alpha,alpha,alpha,3-Tetrafluorotoluene → 2-Fluoro-6-(trifluoromethyl)benzoic acid

Temperature

-78 °C

A mixture of 3-fluorobenzotrifluoride (25.0 g, 0.15 mol) in tetrahydrofuran (200 ml) was cooled to -78° C. in a dry ice/acetone bath under nitrogen atmosphere. To this solution was added dropwise with rapid stirring N-butyl lithium (1.6M, 95.2 ml) at such rate that the temperature did not exceed -60° C. When the addition was complete, the mixture was allowed to stir at -78° C. for an additional five hours. The mixture was then poured over a slurry of dry ice/ether and allowed to come to room temperature. The solvent was removed by evaporation under reduced pressure to obtain a white solid residue. This solid was dissolved in a minimum amount of water, the solution was extracted with diethyl ether (2×100 ml) and the aqueous phase was acidified to pH 2 with dilute hydrochloric acid. An oil formed and this was dissolved in diethyl ether; the solution was washed several times with water and dried over magnesium sulfate. The solvent was removed by evaporation under reduced pressure to give a white solid. NMR analysis indicated this product was a mixture of the title compound and an isomer. A yield of 15.6 g (50 percent of theory) was obtained.

1. additionTo this solution was added dropwise
2. customdid not exceed -60° C
3. additionWhen the addition
4. customto come to room temperature
5. customThe solvent was removed by evaporation under reduced pressure
6. customto obtain a white solid residue
7. extractionthe solution was extracted with diethyl ether (2×100 ml)
8. customAn oil formed
9. washthe solution was washed several times with water
10. dry with materialdried over magnesium sulfate
11. customThe solvent was removed by evaporation under reduced pressure
12. customto give a white solid

ORD record

ord-ce0c886cd0244015ad87d4ea300fd7a9

Source dataset

uspto-grants-1989_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04886883