Combined Pd/C and Montmorillonite Catalysis for One-Pot Synthesis of Benzimidazoles.

A series of nineteen benzimidazoles are prepared from ortho -nitroanilines via one-pot transfer hydrogenation, condensation, and dehydrogenation enabled by the concurrent use of two heterogeneous catalysts: montmorillonite-K10 and Pd/C. This strategy is further employed to accomplish a five-step, three-component synthesis of an antifungal benzimidazoquinazoline using a simple one-pot procedure.