 '4Acetone .......... 0 *7070 , , 0'45 8.0,) ............ 1 -0365 ), 0'665 8.0, , ............... 1.0607 ,) 0.96 11.3d-Camphore thylirnide, c,H,,<~~>N co E t.d-Camphorimide (5 grams), 1.125N-potassium hydroxide (27.2c.c.), and ethyl iodide (4.4 grams) were heated together on thewater-bath for two hours ; after filtration, the alcohol was evaporatedoff, and the residual sweet-smelling oil washed with dilute sodiumhydroxide. The required ethyl derivative remained as an almostcolourless solid, which crystallised from dilute alcohol in long, whiteneedles, melting at 5 1 - 5 2 O ; the following determinations ofrotatory power were made :Solvent.Weight in 25 C.C. a, in 2-dcm. tube.Alcohol ............... 0.5216 gram + 052" ............... 0 -5370 , , 0.54), ............... 0.7588 ,, 0.76,) ............... 0'9757 , , 0.955Acetone ............ 0.5886 ,, 0.395,, ............ 0.7348 ,, 0 '52 ............ 1 '1890 ,) 0 -81 9 )[a],. + 12'4"12.612.512.58'48.88 '5Both the methyl and ethyl derivatives of d-camphorimide arepractically inactive in benzene solutions.d-Camphorb enzyZimi.de.This substance was obtained by Hoogewerff and van Dorp (loc.cit.) by heating benzylammonium camphorbenzylamate ; it is morereadily obtained by heating d-camphorimide (5 grams) with 1*125N-alcoholic potash (27.2 c.c.) and benzyl chloride (3.5 grams) on thewater-bath for two hours, evaporating off the alcohol, and addingdilute sodium hydroxide.An almost quantitative yield of thesolid product is obtained, which, after crystallisation from dilutDERIVATIVES OF D-CAM PHORIMIDE. 2241alcohol, melts at 60-62O. The following determinations of rotatorypower were made:Solvent. Weight in 25 C.C.Alcohol.. .............0'4539 gram) ) ............... 0.5776 , ,), ............... 0'8032 ,,Acetone ............ 0'7067 ) )), ............ 0.7358 ) ))) ............ 0,8361 ,,,, ............ o m 4 a ,,Benzene ............ 05476 ),)) ............ 0.9557 ,)aD in 2-dcni. tube.+ 0-46"0-560 -780.670.710.8150'940 -230.37[a],.-!- 12.7"12'112.111.912'012.211'95 - 24.8As in the previous cases the specific rotatory power is muchsmaller in benzene than in alcohol or acetone solutions.d-Camphor-p+itrob enzylimide, C,H,,(CO>N*CH,*C,H,.NO,. coCamphorimide (5 grams) dissolved in 1*125N-alcoholic potash(22.5 c.c.) wits heated with pnitrobenzyl chloride (4.75 grams) for ashort time on the water-bath; after separating the alcohol andtreating with dilute sodium hydroxide, the required derivative wasobtained as a yellow solid, which, after crystallisation from alcohol,formed yellow needles, melting at 133O :0.1985 gave 0.4709 CO, and 0.1142 H,O.The following determinations of rotatory power were made :Solvent. Weight in 25 C.C.a, i n 2-dcm. tubes. [.ID.Acetone ............ 0'5071 gram + 0 -48" + i i w) ) ............ 0.6795 ), 0'67 12.3), ............ 0.7848 ,) 0.775 12.3Benzene ............ 0.5630 ,) 0.115 2.6), ........... 0.9928 ,, 0.225 2.8The rotatory power has again a smaller value in benzene than inC= 64.69 ; H= 6.39.CllH2,04N2 requires C = 64.54 ; H = 6-33 per cent.acetone solutions.d-Camphorsodioimide, C,H,,<CO>NNa. coThis substance separates aa a white, flocculent mass on warminga solution of sodium (0.63 gram) in alcohol (2 c.c.) and benzene(5 c.c.), with addition of d-camphorimide (5 grams) dissolved inbenzene (20 c.c.); after collection and drying in a vacuum, thesubstance was analysed :0.6025 gave 0.1990 Na#04. Na= 10.70.The compound is readily soluble in water or alcohol, and is atC,,HI4O,NNa requires Na = 11.33 per cent.once decompoaed by acids.UNIVERSITY CHEMICAL LABORATORY,CAMBRIDGE

ISSN:0368-1645    

DOI:10.1039/CT9109702237

出版商:RSC    

年代:1910

数据来源: RSC