A novel protocol for solvent-free synthesis of 4,6-diaryl-3,4-dihydropyrimidine-2(1H)-ones catalyzed by metal oxide–MWCNTs nanocomposites

• Easy reaction condition, recyclable green catalyst and reduced environmental impacts.
• The catalyst has high activity, selectivity, reusability, reasonable cost and long lifetime.
• TiO2–MWCNTs catalyst is significantly more effective than other acid catalysts in the Biginelli-like reaction.

A Biginelli-like condensation is described using acetophenone as active methylene compound with aldehydes and urea to furnish pyrimidinone analogues under solvent-free conditions. In this paper, besides the preparation of nanocomposites based on MWCNTs, our investigations have been focused on the catalytic efficiency of metal oxide–MWCNTs composites. The requisites of a good catalyst are high activity, selectivity, reusability, reasonable cost and long lifetime. The application of solvent-free conditions and transition metal oxides decorated–MWCNTs (MOx–MWCNTs) nanocomposites as attractive, effective and reusable catalysts leads to the efficient synthesis of 4,6-diaryl-3,4-dihydropyrimidin-2-(1H)-ones. This recyclable heterogeneous catalytic system provides a simple strategy to generate a variety of pyrimidinones under solvent-free conditions. Utilization of easy reaction condition, recyclable green catalyst, reduced environmental impacts and simple work-up make this methodology as an interesting option for the eco-friendly synthesis of Biginelli-like compounds.