An efficient Biginelli one-pot synthesis of new benzoxazole-substituted dihydropyrimidinones and thiones catalysed by alumina-supported trifluoromethane sulfonic acid under solvent free conditions
An efficientsynthesis of benzoxazole-substituted 3,4-dihydropyrimidinones (DHPMs) using alumina supported trifluoromethanesulfonicacid as the catalyst for the first time from an aldehyde, β-keto ester, and benzoxazole-substituted urea and thiourea under solvent-free conditions is described. When compared with the classical Biginelli reaction conditions, this new method consistently has the advantage