Citric Acid → (2r,3s)-2-(4-Cyano-2-methyl-3-(trifluoromethyl)phenylamino)-3-hydroxybutanoic acid

HRID 1254703Notes

Reaction equation

F[C:2]1[CH:9]=[CH:8][C:5]([C:6]#[N:7])=[C:4]([C:10]([F:13])([F:12])[F:11])[C:3]=1[CH3:14].C1[C:20]([CH2:21][C@@H:22]([NH2:26])[C:23]([OH:25])=[O:24])=CC=C(OC2C=CC(O)=CC=2)C=1.C([O-])([O-])=[O:36].[K+].[K+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CS(C)=O>[C:6]([C:5]1[CH:8]=[CH:9][C:2]([NH:26][C@H:22]([C@@H:21]([OH:36])[CH3:20])[C:23]([OH:25])=[O:24])=[C:3]([CH3:14])[C:4]=1[C:10]([F:13])([F:12])[F:11])#[N:7]

Participants

Conditions

Temperature: 75 °C

Procedure

4-fluoro-3-methyl-2-(trifluoromethyl)benzonitrile (1.0 g, 4.92 mmol) and D-theronine (703 mg, 90 mmol) were added to DMSO (15 mL). K2CO3 (3.26 g) was added to the reaction mixture and stirred at 75° C. for 24 h. The reaction mixture was cooled to room temperature and poured slowly in to a 10% citric acid solution and stirred for 10 min at room temperature. The solution was extracted with EtOAc several times to give the crude product. The crude product was chromatographed with a gradient of hexanes/EtOAc and then with EtOAc, 100% to give the final product (400 mg). 1H NMR (500 MHz, acetone-d6, δ in ppm) 7.62 (d, J=9 Hz, 1H), 6.98 (d, J=9 Hz, 1H), 5.52 (d, J=9 Hz, 1H), 4.52 (m, 1H), 4.32 (m, 1H), 2.35 (s, 3H), 1.35 (d, J=6 Hz, 3H).

Workup

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

Sources & evidence

ORD record: ord-daca09fcf85c4db8b583f3b6b21b2510
Source dataset: uspto-grants-2013_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08455525B2

Reaction notes

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