Green Protocol for the Synthesis of Catalyst Free Biginelli Products

Applications of multicomponent reactions (MCRs) in the preparation of diverse types of heterocyclic compounds carries a unique place in chemical synthesis. Biginelli reaction, among the loop of multicomponent reactions, provide an efficient way to access of highly functionalized dihydropyrimidones (-thiones) (DHPMs). In the current study, we employed multicomponent Biginelli reaction to synthesis range of different dihydropyrimidones (-thiones) derivatives in variable yields. A solvent-free eco-friendly green protocol without any expensive catalyst has been optimized and expand to synthesize series of DHMPS in 34 to 72% yield. The optimized method proved to be successful with various types of different aromatic aldehydes, 1, 3-dicarbonyl compounds and urea (thiourea) under solvent and catalyst free condition to access dihydropyrimidones (­thiones). Different spectroscopic techniques include NMR, FTIR etc. have used to confirm the structures of compounds. Further exploration of Biginelli reaction to prepare DHPMs and related compounds is under way in the lab and will be published in due course.