Pd(II) Catalyzed Oxidative Degradation of Paracetamol by Chloramine-T in Acidic and Alkaline Media

Pd(II) catalyzed oxidation of paracetamol (PA) by sodium N-chloro p-toluenesulfonamide (chloramine-T or CAT) was studied in HClO4 and NaOH solutions at 303 K. The stoichiometry and the oxidation product in both solutions were found to be the same. The determined stoichiometric ratio was 1:2 ([PA]: [CAT]) and quinone oxime was identified as the oxidized product of PA. However, the kinetics patterns in both media were different. In the acidic medium, the rate law was -d[CAT]/dt = k[CAT][PA](0.9)[Pd(II)](0.8)[H+](-0.4) and the rate law was -d[CAT]/dt = k[CAT][PA](0.9)[Pd(II)] [PTS](-0.4)[NaOH](-1) in the alkaline medium. p-Toluenesulphonamide (PTS) is the reduced product of CAT. The kinetics of the reaction was studied as a function of temperature, ionic strength, concentration of the salt, concentration of the added reaction product, and dielectric constant of the medium to learn the mechanistic aspects of the reaction. A plausible mechanism is proposed, which is consistent with the kinetics, stoichiometry, and product of the reaction.