Bismuth(III)-Catalyzed Synthesis of Dihydropyrimidinones: Improved Protocol Conditions for the Biginelli Reaction

Abstract

An efficient synthesis of 3,4-dihydropyrimidines using bismuth chloride as a catalyst from an aldehyde, β-keto ester and urea in acetonitrile is described. Compared to the classical Biginelli reaction conditions, this new method consistently has the advantage of good yields (56-97%).