To a solution of Z-PheOH (0.207 g, 0.69 mmol) in THF (4 mL), cooled to -20° C., were added NMM (76 uL, 0.69 mmol) and IBCF (90 uL, 0.69 mmol). After 10 minutes, a chilled (-10° C.) solution of PheCH2F hydrochloride (0.15 g, 0.69 mmol) in DMF (1 mL) was added, followed by NMM (76 uL, 0.69 mmol). The mixture was stirred for 30 minutes. 1M HCl (5 mL) was added. The solution was extracted with ethyl acetate (30 mL), washed with saturated aqueous NaHCO3 (6 mL), brine (4 mL), dried over MgSO4, filtered, and evaporated to dryness. The residue was crystallized from ethyl acetate/hexane, yielding 0.22 (53%) of Z-Phe-PheCH2F.
