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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence