KINETICS OF THE PEROXYMONOPHOSPHORIC ACID OXIDATION OF AROMATIC-AMINES

Oxidation of N, N-dimethylaniline (1a) and methyldiphenylamine (1b) with peroxymonophosphoric acid in aqueous acetonitrile at 30 °C gives the corresponding N-oxides. The oxidation obeys the rate equation: v = k2-[amine]t[peracid]t-The effect of the acidity of solution shows that neutral amine alone can react with peracid, the rate being determined by a nucleophilic attack of amine on peracid oxygen. The reactivity of H3PO5 to amine is ~100 times higher than that of H2PO5-, and the reactivity of 1a to peracid is ~100 times higher than that of 1b. These results are discussed on the basis of both a plot of rate constant vs. pH and acidity constants of H3PO5 and conjugate acids of amines. © 1979, American Chemical Society. All rights reserved.