Kinetics of acetonitrile-assisted oxidation of tertiary amines by hydrogen peroxide

The rate of oxidation of tertiary amines by aqueous hydrogen peroxide is increased in the presence of acetonitrile due to the formation of a reactive intermediate. The active oxidant, presumably peroxyacetimidic acid, was quantified by a photometric method. Activation parameters of the acetonitrile-assisted and non-assisted oxidations are given in the temperature range 20 to 40 degreesC. The increased rate of the assisted oxidation is explained by the low enthalpy of activation although the entropy of activation is more negative due to a highly ordered transition state.