Kinetics of reaction of P-chloranil with pyridine in aqueous dioxane

The rate of reaction of p-chloranil with pyridine has been measured in different dioxane-water mixtures at different temperatures. The reaction is found to follow an overall third order kinetics, first with respect to chloranil and second with respect to pyridine. The reaction rate increases with increasing dielectric constant of the medium. A mechanism involved in the rate-determining steps, has been proposed for the reaction. Various activation parameters have been calculated and discussed