A Rapid and Efficient Biginelli Reaction Catalyzed by Zinc Triflate

Abstract An efficient and practical procedure for the synthesis of dihydropyrimidinones from aldehydes, 1,3‐dicarbonyl compounds and urea under solvent‐free reaction condition using zinc triflate as a catalyst is described. In comparison with the classical Biginelli reaction, the yields for this new procedure increased from 20%—50% to 75%— 98% while the reaction time was significantly shortened from 18 h to 20 min.