Solvent free synthesis of 3,4-dihydropyrimidine-2-(1H)-ones/thiones catalyzed by N,O-bis(trimethylsilyl)acetamide and dicyclohexyl carbodimide

We report herein, the usage of N,O-bis(trimethylsilyl) acetamide (BSA) and dicyclohexyl carbodimide (DCC) as two new catalysts for three component condensation of an aldehyde, ethyl acetoacetate and urea/thiourea under solvent free conditions at 100 degrees C to afford the corresponding 3,4-dihydropyrimidine-2-(1H)-ones/thiones (DHPMs) in good to excellent yields. A comparative study of these two catalysts was made and presented. (C) 2012 Production and hosting by Elsevier B.V. on behalf of King Saud University.