Comparative Kinetic Study of Palladium(II) Catalyzed and Uncatalyzed Oxidation of Ambroxol Hydrochloride with Potassium Permanganate in an Aqueous Alkaline Medium: A Mechanistic Approach

Document Type : Regular Article

Authors

1 Department of Chemistry and Research in Chemistry, Visvesvaraya Technological University, SEA college of engineering & technology, Bangalore-560049, Karnataka, India

2 Department of Chemistry, New Horizon College of Engineering, Outer Ring Road, Bangalore-560103, Karnataka, India

3 Department of Chemistry, PES Institute of Technology and Management, Sagar Road, Guddada Arakere, Kotegangoor, Shivamogga- 577204, Karnataka, India

10.22036/pcr.2022.361486.2191

Abstract

The comparative kinetic study of the oxidation process of ambroxol hydrochloride (AMH) by potassium permanganate (KMnO4) in an alkaline aqueous environment in the presence and absence of palladium (II) catalyst has been analyzed at 25oC. The reaction shows the dependence of the first order on KMnO4 and fractional order with respect to AMH, sodium hydroxide medium. The addition of the salt component has no effect on the reaction. Dependence of temperature, dielectric constant and intervention of free radicals had been also studied. The reaction stoichiometry was found to be 1:1 relative to the substrate and oxidant respectively. The obtained oxidation products are identified as 2-amino-3,5-dibromobenzaldehyde hydrochloride and 4-aminocyclohexanone by liquid chromatography-mass spectra. Thermodynamic parameters such as, change in entropy, enthalpy and free energy, and activation energy regarding the slow step of the mechanism are calculated and included in the table. Moreover, a suitable mechanism for the reaction is proposed and rate laws are derived and verified.

Graphical Abstract

Comparative Kinetic Study of Palladium(II) Catalyzed and Uncatalyzed Oxidation of Ambroxol Hydrochloride with Potassium Permanganate in an Aqueous Alkaline Medium: A Mechanistic Approach

Keywords