反应详情

To a solution of 2(S)-(2(S)-hydroxypropyl) piperazine-1,4-dicarboxylic acid di-tert-butyl ester and 2(S)-(2(R)-hydroxypropyl) piperazine-1,4-dicarboxylic acid di-tert-butyl ester (5.11 g, 14.8 mmol) in dichloromethane (100 mL) stirring at 0° C., add trifluoroacetic acid (25 mL). Warm the mixture to room temperature and stir. After 18 hours evaporate to a yellow oil. Dilute the mixture with methanol and apply to a 60 g SCX column. Wash with methanol and elute with 2N ammonia in methanol to obtain the title compound (mixture of diastereoisomers) as an oil (1.932 g, 90%): mass spectrum (APCI): m/z =145.1 (M+1).

1. customAfter 18 hours evaporate to a yellow oil
2. additionDilute the mixture with methanol
3. washWash with methanol
4. washelute with 2N ammonia in methanol