Quinoxaline synthesis in novel tandem one-pot protocol

A variety of quinoxalines were synthesized via tandem one-pot procedure for the first time in water medium. The key strategy was the in situ preparation of alpha-halo-beta-keto esters by the reaction of N-bromo succinimide with beta-keto esters and further condensation with phenylene diamines. This novel eco-friendly approach offers an easy, efficient, and mild synthesis of highly substituted quinoxalines in good yields. (C) 2011 Elsevier Ltd. All rights reserved.