An eco-safe and solvent-free approach for clean and one-pot synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives using Zn(OAc)2•2H2O as an environmental friendly, readily and efficient catalyst

An environmental friendly, economical and clean Biginelli approach in presence of readily available zinc acetate dihydrate (Zn(OAc)(2)center dot 2H(2)O) to access biologically active 3,4-dihydropyrimidin-2-(H)-ones/thiones derivatives via one-pot, three-component reaction of beta-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea in high to excellent yields has been studied. This solvent-free procedure is sustainable and advantageous compared to conventional methods due to short reaction times, one-pot procedure, easy handling, efficient, environmentally benign nature, low-cost and non-toxic catalyst, eco-friendly, ready availability of starting materials and no requirement of chromatographic purification. The products have been characterized by melting points and H-1 NMR spectroscopy.