Preparative syntheses of bis(4-tert-butylphenyl)aminoxyl

Bis(4-tert-butylphenyl)aminoxyl was obtained in 80 and 95% yield by oxidation of the corresponding amine and hydroxylamine with H2O2/WO 4 2− in methanol at 65°C. The oxidation of bis(4-tert-butylphenyl)hydroxylamine to bis(4-tert-butylphenyl)aminoxyl was catalyzed by Cu+ and Ag+ ions which also catalyzed disproportionation of the former to bis(4-tert-butylphenyl)amine and bis(4-tert-butylphenyl)aminoxyl. Mechanisms of the catalytic oxidation of the amine and hydroxylamine and disproportionation of the latter were proposed.