Copper-Oxone Promoted Oxidative C-H Functionalization: Synthesis of 2-Aminobenzothiazoles and Evaluation of Their Antimicrobial Activities

Benzothiazole is one of the most important heterocyclic scaffolds existing in both natural and synthetic compounds. This prominent ring is of undoubted interest due to its broad range of therapeutic benefits as well as chemical reactivity in organic reactions. Therefore, we developed a convenient, rapid and efficient methodology for the ring closure reaction of thioureas to form 2-aminobenzothiazole derivatives. We optimized the reaction conditions by trying various catalysts and oxidants. Copper iodide/oxone catalysis provided the best conditions for the preparation of benzothiazoles. The regioselectivity observed in the ring closure reaction of the naphthyl thiourea derivative was investigated and the obtained experimental results were supported by theoretical calculations. In vitro antimicrobial effects of the compounds were tested against various bacterial and fungal strains. Finally, molecular docking studies were carried out to rationalize the achieved biological results and suggest molecular modifications to design new benzothiazole derivatives.