Spectrophotometric Study of Oxidation Kinetics and Mechanism of Losartan Potassium Using N-chlorosuccinimide
S. Malini *
Department of Chemistry, Dayananda Sagar College of Engineering, Bangalore-560 078, India
Kalyan Raj
Department of Chemistry, BMS College of Engineering, Basavanagudi, Bangalore-560 004, India
N. Nanda
Department of Chemistry, BMS College for Women, Basavanagudi, Bangalore-560 004, India
J. P. Shubha
Department of Chemistry, Don Bosco Institute of Technology, Kumbalgodu, Bangalore-560060, India
*Author to whom correspondence should be addressed.
Abstract
The kinetics of oxidation of Losartan Potassium [LP] by N-Chlorosuccinimide [NCS] in HCl medium is studied spectrophotometrically at 205 nm at 298 K. The reaction rate shows fractional order dependence on [LP], [HCl] and first order dependence on [NCS]. The reaction rate also shows an inverse fractional order in [Cl-]. Addition of reduction product did not have any significant effect on reaction rate. However, an increase in ionic strength decreases and increase in solvent polarity increases the reaction rate. The activation parameters for the reaction are evaluated. The proposed general mechanism and derived rate law are consistent with observations.
Keywords: Kinetics, oxidation, N-chlorosuccinimide, spectrophotometric, losartan potassium