Thermolysis of Ethoxycarbonyl2-Phenyl-2-(Phenylsulfonylhydrazono)EthylMethylenetriphenylphosphoranes. Formation of Substituted Pyridazinones

摘要

Ethoxycarbony2-phenyl-2-(phenylsulfonylhydrazono)ethyl-methylenetriphenylphosphoranes were prepared by the reaction of ethoxy-carbonymethylenetriphenylphosphorane with phenylsulfonylhydrazones of phenacyl bromides. Thermolysis of the phosphoranes gave 6-phenyl-2-phenylsulfonyl-3(2H)-pyridazinones, 6-phenyl-4-phenylsulfonyl-3(2H)-pyridazinones, and 6-phenyl-2-phenylsulfonyl-4-triphenylphosphoranylidene-1,4-dihydro-3(2H)-pyridazinones, together with triphenylphosphine. The structure of disubstituted methylenetriphenylphosphorane was confirmed by an X-Ray diffraction method.