Synthesis of Fused Isoxazoles: A Comprehensive Review

Abstract

Pharmaceutically important isoxazoles are within the wide range of heterocycles. The isoxazole ring, being five-membered, is also found in many bioactive natural products in addition to synthetic drugs. Many significant properties are exhibited by synthetically modified isoxazoles. Fused isoxazoles have widely shown their therapeutic potential as anticancer, insecticidal, antibacterial, antituberculosis, antifungal, antibiotic, antitumor, and antiulcerogenic agents. A variety of strategies are employed for the synthesis of these compounds, which are known for their pharmacological importance. Their synthesis is here reviewed. Synthesized isoxazoles have appeared as good forerunners for many other different molecules. This review summarizes the various synthesis approaches described so far for isoxazoles, providing a detailed study of their synthesis process. Substituted isoxazoles have been well discussed in the literature for their significant biological activities. This review is mainly focused on the synthesis of fused isoxazoles.

Keywords

• isoxazoles
• fused isoxazole
• hydroxylamine hydrochloride