A microwave-mediated catalyst- and solvent-free regioselective Biginelli reaction in the synthesis of highly functionalized novel tetrahydropyrimidines

A series of novel ethyl 2-oxo/thio-4-aryl-6-(arylsulfonylmethyl)-1,2,3,4-tetrahydropyrimidine-5-carboxylates has been synthesized regioselectively by the Biginelli reaction of ethyl 3-oxo-4-(arylsulfonyl)butanoate, aromatic aldehyde and urea/thiourea under microwave irradiation and solvent- and catalyst-free conditions. (C) 2012 Elsevier Ltd. All rights reserved.