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

[Z] -and [E] methyl alpha-O-Carboxyphenyl-B- [3,4-Dichlorophenyl] -P-methylcinnamte and [Z] -and [E] -methyl alpha-O-carboxyphenyl- B- [3,4-Dimethylphenyl] -p-chlorocinnamate

3,4-dichloro-4'-methyl and 4-chloro-3', 4'-dimethyl-benzophenone condense with dimethyl homophthalate to give a mixture of [Z] and [E] methyl alpha-o-carboxyphenyl-B-[3, 4-dichlorophenyl]-p- methylcinnamated [3a] and [Z] and [E] methyl alpha-o-carboxyphenyl- b-[3, 4-dimethylphenyl]-p-chlorocinnamate [3b]. Cyclization of the half esters or their corresponding dicarboxylic acids or anhydrides gives the indenone derivatives which were identified by spectroscopic methods