Potassium Carbonate → (2R,3S)-2-(3-chloro-4-cyano-2-ethylphenylamino)-3-hydroxybutanoic acid

Beteiligte Stoffe

Reaktionsschritte

4-Fluoro-2-chloro-3-ethyl benzonitrile (1.0 g, 5.45 mmol), D-threonine (779 mg, 6.54 mmol), potassium carbonate (1.51 g, 10.9 mmol) and DMSO (6 mL) were heated at 85° C. for 17.5 h. The reaction mixture was allowed to cool to room temperature whereupon water (20 mL) was added followed by citric acid monohydrate (2 g). After stirring for 10 min the mixture was partitioned between EtOAc (40 mL) and water. The organic phase was then washed with water (15 mL), brine (15 mL), dried (Na2SO4) and concentrated to furnish a pale yellow solid (7.2 g). This crude product was then passed through a silica-plug [hexanes-EtOAc (95:5) as eluent] to furnish a white solid (928 mg), which was used directly in the next step.

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