Kinetics and mechanism of the oxidation of L-α-amino-n-butyric acid in moderately concentrated sulfuric acid medium

The reaction kinetics of L-α-amino-n-butyric acid oxidation by permanganate ion have been investigated in moderately strong acid medium using a spectrophotometric technique. In all cases studied an autocatalytic effect, due to Mn+2 ions formed as a reaction product, was observed. Both catalytic and noncatalytic processes were determined to be first order with respect to the permanganate ion and the amino acid. The overall rate equation for this process may be written as: [Formula: see text] where k′1 and k′2 are pseudo-order rate constants for the noncatalytic and catalytic reactions, respectively. The influence of some factors such as temperature and reactant concentration on the rate constants has been studied, and the activation parameters have been calculated. Reaction mechanisms satisfying observations for both catalytic and noncatalytic routes have been presented.Key words: L-α-amino-n-butyric acid, permanganate oxidation, concentrated acidic medium, autocatalysis, free radical intermediates.