反应详情

温度

-15 °C

Boc-L-Ala-L-Glu(OBzl)-ONp (56.0 g, 0.1 mol) was dissolved and cooled to −15° C. TFA was added and the mixture was stirred for 1 hour and gradually warmed to room temperature. Completion of the reaction was monitored by TLC using the system CHCl3:Et-OAc:MeOH=6:3:1. After completion of the reaction, the mixture was evaporated in vacuum, then twice evaporated with iso-propanol and dissolved in 500 ml of EtOAc. N-methylmorpholine was added until the mixture reached a pH level of 9 to 9.5. After 12 hours, the cyclo-L-Ala-L-Glu(OBzl) precipitated. The precipitate was filtered off, washed with EtOAc, ether and hexane. The yield was 21.0 g (70%). Rf=0.55 (CHCl3:EtOAc:MeOH:AcOH=6:3:1:0.1); HPLC data: retention time 15.9 min.

1. temperaturegradually warmed to room temperature
2. customAfter completion of the reaction
3. customthe mixture was evaporated in vacuum
4. customtwice evaporated with iso-propanol
5. dissolutiondissolved in 500 ml of EtOAc
6. additionN-methylmorpholine was added until the mixture
7. waitAfter 12 hours
8. customthe cyclo-L-Ala-L-Glu(OBzl) precipitated
9. filtrationThe precipitate was filtered off
10. washwashed with EtOAc, ether and hexane