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

Abstract

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 °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.

Keywords

• N,O-Bis(trimethylsilyl)acetamide
• Dicyclohexyl carbodimide
• Solvent free
• 3,4-Dihydropyrimidinones
• 3,4-Dihydropyrimidithiones