5-(3,5-Dichloro-phenoxy)-furan-2-carbonyl chloride (0.194 g, 0.6655 mmol) was added under nitrogen to a suspension of 5-bromo-6-(1-methoxycarbonyl-2phenyl-ethoxy)-naphthalen-2-ylmethyl-ammonium; chloride (0.30 g, 0.6655 mmol), prepared in the previous step, in 20 mL of methylene chloride at room temperature. Triethylamine (0.186 mL, 1.33 mmol) was then added to the mixture. The reaction was stirred at room temperature for 18 h (overnight). The reaction was diluted with methylene chloride, extracted one time with 1N HCl and two times with 5% NaHCO3. The organic layer was separated, dried (MgSO4) and the solvent removed under reduced pressure to give 2-[1-bromo-6-({[5-(3,5-dichloro-phenoxy)-furan-2-carbonyl]-amino}-methyl)-naphthalen-2-yloxy]-3-phenyl-propionic acid methyl ester (0.4079 g, 92%) as a tan oil, MS m/z: 668 [M+H]+.
