A novel tandem cyclization of condensed 2,3-dialkynylpyrazines into [1,2,3]triazolo[1′,5′;1,2]pyrido[3,4- b]pyrazines promoted by sodium azide

Abstract

6,7-Dialkynyl-1,3-dimethylpteridine-2,4(1 H,3 H)-diones and 2,3-dialkynylquinoxalines have been shown to react with sodium azide in DMF at room temperature giving rise 9,11-dimethyl-[1,2,3]triazolo[1′,5′;1,2]pyrido[4,3- g]pteridine-8,10(9 H,11 H)-diones and [1,2,3]triazolo[1′,5′;1,2]pyrido[3,4- b]quinoxalines. A novel tandem cyclization involves 1,3-dipolar cycloaddition of an azide ion to the carbon–carbon triple bond followed by intramolecular nucleophilic addition of the intermediate 1,2,3-triazole N-anion to another C C bond.