Efficient Synthesis of Quinoxalines in the Ionic Liquid 1-n-Butylimidazolium Tetrafluoroborate ([Hbim]BF₄) at Ambient Temperature

Abstract

Quinoxaline derivatives have been synthesized in excellent yields using an ionic liquid (IL) (viz., 1-n-butylimidazolium tetrafluoroborate) as a reaction medium as well as promoter from various 1,2-diketones and aryl-1,2-diamines. The process is general for the synthesis of quinoxaline derivatives from aromatic as well as aliphatic-1,2-diketones. The advantages of the present method are ambient reaction temperature, simplicity of operation, high yields of products, the recyclability of the IL, and ecofriendly nature of the reaction medium.

Keywords:

• Aryl-1,2-diamines
• 1,2-diketones
• ionic liquid (IL)
• quinoxalines

ACKNOWLEDGMENTS

T. M. P. thanks the Council of Scientific and Industrial Research (CSIR), New Delhi, for the award of a research fellowship.

Notes

^a The pKa values of the parent acid of the anions.

^b Isolated yield after column chromatography.

^a Isolated yield after column chromatography.