Kinetics and mechanism of oxidation of beta benzoylpropionic acids by pyridinium fluorochromate in aqueous acetic acid medium

摘要

The kinetics of oxidation of beta benzoylpropionic acid and para substituted beta benzoylpropionic acids(KA) by pyridinium fluorochromate(PFC) has been studied in aqueous acetic acid medium in the presence of perchloric acid.The reaction follows first order kinetics each with respect to [PFC],[KA] and [H~+].Electron withdrawing substituents are found to retard the reaction and electron releasing substituents are found to increase the rate of reaction and the rate data obey the Hammett relationship.The products of the oxidation are the corresponding acids.The activation enthalpies and entropies are calculated and the possible mechanism for oxidation reaction is discussed.