ABSTRACT
Nitroxides react in mesomeric forms and are prone to scavenge alkylperoxyls and alkyls (3,15,70). Trapping of alkylperoxyls by 143 (R == H), derived from unsubstituted diphenylamine 22 (R == H), results in volatile unsubstituted 1,4-benzoquinone, nitrosobenzene, and nitrobenzene. Nitroxides 143 (R == tert-alkyl) or 144 (R = OC2HS) are more stable to oxidative degradation than 143 (R == H) owing to the presence of substituents in the para-position to the nitroxide moiety. Nitroxide 145 is oxidized by alkylperoxyls into quinone imine N-oxide 156.
