2,3-Dihydro-thieno(3,4-b)(1,4)dioxin-5,7-dicarboxylic acid → 3,4-Ethylenedioxythiophene

HRID 1270686

Reaction equation

HRID 1270686 reaction equation
[CH2:1]1[CH2:9][O:8][C:7]2[C:3](=[C:4](C(O)=O)[S:5][C:6]=2C(O)=O)[O:2]1>[Cu].CS(C)=O>[CH2:1]1[CH2:9][O:8][C:7]2[C:3](=[CH:4][S:5][CH:6]=2)[O:2]1

Participants

4

Reactant 1

HCID 7288412,3-Dihydro-thieno(3,4-b)(1,4)dioxin-5,7-dicarboxylic acid

Product 1

HCID 44218643,4-EthylenedioxythiopheneYield 99.6%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 679Dimethyl SulfoxideSolvent

Procedure

3,4-Ethylenedioxythiophene-2,5-dicarboxylic acid (460 g) and a copper powder (46 g) were added to DMSO (1200 g) at room temperature. The reaction mixture was stirred under an oxygen atmosphere for 30 minutes at room temperature and then heated at 120° C. for 6 hours. The reaction mixture was then poured into ice water (1200 mL), and the crude product was extracted with ethyl acetate. After drying over anhydrous sodium sulfate, the solvent was removed by evaporation. The residue was vacuum-distilled at 30 mmHg to give 283 g of 3,4-ethylenedioxythiophene at high purity (99.7% or higher). The purity was confirmed by gas chromatographic analysis (compared to decane as an internal standard). The chemical structure was confirmed by mass analysis and 1H-NMR.

Workup

  1. temperatureheated at 120° C. for 6 hours
  2. extractionthe crude product was extracted with ethyl acetate
  3. dry with materialAfter drying over anhydrous sodium sulfate
  4. customthe solvent was removed by evaporation
  5. distillationThe residue was vacuum-distilled at 30 mmHg

Sources & evidence

ORD record
ord-707af3abf38d4a588f22f0ea49e65955
Source dataset
uspto-grants-2007_04
Patent number
US07202369B2

Linked notes

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