Annulation of pyrrole ring in 4-acylpyridine-3,5-dicarbonitriles in the presence of ammonia

4-Acyl-2-amino-6-chloropyridine-3,5-dicarbonitriles underwent heterocyclization in the presence of ammonia in aqueous dioxane medium, involving the ortho-ketonitrile fragment while preserving the halogen atom. The pyrrole ring annulation process proceeded regioselectively with the formation of a single positional isomer.