Potassium Carbonate → (2R,3R)-2-(3-Chloro-4-cyanophenylamino)-3-hydroxybutanoic acid

Participants

Reaction Conditions

Reaction Steps

To a suspension of D-allo-threonine (5.08 g, 42.7 mmol) and K2CO3 (10.32 g, 74.7 mmol) in DMSO (50 mL) was added 2-chloro-4-fluorobenzonitrile (5.53 g, 35.5 mmol) at room temperature. The reaction mixture was heated to 75° C. and stirred for 39 h. The reaction mixture was allowed to cool to room temperature and quenched with H2O (400 mL) and extracted with EtOAc (3×200 mL). The aqueous layer was then acidified with solid citric acid and extracted with EtOAc (2×100 mL). The later organic extracts were combined, washed with H2O (3×150 mL), dried (Na2SO4), filtered and concentrated under reduced pressure to provided the title compound as a brown solid (9.04 g, 100%): 1H NMR (400 MHz, acetone-d6, δ in ppm) 7.51 (d, J=8.8 Hz, 1H), 6.97 (d, J=2.3 Hz, 1H), 6.83 (dd, J=2.4, 8.8 Hz, 1H), 6.31 (br d, J=7.6 Hz, 1H), 4.28-4.20 (m, 2H), 1.31 (d, J=6.5 Hz, 3H).

Provenance & Evidence