A mixture of 2-(4-bromo-2,6-dimethylphenoxy)ethanol (0.65 g), 4-carboxyphenylboronic acid (0.87 g), tetrakis(triphenylphosphine)palladium(0) (0.15 g), cesium fluoride (2.40 g), 1,4-dioxane (7.5 mL), ethanol (2.5 mL) and water (1.5 mL) was stirred at 90° C. overnight under an atmosphere of argon. Water and ethyl acetate were added to the reaction mixture. The organic layer was separated, washed with water and brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (eluent:ethyl acetate/n-hexane=1/1-2/1) to afford the title compound (0.29 g).
