A Facile Approach to the Synthesis of 3-Acylisoxazole Derivatives with Reusable Solid Acid Catalysts

Abstract

Nitrile oxides were formed from nitro ketones using silica gel-supported sodium hydrogen sulfate (NaHSO4/SiO2) or Amberlyst 15 as solid acid catalyst, and then the corresponding 3-acylisoxaszoles were obtained by reacting with alkynes via the 1,3-dipolar [3+2] cycloaddition. These heterogeneous catalysts are easily separable from the reaction mixture and reused. This synthetic method provides a facile, efficient, and reusable production of 3-acylisoxazoles.