Straightforward synthesis of quinoxaline-furan bis-heterocyclic structures via a multicomponent reaction

An efficient and straightforward synthetic strategy based on the higher-order multicomponent reactions (MCRs) is established for the synthesis of quinoxaline-furan bis-heterocyclic structures. The process includes a one-pot, pseudo-five component reaction of 3,4-diaminobenzoic acid, a 1,2-dicarbonyl compound, a dialkyl acetylenedicarboxylate, and two equivalents of an isocyanide as the readily available precursors. The noticeable features of the method are pot and atom economy, seven new bond formations, operational simplicity, high yields, and applicability on the gram-scale. Indolo[2,3-b]quinoxaline-furan tris-heterocycles were also synthesized using isatin derivatives via consecutive reactions.