Ultrasound promoted and SiO2/CCl3COOH mediated synthesis of 2-aryl-1-arylmethyl-1H-benzimidazole derivatives in aqueous media: An eco-friendly approach

Ultrasonic irradiation is an efficient and innocuous technique of reagent activation for synthesizing organic compounds. First one-pot synthesis of 2-aryl-1-arylmethyl-1H- benzimidazole derivatives from o- phenylenediamine and an aromatic aldehyde in the presence of silica gel supported trichloroacetic acid (SiTCA) was carried out with excellent yields at 50∘C by sonication. This method provided several advantages such as green solvent, inexpensive catalyst, simple experimental methodology, shorter reaction time and higher yield.