A general method for the synthesis of structurally diverse quinoxalines and pyrido-pyrazine derivatives using camphor sulfonic acid as an efficient organo-catalyst at room temperature

Abstract

A mild, convenient, eco-friendly, general and practical approach has been developed for the synthesis of a series of structurally diverse quinoxaline derivatives via the condensation reactions of various 1,2-diaminobenzene derivatives and 1,2-dicarbonyls such as phenanthrene-9,10-dione, acenaphthylene-1,2-dione or benzil using a catalytic amount of camphor sulfonic acid as an efficient, commercially available, low cost, organo-catalyst in aqueous ethanol at room temperature. Under the same optimized conditions we were also able to synthesis dibenzo[f,h]pyrido[2,3-b]quinoxaline as well as 10-bromoacenaphtho[1,2-b]pyrido[2,3-e]pyrazine from the reactions of pyridine-2,3-diamines and phenanthrene-9,10-dione or acenaphthylene-1,2-dione respectively.

Graphical Abstract

Keywords:

• Quinoxalines
• pyrido-pyrazine
• camphor sulfonic acid
• room temperature
• organocatalysis

Acknowledgements

Dr. B. Banerjee is thankful to the Indus International University, Una, Himachal Pradesh, India and the Kartha Education Society, Mumbai, India for the support. Authors are grateful to AMRC, IIT Mandi, Himachal Pradesh, India for the spectral measurements such as ¹H and ¹³C NMR and HRMS data.

Disclosure statement

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