Copper-catalysed reaction of 2-chloroimidazoles and 2-chlorobenzimidazoles with dimethylamine

The preparation of 2-dimethylamino-benzimidazoles and -imidazoles from the corresponding 2-chloro compounds by reaction with dimethylamine is assisted by the presence of copper salts. In the absence of a copper catalyst, 2-chloroimidazoles fail to react. Kinetic studies indicate a mechanistic relationship to other copper-catalysed reactions for which arylcopper(I) intermediates have been proposed.