Oxidation of metformin with alkaline chloramine-B: Delineation of reaction mechanism and kinetic modeling

484-488<span style="font-size:9.0pt; mso-bidi-font-size:12.0pt" lang="EN-US">The kinetics and mechanism of oxidation of metformin hydrochloride (MET) with sodium N-chlorobenzenesulfonamide or chloramine B have been investigated in alkaline medium at 308 K. The reaction rate shows a first order dependence of rate each on [CAB]o and [MET]o, and an inverse-first order dependence on [OH-]. The stoichiometry of the reaction is found to be in the mole ratio of 1:1. The oxidation products are characterized as metformin <i style="mso-bidi-font-style: normal">N-oxide by GC-MS data. Activation parameters have been computed from the Arrhenius plot. The conjugate acid (PhSO2NHCl) is postulated as the reactive oxidizing species. The observed experimental results have been justified by a plausible reaction mechanism and the related kinetic rate law has been devised.