Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Using Ce(SO₄)₂-SiO₂ as a Heterogeneous and Recyclable Catalyst

Abstract

A simple and efficient synthesis of 3,4-dihydropyrimidinones or thiones is described, using silica-supported ceric sulfate [Ce(SO₄)₂-SiO₂] as a heterogeneous catalyst from an aldehyde, 1,3-dicarbonyl compound, and urea or thiourea at 110 °C under solvent-free conditions. Compared with the classical Biginelli reaction, this new method consistently has better yields, short reaction time, easy separation, and tolerance toward various functional groups.

Keywords:

• Biginelli
• Ce(SO₄)₂-SiO₂
• 3,4-dihydropyrimidinones
• solvent-free

ACKNOWLEDGMENT

We gratefully acknowledge the financial support from the Key Discipline of Industrial Catalysis.

Notes

^a Isolated yield (%) of product.

^b Isolated yield (%) of the catalyst recycling reactions.

^c Reaction conditons: aldehyde (50 mmol), 1,3-dicarbonyl compound (50 mmol), urea (75 mmol), and Ce(SO₄)₂ (0.3 g), 110 °C, 40 min.