Diphenylnitroxide and Diphenylamino Derivatives from the Reactions of Nitrogen Monoxide and Nitrogen Dioxide with Nitrosobenzene

Recently, we observed that when nitroarenes were reacted with nitrogen monoxide •NO and nitrogen dioxide •NO2 inside the e.s.r. cavity the signals of the corresponding diphenylnitroxides were detected. In order to better understand the reactivity of these two radical species, •NO and •NO2, which can both have deleterious effects (nitrosative and oxidative stress), we tried to obtain further insights on this reaction by carrying it out also on a macroscale level. The isolated compounds, reported in the Scheme, were all justified through the intermediate formation of a diphenylnitroxide. A mechanism for the reaction is proposed in this communication and it is also supported by the data already reported in the literature concerning the reaction between indolinonic nitroxides and nitric oxide.