Periodate Oxidation of Aromatic Amines— Kinetics and Mechanism of Oxidation of p-Toluidine in Acetone-Water Medium

Abstract

The kinetics of the periodate oxidation of p-toluidine in acetone-water

medium has been followed spectrophotometrically. The total

order of reaction is two, being first order in each reactant. The

rate-pH profile has been given and discussed. The rate decreased

with a decrease in dielectric constant while no appreciable increase

in rate with an increase in ionic strength has been observed. The

reaction was found insensitive towards free radical scavengers. The

activation parameters have been evaluated. The main product isolated

and characterised was 4-methyl-o-benzoquinone. The

stoichiometry of 2 mol of periodate: 1 mol of p-toluidine was

observed. A suitable mechanism has been proposed and the rate law

derived.