Microwave-assisted multicomponent reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and their corresponding 2(1H)-thiones using lanthanum oxide as a catalyst under solvent-free conditions

An efficient synthesis of 3,4-dihydropyrimidinone derivatives using lanthanum oxide as a catalyst, from aldehydes, β-keto ester and urea/thiourea without solvent under the irradiation of microwave is described. Compared with classical Biginelli reaction conditions, this new method has the advantage of excellent yields and shorter reaction times.