Synthesis and Application of Nano Vanadium‐Oxo Pyridiniumporphyrazinato Sulfonic Acid for Synthesizing Pyrazole and Dihydropyrano[2,3]pyrazole Derivatives

In this study, we presented a description of designing and synthesizing an original nano‐N‐sulfonated (‐SO3H) phthalocyanine molten salt (vanadium‐oxo pyridiniumporphyrazinato sulfonic acid) [VO(TPPASO3H)]Cl as a recyclable and efficient heterogeneous catalyst with thermal stability for synthesizing pyrazole and dihydropyrano[2,3]pyrazole derivatives. After recycling and reapplying five times, this catalyst indicated no significant decrease in the catalytic activity. Nano‐N‐sulfonated (−SO3H) phthalocyanine molten salt (vanadium‐oxo pyridiniumporphyrazinato sulfonic acid) [VO(TPPASO3H)]Cl as a heterogeneous and recyclable catalyst with dual active sites (Bronsted and Lewis acid sites) was designed and applied for synthesis of dihydropyrano pyrazole and pyrazole derivatives. According to the obtained results of this study, the method reported here offers some considerable benefits such as short reaction times, high yields, simple and easy work‐up, mild and solvent‐free reaction conditions.