Solvent-free one-pot synthesis of Biginelli compounds using acid / meglumine as high efficient catalyst

چکیده مقاله

Biginelli reaction is among the most well-known one-pot multicomponent reactions involving a cyclocondensation of an aldehyde, β-ketoester, and urea/thiourea to yield dihydr primidin- 2(1H)-ones/thiones (DHPMS).1 The 3,4-dihydropyrimidin-2(1H)-ones/thiones are synthetically useful and important heterocyclic scaffolds, which have exhibited a wide range of important biological and pharmacological activies.2 In recent years, Biginelli reaction has been performed under a wide variety of conditions, and several improvements for the experimental procedures have been made; although, it has been traditionally catalyzed by acids and bases.3 In many chemical processes, acids and bases are used to activate reactants simultaneously or sequentially. The integration of both base and acid has great potential to enhance known reactivity and drive the development of new chemical reactions with high value.4 Here meglumine and acetic acid were used in simple and green one step multicomponent synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones under solvent free conditions at 100oC is reported (Scheme 1). The method is operationally simple, environmentally benign, and has relatively high yields. The reaction products were characterized with 1HNMR, 13CNMR and IR spectroscopic method.