A facile synthesis of benzimidazole derivatives over zinc sulfide nanoparticles as heterogeneous catalyst

An efficient and eco-friendly method for the synthesis of benzimidazole derivatives through the one-pot cyclocondensation of the substituted aldehydes with o-phenylenediamines over zinc sulfide nanoparticles (nano-ZnS) in ethanol as solvent at 70 °C has been described. The present method has several advantages such as high yields, easy purification, mild reaction conditions, easy work-up and short reaction times. The nanoparticles are easily synthesized, cheap, air and moisture stable, and also heterogenic and green catalysts.