Brønsted Acidic Ionic Liquid as an Efficient and Reusable Catalyst for One-Pot, Three-Component Synthesis of Pyrimidinone Derivatives via Biginelli-Type Reaction Under Solvent-Free Conditions

Abstract

A mild and efficient method has been developed for the preparation of pyrimidinone derivatives from the reaction of aromatic aldehydes with cyclopentanone and urea or thiourea in the presence of N-(4-sulfonic acid) butyl triethyl ammonium hydrogen sulfate ([TEBSA][HSO₄]) as the Brønsted acidic ionic liquid and effective catalyst under thermal and solvent-free conditions. Good yields, short reaction times, straightforward workup, reusability of the catalyst, and green conditions are the most obvious advantages of this procedure.

Keywords:

• Biginelli-type reaction
• Brønsted acidic ionic liquid
• one-pot
• pyrimidinone
• solvent-free

ACKNOWLEDGMENTS

We gratefully acknowledge the funding support received for this project from the Isfahan University of Technology (IUT), the government of Iran (A. R. H.), and Grants GM 033138, MH 065503, NS 033650 (A. E. R.) from the National Institutes of Health. Further financial support from the Center of Excellency in Sensor and Green Chemistry Research (IUT) is gratefully acknowledged.

Notes

^a Aldehyde/cyclopentanone/urea or thiourea/IL = 1:1:1.2:0.15.

^b Yields refer to isolated pure products and all synthesized pyrimidinone derivatives were characterized by spectral data (IR, ¹H and ¹³C NMR), melting points and comparison with authentic samples.