Facile synthesis of benzimidazole, benzoxazole, and benzothiazole derivatives catalyzed by sulfonated rice husk ash (RHA-SO3H) as an efficient solid acid catalyst

摘要

A mild, simple, and efficient solvent-free method, with sulfonated rice husk ash as solid acid catalyst, has been developed for preparation of benzimidazole, benzoxazole, and benzothiazole derivatives. The products are obtained in good to high yields after very short reaction times, and the catalyst can be reused five times without loss of its catalytic activity.