Sodium borohydride → Tert-butyl 3-fluoro-4-hydroxypiperidine-1-carboxylate

Temperature

0 °C

tert-Butyl 3-fluoro-4-oxopiperidine-1-carboxylate [van Niel, M. B.; et al.; J. Med: Chem. 1999, 42, 2087-2104] (52.27 g, 241 mmol) was dissolved in anhydrous MeOH (600 mL), cooled to 0° C. and treated in portions with sodium borohydride (37.8 g, 361 mmol) over a 15 minute period. After stirring at 0° C. for 30 minutes, the mixture was stirred at ambient temperature for 4 hours. The mixture was concentrated under reduced pressure and the residue was partitioned between saturated ammonium chloride solution (400 mL) and EtOAc (400 mL). The aqueous layer was extracted with EtOAc and the combined organic extracts were washed with brine (200 mL), dried over Na2SO4, filtered and concentrated to provide the desired product as a thick oil that slowly solidified upon standing (52.7 g).

1. stirringthe mixture was stirred at ambient temperature for 4 hours
2. concentrationThe mixture was concentrated under reduced pressure
3. customthe residue was partitioned between saturated ammonium chloride solution (400 mL) and EtOAc (400 mL)
4. extractionThe aqueous layer was extracted with EtOAc
5. washthe combined organic extracts were washed with brine (200 mL)
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-100b793e319c4a02a5a8a367b1615fbf

Source dataset

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08138181B2