A solution containing (2S)-1-amino-3-phenoxy-2-propanol (Example 53, 11.97 mmol, 1.0 eq.), (2R)-6-iodo-3,4-dihydro-2H-chromene-2-carboxylic acid (Example 7, 11.97 mmol, 1.0 eq.), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (23.98 mmol, 2.0 eq.), 1-hydroxybenzotriazole hydrate (23.94 mmol, 2.0 eq.), and triethylamine (23.94 mmol, 2.0 eq.) in CH2Cl2 (200 mL) was stirred at room temperature for 3 hours. To the resulting solution was added water and two-phase mixture was extracted with CH2Cl2. The organic extracts were washed with water and brine, dried over anhydrous sodium sulfate, concentrated and purified by medium pressure column chromatography (Biotage 40S normal phase silica gel column, hexanes:EtOAc=2:1). The product was obtained as a white solid in 77% yield. MH+=454.1, retention time (LC-MS)=3.03 min.
