S h d h e d C p r~o n arom hypot.hrJtr G) &yp*thtru (a) c v t p w f. 0. .

By WINIFRED GRACE HURST and JOCELYN FIELD THORPE. THE first reference to the fact that th0 reduction of aromatic nitro-compounds to the corresponding aminoderivatives through the agency of tin and hydrochloric acid often leads to the production of by-products containing chlorine seems to have been made by Fittig (Ber., 1875, 8, 15), who was able t o isolate some chlorobromoaniline by the reduction of pbromonitrobenzene. Subsequently, Kock (Ber., 1887, 20, 1569) obtained considerable quantities of pchloroaniline by the reduction of nitrobenzene under similar experimental conditions. No one who has used this method of reduction can have failed to notice the production of these halogenated by-products, although very few atkempts seem to have been made either to identify them or t o work out an experimental basis for their formation. That, under certain conditions, they may constitute the main product of the reaction, has been shown by Gabriel and Stelzner (Ber., 1896, 29, 305), who, by the reduction of nitromethylindazole, obtained only the chloroaminomethylindazole : c1 Gabriel and Stelzner consider that the reaction is due to, the formation of the intermediate hydroxylamine derivative, which, in the presence of the halogen acid, passes into the halogen substituted amine in accordance with the observation of Bamberger (Ber., 1895, 28, 251). They also observe that if the para-position is occupied, the halogen enters the ortho-position, as, for example, in the productJon of chlorobromoaniline in the manner described by Fittig (Eoc. cit.). During the autumn months, bhe staff and research students of this laboratory have been engaged in the preparation of considerable quantities of phenacetin, and, in the first instance, this substance was prepared by the method recommended by Hinsberg (Amnalen, 1899, 305, 278), in which tin and concentrated hydrochloric acid are used as the reducing agents, and the product is directly acetylated by acetic anhydride :

No abstract

The formation of ethyl /3-imino-a-cyanoglutarate in tho foregoing condensation is evidently analogous to the production of the dimolecular nitriles which E. von Meyer (J. p r. Clhem., 1889, [ ii ],39,189) and Riess and E. von Meyer (ibid., 1885, [ ii], 31, 112) prepared by t h e action of sodium on a solution of the nitrile in dry ether. They represent this reaction as occurring in the following way : MeCiN +-~ Me$!:NNa Me$XNH MeCHNa.CN MeCH'CN MeCNa'CN or From our experiments, however, it would appear that the nitrile group of the sodium derivative passes into the imino-group in accordance with the equation given on the previous page, The greatest yield of the condensation product is formed when the reacting substances are in the proportion of one molecule of ethyl cyanoacetate to one molecule of its sodium derivative. A greater or less amount of sodium than this proportionately diminishes the yield. The similarity between the reactions of substances containing the groups C:NH and CO is clearly shown by the behaviour of ethyl P-imino-a-cyanoglutarate towards reagents. Thus with strong alksline hydrolytic agents it is completely decomposed into the alkali salt of malonic acid in accordance with the equation : CO,Et*CH,*C(:NH)~CH(CN)*CO,Et + 4NaOH + 2H,O 5 2CH,(CO,Na), + 2NH, + 2EtOH, behaving therefore in the same way as would a compound having the formula C0,Et 'CH;CO*CH(CN) 'C0,Et. Again, the hydrogen atoms marked 1, 2, and 3 in ethyl p-imino-a-cyanoglutarate, CO,Et*CHH*C(:NH) *CH(CN) *CO,Et, (1) (3) (2) are replaceable by sodium in the order indicated by the numerals, Ethyl P-imino-a-cyanoglutarate, CO,Et*CH,*C(:NH)'CH(CN)*CO,Et, gives ethyl P-imino-a-cyano-aa'-dimethylglutarate, CO,Et-CHMe=C(: EH)*CMe(CN)*CO,Et, on treatment with sodium ethoxide and methyl iodide, and this substance is identical with the compound prepared by the condensation of ethyl cyanomethylacetate with its sodium derivative, which evidently takes place in accordance with the equation :

BIATI'ERS OF THE OXAZINE SERIES. * The method of nuinbering is that recommended by Kehrmaiin and Gaulie (Ber.