Citric Acid → (3-Chloro-4-cyano-2-methylphenyl)-D-threonine

Participants

Reaction Conditions

Reaction Steps

2-chloro-4-fluoro-3-methylbenzonitrile (CAS 796600-15-2, 45 g, 265.4 mmol) was mixed together with H-D-Thr-OH (37.92 g, 318.4 mmol) in DMSO (250 mL). K2CO3 (73.35 g, 530.7 mmol) was added to the reaction mixture and the reaction mixture stirred at 75° C. for 24 h. The reaction mixture was cooled 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 on silica gel with a gradient of hexanes/EtOAc and then with EtOAc, 100% to get the purified final product (39.0 g, 54%) 1H NMR(500 MHz, Acetone-d6, δ in ppm) 7.49 (d, J=9 Hz, 1H), 6.70 (d, J=9 Hz, 1H), 5.38 (d, J=10 Hz, 1H), 4.47 (d, J=6 Hz, 1H), 4.25 (m, 1H), 2.34 (s, 3H), 1.33 (d, J=6 Hz, 3H).

Provenance & Evidence