2-Trihalogenomethylbenzazoles. Part II. Reactions of 2-trihalogenomethylbenzimidazoles with ammonia and amines

Abstract

Reaction of 2-trichloromethylbenzimidazoles with ammonia and primary aryl and alkyl amines yielded the 2-nitrile and 2-amidines, respectively. Under acid conditions primary arylamines gave the benzimidazole-2-carboxyanilides. The corresponding di-alkylcarboxyamides were obtained from the reaction of the 2-trichloromethyl group with secondary amines. The 1,6-elimination mechanism postulated for the reaction of 2-trichloromethylbenzimidazoles with nucleophiles is supported by isolation of intermediates in special cases and by the differential reactivity of fluorine-containing 2-trihalogenomethylbenzimidazoles and of 2-trichloromethylbenzothiazole.