Heteropoly acid supported on activated natural clay-catalyzed synthesis of 3,4-dihydropyrimidinones/thiones through Biginelli reaction under solvent-free conditions

Dihydropyrimidinones/thiones (DHPM's) have been prepared by one-pot condensation of methyl acetoacetate, aldehydes, urea/ thiourea in the presence of heteropoly-11-tungsto-1-vanadophosphoric acid, H-4[PVW11O40].32H(2)O, (HPV) supported on activated natural clay (HPVAC) under solvent-free reaction condition have been proposed. The DHPM derivatives were identified through elemental analysis and melting point measurements and characterized by FT-IR, H-1-NMR, C-13-NMR spectroscopic methods.