transesterification of trimethylphosphate catalyzed by sodium aloxides

the transesterification process of trimethylphosphate with ethanol and isopropanol is examined. it is found that the reaction does not proceed in the absence of base even at temperature up to 100°c, whereas in the presence of sodium alkoxide as a catalyst it takes place at room temperature leading to a mixture of mono-,bi-, tri-substitute esters as well as the minor by-products resulting from the nucleophilic attack of the alkoxide ion on the alkyl groups of the starting ester.. the substitution extent is dependent on the relative concentration of the reactants, the temperature, the solvent, and the amount of the catalyst used.