Ruthenium(III) catalysed oxidation of gabapentin (neurontin) by diperiodatocuprate(III) in aqueous alkaline medium—A kinetic and mechanistic study

The oxidation of a neuroleptic drug gabapentin (GP) by a new oxidant diperiodatocuprate(III) (DPC) has been studied in an aqueous alkaline medium. A minute amount (10−7 mol dm−3) of ruthenium(III) is sufficient to catalyse the reaction. The reaction is first order in [DPC] in the presence of ruthenium(III). The order in [GP] is less than unity, whereas that in [Ru(III)] is unity. Increase in [OH−] accelerates the reaction rate. A plausible mechanism involving the active species of oxidant and catalyst is proposed. The reaction constants in the mechanism have been evaluated.

Graphical abstractThe mechanistic investigation of oxidation of neuroleptic drug gabapentin by diperiodatocuprate(III) (DPC) has been carried out in the presence of minute amounts of ruthenium(III) catalyst in an aqueous alkaline medium. The reaction is found to be first order with respect to both DPC and ruthenium(III) concentrations and less than unity order with respect to gabapentin concentrations. The active species of Cu(III) and Ru(III) in the reaction medium are [Cu(OH)2(H3IO6)(H2IO6)]4− and [Ru(H2O)5(OH)]2+, respectively. Figure optionsDownload full-size imageDownload as PowerPoint slide