Carbon Dioxide → 2,4-dibromo-6-fluorobenzoic acid

Temperature

0 °C

A solution of n-BuLi (20 mL, 50.0 mmol) was added dropwise to a solution of diisopropylamine (5.6 g, 55.0 mmol) in 200 mL of THF at −70° C. The mixture was stirred at 0° C. for 15 minutes and then recooled to −70° C. A solution of 1,3-dibromo-5-fluorobenzene (12.7 g, 50.0 mmol, in 50 mL of THF) was added dropwise. The resulting mixture was stirred at −70° C. for 2 hours then poured into fresh dry ice and stirred overnight. The mixture was diluted with 1 L of ether and washed with water twice. The combined water layer was washed with ether then acidified to pH=2 with hydrochloric acid and extracted with EtOAc twice. The combined EtOAc layer was washed with brine, dried over anhydrous Na2SO4 and concentrated to give 2,4-dibromo-6-fluorobenzoic acid as white solid.

1. customrecooled to −70° C
2. stirringThe resulting mixture was stirred at −70° C. for 2 hours
3. stirringstirred overnight
4. washwashed with water twice
5. washThe combined water layer was washed with ether
6. extractionextracted with EtOAc twice
7. washThe combined EtOAc layer was washed with brine
8. dry with materialdried over anhydrous Na2SO4
9. concentrationconcentrated

ORD record

ord-3c42f4ae80e1419786c771f4b700cd32

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08673920B2