Stoichiometry and Kinetics of the Cobalt(III) Oxidation of Acetamide, Formamide, N-Methylformamide and N,N-Dimethylformamide in Acid Perchlorate Solutions

Abstract

The oxidation of acetamide, formamide, N-methylformamide and N,N-dimethylformamide by cobalt(III) in perchloric acid at 20°C has been investigated. The reaction requires nearly three moles of cobalt(III) for one mole of amide (except acetamide) and nearly one mole of cobalt(III) is consumed per mole of acetamide, and leads in each case to the formation of the respective amines. The oxidation of the amides is found to obey the rate law

-d[Co^III]/dt = (k' + k''[H⁺])[Co³⁺]

A free-radical mechanism has been proposed for the reaction. Activation energies and entropies are calculated for each reaction.