ON THE MECHANISM OF ALKALINE HYDROGEN-PEROXIDE OXIDATION OF THE LIGNIN MODEL P-HYDROXYACETOPHENONE

The oxidation of p-hydroxyacetophenone by a small excess of alkaline hydrogen peroxide has been found to be an autocatalysed process in which hydroquinone monoacetate and the peracetate ion are generated and consumed at similar rates. The reaction proceeds at a maximum rate when the base concentration is about 0.3 M. A chain-type mechanism that involves peracetate as the oxidizing agent is proposed for the reaction that explains the observed dependence of rate on base concentration. At high pH o-hydroxyacetophenone reacts by the same mechanism, whereas m-hydroxyacetophenone does not react with hydrogen peroxide under these conditions.