Sodium Hydroxide → 3-(Octadecyloxy)-5-(phenylmethoxy)benzoic acid

A mixture of 3.0 g (7.1 mmol) of 3-hydroxy-5-(octadecyloxy) benzoic acid methyl ester, 0.93 ml (7.85 mmol) of benzyl bromide and 2.0 g (14.5 mmol) of potassium carbonate in 50 ml of DMF was stirred at 85° for 50 hours. The solvent was removed at reduced pressure and the residue was extracted with methylene chloride. The extract was concentrated and recrystallized from methylene chloride-methanol to give 3.24 g (89% yield, mp 62°-64°) of 3-(octadecyloxy)-5-(phenylmethoxy)benzoic acid methyl ester. A solution of 3.24 g (6.3 mmol) of 3-(octadecyloxy)-5-(phenylmethoxy) benzoic acid methyl ester and 3 ml (18 mmol) of 6N NaOH in 100 ml of methanol and 25 ml of dioxane was stirred at reflux for 3.5 hours. The solvents were removed at reduced pressure and the residue was acidified and extracted with ethyl acetate. The dried extract was concentrated to a solid which was recrystallized from methylene chloride-hexane to give 2.77 g (88% yield, mp 101°-103°) of 3-(octadecyloxy)-5-(phenylmethoxy)benzoic acid.