RUHEMANN : XANTHOXALANIL AND ITS ANALOGUES. 1847 CLXXVIII.-XccnthoxaZa.ilil and its A YL cc 1 og u es. By SIEGFRIED RUHEMANN. RECENTLY (Trans., 1906, 89, 1236) it has been shown that the yellow product which W. Wislicenus and Sattler (Bey., 1889, 24, 1245) obtained by the action of sodium ethoxide on a mixture of ethyl oxalate and acetanilide had the composition C2,,Hl2O,N2 ; it was found also that similar compounds could be prepared by using, instead of acetanilide, the acetyl derivatives of o-toluidine, p-toluidine, and a-naphthylamine. This reaction has now been applied t o the produc- tion of analogous substances from the acetyl derivatives of m-xylidine, pseudocumidine, P-naphthylamine, and p-aminophenetole. It was sug- gested (Zoc. cit.) that the formation of xanthoxalanil was preceded by the production of sodio-oxalacetanil, which, on treatment with a mineral acid, yielded the coloured condensa- tion product.Its constitution accordingly was represented by the formula This view concerning the mode of formation of xanthoxalanil induced me to examine whether the solution of sodio-oxalacetanil, when treated with pyruvic acid, instead of with a mineral acid, furnished the compound CO 7H2 PhN<CO*C:C(CH,)*CO,II’ just as indoxyl condenses with the ketonic acid to yield the correspond- ing indogenide; I found, however, that this reaction did not take place, but that in this case also xanthoxalanil was formed. I n my previous communication (Zoc. cit., p. 1239) I pointed out that1848 RUHEMANN : XANTHOXALANIL AXD ITS ANALOGUES. xanthoxalanil, on heating with an alkali, might be expected to undergo the following decomposition : PhN<co'FH2 ?o'co>NPh + 5H20 = 2C6H,*NH2 + (C02H), + co*c=c-co CO,H*CH,*C(CO,H): CH*CO,H, and furnish aconitic acid or its stereoisomeride. W.Wislicenus and Sattler (Zoc. cit.) had already studied this reaction; they stated that the compound was completely decomposed by caustic potash and yielded, besides aniline and oxalic acid, a mixture of volatile organic acids which reduced silver solutions, but they did not succeed in proving the presence of acetic acid which they expected to be formed. On repeat- ing this experiment I was able to prove that the alkaline solution, which wzts produced by the action of caustic potash on xanthoxalanil, contained oxalic acid and dianilaconitic acid.Their formation might be represented by the equation (C02H), + C,H,(CO,H)( CO*NHPh),. Similar to the decomposition of xanthoxalanil is the behaviour of alkalis towards its analogues ; thus from xanthoxalo-m-xylidil, m-dixylil- aconitic acid could be obtained. On hydrolysis of dianilaconitic acid with concentrated hydrochloric acid, aconitic acid is produced. These facts support the constitution of xanthoxalanil and its analogues which I put forward from the mode of their formation. These compounds when reduced with zinc dust and acetic acid, are transformed into colourless substances. Up t o the present I have isolated the reduction product which is formed from m-xanthoxalo- rn-xylidil. Its composition, C,,H,,O,N,, indicates that, under the influence of the reducing agent, the yellow condensation product has united with six atoms of hydrogen.There cannot be any doubt that two of them are rinited wibh the unsaturated group of the molecule of the yellow compound ; I hope to be able to ascertain the position of the other four hydrogen atoms in the reduced substance by examining the behaviour of this substance towards alkalis. The results of this examination, and of the further study of xanthoxalanil and its analogues, will be published shortly.RUHEMANN : XANTHOXALANIL AND ITS ANALOGUES. 18413 E X P E R I rd E N T AL. X c m thoxa lo -m-xylidi I , This substance is prepared in the same way as xanthoxalanil by adding ethyl oxalate to sodium ethoxide suspended in dry benzene, and mixing the solution which is thus produced with aceto-m-xylidide dissolved in benzene.The product, after standing for several days, is shaken with water, the aqueous layer filtered and treated with an excess of dilute hydrochloric acid, when a yellow solid is precipitated in the course of a few hours. This is readily soluble in hot nitrobenzene, sparingly, however, in boiling glacial acetic acid, and, on cooling, crystallises from either solution in yellow plates which melt and decompose at about 244' after having begun to darken a few degrees before : 0.2280 gave 13-6 C.C. moist nitrogen at 20' and 756 mm. N= 6.78. C,,H,,O,N, requires N = 6.73 per cent. Xanthoxulo-+-cumidil, Aceto-$-cumidide reacts with sodium ethoxide and ethyl oxalate under the same conditions as the former compound, and yields a yellow condensation product.This is very readily soluble in hot nitrobenzene, but sparingly so in boiling glacial acetic acid, and, on cooling, crystallises in yellow prisms which begin to darken a t 220' and melt at about 250' with decomposition : 0-2014 gave 0,5190 CO, and 0.0950 H,O. 0 2498 ,, 14 C.C. moist nitrogen at 18' and 757 mm. N = 6-44. C2,H2,O,N2 requires C = 70.27 ; H = 5.40 ; N = 6-30 per cent. C = 70% ; H = 5.46. Xanthoxa lo-/3-nuphth y Zuni I , This substance is formed from aceto-/3-naphthalide in the same way as its stereoisomeride. It differs from it inasmuch as it dissolves in boiling nitrobenzene with great difficulty, and, on cooling, crystallises in bronze-coloured, shining plates which decompose at about 290" :1850 RUHEMANN : XANTHOXALANIL AND ITS ANALOGUES.0.2013 gave 0.5375 CO, and 0.0635 H20. 0.2192 ,, 12.2 C.C. moist nitrogen a t 27" and 'i60 mm. N = 6.14. C= 72232 ; I3=3*53. C2SH1SOSN2 requires C = 73.0 ; H = 3.47 ; N = 6.08 per cent. Xanthoxa Eo- p-e thoxylanil, ( p)C2H,0*C,H,-N<co*~H2 co*c== ?o*Co>N*C,H,*OC2H,( c-co p). This compound is prepared in the same way as the former substances by the action of phenacetin on ethyl oxalate in the presence of sodium ethoxide. Owing to the fact that phenacetin is sparingly soluble in benzene, a large quantity of the solvent is required. The condensation product is sparingly soluble in glacial acetic acid, but readily so in hot nitrobenzene, and, on cooling, crysballises in orange plates which melt at about 260' with decomposition : N= 6.25.0.2493 gave 13.6 C.C. moist nitrogen a t 1s' and 755 mm. C,,H2,07N2 requires N = 6.25 per cent. Action of Alkalis o n Xanthoxakcnil and its Homologues. On digesting xanthoxalanil with dilute caustic potash on the water- bath, it dissolves and deposits an oil which was identified as aniline. The yellow alkaline solution, after removal of the aniline by ex- traction with ether, when treated with an excess of dilute hydro- chloric acid, yields a solid. This dissolves in sodium carbonate and is precipitated on adding an acid to the solution. This property has been made use of for purifying the compound. It is readily soluble in alcohol, and crystallises from this solution in bunches of colourless needles which melt at 199-ZOOo after having begun t o soften a few degrees before : 0.2048 gave 0,4992 CO, and 0.0913 H20.0.2116 ,, 16.4 C.C. moist nitrogen a t 25' and 769 mm. N=8*75. The behaviour of this substance, which is recorded below, charac- terises it as dianilaconitic acid. Michael (Amer. Chenz. J., 1887, 9, 192) obtained a compound with this formula by allowing an aqueous solution of the dianiline salt of aconitic acid to remain for some time at the ordinary temperature ; he stated that it crystallised from alcohol in long, prismatic needles, which had a faint pink shade and melted at 188-1 89". These properties of Michael's dianilaconitic acid hardly differ from the behaviour of the substance which I obtained from xanthoxalanil except in the melting point. Indeed, isomeric dianil derivatives would correspond to a compound having the C = 66-48 ; H = 4.95.C,,H,,O,N, requires C = 66-67 ; H = 4.94 ; N = 5-64 per cent.RUHEMANN : XANTHOXALANIL AND ITS ANALOGUES. 1851 same structure as aconitic acid, but a closer comparison of the two substances will be necessary before they can be regarded as different. The production of d ianilaconitic acid from xnnt hoxalanil is accom- panied by the formation of oxalic acid. This is contained in the acid filtrate from the derivative of aconitic acid ; it was characterised by a calcium determination of the salt which is precipitated from the solution by means of ammonia, calcium chloride, and acetic acid : 0.4410, on ignition, left 0.1695 CaO. CaC20,,H20 requires CaO = 38.35 per cent. That the compound which is formed from xanthoxalanil is indeed dianilaconitic acid follows from its behaviour on hydrolysis, when aconitic acid and aniline are produced. This decomposition may be effected by caustic potash, as is indicated already by the fact that aniline is formed on digesting xanthoxalanil with the alkali, but it is preferable to use concentrated hydrochloric acid for this purpose. The solid dissolves after two to three hours' boiling wiLh the acid.The solution, when cold, is extracted several times with ether and the ethereal solution decolorised with animal charcoal ; on evnpor- ating the ether, colourless crystals of an acid separate which was identified as aconitic acid by the melting point (186-187') and by the analysis of the silver salt : CaO = 38.43. 0.2520, on ignition, left 001642 Ag.Ag = 65-15, C,H,O,Ag, requires Ag = 65-45 per cent, Di-m-xyZidiZaconitic Acid, C,H,(C02H)[CO*NH6CBH3( CEt3)2],. On digesting xanthoxalo-mxylidil with dilute aqueous caustic potash, it turns red and then rapidly dissolves. The yellow solution, when treated with an excess of dilute hydrochloric acid, yields a solid which readily dissolves in boiling alcohol and, on cooling, crystallises in bunches of colourless needles ; these, after recrystallisation from the same solvent, melt at 196-197' with evolution of gas: N= 7.49. C2,H2,O,N2 requires N = 7.37 per cent 0.2193 gave 14.4 C.C. moist nitrogen a t 20' and 758 mm. Reduction of Xar~thoxalo-rn-xylidil. The boiling solution of xanthoxalo-m-xylidil i n glacial acetic acid is decolorised by zinc dust ; on adding water to the filtrate, a solid is precipitated which dissolves slowly in cold sodium carbonate solution with the exception of a small quantity of a resinous product. The filtrate, when treated with an excess of hydrochloric acid, yields a VOL. LXXXIX. 6 F1852 FRANKLAND AND TWISS: THE INFLUENCE OF VARIOUS white precipitate which crystallises from dilute alcohol in colourless plates melting at 160--161° : 0.2013 gave 0.5025 CO, and 0.1118 H20. 0.2116 ,, 12.2 C.C. moist nitrogen at 17" and 755 mm. N = 6.64. C24H2605N2 requires C = 68.24 ; H = 6-16 ; N = 6-63 per cent. C=68*13 ; H=6-17. 0.2020 ,, 0.5055 CO, ,, 0.1121 H20. C= 68.24 ; H= 6.16. The substance is fairly soluble in cold alcohol, readily so when hot; the alcoholic solution gives with ferric chloride a deep violet coloration which, on warming, changes to red. GONVILLE AND CAIUS COLLEGE, CAMBRIDGE.