The Chichibabin reaction in the Aminopyridine, azaindole, and azaindoline series

Abstract

2-Aminopyridine, unlike the 3- and 4-isomers, is animated by sodium amide with the formation of 2,6-diaminopyridine. Among the dimethylaminopyridines, the 3- and 4-isomers are more active in the Chichibabin reaction, while 2-dimethylaminopyridine is converted with great difficulty under the action of sodium amide into 2,6-diaminopyridine with the initial replacement of the dimethylamine residue by an amino group. Azaindoles and azaindolines do not take part in the animation reaction. In 1-phenyl-5-azaindole, under the action of sodium amide, the pyrrole ring opens with the formation of 4-anilino-3-vinylpyridine.