Sharif University of Technology Scientia Iranica 1026-3098 25 3 2018 06 01 Nano kaolin-SO3H as a new efficient and reusable catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles under solvent-free conditions 1344 1353 20338 10.24200/sci.2018.20338 EN Abdolhamid Bamoniri Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I. R. Iran Nahid Yaghmaeiyan-Mahabadi Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I. R. Iran Journal Article 2017 01 22 Nano kaolin-SO₃H as a new reusable and green heterogeneous catalyst was prepared by reaction of kaolin nanoparticles with chlorosulfonic acid. This new type of solid acid which contains the properties of a Lewis acid (Al³⁺) and a Brønsted acid (SO₃H group), was characterized by FT-IR, XRD, SEM, TEM, XRF, EDS and TGA. Nano kaolin-SO₃H was used as a recoverable acidic heterogeneous catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles <em>via</em> three component condensation of 1,2-diketones, various aromatic aldehydes and ammonium acetate. Short reaction time, simple work-up, high yields, solvent-free conditions and environmental friendly catalyst are some advantages of this protocol. https://scientiairanica.sharif.edu/article_20338_599c5a525961345579e8b8ad461411cc.pdf