To a mixture of 4-[1-(4-bromo-phenoxyl)-heptyl]-benzoic acid (1700 mg, 4.35 mmol) in methylene chloride (43 mL) are added triethyl amine (1.82 mL, 13.4 mmol), DMAP (5.0 mg), 3-amino-propionic acid methyl ester (910 mg, 6.52 mmol) and EDCI (2507 mg, 13.04 mmol) at room temperature. The reaction mixture is stirred at room temperature overnight, loaded on silica gel, eluted with eluted with hexanes with a gradient from 0% of ethyl acetate to 100% of ethyl acetate giving racemic 3-{4-[1-(4-bromo-phenoxyl)-heptyl]-benzoylamino}-propionic acid methyl ester (1660 mg).
