Water → (2R)-2-(4-bromophenyl)-3,3-difluoropropane-1,2-diol

To a 250 mL flask charged with commercial AD-mix-beta (7 g) were added t-BuOH (25 mL) and H2O (25 mL). The mixture was stirred at room temperature to give 2 clear phases and the low phases appeared yellow orange. After cooling to 0° C., 1-bromo-4-[1-(difluoromethyl)vinyl]benzene (1.1 g, 4.7 mmol) was added at once and the mixture was stirred at approximately 4° C. overnight. A bright yellow mixture resulted. The mixture was kept at 0° C. and solid sodium sulfite (8 g, 64 mmol) was added. The mixture was warmed to room temperature and stirred for 30 min. Ethyl acetate (50 mL) was added and the organic layer was separated. The aqueous layer was extracted with ethyl acetate (2×10 mL). Combined ethyl acetate extracts were dried (Na2SO4) and concentrated. Purification by combined Flash (40 g column; eluted with hexanes—Ethyl acetate (20% -60%) in 25 min.; flow rate: 35 mL/min and collected 18 mL/fraction) yielded the title compound as a colorless oil.

1. customto give 2 clear phases
2. temperatureAfter cooling to 0° C.
3. stirringwas stirred at approximately 4° C. overnight
4. customA bright yellow mixture resulted
5. customwas kept at 0° C.
6. temperatureThe mixture was warmed to room temperature
7. stirringstirred for 30 min
8. customthe organic layer was separated
9. extractionThe aqueous layer was extracted with ethyl acetate (2×10 mL)
10. dry with materialCombined ethyl acetate extracts were dried (Na2SO4)
11. concentrationconcentrated
12. customPurification
13. washby combined Flash (40 g column; eluted with hexanes—Ethyl acetate (20% -60%) in 25 min.; flow rate: 35 mL/min and collected 18 mL/fraction)

ORD record

ord-f2147940b338463e8b28e5a23faac1d0

Source dataset

uspto-grants-2008_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07407959B2