Structural and specific solvent effects on the kinetics of Alkaline hydrolysis of methylacrylate and methylmethacrylate esters

ABSTRACT

The rates of alkaline hydrolysis of methyl prop-2-enoic acid [methylacrylate] 1 and methyl-2-methyl-prop-2-enoic acid [methylmethacrylate] 2 were studied at temperatures ranging from 10 to 35 degree in two series of dioxane-water and acetone-water mixtures containing 10 to 75 percent by volume of the organic component. The rate constants were found to be higher in acetone-water mixtures and decreased with increasing the dielectric constant of the medium. The kinetic studies and application of the differential method show that the rate follows a second order kinetic equation, first order with respect to both ester and hydroxide ion and the reaction proceeds by a B[Ac2] mechanism. The distance of closest approach of solvent molecules to the activated complex b and the distance of closest approach of solvent molecules to the transition state G were computed