Synthesis of 1H-benzimidazoles via the condensation of o-phenylenediamines with DMF promoted by organic acid under microwave irradiation.

An effective, green and eco-friendly method was developed to synthesize 1H-benzimidazole under microwave irradiation. The reactions of substituted o-phenylenediamine with DMF were efficiently promoted by butanoic acid, and the desired product 1H-benzimidazole derivatives were obtained in good to excellent yields. Compared with the conventional heating method, microwave irradiation significantly reduced the reaction time and improved the yields of the target products. [ABSTRACT FROM AUTHOR]