Dimethyl Sulfoxide → 2,3,4,5-Tetrafluorobenzoic acid

HRID 2231406Notes

Reaction equation

HRID 2231406 reaction equation
[F:1][C:2]1[C:10]([F:11])=[C:9]([F:12])[C:8]([F:13])=[C:4](C(O)=O)[C:3]=1[C:14]([OH:16])=[O:15].CS(C)=O.C(OCCCC)CCC.S(=O)(=O)(O)O>C1(C)C=CC=CC=1.O.C(N(CC)CC)C>[F:1][C:2]1[C:10]([F:11])=[C:9]([F:12])[C:8]([F:13])=[CH:4][C:3]=1[C:14]([OH:16])=[O:15]

Participants

8

Reactant 4

HCID 679Dimethyl SulfoxideHCID 1118Sulfuric AcidHCID 8909Butyl etherHCID 695443,4,5,6-Tetrafluorophthalic acid

Product 1

HCID 2975492,3,4,5-Tetrafluorobenzoic acidYield 94%

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 1140TolueneSolventHCID 8471TriethylamineSolvent

Procedure

3,4,5,6-Tetrafluorophthalic acid (58 g) was added to a two liter flask. Dimethyl sulfoxide (230 ml) followed by triethylamine (11.5 ml) were then added and the mixture heated over a 20 minute period to 115°-120° C. The solution was heated with stirring at 115°-120° C. for another 35-40 minutes and then cooled with an ice bath. Demineralized water (580 ml) followed by n-butyl ether (250 ml) and toluene (350 ml) were added. Sulfuric acid (99%, 3.5 ml) was then cautiously added with stirring and cooling. The layers were separated and the aqueous layer extracted with two portions of toluene (580 ml and 290 ml). The combined organic layers were extracted with 2% aqueous sulfuric acid (3×150 ml). The organic layer was dried over anhydrous sodium sulfate (60 g) and Darco S-51 (11.5 g) was added. After filtering the mixture was concentrated under reduced pressure and the resulting solid dried under vacuum at 50°-60° C. for seven hours to give 2,3,4,5-tetrafluorobenzoic acid (44.3 g, 94%); mp 77°-80° C.

Workup

  1. additionwere then added
  2. temperaturethe mixture heated over a 20 minute period to 115°-120° C
  3. temperatureThe solution was heated
  4. temperaturecooled with an ice bath
  5. additionwere added
  6. stirringwith stirring
  7. temperaturecooling
  8. customThe layers were separated
  9. extractionthe aqueous layer extracted with two portions of toluene (580 ml and 290 ml)
  10. extractionThe combined organic layers were extracted with 2% aqueous sulfuric acid (3×150 ml)
  11. dry with materialThe organic layer was dried over anhydrous sodium sulfate (60 g) and Darco
  12. addition(11.5 g) was added
  13. filtrationAfter filtering the mixture
  14. concentrationwas concentrated under reduced pressure
  15. customthe resulting solid dried under vacuum at 50°-60° C. for seven hours

Sources & evidence

ORD record
ord-cb4987bf160245a18ae55c9454447734
Source dataset
uspto-grants-1988_11
Patent number
US04782180

Reaction notes

Loading…