One pot, three component synthesis of spiroindenoquinoxaline pyrrolidine fused nitrochromene derivatives following 1,3-dipolar cycloaddition

Abstract

An expedient one-pot sequential three-component synthesis of a series of diverse spiroindenoquinoxaline pyrrolidine fused nitrochromene derivatives following 1,3-dipolar cycloaddition of azomethine ylides generated in situ by the condensation of indenoquinoxalone and α-amino acids (L-proline and L-phenyl alanine) with 3-nitrochromenes as dipolarophile under classical as well as microwave irradiation is described. The protocol provides a mild reaction condition, high yield of the products, high regioselectivity, and operational simplicity to assemble complex structural entity in a single operation with good to excellent yield. The regio and stereochemical outcome of the cycloaddition reaction is ascertained by spectroscopic and single crystal X-ray analysis.

Graphical Abstract

Keywords:

• Azomethine ylides
• 1,3-dipolar cycloaddition
• indenoquinoxaline
• multicomponent reactions
• spiro compounds
• nitrogen heterocycles
• 3-nitro-2H-chromene

Acknowledgments

SN and SRM are thankful to CSIR, New Delhi [02(0218)/14/EMR-II], DRDO, New Delhi ERIP/ER/1203083/M/01 for providing research grant and also thankful to DST-FIST, New Delhi for providing NMR facility.