[NH2:1][C@@H:2]([CH2:6][CH3:7])[C:3]([OH:5])=[O:4].Cl[C:9](Cl)([O:11]C(=O)OC(Cl)(Cl)Cl)Cl>O1CCCC1>[CH2:6]([C@H:2]1[C:3](=[O:5])[O:4][C:9](=[O:11])[NH:1]1)[CH3:7]To a suspension of (2S)-2-aminobutanoic acid (10 g) and activated carbon (116 mg) in tetrahydrofuran (50 mL) was added dropwise a solution of triphosgene (10.07 g) in tetrahydrofuran (50 mL) at room temperature, and the mixture was stirred at 50° C. for 2 hr. The same experimental process was performed twice, in each of which insoluble materials were filtered off with celite, and the filtrates were combined and concentrated under reduced pressure. The residue was washed with hexane to give the title compound as a solid (yield: 22.39 g, 89%).
Wird geladen…