2,2-Difluorosuccinic acid → 3,3-Difluorooxolane-2,5-dione

HRID 2309587Notes

Reaction equation

HRID 2309587 reaction equation
[F:1][C:2]([F:10])([CH2:6][C:7]([OH:9])=[O:8])[C:3](O)=[O:4]>FC(F)(F)C(OC(=O)C(F)(F)F)=O>[F:1][C:2]1([F:10])[CH2:6][C:7](=[O:9])[O:8][C:3]1=[O:4]

Participants

3

Reactant 1

HCID 695812,2-Difluorosuccinic acid

Product 1

HCID 131892433,3-Difluorooxolane-2,5-dione

Reagents, catalysts & solvents 1

HCID 9845Trifluoroacetic anhydrideSolvent

Procedure

2,2-Difluorosuccinic acid (120 g, 0.78 moles) and trifluoroacetic anhydride (540 mL) are refluxed (bath temperature 80° C.) for 2 hours. Most of the trifluoroacetic acid is distilled utilizing a short Vigreux column, the final traces are removed under vacuum (12 mm Hg, 50° C.) and finally by stripping twice with carbontetrachloride. The oily residue solidifies on scratching with petroleum ether. Filtration and washing with petroleum ether yields 2,2-difluorosuccinic anhydride as slightly violet crystals: 98 g (92%).

Workup

  1. distillationMost of the trifluoroacetic acid is distilled
  2. customthe final traces are removed under vacuum (12 mm Hg, 50° C.)
  3. filtrationFiltration
  4. washwashing with petroleum ether

Sources & evidence

ORD record
ord-a83e37284843493289113ef30d036e5e
Source dataset
uspto-grants-1987_09
Patent number
US04695654

Reaction notes

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