Addition reactions of heterocyclic compounds. Part LIII. Reactions of benzimidazoles with propiolic esters

Abstract

Reactions of methyl propiolate with benzimidazole and its 2-alkyl and aryl derivatives, in acetonitrile, gave the corresponding methyl 3-trans-(benzimidazol-1-yl)acrylates, whereas a reaction with benzimidazole in methanol gave the cis-isomer exclusively. Similar acrylates were formed from methyl tetrolate and methyl phenylpropiolate. Other products were pyrrolo[1,2-a]quinoxalines and a pyrrolo[1,2-a]benzimidazole.