Phosphoric acid/titanium oxide-zirconium oxide as an effective reusable nanocatalyst for microwave-promoted synthesis of 2-arylbenzothiazole derivatives

Abstract

This study aims to demonstrate an approach for the synthesis of 2-arylbenzothiazole derivatives. Benzaldehyde and 2-aminothiophenol were reacted in a one-step process using ethylene glycol as the optimal solvent, promoting a sustainable methodology. Titanium and zirconium salts served as catalysts to facilitate the reaction, while phosphoric acid was used to activate the metal oxide mixture. The catalyst was recyclable and could be reused after repeated washing. The structure of the H₃PO₄/TiO₂–ZrO₂ (1 : 1)-surf catalyst was characterized using several techniques, including FT-IR, XRD, FE-SEM, and EDX analyses. The structures of the synthesized organic compounds were confirmed by melting point determination, FT-IR, ¹H NMR, and ¹³C NMR spectroscopy, and mass spectrometry analyses.