One-pot Synthesis of quinoxaline Derivatives via Palladium-catalyzed reactions

The pyrrolo[1,2-a]quinoxaline skeleton is present in various heterocyclic compounds possessing interesting biological activities. Quinoxaline derivatives display a broadspectrum of biological activities including anti-microbial,[1] anti-inflammatory [2] and anticancer [3] properties. A literature survey shows that the synthesis of quinoxalines,starting from the quinoxaline moiety, has been under explored. Consequently, the development of new synthetic strategies for the synthesis of quinoxaline derivativesfrom the quinoxaline scaffold are important. In this research work, new quinoxalines were synthesized through the multicomponent reaction of 3-substituted 2-chloroquinoxalines, benzoic acids and propargyl bromide in the presence of a palladium-copper catalytic system. This onepot process provided an efficient and successful approach for the construction of 1,4- disubstituted quinoxalines with good-to-high yields. All the new synthesized compounds were characterized by the analytical spectral data