Efficient and Convenient Protocol for the Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazoles Using HClO₄-SiO₂ as a Heterogeneous Recyclable Catalyst

Abstract

Silica-supported perchloric acid (HClO₄-SiO₂) was found to be a new, highly efficient, inexpensive, and reusable catalyst for a rapid and efficient synthesis of various 1,2,4-oxadiazoles with good to excellent yields under solvent-free conditions. The present methodology has been effectively utilized for the synthesis of oxolamine, an anti-inflammatory drug.

GRAPHICAL ABSTRACT

Keywords:

• Acid anhydrides
• amidoxime
• HCLO₄-SiO₂
• 1,2,4-oxadiazole
• reusable catalyst

ACKNOWLEDGMENTS

We sincerely thank Sri G. Ganga Raju, chairman, and G. Rama Raju, director, Laila Impex, for analytical support.

Notes

^a Isolated yield.

^a Isolated yield.