Kinetics and mechanism of the oxidation of primary alcohols by N-bromoacetamide in alkaline solution

Abstract

The kinetics of the oxidation of seven primary alcohols by N-bromoacetamide has been studied in alkaline solution. The main product of the oxidation is the corresponding aldehyde. The reaction is first order with respect to the oxidant and alcohol. The oxidation of [1,1-²H₂]ethanol indicates an absence of a primary kinetic isotope effect. The rate decreases with the increase in the concentration of hydroxide ion. Addition of acetamide decreases the reaction rate. The rates were determined at five different temperatures and the activation parameters were evaluated. The activation enthalpies and entropies of the oxidation of seven alcohols are linearly related. Hypobromite ion has been postulated as the reactive oxidizing species. A mechanism involving rate-determining nucleophilic attack of hypobromite ion on the alcohol molecule has been proposed.