Citric Acid → (2R,3S)-2-(3-chloro-4-cyanophenylamino)-3-hydroxybutanoic acid

HRID 563200Notes

Reaction equation

[Cl:1][C:2]1[CH:9]=[C:8](F)[CH:7]=[CH:6][C:3]=1[C:4]#[N:5].[NH2:11][C@@H:12]([C:16]([OH:18])=[O:17])[C@H:13]([CH3:15])[OH:14].C([O-])([O-])=O.[K+].[K+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CS(C)=O>[Cl:1][C:2]1[CH:9]=[C:8]([NH:11][C@H:12]([C@@H:13]([OH:14])[CH3:15])[C:16]([OH:18])=[O:17])[CH:7]=[CH:6][C:3]=1[C:4]#[N:5]

Participants

Conditions

Temperature: 75 °C

Procedure

2-chloro-4-fluorobenzonitrile (60702-69-4) (2.0 g, 12.86 mmol) was mixed together with H-D-Thr-OH (1.84 g, 15.43 mmol) in DMSO (30 mL). K2CO3 (3.73 g, 27.0 mmol) was added to the reaction mixture and stirred at 75° C. for 24 h. The reaction mixture was cooled down to room temperature and poured slowly into a 10% citric acid solution and stirred for 10 min at room temperature. The solution was extracted with EtOAc several times to get the crude product. The crude product was chromatographed with a gradient of hexane EtOAc and then with EtOAc, 100% to get the pure final product 1.8 g): 1H NMR (500 MHz, acetone-d6, δ in ppm) 7.51 (d, J=9 Hz, 1H), 6.95 (s, 1H), 6.82 (d, J=9 Hz, 1H), 5.17 (d, J=9 Hz, 1H), 4.42 (m, 1H), 4.22 (d, J=6 Hz, 1H), 2.34 (s, 3H), 1.28 (d, J=6 Hz, 3H).

Workup

temperatureThe reaction mixture was cooled down to room temperature
stirringstirred for 10 min at room temperature
extractionThe solution was extracted with EtOAc several times
customto get the crude product
customThe crude product was chromatographed with a gradient of hexane EtOAc

Sources & evidence

ORD record: ord-9f3cecf384d14de79f1f453782570798
Source dataset: uspto-grants-2011_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08067448B2

Reaction notes

Loading…