FULL PAPER MNPs@SiO 2 ‐Pr‐AP: A new catalyst for the synthesis of 2‐amino‐4‐aryl thiazole derivatives Ramin Ghorbani‐Vaghei | Sedigheh Alavinia | Zohreh Merati | Vida Izadkhah Department of Organic Chemistry, Faculty of Chemistry, Bu‐Ali Sina University, 6517838683, Iran Correspondence Ramin Ghorbani‐Vaghei, Department of Organic Chemistry, Faculty of Chemistry, Bu‐Ali Sina University, 6517838683, Iran. Email: rgvaghei@yahoo.com A simple and efficient synthesis of 2‐amino‐4‐aryl thiazole derivatives was carried out through the reaction of substituted acetophenones and thiourea using three different types of catalytic systems including N,N,N′,N′‐ tetrabromobenzene‐1,3‐disulfonamide [TBBDA], poly(N,N′‐dibromo‐N‐ethyl- benzene‐1,3‐disulfonamide) [PBBS] and a combination of TBBDA and nano‐ magnetic catalyst supported with functionalized 4‐amino‐pyridine silica (MNPs@SiO 2 ‐Pr‐AP). The results showed that the use of TBBDA along with the MNPs@SiO 2 ‐Pr‐AP gains the highest yields of the products in the shortest reaction time. KEYWORDS 2‐Amino‐4‐aryl thiazole, magnetic nanoparticles, nano catalyst, solvent‐free, thiourea 1 | INTRODUCTION The synthesis of organic compounds via green, mild, and simple procedures is currently receiving considerable attention of chemists. In recent years, the solvent‐free organic reactions have captured great interests owing to their many advantages including high efficiency and selectivity, easy separation and purification, mild reaction conditions, reduction in wastes, and benefits to the indus- try and environment. [1] In recent decades, heterocyclic compounds have attracted much attention because of their abundance, and their increasing importance in the field of pharmaceuticals [2] and chemical industries. [3] Thi- azole and its derivatives have been shown to possess a broad range of biological activities. For example, thiamine is known as vitamin B 1 , Ritonavir is an anti‐HIV agent, and Nizatidine is an anti‐acid agent for the treatment of gastroesophageal reflux disease (Figure 1). [4] Hantzsch, Tchernic, Cook‐Heilborn, and Gabriel methods are some common routes for the preparation of thiazoles. [5] Till now, these methods have been accomplished using differ- ent catalysts such as Bismuth chloride, [6] ammonium‐12‐ molybdophosphate, [7] cyclodextrin, [8] I 2 , [9] and I 2 with nanochitosan. [10] Therefore, further development on the environmental impact of the synthesis of thiazoles is of interest and still in much demand. Metal oxide nanostructures such as iron, have gained significant importance as they have been demonstrated to be applicable in catalytic technology which cannot be usually achieved by their bulk counterparts. [11] In contin- uation of our research in the field of application of metal nanoparticles as heterogeneous catalysts in organic reactions, 12a–c in this study, three convenient methods for the one‐pot synthesis of 2‐amino‐4‐aryl thiazole derivatives from substituted acetophenones and thiourea are described in which TBBDA, PBBS, or a combination of TBBDA and magnetic nanoparticles supported with functionalized 4‐amino‐pyridine silica (MNPs@SiO 2 ‐Pr‐AP) are investigated as catalytic systems. 2 | EXPERIMENTAL 2.1 | Materials and instrumentation All commercially available chemicals were obtained from Merck and Fluka companies and used without further purification otherwise stated. Nuclear magnetic resonance (NMR) spectra were recorded in DMSO‐d 6 on Received: 11 July 2017 Revised: 3 September 2017 Accepted: 10 September 2017 DOI: 10.1002/aoc.4127 Appl Organometal Chem. 2017;e4127. https://doi.org/10.1002/aoc.4127 Copyright © 2017 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/aoc 1 of 10