Mechanistic investigation of oxidation of paracetamol by sodium N-chlorohenzenesulphonamide in acid medium

摘要

Oxidation of paracetamol (PAM) by sodium N- chlorobenzenesulphonamide (chloramine-B or CAB) in HCIO4` medium at 30 deg.C was studied. The rate is first order in [CAB]O and fractional order each in 30 deg. C was stydued, The rate is first order in [CAB]0 and fractional order each *? product benzenesulphonamide or halide ions had no significant effect on the reaction rate. The solvent isotope effect was studied using D2O. Decrease in dielectric constant of the medium increases the rate. Activation parameters for the overall reaction have been computed. Michaelis-Menten type of kinetics has been proposed and activation parameters for the rate-limiting step have also been computed. 4-Amino-2,6-dichlorophenol was identified as the oxidation product of PAM. A mechanism consistent with the observed results is proposed and discussed.