Carbon Dioxide → 2-chlorothiophene-3-carboxylic Acid

HRID 1197426Notes

Reaction equation

HRID 1197426 reaction equation
[Cl:1][C:2]1[S:3][CH:4]=[CH:5][C:6]=1Br.[C:8](=[O:10])=[O:9].CC(C)=O.C([Li])CCC.C(=O)=O>C(OCC)C>[Cl:1][C:2]1[S:3][CH:4]=[CH:5][C:6]=1[C:8]([OH:10])=[O:9]

Participants

6

Reactant 4

HCID 280Carbon DioxideHCID 27245593-Bromo-2-chlorothiopheneHCID 18522661Acetone cardiceHCID 178418339Butyllithium

Product 1

HCID 36627282-chlorothiophene-3-carboxylic AcidYield 90%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a round bottomed flask were added 2-chloro-3-bromothiophene (26.2 g, 132.7 mmole) along with diethyl ether (390 mL). The reaction was cooled to -78° C. (dry ice/acetone) and 1.6M n-butyllithium (87.0 mL, 139.0 mmole) was added dropwise. The reaction was stirred for 1.5 hours after which an excess of CO2 (~25.0 g) was added all at once. The reaction was warmed to room temperature and poured onto ice/water. The mixture was extracted with 10% sodium carbonate solution and the basic aqueous layer was washed with methylene chloride. The basic solution was then acidified to a pH 3.0 and extracted with diethyl ether. The organic layer was washed with water, brine, and dried (MgSO4). Solvent removal yielded 19.32 g of an off-white solid (90%) which was used as is.

Workup

  1. additionwas added dropwise
  2. additionwas added all at once
  3. additionpoured onto ice/water
  4. extractionThe mixture was extracted with 10% sodium carbonate solution
  5. washthe basic aqueous layer was washed with methylene chloride
  6. extractionextracted with diethyl ether
  7. washThe organic layer was washed with water, brine
  8. dry with materialdried (MgSO4)
  9. customSolvent removal

Sources & evidence

ORD record
ord-e1a4fc9d5b724023a80387c800ed505b
Source dataset
uspto-grants-1994_01
Patent number
US05276025

Reaction notes

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