Gallium (III) chloride-catalyzed synthesis of 3,4-dihydropyrimidinones for Biginelli reaction under solvent-free conditions

Abstract

We describe the syntheses of 3,4-dihydropyrimidinones or analogous thioketones by a one-pot cyclocondensation of acetoacetates, aldehydes and urea or thiourea using gallium (III) chloride as catalyst under solvent-free conditions. The improved Biginelli reaction not only features a simple procedure, high yields and easy purification of production, but also the recycled catalyst could be directly reused for many times while the yields of reaction would not decrease.

Keywords:

• gallium (III) chloride
• Biginelli reaction
• dihydropyrimidinones
• solvent-free

Public Interest Statement

A traditional concept in chemistry primarily seeks to increase reaction yield. With the development of chemical industry, people have come to realize chemical hazards to health, community safety and the environment. Now researchers in chemistry are more concerned with benign chemical process, such as solvent-free reaction, recyclable catalyst, aqueous organic reaction and so on.

This article was based on cycling economy and concept of green chemistry, and studied the syntheses of Dihydropyrimidinones or analogous thioketones by using gallium (III) chloride to replace HCl as catalyst under solvent-free conditions. The improved Biginelli reaction not only features a simple procedure, high yields and easy purification of production, but also the recycled catalyst could be directly reused for many times.

Green environment is our goal and we are always trying to come up with new, green and safe ways to resolve the pollution problem of conventional chemical methods..

Additional information

Notes on contributors

Shizhen Yuan

Prof. Shizhen Yuan’s group’s key research activities

Our research interests are focused on the development of new reactions for building carbon–carbon, carbon–hydrogen, and carbon–heteroatom bonds with particular emphasis on selectivity, cost, and environmental impact. The contents of research include the following areas:

1. Green organic metal reactions: Barbier–Grignard reaction and Pinancol couple reaction in aqueous media, Knoevenagel condensation under solvent-free conditions.

2. Green synthesis of heterocyclic compounds: novel synthetic methods of Pyrroles, Oxazoles, Quinolinones, Dihydropyrimidinones.

3. The asymmetric synthesis of chiral reagent: such as Preparation of L-Proline Chiral Bonded Silica Gels and Their Application in Beer.

4. Chemistry of natural products: extraction and separation of effective components and structure identification.

We hope that research in our lab could help improve some traditional synthetic methods, and in particular provide better solutions to current existing issues related to medicines, materials, and energy.