Dihydropyridazines. III . Reactions with oxygen

The reactions of oxygen with a series of dihydropyridazines have been explored. The primary reaction other than aromatization appears to occur from the 1, 4-dihydro tautomer. A single crystal x-ray structure has been determined on the product from the reaction of oxygen with 3, 6-diphenyl-4, 4-dimethyl-1, 4-dihydropyridazine.