Hydrochloric Acid → 105637-38-5

Participants

Reaction Conditions

Reaction Steps

(3S)-3-(benzyloxycarbonylphenylalanylamino)-1-fluoro-2-butanone Z-phenylalanine (2.29 g, 7.65 mmol) was dissolved in THF (35 mL). The solution was cooled to -10° C. (methanol/ice bath). N-methylmorpholine (NMM; 0.84 mL, 7.65 mmol) was added, followed by isobutyl chloroformate (IBCF; 0.991 mL, 7.65 mmol), added over 3 minutes. With stirring, in a separate flask cooled to -15° C., p-TsOH.AlaCH2F (2.11 g, 7.65 mmol) was dissolved in DMF (7 mL). This solution was added to the mixed anhydride. NMM (0.84 mL, 7.65 mmol) was added. The reaction mixture was stirred for 45 minutes at between -10° C. and -5° C. 1M HCl (50 mL) was added. The mixture was extracted with ethyl acetate (2×50 mL). The organic phases were combined, washed with saturated aqueous NaHCO3 (2×50 mL), brine (50 mL), dried over MgSO4, filtered, and evaporated to dryness. The crude solid was precipitated from 7:1 hexane/CH2Cl2 (100 mL). After filtration, the solid was recrystallized from isiporpanol, yielding pure Z-Phe-AlaCH2F (2.13 g, 72% from p-TsOH.AlaCH2F).

Provenance & Evidence