Solvent-Free One-Pot Synthesis of Diverse Dihydropyrimidinones/Tetrahydropyrimidinones Using Biginelli Reaction Catalyzed by Fe₃O₄@C@OSO₃H

Abstract

One-pot synthesis of 3,4-dihydropyrimidinone/thione and 3,4,5,6-tetrahydropyrimidinone/thione derivatives was successfully performed in high yields through the reaction of aromatic aldehyde, β-dicarbonyl, urea/thiourea using Fe₃O₄@C@OSO₃H nano-catalyst under solvent-free conditions at 80 °C. Fe₃O₄@C@OSO₃H was introduced as an efficient magnetic nano-catalyst in Biginelli condensation with powerful reusability. The great yield of products, fast reaction time, simple work-up procedure, as well as usage of nontoxic, reusable, and easily recoverable catalyst with an external magnet was counted as advantages of the applied process. The magnetic nano-catalyst was removed after reaction completion and reused seven times at the same conditions without significant decay in catalyst activity. The magnetic nano-catalyst was synthesized through a simple and inexpensive two steps method and characterized by FT-IR, EDX, SEM, TEM, DLS, XRD, and VSM techniques.

Graphical Abstract

Keywords:

• 34-Dihydropyrimidinones/thione
• 3456-Tetrahydropyrimidinone/ thione
• One-pot reaction
• Biginelli condensation
• Magnetic nano-catalyst
• Fe₃O₄@C@OSO₃H