Heteropolyacids as Green and Reusable Catalysts for the Synthesis of Isoxazole Derivatives

Abstract

Heteropolyanions with different structures, including Keggin, Dawson, Preyssler, mixed addenda, and sandwich types, catalyzed the formation of 1,3‐diphenyl‐isoxazole from the condensation of 1,3‐diphenyl‐propane‐1,3‐dione and hydroxylamine hydrochloride in different solvents and under heating conditions. Our data vividly indicate that H₃PW₁₁CuO₄₀ is the catalyst of choice and could catalyze the synthesis of other isoxazole derivatives in high yields and good selectivities.

Keywords:

• β‐dicarbonyl compounds
• heteropolyacids
• HPAs
• hydroxyl amine
• isoxazole derivatives