[ i39 ] 



No. 18. 



THE ACTION OF THE OXIDES AND THE OXYACIDS OF NITEOGEN 



ON THE PHENYLUEEAS. 



By HUGH EYAN, D.Sc, 



AND 



PETEE K. O'TOOLE, M.Sc., 

 University College, Dublin. 



[Read December 19, 1922. Piinled February 22, 1923.] 



Introduction. 



In experiments already described [H. Eyan and A. Donnellan, p. 113] it was 

 found that the replacement of the imino hydrogen atom of diphenylamine by a 

 carbethoxy radical decreased the readiness with which the substance could be 

 nitrated. As diphenylui-e thane possessed, however, no basic properties, it appeared 

 of interest to study the nitration of substances, such as diphenylurea, in which the 

 OOOEt radical of the urethane would be replaced by an aniido group, CONH^. 

 In this communication we describe therefore the results of experiments which we 

 have carried out with phenylureas in a manner similar to those described for the 

 urethanes. 



If all the hydrogen atoms of the amino groups of urea are not replaced by alkyl 

 radicals, or if one or more of the latter is capable of reacting with the oxides or 

 the oxyacids of nitrogen, a substituted urea may function like diphenylamine 

 towards these oxides and oxyacids. We have examined all the phenylureas except 

 tetraphenylurea, and in all those examined there was at least one hydrogen atom 

 attached directly to nitrogen. 



Our experiments were mainly directed towards the investigation of the action 

 of the oxides and the oxyacids of nitrogen on the phenylureas at the ordinary 

 temperature and at low concentrations of the interacting substances. 



Phenylurea and as-dipheuylurea, as would be expected, reacted similarly with 

 the oxides of nitrogen, each easily splitting off the free amino group. The former 

 yielded nitro-phenol, whilst the latter gave diphenylamine derivatives. 

 s-Diphenylurea and triphenylurea, on the contrary, reacted readily without 

 decomposition, the former giving a diuitrc derivative and the latter a trinitro 

 derivative. Only s-diphenylurea yielded a nitroso compound with oxides of 

 nitrogen. 



Phenylurea and s-diphenylurea reacted with nitrous acid, giving nitroso 

 derivatives, whereas nitrous acid had no action on either as- diphenylurea or 

 triphenylurea. 



In acetic acid solution at low concentrations with nitric acid, only triphenylurea 

 was nitrated. It yielded a di- and a trinitro derivative. Phenylurea, however, 

 formed a nitrate. 



SOIENT. PKOO. E.D.S., VOL. XVII, NO. 18. 2d 



