Carbon tetrabromide → 4-nitro-2-(trifluoromethoxy)benzyl bromide

Temperature

0 °C

Add (4-bromo-2-(trifluoromethoxy)phenyl)methanol (9.757 g, 36 mmol) and dichloromethane (180 mL) to a 500 mL flask equipped with a magnetic stir bar and N2 inlet. Cool the solution to 0° C. and then treat with triphenylphosphine (11.33 g, 43 mmol) and carbon tetrabromide (14.26 g, 43 mmol). Stir the reaction at 0° C. for 45 minutes, warm to room temperature and stir an additional 1 hour. Wash the reaction with water (2×180 mL) and saturated sodium chloride solution (1×180 mL), then dry over anhydrous magnesium sulfate. Filter through Celite® and concentrate under vacuum to dryness. Dissolve the residue in hexanes, filter to remove the triphenyl phosphine oxide, and concentrate to a colorless oil. Purify the crude product via silica gel chromatography eluting with hexanes to afford 10.5 g (88%) of the product as a colorless oil: 1H NMR (300 MHz, CDCl3) δ 7.46-7.40 (m, 2H), 7.38-7.33 (m, 1H), 4.46 (s, 3H).

1. customequipped with a magnetic stir bar and N2 inlet
2. customthe reaction at 0° C. for 45 minutes
3. temperaturewarm to room temperature
4. stirringstir an additional 1 hour
5. washWash
6. customthe reaction with water (2×180 mL) and saturated sodium chloride solution (1×180 mL)
7. dry with materialdry over anhydrous magnesium sulfate
8. filtrationFilter through Celite®
9. concentrationconcentrate under vacuum to dryness
10. dissolutionDissolve the residue in hexanes
11. filtrationfilter
12. customto remove the triphenyl phosphine oxide
13. concentrationconcentrate to a colorless oil
14. customPurify the crude product via silica gel chromatography
15. washeluting with hexanes

ORD record

ord-065c23b4944c4383a2ffeb50fb124e9c

Source dataset

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08088776B2