New routes to selectively methylated benzimidazoles

Abstract

Abstract The use of intermediate benzotriazol‐l‐yl derivatives simplified the procedures for the preparation of 5‐methoxy‐l‐methylbenzimidazole and 6‐methoxy‐l‐methylbenzimidazole starting from 4‐methoxy‐2‐nitro‐aniline. This strategy represents a novel and potentially general method for synthesis of 5‐ and 6‐substituted‐l‐methylbenzimidazoles from 4‐substituted anilines. Preparation of l‐methyl‐5‐nitrobenzimidazole by reaction of 2‐chloro‐5‐nitroaniline with methylamine and condensation of the obtained diamine with formic acid represents a special case.