An unprecedented reaction of diethyl azodicarboxylate with imidazolium ylides

Abstract

3-Phenacyl- and 3-alkoxycarbonylmethyl-1-methylimidazolium bromides react with two molecules of diethyl azodicarboxylate in the presence of triethylamine with the extrusion of the imidazole ring and the concomitant migration of an ethoxycarbonyl group to yield 3-substituted tetraethyl 1,2,4,5-tetra-azapent-3-ene-1,1,2,5-tetracarboxylates (5), the structure of which has been confirmed by X-ray crystallography, (6), and (7).