One-Pot Synthesis of Benzimidazoles in Water in the Presence of SiO2-OPO3H

Silica-bound phosphoric acid (SiO2-OPO3H), as an eco-friendly, reusable, and heterogeneous catalyst, was applied for synthesis of 2-substituted benzimidazoles in water at 70A degrees C. Very short reaction times, clean work-up, and high yields are among the advantages of this protocol.