P₂O₅/SiO₂ as an Efficient, Green and Heterogeneous Catalytic System for the Solvent-Free Synthesis of 3,4-Dihydropyrimidin-2-(1H)-ones (and -Thiones)

Abstract

A simple, green and efficient solventless procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (and -thiones) from aldehydes, β-ketoesters and urea or thiourea in the presence of catalytic amount of silica-supported P₂O₅ (P₂O₅/SiO₂) at 85 °C is described. Using this method, the title compounds were produced in high yields.