Carbon Dioxide → 2-Fluoro-5-methoxybenzoic acid

Temperature

0 °C

Alternatively, a solution of 4-fluoroanisole (500 mg, 4.0 mmol) in THF (10 mL) was added to a cooled solution (−78° C.) of 2,2,6,6-tetramethylpiperidine (1.1 g, 7.9 mmol) and BuLi (5 mL, 1.6 M in hexanes, 7.9 mmol) in THF (10 mL) at a slow rate to maintain the temperature below −70° C. The mixture was maintained at this temperature for 12 h, and then dry CO2 gas was passed into the solution. The resulting mixture was allowed to warm up to 0° C. and then HCl (1 M, 10 mL) was added and the product was extracted with diethyl ether. The combined organic extracts were then dried over sodium sulfate, washed with water and brine, filtered and evaporated. The crude solid was then partioned between sodium hydroxide (1 M, 10 mL) and diethyl ether. The aqueous phase was then acidified with HCl (1 M) and the product extracted with diethyl ether. Evaporation afforded the title compound (268 mg, 40%) as a white solid. MS m/e=168.9 (M−H).

1. temperatureto maintain the temperature below −70° C
2. temperatureThe mixture was maintained at this temperature for 12 h
3. extractionthe product was extracted with diethyl ether
4. dry with materialThe combined organic extracts were then dried over sodium sulfate
5. washwashed with water and brine
6. filtrationfiltered
7. customevaporated
8. extractionthe product extracted with diethyl ether
9. customEvaporation

ORD record

ord-ad9e55c60d9949a793a6bf622bf48f1e

Source dataset

uspto-grants-2005_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06846832B2