Sulphur–nitrogen compounds. Part 5. The oxidation of N-aryl-N-(arylsulphonyl)hydroxylamines: preparation of N-aryl-NO-bis(arylsul-phonyl)hydroxylamines

Abstract

Oxidation of the compounds R¹(R²SO₂)NOH (R¹, R²= Ph, Ph; p-ClC₆H₄, Ph; p-ClC₆H₄, p-MeOC₆H₄; or Ph, Me) yields NNO-trisubstituted hydroxylamines R¹(R²SO₂) NOSO₂R², together with R¹NO₂ and R¹NN(O) R¹ When R¹, R²= Ph, Ph; p-ClC₆H₄, Ph; or Ph, Me the oxidation proceeds via rhe aminyl oxide radicals R¹(R²SO₂)NO˙: when R¹, R²=p-ClC₆H₄, p-MeOC₆H₄ the radical (p-ClC₆H₄)₂NO˙ is also formed. Apparently pure samples of (RSO₂)₂NOSO₂R (R =p-XC₆H₄: X = H, Me, Cl, or F) contain low concentrations of the radicals (RSO₂)₃NO˙ Carbon-13 n.m.r. spectroscopy shows that the compounds (RSO₂)₂NH, (RSO₂)₂NOH, and (RSO₂)₃N contain only one type of R, but that (RSO₂)₂NOSO₂R contain two types of R and hence are NNO-tri-substituted hydroxylamines rather than amine oxides. Similarly Ph(PhSO₂)NOH contains two phenyl sites but Ph(PhSO₂) NOSO₂Ph contains three.