Reaction of 5‐Acetyl‐10,11‐didehydro‐5H‐dibenz(b,f)azepine with Pyrrole, N‐Methylpyrrole, Imidazole and N‐Methylimidazole: Cycloaddition versus Michael Addition.

Reaction of 5-acetyl-10-bromo-5H-dibenz[b, f]azepine 1 with potassium t-butoxide results in the reactive intermediate 5-acetyl-10,11-didehydro-5H-dibenz[b, f]azepine (2). The intermediate 2 reacts with N-methylpyrrole to give a mixture of the Michael addition adduct 10-(2-N-methylpyrrolyl)-5H-dibenz[b, f]azepine (9) and the Diels-Alder/retro Diels Alder adduct 8H-(N-methylpyrrolo[3,4-d]dibenz[b, f]azepine (8a). Reaction of 2 with pyrrole gives a mixture of two Michael addition adducts 10-(1-pyrrolyl)-5H-dibenz[b, f]azepine (16) and 10-(2-pyrrolyl)-5H-dibenz[b, f]azepine (18). Reaction of 2 with imidazole results in the Michael addition adduct 10-(1-imidazolyl)-5H-dibenz[b, f]azepine (21).