[ 119 ] 



No. 15. 



THE ACTION OF THE OXIDES AND THE OXYACIDS OF NITEOGEN 

 ON ETHYL-0-TOLYLUEETHANE. 



By HUGH RYAN, D.Sc, 



AND 



NICHOLAS CULLINANE, Ph.D., 

 University College, Dublin. 



[Read Decemher 19, 1922. Printed Febbuary 22, 1923.] 



Intkoductiok. 



In previous communications it was shown that a substituted diphenylaniine, such 

 as diphenylnitrosamine [H. and P. Eyan, Proc. E.I. A., xxxiv, B, pp. 194,212], 

 nitrates more easily and more smoothly than diphenylamiue. It was, however, 

 found later [H. Eyan and A. Donnellan, p. 113] that the urethane formed by the 

 substitution of a carbethoxy group for the imino hydrogen atom of diphenylamine 

 was less easily nitrated than the parent amine. 



It appeared of interest, therefore, to study the behaviour of other aromatic 

 urethanes towards the oxides and the oxyacids of nitrogen at low temperatures and 

 concentrations of the interacting substances. This study, although at first 

 necessarily a qualitative one, might be expected to throw some light on the influence 

 of a urethane group on the ease of nitration of an aromatic nucleus. 



Ethyl-o-tolylurethane was selected for our experiments. Since the imino hydrogen 

 atom of the parent substance, o-tolylurethane, was replaced by the ethyl radical, the 

 possibility of the formation of an easily nitratable nitroso compound was excluded. 



o-Tolylurethane has been obtained by Lachmann [Ber. Dtsch. Chem. Ges., xii 

 (1879), p. 1349; ef. Merz, ibid., vi (1873), p. 444; Cosack, ibid., xii (1879), 

 p. 1450 ; Nevile and Wiuther, ibid., xii (1879), p. 2324] by the condensation of 

 o-toluidine with ethyl chloroformate, and by the action of alcoholic potash on the 

 dichloride of o-tolylisonitrile. 



Ethyl-o-tolylurethane, for which we are indebted to Nobel's Explosives Com- 

 pany, has not, however, been hitherto described in the literature. It is a colourless, 

 oily liquid, which boils at 255° C. 



In every ease where the oxides or the oxyacids of nitrogen interacted with 

 ethyl-o-tolylurethane at the ordinary temperature, or at more or less high 

 temperatures, directly, or in the presence of solvents, the ethyl radical attached to 

 the imino nitrogen atom was invariably eliminated, the products being in all cases 

 nitro derivatives of o-tolylurethane. The nitro-o-tolylurethanes previously 

 described have all been prepared from the corresponding nitro-o-toluidines, and 

 in no case was any of them got by nitration of the urethane. 



SCIENT. PROC. K.D.S., VOL. XVII, NO. 15. T 



