Bismuth triflate catalyzed one-pot synthesis of 3,4-dihydropyrimidin-2 (1H)-ones: An improved protocol for the Biginelli reaction

摘要

An efficient synthesis of 3,4-dihydropyrimidinones (DHPMs) using bismuth triflate as the catalyst for the first time from an aldehyde, ss-keto ester and urea in acetonitrile is described. Compared to the classical Biginelli reaction conditions, this new method consistently has the advantage of excellent yields (58-95%) and short reaction time (1-4 h) at room temperature. [References: 23]