Water → 3,4,5,6-Tetrafluorophthalic acid

HRID 2231414Notes

Reaction equation

HRID 2231414 reaction equation
S(=O)(=O)(O)O.O.[F:7][C:8]1[C:17]([F:18])=[C:16]([F:19])[C:15]([F:20])=[C:10]([C:11]([O:13]C)=[O:12])[C:9]=1[C:21]([O:23]C)=[O:22]>C(O)(=O)C>[F:7][C:8]1[C:17]([F:18])=[C:16]([F:19])[C:15]([F:20])=[C:10]([C:11]([OH:13])=[O:12])[C:9]=1[C:21]([OH:23])=[O:22]

Participants

5

Reactant 3

HCID 962WaterHCID 1118Sulfuric AcidHCID 616675dimethyl tetrafluorophthalate

Product 1

HCID 695443,4,5,6-Tetrafluorophthalic acidYield 73.3%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Sulfuric acid (99%, 45 ml) was added cautiously to water (45 ml) and the resulting solution mixed with glacial acetic acid (450 ml). To this solution was added dimethyl 3,4,5,6-tetrafluorophthalate (90.0 g) and the resulting mixture heated at reflux for six hours. The solution was concentrated under reduced pressure to remove acetic acid and water. Fresh acetic acid (450 ml) and water (75 ml) were added to the residue and refluxing continued overnight (16 hours). The solution was concentrated again under reduced pressure to a semisolid. Hydrochloric acid (37%, 150 ml) was added and the mixture warmed until all the solids dissolved. The solution was concentrated under reduced pressure to 125 ml. Cooling gave crystals which were collected and washed with 37% hydrochloric acid. Recrystallization from 130 ml 24% hydrochloric acid followed by drying under vacuum at room temperature gave tetrafluorophthalic acid (59 g, 73%); mp 159°-161° C.

Workup

  1. temperaturethe resulting mixture heated
  2. temperatureat reflux for six hours
  3. concentrationThe solution was concentrated under reduced pressure
  4. customto remove acetic acid and water
  5. additionFresh acetic acid (450 ml) and water (75 ml) were added to the residue
  6. temperaturerefluxing continued overnight (16 hours)
  7. concentrationThe solution was concentrated again under reduced pressure to a semisolid
  8. additionHydrochloric acid (37%, 150 ml) was added
  9. temperaturethe mixture warmed until all the solids
  10. dissolutiondissolved
  11. concentrationThe solution was concentrated under reduced pressure to 125 ml
  12. temperatureCooling
  13. customgave crystals which
  14. customwere collected
  15. washwashed with 37% hydrochloric acid
  16. customRecrystallization from 130 ml 24% hydrochloric acid
  17. customby drying under vacuum at room temperature

Sources & evidence

ORD record
ord-667f6248ca5046958d5b0c4ed03a8059
Source dataset
uspto-grants-1988_11
Patent number
US04782180

Reaction notes

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