One-pot Three-component Solvent-free Synthesis of Benzo[4,5]imidazo[1,2-a]pyrimidine Derivatives Catalyzed by Sulfamic Acid

A simple convenient procedure for the synthesis of benzo[4,5]imidazo[1,2-a]pyrimidine derivatives was developed through a three-component reaction of aldehyde, beta-dicarbonyl compound and 2-aminobenzimidazole catalyzed by sulfamic acid in a solvent-free condition. The new protocol has the advantages of high yield, low cost, reduced environment impact, wide scope and convenient procedure.