Abstract

A comparative study on various reaction techniques for the preparation of Biginelli compounds and a solvent-free sonication induced green approach through condensation of aldehydes, β-ketoester and urea/thiourea, catalyzed by an acid, to obtain title compounds in a synthetically useful manner is presented.

Keywords: calcium channel blockers, green chemistry, 3,4-dihydropyrimidinones, sonication, Biginelli compounds