N-halo compound, N-chloroisonicotinamide (NCIN), in aqueous acetonitrile medium have been investigated. The observed rate of oxidation is first order in [oxidant] and [substrate]. An increase in the dielectric constant of the medium decreases the rate. Variation in ionic strength of the medium has no significant effect on the rate and the addition of the reaction product, isonicotinamide has a slight retarding effect on the rate. The reaction follows first order dependence of rate on [substrate] and [oxidant]. The rate increases with the decrease in dielectric constant of the medium. Variation of ionic strength and the addition of isonicotinamide has significant effect on the reaction rate. A suitable mechanism has been proposed and a rate law explaining the experimental results is obtained.
