Ethyl chloroformate → HCID 57758742, compound

To a solution of (4R)-4-fluoromethyl-2-oxo-1-[(1R)-1-phenylethyl]pyrrolidine (34.1 g, 154 mmol) and ethyl chloroformate (16.1 mL, 169 mmol) in tetrahydrofuran (500 mL), lithium bistrimethylsilyl amide (323 mL, 323 mmol, 1.0M solution in tetrahydrofuran) was added at 0° C., and the mixture was stirred at the same temperature for 30 minutes. Saturated aqueous solution of ammonium chloride (700 mL) was added to reaction mixture at the same temperature, and the mixture was extracted with ethyl acetate (700 mL×2). The organic layer was washed with saturated aqueous solution of sodium chloride (500 mL), and dried with anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (elution with hexane:ethyl acetate, 5:1→2:3) to obtain 35.0 g (77%) of the title compound as a pale yellow oily substance.

1. extractionthe mixture was extracted with ethyl acetate (700 mL×2)
2. washThe organic layer was washed with saturated aqueous solution of sodium chloride (500 mL)
3. dry with materialdried with anhydrous sodium sulfate
4. filtrationAfter filtration
5. concentrationthe filtrate was concentrated under reduced pressure
6. customthe residue was purified by silica gel column chromatography (elution with hexane:ethyl acetate, 5:1→2:3)

ORD record

ord-fe41bd31ff00482b8fac0a5a69623e79

Source dataset

uspto-grants-2009_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07563805B2