Abstract

OXIDATION OF TORSEMIDE BY POTASSIUM PERMANGANATE IN AQUEOUS ALKALINE MEDIUM-A KINETIC AND MECHANISTIC APPROACH

Ramyashree H. and *Vidyavati Shastry

ABSTRACT

Study of kinetics and oxidation of Torsemide(TOR) was studied spectrophotometrically by monitoring the decrease in the absorbance of potassium permanganate at 525nm in aqueous alkaline medium at 25°C at constant ionic strength 0.5 mol dm-3. The reaction exhibits 1:2 stoichiometry. The reaction was first order with respect to manganese(VII). The oxidation products were identified by using LCMS peak. Effect of torsemide, potassium permanganate, sodium hydroxide and ionic strength was studied at different concentration. As the reaction rate increases with increases in alkali concentration. Increase in the ionic strength has no effect on rate constant. On the basis of experiment suitable mechanism is suggested. Mechanism involving the formation of a complex between torsemide and potassium permanganate. Reaction rate has been carried out at five different temperatures and activation parameters ΔH# (kJ mol s-1) and ΔS# (Jk-1mol-1) were calculated. ΔS# has negative value which indicates oxidation occurs via inner sphere mechanism.

Keywords: Kinetics, Oxidation, Potassium permanganate, Spectrophotometer, Torsemide.