Citric Acid → (R)-2-(3-chloro-4-cyano-2-methylphenylamino)-3-hydroxy-3-methylbutanoic acid

Participants

Reaction Conditions

Reaction Steps

2-chloro-4-fluoro-3-methylbenzonitrile (1.06 g, 6.26 mmol) was mixed together with (R)-2-amino-3-hydroxy-3-methylbutanoic acid (1.00 g, 7.51 mmol) in DMSO (25 mL). K2CO3 (1.73 g, 12.52 mmol) was added to the reaction mixture and stirred at 75° C. for 24 h. Then the reaction mixture was cool down 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 get the crude product. The crude product was chromatographed with a gradient of hexane/EtOAc (4:6) and then with EtOAc, 100% to get the title compound (1.40 g). 1H NMR (500 MHz, acetone-d6, δ in ppm) 7.51 (d, J=9 Hz, 1H), 6.72 (d, J=9 Hz, 1H), 5.48 (d, J=9 Hz, 1H), 4.16 (d, J=9 Hz, 1H), 2.34 (s, 3H), 1.43 (s, 3H) 1.41 (s, 3H).

Provenance & Evidence