A mixture of 3-(4-{[4′-(2-ethoxyethoxy)-2′,6′-dimethylbiphenyl-3-yl]methoxy}-2-fluorophenyl)propanoic acid (0.233 g, 0.500 mmol), 7 M ammonia/methanol (0.4 mL, 2.80 mmol) solution, 1-ethyl-3-(3-aminopropyl)carbodiimide hydrochloride (2.88 g, 1.50 mmol), 1-hydroxybenzotriazole (0.230 g, 1.50 mmol), 1,8-diazabicyclo[5.4.0]-7-undecene (0.448 mL, 3.00 mmol), triethylamine (0.502 mL, 3.60 mmol) and acetonitrile (3 mL) was stirred at room temperature for 27 hrs. The reaction mixture was poured into saturated aqueous sodium hydrogen carbonate solution and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography (50% ethyl acetate/hexane-ethyl acetate) to give the title compound (0.186 g, yield 80%) as a colorless oil.
