Highly efficient microwave-assisted one-pot synthesis of 4-aryl-2-aminothiazoles in aqueous medium

• Published in: Environmental chemistry letters 2017-09, Vol.15 (3), p.475-479
• Main Authors: Wagare, Devendra S., Netankar, Prashant D., Shaikh, Mujahed, Farooqui, Mazahar, Durrani, Ayesha
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Aqueous chemistry; Aromatic compounds; Benign; Chemical compounds; Chemical synthesis; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Geochemistry; Irradiation; Ketones; Microwave communications; N-Bromosuccinimide; Original Paper; Penicillin; Pollution; Polyethylene glycol; Polyethylenes; Solvents; Thiamine; Thiazoles; Thioureas; Vitamin B1; Vitamins; Yields
• ISSN: 1610-3653; 1610-3661
• DOI: 10.1007/s10311-017-0619-1

The thiazole ring system is one of the most important heterocycles in nature, as it represents an important structural motif of many biological compounds, including vitamin B 1 (Thiamin), carboxylase and penicillin. There is, therefore, an urgent need to design rapid, efficient and environmentally benign protocols for the synthesis of thiazoles. Herein, we have developed a one-pot protocol for the synthesis of 4-aryl-2-aminothiazoles from the reaction of aromatic ketones, NBS ( N -Bromosuccinimide) and thioureas under microwave irradiation at 80–85 °C in PEG (polyethylene glycol)-400 and water as a green reaction medium. The products were obtained in 84–89% yields in 28–32 min. The method has several advantages such as use of green solvent, easy work-up, excellent yield and avoiding use of lachrymatric α-haloketones.