3-Fluoroanisole → 2-Bromo-3-fluoroanisole

Temperature

-78 °C

The 3-fluoro anisole (15 g, 119 mmol) was placed in THF (300 mL) and cooled to about −78° C., and then n-BuLi (89 mL 1.6 M in hexanes) was added while maintaining the temperature at around −70° C. The mixture was stirred for about 15 minutes, and bromine (18.9 g, 119 mmol) was added over 10 minutes. The mixture was warmed to r.t. and stirred overnight. The mixture was quenched with water, diluted with ether (500 mL) and partitioned between water/ether (1/1 300 mL). The water layer was back extracted with ether (250 mL), and the combined organic fractions were dried, filtered and concentrated. The dark residue was distilled under house vacuum (product 115–130° C.) to recover about 13.8 g of the product as a gray oil (57%).

1. temperaturewhile maintaining the temperature at around −70° C
2. temperatureThe mixture was warmed to r.t.
3. stirringstirred overnight
4. customThe mixture was quenched with water
5. additiondiluted with ether (500 mL)
6. custompartitioned between water/ether (1/1 300 mL)
7. extractionThe water layer was back extracted with ether (250 mL)
8. customthe combined organic fractions were dried
9. filtrationfiltered
10. concentrationconcentrated
11. distillationThe dark residue was distilled under house vacuum (product 115–130° C.)
12. customto recover about 13.8 g of the product as a gray oil (57%)

ORD record

ord-5719310a41834985abbfe4ef4bda9c4d

Source dataset

uspto-grants-2007_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07186715B2