Carbon nanotubes supported by titanium dioxide nanoparticles as recyclable and green catalyst for mild synthesis of dihydropyrimidinones/thiones

• High yields, short reaction times, and simple work-up procedures.
• Ethanol was the best solvent compared to other organic solvents.
• 0.03 g TiO2–CNTs was the optimum amount in the synthesis of pyrimidinones.

The catalytic activity of titanium dioxide supported on carbon nanotubes has been investigated in a one-pot three components condensation reaction (Biginelli reaction). The TiO2–CNT nanocomposites as catalyst are highly stable and completely heterogeneous and they can be recycled several times. Compared to the classical Biginelli reaction conditions, the present methodology offers several advantages such as excellent yields, simplicity, fast and clean reactions and short reaction times.