A mixture of 30 g (0.123 mol) of 3,5-dihydroxybenzoic acid phenylmethyl ester, 40.9 g (0.123 mol) of 1-bromooctadecane, 17 g (0.123 mol) of anhydrous potassium carbonate in 500 ml of acetone and 10 ml of DMF was stirred at reflux for 25 hours. The reaction mixture was filtered and the filtrate was concentrated at reduced pressure to a solid. The residue was treated with water and the product was extracted with methylene chloride. The dried extract was concentrated at reduced pressure to a solid which was purified by HPLC using 1% ethyl acetate-methylene chloride to give 22 g (36% yield, mp 72°-75°) of 3-hydroxy-5-(octadecyloxy)benzoic acid phenylmethyl ester. The structure was confirmed by nmr and mass spectra.
