Carbon Dioxide → 4-Bromo-2,3,5,6-tetrafluorobenzoic acid

HRID 1681190Notes

Reaction equation

HRID 1681190 reaction equation
C([Li])CCC.Br[C:7]1[C:12]([F:13])=[C:11]([F:14])[C:10]([Br:15])=[C:9]([F:16])[C:8]=1[F:17].[C:18](=[O:20])=[O:19].Cl>O1CCCC1.O>[Br:15][C:10]1[C:11]([F:14])=[C:12]([F:13])[C:7]([C:18]([OH:20])=[O:19])=[C:8]([F:17])[C:9]=1[F:16]

Participants

7

Reactant 4

HCID 280Carbon DioxideHCID 313Hydrochloric AcidHCID 676531,4-Dibromo-2,3,5,6-tetrafluorobenzeneHCID 178418339Butyllithium

Product 1

HCID 2981734-Bromo-2,3,5,6-tetrafluorobenzoic acidYield 81.5%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-70 °C

Procedure

n-Butyllithium (42 ml, 2.4M in hexane) was slowly added to a solution of 30.78 g ,1,4-dibromo-2,3,-5,6-tetrafluorobenzene in 200 ml tetrahydrofuran cooled to -70° C. under nitrogen. Solid carbon dioxide (about 12 g) was then added to the stirred mixture which was then allowed gradually to warm to 0° C. at which point 16 ml 6M hydrochloric acid and 16 ml water were added. The reaction mixture was concentrated and the residue extracted with methylene dichloride. The extract was washed with concentrated sodium chloride solution, dried (magnesium sulfate) and concentrated to dryness to give 22.23 g (81.5%) 4-bromo-2,3,5,6-tetrafluorobenzoic acid, m.p. 128°-135° C.

Workup

  1. additionwere added
  2. concentrationThe reaction mixture was concentrated
  3. extractionthe residue extracted with methylene dichloride
  4. washThe extract was washed with concentrated sodium chloride solution
  5. dry with materialdried (magnesium sulfate)
  6. concentrationconcentrated to dryness

Sources & evidence

ORD record
ord-01c8f016aa194c838b58c1d40cb38340
Source dataset
uspto-grants-1992_12
Patent number
US05169853

Reaction notes

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