Stable nitroxide radicals from phenylisatogen and arylimino-derivatives with organo-metallic compounds

Stable nitroxide radicals were obtained by the oxidation of 1-hydroxyindolines prepared by allowing the organo-metallic compounds to act upon 2-phenylisatogen and arylimino-derivatives. In both cases nitroxides are obtained with a ^N of approximately 9 gauss, in agreement with similar known compounds. The ESR spectra of numerous nitroxide radicals are discussed and a number of cases of magnetic non-equivalence of methylenic protons adjacent to asymmetric carbon are brought to light.