Silica sulfuric acid as an efficient and recoverable catalyst for the synthesis of trisubstituted imidazoles

Trisubstituted imidazoles have been synthesized in high yields in the presence of silica sulfuric acid as a catalyst. The reaction is carried out in water, a very green solvent, under reflux conditions. The reaction work-up is simple and the catalyst is easily separated from the products by filtration. (c) 2006 Elsevier B.V. All rights reserved.