ZrO2-pillared clay: An efficient catalyst for solventless synthesis of biologically active multifunctional dihydropyrimidinones

A novel protocol using ZrO2-pillared clay (Zr-PILC), prepared by us as a mild recyclable solid acid catalyst for multicomponent one-pot synthesis of dihydropyrimidinones under solvent free conditions both by thermal and microwave heating using the Bronsted and Lewis acidity (proposed mechanism) of Zr-PILC is reported. The efficacy of the procedure is exemplified by the synthesis of biologically active racemic mixture of monastrol and nitractin (a potent lead anti-cancer drug and antibacterial, antiviral drug, respectively).