A four-component modified Biginelli reaction: A novel approach for C-2 functionalized dihydropyrimidines

Abstract

A novel four component modified Biginelli reaction for the synthesis of C-2 functionalized dihydropyrimidines has been established. The approach uses assembly of less explored acetyl acetone with aromatic aldehyde, thiourea and dimethyl sulphate to construct a novel 5-acetyl 2-methylthio dihydropyrimidine system which works as an efficient well-designed intermediate for generating C-2 modified Biginelli libraries with nitrogen nucleophiles. Phenyl hydrazine, semicarbazide and aryl semicarbazides are successfully used as N-nucleophiles to generate C-2 functionalized dihydropyrimidine derivatives which fulfil the demands of active pharmacophore. Time economy, step economy and a single pot reaction with moderate to excellent yield are the major advantages of this novel method.