Azepinones. II. Syntheses of substituted pyridazines

Abstract

Two attempted synthetic routes to diphenyldiazatropones are described. Cyclization with hydrazine of 2-oximino-1,5-diphenylpentane-1,5-dione (IV) yielded substituted pyridazines rather than perhydrodiazepines. Oximination of the diphenyldihydrodiazepine (II) was successful, but attempts to dehydrogenate the ring proved only promising. A new and fully conjugated 10 π-electron system, the pyridazotriazole (VII), is described, as well as some unexpected rearrangements of the oxime (V).