TURKISH JOURNAL OF CHEMISTRY, vol.22, no.2, pp.137-142, 1998 (SCI-Expanded)
3,4-Diformyl-2,5-dimethylpyrrole (1) reacts with 1,2-diphenyl-1,2-diamine derivatives to form the potentially tautomeric 2:2 macrocyclic adduct (6)=(7). H-1 and C-13 n.m.r. spectral data along with acidity measurements indicate that the 2-azafulvene structure (7) is predominant for all adducts.