Reactions of 4-hydrazinocarbonylmethylene 3-arylsydnones and 3-(4-Hydrazinocarbonylphenyl)sydnones

Article abstract of DOI:10.1002/jccs.199900008

The phenyl ring of 3-(4-hydrazinocarbonylphenyl)sydnone activates a hydrazinocarbonyl group to undergo a series of reactions for preparing heterocyclic compounds including oxadiazoles, dihydropyrroles, and pyrroles. However, the hydrazinocarbonyl group on the C(4)-CH₂ resists a cyclization under the same reaction conditions.