Ultrasound mediated chemical synthesis of 2-aryl substituted benzothiazoles derivatives using merrifield resin supported ionic liquid as organocatalyst

Herein, the study synthesized a series of reusable and efficient Benzoxazolium-based Merrifield resin Supported Ionic Liquids (MRBO-SILs) as organocatalyst by refluxing a mixture of merrifield resin (chemically inert and non-toxic) and benzoxazole. The synthesized catalyst MRBO-SILs were used for the greener synthesis of wide range of medically active 2-substituted benzothiazoles from substituted aldehydes and 2-aminothiophenol in 60% EtOH under ultrasonication. The resulting protocol is remarkably effective for synthesis because it adheres to green chemistry principles and has many more advantages than those mentioned in earlier studies. These advantages include a smooth reaction, the use of EtOH as a solvent, short reaction time (2–5 min), excellent yield (> 95%), ambient temperature (25 ℃), an easy workup procedure, catalyst recycling, and high atom economy. Furthermore, the catalyst's catalytic activity would not diminish even after eight cycles of reuse.

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