Reaction of 3,4-diformyl-2,5-dimethylpyrrole with 1,2(substituted) diphenyl-1,2-diaminoethanes

Abstract

3,4-Diformyl-2,5-dimethylpyrrole (1) reacts with l,2-diphenyl-l,2-diamine derivatives to form the potentially tautomeric 2:2 macrocyclic adduct (6)=(7). $^1H$ and $^{13}C$ N.M.R. spectral data along with acidity measurements indicate that the 2-azafulvene structure (7) is predominant for all adducts.