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

Turk J Chem. 2021 Sep 21;45(6):1980-1987. doi: 10.3906/kim-2105-59. eCollection 2021.

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.

Keywords: 2-Methylthio-1; 4-DHPMs; 4-MCR; Biginelli reaction; N-nucleophiles; green synthesis.