Superoxide Ion Promoted Synthesis of 2-Arylbenzimidazoles from Schiff Bases

Background: Benzimidazoles exhibit a wide range of biological activities, including antiparasitic, antiulcer, antihypertensive, antihistaminic, anticancer, antiemetic and antiinflammatory agents. Methods: Tetraethylammonium superoxide has been generated in situ by the phase transfer reaction of potassium superoxide and tetraethylammonium bromide in dry dimethylformamide at room temperature and subsequently allowed to react with a number of Schiff's bases. Results: The Synthesis of 2-arylbenzimidazoles from Schiff bases using in situ generated tetraethylammonium superoxide in dry DMF, at room temperature. Conclusion: The role of in situ generated Et4NO2 as an efficient agent to promote the synthesis of 2-arylbenzimidazole from Schiff base has been demonstrated under mild conditions.