A two‐phase second‐order reaction: Kinetics of epoxidation of methyl 12,13‐epoxyoleate

Abstract

The kinetics of epoxidation of methyl 12,13epoxyoleate with peracetic acid have been studied. Chloroform and benzene solvents were used at 25, 30 and 40 C. A second-order equation was developed to determine the rate constants in this two-phase system. Variation of the relative phase volumes provides a convenient method for controlling the rate of reaction. Differences in the ±S ° of activation for the formation of the two isomeric diepoxides were greater than 1 eu in all cases. If the usual integrated second-order equation is used, the rate constant will be in error. The magnitude of the error is related to the partition coefficient of the species distributed between the phases and the volume ratios of the two phases. Other errors in the rate constant were determined by expressing K as a function of time, temperature and the concentration of reactants at any time in the reaction. The total differential of K divided by K, to get the relative error, was evaluated at various reaction times. The choice of best times for the determination of the rate constant was dictated from the error analysis.

Electrocatalytic reduction of ethylene dibromide by vitamin B12 in a surfactant-stabilized emulsion

“…However, by analogy with other alkyl bromides (25), vicinal dihalides should be substantially partitioned into the hydrocarbon phase. Thus, the true rate constant in the aqueous phase is attenuated in kx by partition of the substrate (26).…”