Green synthesis and structural characterization of novel N1-substituted 3,4-dihydropyrimidin-2(1H)-ones

Abstract

Abstract Novel N1-substituted 3,4-dihydropyrimidin-2(1H)-one derivatives were synthesized through Biginelli condensation of aromatic aldehydes, β-ketoesters, and monosubstituted (thio)ureas in the presence of copper methanesulfonate at 90°C under solvent-free conditions. The screening of the catalysts showed the copper methanesulfonate was the best. Its catalytic activity remained after three times of use. The products were characterized by IR, 1H NMR, 13C NMR, elemental analysis, and X-ray single crystal diffraction technique. A reasonable reaction mechanism was proposed.