Carbon Dioxide → 3-Bromo-2,6-difluorobenzoic acid

Temperature

-78 °C

To a mixed solution of 1.6N solution of n-butyllithium in hexane (9.4 ml, 15.0 mmol) and tetrahydrofuran (20 ml) were successively added 2,2,6,6-tetramethylpiperidine (2.50 ml, 15.0 mmol) and 1-bromo-2,4-difluorobenzene (2.90 g, 15.0 mmol) at −78° C., and the mixture was stirred at −78° C. for 1 hr. The pulverized dry ice (5 g) was added, and the mixture was stirred at −78° C. for 2 hr. Saturated aqueous ammonium chloride solution (5 ml) was added to the reaction mixture, and the mixture was stirred at room temperature for 30 min. Water (10 ml) and 1N hydrochloric acid (30 ml) were added, and the mixture was extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. Hexane was added to the residue, and desired product (2.30 g, 64.6%) was collected by filtration as a solid.

1. customat −78° C.
2. stirringthe mixture was stirred at −78° C. for 2 hr
3. stirringthe mixture was stirred at room temperature for 30 min
4. extractionthe mixture was extracted with ethyl acetate
5. washThe extract was washed with water
6. dry with materialdried over anhydrous magnesium sulfate
7. customThe solvent was evaporated under reduced pressure
8. additionHexane was added to the residue, and desired product (2.30 g, 64.6%)
9. filtrationwas collected by filtration as a solid

ORD record

ord-719d73be3cbd4829b114b3a4133cd407

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08247403B2