Kinetic and Mechanistic Studies of Pd(II) Catalyzed Oxidation of Some α‐Hydroxy Acids by Sodium N‐Bromobenzenesulfonamide in Hydrochloric Acid Solutions

Abstract

Oxidations of glycolic acid, lactic acid, and α‐hydroxybutyric acid by bromamine‐B (BAB) catalyzed by Pd(II) in HCl solutions have been kinetically studied at 30 ± 0.1 °C. The results are compared with the oxidation of β‐hydroxybutyric acid in the presence of Pd(II) in HCl solutions. The reaction rate shows a first‐order dependence on [BAB], Pd(II), and fractional‐order dependence on [HCl]. The reaction rate is independent of [hydroxy acids]. Additions of halide ions and the reduction product of BAB, benzenesulfonamide (BSA), have no effect on the rate. The variation of ionic strength and dielectric constant of the medium has no effect on the rate. Activation parameters have been evaluated from the Arrhenius plot. A general mechanism consistent with experimental results has been proposed.

Keywords:

• Kinetics
• Mechanism
• Palladium(II) catalyst
• α‐Hydroxy acid
• Bromamine‐B

Acknowledgment

One of the authors (Mallamma) is grateful to the University Grants Commission, New Delhi, for awarding a Teacher Fellowship to pursue graduate work.