反应详情

温度

0 °C

6.3 ml (49.7 mmol) of chlorotrimethylsilane are added to a solution of 5.0 g (24.9 mmol) of 3,5-difluoro-DL-phenylalanine in dichloromethane (150 ml) and the reaction mixture is heated to reflux for 1 h. After cooling to 0° C., 9.7 ml (55.9 mmol) of ethyldiisopropylamine are added slowly and then, dropwise, 3.64 g (24.9 mmol) of trans-2-heptenoyl chloride. The reaction mixture is stirred overnight with slow warming to RT and remains standing at RT for 2 days. For working up, it is evaporated to dryness in vacuo, the residue is taken up using diethyl ether and extracted with 2.5 pc. aqueous sodium hydrogencarbonate solution (250 ml). The aqueous phase is extracted twice with ether, and the combined organic phases are extracted a further three times with sodium hydrogencarbonate solution. The combined aqueous phases are brought to pH=2 using 1N aqueous hydrochloric acid and extracted three times with ethyl acetate. The combined ethyl acetate phases are dried over sodium sulfate, filtered, and the solvent is concentrated in vacuo. The residue is washed by stirring with diethyl ether and filtered. The filter residue is isolated, the filtrate is concentrated and again treated with diethyl ether. After repetition twice, a total of 6.12 g (79% of th.) of product are obtained as a colorless solid.

1. temperaturethe reaction mixture is heated
2. temperatureto reflux for 1 h
3. temperaturewith slow warming to RT
4. waitremains standing at RT for 2 days
5. customit is evaporated to dryness in vacuo
6. extractionextracted with 2.5 pc
7. extractionThe aqueous phase is extracted twice with ether
8. extractionthe combined organic phases are extracted a further three times with sodium hydrogencarbonate solution
9. extractionextracted three times with ethyl acetate
10. dry with materialThe combined ethyl acetate phases are dried over sodium sulfate
11. filtrationfiltered
12. concentrationthe solvent is concentrated in vacuo
13. washThe residue is washed
14. stirringby stirring with diethyl ether
15. filtrationfiltered
16. customThe filter residue is isolated
17. concentrationthe filtrate is concentrated
18. additionagain treated with diethyl ether
19. customAfter repetition twice, a total of 6.12 g (79% of th.) of product are obtained as a colorless solid