2-(4-Benzyloxy-2-carboxymethyl-phenoxy)-2-methyl-propionic acid ethyl ester (500 mg, 1.34 mmol), ammonium chloride (108 mg, 2.02 mmol), EDC (3.86 mg, 2.01 mmol), and N-hydroxybenzotriazole hydrate (272 mg, 2.01 mmol) were combined in a flask and diluted with DMF (5 mL). Ethyl diisopropyl amine (0.70 mL, 4.0 mmol) was added. The solution was stirred for 18 h and partitioned between EtOAc (25 mL) and 1N HCl (10 mL). The organic layer was washed with saturated NaHCO3 solution (10 mL) then brine (10 mL), dried (Na2SO4), and concentrated. The crude product was purified by radial chromatography (hexanes/EtOAc 1/2 to 1/4) to give the title compound (430 mg, 86%).
