Nucleophilic attacks on carbon–nitrogen double bonds. Part 4. Substitution of N-arylbenzimidoyl cyanides by amines in acetonitrile and by alkoxides in alcohols

Abstract

The substitution of the cyano-group of N-arylbenzimidoyl cyanides PhC(CN)NC₆H₄Y by nucleophiles was studied. With amines in acetonitrile several reactions had showed first-(k′) and second-order (k″) terms in the amine. With EtO^– in EtOH, both zero-(k⁰) and first-order (k′) terms in the nucleophile were found, while with Bu^tO^– in Bu^tOH the reaction is of first order in the base. It is suggested that a common initial step in these reactions is nucleophilic attack of the amine, an alkoxide ion, or ethanol on the imidoyl cyanide. The subsequent expulsion of the leaving group may be uncatalysed or amine-catalysed in acetonitrile, and solvent-assisted in the alcohols. The reactiois were compared with those of the corresponding N-arylbenzimidoyl chlorides.