p-TSA-catalyzed a simple and efficient one-pot eco-friendly synthesis of functionalized new isoxazolyl-4-hydroxyindole-3-carboxylate derivatives in aqueous medium

Abstract

A simple, efficient, cost-effective and one-pot eco-friendly protocol has been developed for the synthesis of new isoxazolyl-4-hydroxyindole-3-carboxylate derivatives by using 4-amino-3-methyl-5-styrylisoxazoles, 2,3-diketoesters and 1,3-cyclohexanediones, in the presence of p-toluenesulfonic acid (p-TSA) catalyst in aqueous medium. The advantages of this protocol are inexpensive catalyst, metal-free, shorter reaction time, environmentally friendly, high yields, water as a solvent, wide substrates scope and easy purification.

GRAPHICAL ABSTRACT

Keywords:

• Isoxazolyl-4-hydroxyindole-3-carboxylates
• Green chemistry
• One-pot
• synthesis
• Aqueous medium

Acknowledgments

Vanaja Rani thanks the Department of Chemistry Koneru Lakshmaiah Education Foundation for providing research facilities. We are grateful to Prof. Ravindhranath and Dr. NAGI REDDY for their valuable support and discussions.

Disclosure statement

No potential conflict of interest was reported by the author(s).