Application of the bischler reaction to the preparations of some pyrrolopyridines and the novel dipyrrolopyridine system

Abstract

The Bischler reaction, using α-hydroxy-ketones and 2,6-diaminopyridine, has yielded 6-amino-1H-pyrrolo-[2,3-b]pyridines and the novel system 1,7-dihydrodipyrrolo[2,3-b:3′,2′-e]pyridine with a variety of alkyl and aryl substituents. The reaction failed to give the corresponding unsubstituted heterocycles. 2,6-Diphenyl-1,7-dihydrodipyrrolo[2,3-b:3′,2′-e]pyridine is shown to undergo ready reaction with electrophilic reagents to give 3,5-substituted derivatives.