BEHAVIOR OF THE HETERO-RING IN γ-PHENYL-Δβ,γ-BUTENOLIDE DERIVATIVES TOWARD HYDRAZINES. ACID REARRANGEMENT OF 4-PHENYLAZO-2-PHENYLOXAZOLIN-5-ONE

The substituted pyridazinones 3-phenyl- and l,3-diphenyl-5-benzylidene-1,4,5,6-tetra-hydropyridazinone-6 have been prepared from α-phenacylcinnamic acid hydrazide and α-phenacylcinnamic acid phenylhydrazone, respectively. The dipyridazinone 5,5-di(3-phenyl-1,4,5,6-tetrahydro)pyridazinone-6 was prepared from the dilactone IV, isolated as a side product in the synthesis of lactone VI.Rearrangement of 4-phenylazo-2-phenyloxazolin-5-one now has been found to proceed also in the presence of acidic reagents.