One-pot Preparation of 2,4,5-Trisubstituted and 1,2,4,5-Tetrasubstituted Imidazoles Using Poly(4-vinylpyridinium Butane Sulfonic Acid) Hydrogen Sulfate, as an Efficient Heterogeneous Poly(ionic Liquid) Solid Acid Catalyst under Solvent-free Conditions

Abstract

One-pot preparation of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles has been conducted in the presence of poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate, P(4VPBSA)HSO₄, as an efficient dual acidic catalyst under solvent-free conditions. Reusability of the catalyst, easy work-up procedure, eco-friendly reaction conditions, short reaction times and high yields of the products illustrate the utility of this approach.