An ecofriendly and efficient approach for three-component synthesis of benzothiazoles: research on catalytic application of Fe3O4@DOP-Amide/Imid-CuCl2 nanocomposite

Benzothiazole derivatives have high biological activity potential and are present in many natural and medicinal products. For these reasons, the synthesis of benzothiazoles is very important in organic synthesis. In this synthetic approach, we found that the utilization of Fe₃O₄@DOP-Amide/Imid-CuCl₂ nanocomposite in the presence of KOAc in ChCl-Urea as solvent is an eco-friendly and efficient catalytic system for the synthesis of 2-aryl benzothiazoles through one-pot three-component reactions of 2-iodoaniline and aromatic aldehydes with thiourea as sulfur source. Under this catalytic system, a broad spectrum of 2-aryl benzothiazoles were successfully synthesized with high to excellent yields. Compared to the reported catalysts or magnetic nanocatalysts, the Fe₃O₄@DOP-Amide/Imid-CuCl₂ nanocatalyst has the following series of features: design of a magnetic ligand through ammonolysis reaction, high magnetic property of the Fe₃O₄@DOP-Amide/Imid-CuCl₂ nanocatalyst, high catalytic activity in the synthesis of benzothiazole derivatives, reusability and high stability of the synthesized magnetic catalyst. The SEM, VSM, BET, and ICP-OES techniques revealed that the recovered Fe₃O₄@DOP-Amide/Imid-CuCl₂ catalyst (after 8 times) had high stability because the magnetic nature, structure, and surface of the recovered catalyst was similar to the fresh catalyst.

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