Kinetics and mechanism of oxidation of aromatic aldehydes by 1-chlorobenzimidazole in aqueous acetic acid medium

The kinetics of oxidation of aromatic aldehydes by a new oxidant, 1-chlorobenzimidazole (CBI) has been studied in 90% (v/v) aceticacid-water mixture. The reaction shows first order dependence each in [CBI], [Aldehyde] and [H] ions. Increase in acetic acid content of the solvent medium increases the rate of reaction. Electron donating groups accelerate the rate, while electron withdrawing groups decrease the rate. Activation parameters have been calculated. A mechanism in conformity with kinetic data has been proposed.