Carbon Dioxide → 5-Fluoro-2,2-dimethyl-2H-1,3-benzodioxole-4-carboxylic acid

HRID 2226097Notes

Reaction equation

HRID 2226097 reaction equation
[CH3:1][C:2]1([CH3:12])[O:6][C:5]2[CH:7]=[CH:8][C:9]([F:11])=[CH:10][C:4]=2[O:3]1.C([Li])CCC.[C:18](=[O:20])=[O:19]>O1CCCC1>[CH3:1][C:2]1([CH3:12])[O:6][C:5]2[CH:7]=[CH:8][C:9]([F:11])=[C:10]([C:18]([OH:20])=[O:19])[C:4]=2[O:3]1

Participants

5

Reactant 3

HCID 280Carbon Dioxide2×HCID 189662825-Fluoro-2,2-dimethyl-2H-1,3-benzodioxoleHCID 178418339Butyllithium

Product 1

HCID 189662885-Fluoro-2,2-dimethyl-2H-1,3-benzodioxole-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

In a flask were placed 29.3 g (0.174 mole) of 2,2-dimethyl-5-fluoro-1,3-benzodioxole and 200 mL of dry tetrahydrofuran, and the resulting solution was cooled to -78° C. To this solution was added dropwise 66.4 mL (0.166 mole) of a 2.5 M solution of n-butyllithium in hexanes. This mixture was stirred at -78° C. for one hour after which a carbon dioxide atmosphere was placed above the reaction mixture. The temperature was allowed to warm to ambient conditions during a 16 hour period while maintaining the carbon dioxide atmosphere. At the conclusion of this period the solvent was evaporated under reduced pressure, and diethyl ether was added to the residue. This mixture was extracted with water, and the water extract was in turn extracted with diethyl ether. The aqueous phase was separated and acidified with hydrochloric acid. The acidified mixture was then extracted with methylene chloride. The methylene chloride extract was washed with water, dried over anhydrous magnesium sulfate, and filtered. The filtrate was evaporated under reduced pressure, leaving 19 g of 2,2-dimethyl-5-fluoro-1,3-benzodioxol-4-ylcarboxylic acid as the residue. The NMR spectrum was consistent with the proposed structure.

Workup

  1. customIn a flask were placed
  2. temperatureto warm to ambient conditions during a 16 hour period
  3. customAt the conclusion of this period the solvent was evaporated under reduced pressure, and diethyl ether
  4. additionwas added to the residue
  5. extractionThis mixture was extracted with water
  6. extractionthe water extract
  7. extractionextracted with diethyl ether
  8. customThe aqueous phase was separated
  9. extractionThe acidified mixture was then extracted with methylene chloride
  10. extractionThe methylene chloride extract
  11. washwas washed with water
  12. dry with materialdried over anhydrous magnesium sulfate
  13. filtrationfiltered
  14. customThe filtrate was evaporated under reduced pressure

Sources & evidence

ORD record
ord-ba2be1ac37934f69bbd644c320f8da9b
Source dataset
uspto-grants-1994_09
Patent number
US05346881

Reaction notes

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