to our previous work1 concerning simple aromatic esters, a number of typical mesitoic esters were prepared in the absence of organic solvent under solid-liquid PTC conditions. The reactions were performed with stoichiometric amounts of mesitoic acid (2, 4, 6- trimethylbenzoic acid) and an alkylating agent in the presence of an excess (2.5 equiv/mol) of a powdered base (KOH or for comparison