Three component condensations catalyzed by iodine–alumina for the synthesis of substituted 3,4-dihydropyrimidin-2(1H)-ones under microwave irradiation and solvent-free conditions

Condensation of an aldehyde, ethyl acetoacetate and urea or thiourea under microwave irradiation in the presence of 10% iodine adsorbed on neutral alumina gives substituted 3,4-dihydropyrimidin-2(1H)-ones in excellent yields.