Kinetics and mechanism of oxidation of amino acids by N-chloronicotinamide in aqueous acetic acid medium

Department of Chemistry, National College, Tiruchirapalli-620 001, India

Department of Chemistry, St. Joseph's College, Tiruchirapalli-620 002, India

Manuscript received 10 September 1997, revised 31 July 1998, accepted 16 November 1998

Kinetics of oxidation of ten a-amino acids by N-chloronicotinamide (NCN) in aqueous acetic acid medium in presence of hydrochloric acid have been investigated. The observed rate of oxidation is first order in both (oxidant) and [HCI]. A small increase in rate is observed with increase in [amino acid). A decrease in the dielectric constant of the medium increases the rate. Addition of nicotinamide (NA), the reduction product of NCN, has a retarding effect on the rate of oxidation. The corresponding aldehydes, ammonia and carbon dioxide have been identified as the oxidation products. Molecular chlorine has been postulated as the reactive oxidising species in the reaction.