THE EFFECT OF IODIDE-ION IN PHASE-TRANSFER CATALYTIC SYNTHESES OF BENZYL-ESTERS

In order to examine the effect of iodide ions on reaction catalyzed by phase-transfer technique, we made kinetic studies, under the influence of added NaI, on the synthesis of benzyl esters from benzyl chloride and sodium carboxylate. These carboxylates include sodium acetate, sodium benzoate, sodium salicylate and sodium formate; the catalyst was a quaternary ammonium salt. The results reveal that iodide ions at a suitable concentration accelerate the reaction, whereas iodide ions in excess poison the catalyst. The optimum concentration varies with the reaction system. This critical concentration depends upon the distribution coefficient of the intermediates formed in the reactions.