Kinetics of yohimbine and reserpiline oxidations by peroxodisulphate

Abstract

The kinetics of yohimbine and reserpiline oxidations by peroxodisulphate in aqueous solution have been investigated. The results suggest that the reactions proceed via reversible formation of a 3H-indole (indolenine) intermediate, which subsequently decomposes to yield a 3,4-didehydro derivative. The values of the equilibrium and rate constants are reported. Potassium chloride showed a retarding effect on the reaction; the effect of Ag⁺ cations was negligible. A mechanism involving nucleophilic displacement on peroxide oxygen is proposed.