Tributylhexadecylphosphonium bromide: An efficient reagent system for the one-pot synthesis of 2,4,5-trisubstituted imidazoles

Abstract

The reaction of benzil, an aromatic aldehyde, and ammonium acetate in ethanol at reflux in the presence of tributylhexadecylphosphonium bromide as catalyst affords a 2,4,5-trisubstituted imidazole. The present methodology offers several advantages over the literature methods, including excellent yields, shorter reaction times, environmentally benign milder reaction conditions, cost-effectiveness of catalyst, easy workup, and purification of products by nonchromatographic methods.