Reactions of 1H-1,2- and 1H-1,3-diazepines with dimethyl acetylenedicarboxylate
Abstract
The title reactions yield the 3a, 7a-dihydropyrrolo[3,2-b]pyridines (2) and 3a,7a-dihydroindazoles (9), respectively, probably via the diazonine intermediates (4) and (8) derived from the initially formed [2 + 2]π cycloadducts; the indazoles (9) further react with the reagent to give the dimethyl phthalates (6) and the pyrazoles (7)via the [4 + 2]π cycloadducts (10).