Formation of reissert analogs from benzimidazole and use of carboxylic acids in a retro-reissert reactionReissert Analogs from Benzimidazole

Reissert analogs have been formed in high yields from benzimidazole using trimethylsilyl cyanide and chloroformates. A retro-Reissert reaction can be effected on the products, their carbon-2 alkylated derivatives and benzothiazole analogs, by treatment with hexanoic or benzoic acids.