The reaction of ethyl bromoacetate with substituted phenoxyacetate ions in 90% aqueous acetone is found to follow total second order kinetics, first order in each reactant. The reaction is accelerated by electron-releasing and retarded by electron-withdrawing substituents in the phenoxyacetate ion. The reaction shows an excellent Hammett fit, ρ=−0·242 at 40°C. The attenuation ratio (πz) is found to be 0·695, indicating the damping effect of the oxymethylene group −O−CH2−. A satisfactory Brönsted correlation is observed for the reaction, α=1·1 at 25°C. The isokinetic relationship is obeyed in the present reaction series, β (isokinetic temperature)=334 K.
