Hydrochloric Acid → (2R,3S)-3-((tert-Butoxycarbonyl)amino)-2-hydroxy-4-phenylbutanoic acid

HRID 393400Notes

Reaction equation

[CH2:1]([C@H:8]1[C@H:12]([C:13]([OH:15])=[O:14])[O:11][C:10](=[O:16])[NH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O=[C:18]1NCC(C(O)=O)O1.[OH-].[K+].Cl.[CH3:29][CH:30]([OH:32])[CH3:31]>ClCCl>[C:30]([O:32][C:10]([NH:9][C@@H:8]([CH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1)[C@@H:12]([OH:11])[C:13]([OH:15])=[O:14])=[O:16])([CH3:18])([CH3:31])[CH3:29]

Participants

Conditions

Temperature: 90 °C

Procedure

To (4S,5R)-4-benzyl-2-oxo-5-oxazolidinecarboxylic acid obtained in the same manner as in Example 4 (2.39 g) were added 2-propanol (6.7 ml) and 8N aqueous potassium hydroxide solution (6.7 ml), and the mixture was stirred at 90° C. for 3 hr. The mixture was cooled to room temperature and adjusted to pH=8 with 6N aqueous hydrochloric acid solution. To the reaction mixture was added di-tert-butoxycarbonate (2.83 g) dissolved in 2-propanol (6.7 ml) and the mixture was stirred at room temperature for 12 hr. After adjusting the mixture to pH=3, dichloromethane (20 ml) was added to extract the mixture. The solvent of the organic layer was removed under reduced pressure to give crude crystals of (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutyric acid (2.88 g). The crude crystals were analyzed by HPLC to confirm that (2R,3S)-3-tert-butoxycarbonylamino-2-hydroxy-4-phenylbutyric acid (2.55 g, yield 80%) was obtained.

Workup

temperatureThe mixture was cooled to room temperature
stirringthe mixture was stirred at room temperature for 12 hr
additionwas added
extractionto extract the mixture
customThe solvent of the organic layer was removed under reduced pressure

Sources & evidence

ORD record: ord-e3f2b7cf418547b39a5486733f284d42
Source dataset: uspto-grants-2004_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06806384B2

Reaction notes

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