Mn(OAc)3·2H2O-mediated three-component, one-pot, condensation reaction: an efficient synthesis of 4-aryl-substituted 3,4-dihydropyrimidin-2-ones

4-Aryl-substituted 3,4-dihydropyrimidin-2-ones are synthesized in high yields by one-pot cyclocondensation reactions of aldehydes, β-ketoesters and urea using a catalytic amount of manganese acetate in refluxing acetonitrile.