M(HSO(4))(n)-promoted synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazole derivatives

We have developed a highly selective synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles from the reaction of o-phenylenediamines and aromatic aldehydes in the presence of metal hydrogen sulfates [M(HSO(4))(n)] in water and also under solvent-free conditions in good to excellent yields.