反应详情

20 mg (37 μmol) of (2S)-2-tert.-Butoxycarbonylamino-5-{2-[4-(2-fluoro-ethoxy)-phenyl]-ethyl}-hexanedioic acid di-tert.-butyl ester were dissolved in 2 mL dichloromethane (dried over 4{acute over (Å)} molecular sieve) and 1 mL trifluoroacetic acid were added. The reaction was stirred at room temperature for 30 min, after which the solution was directly applied to reversed phase chromatography on a Biotage system (Flash 12+M cartridge, A=water, B=acetonitrile, A 1 CV, A to 50% B in 10 CV, 2 CV 50% B, 12 mL/min). Fraction 6 was lyophilized to give 2 mg (11%) of (2R,5RS)-2-Amino-5-{2-[4-(2-fluoro-ethoxy)-phenyl]-ethyl}-hexanedioic acid as the Tfa-salt.