Trifluoroacetic acid → 10,11-dihydro-10,10,11,11-tetrafluoro-5H-dibenzo[a,d]cyclohepten-5-one

HRID 1282892Notes

Reaction equation

HRID 1282892 reaction equation
[F:1][C:2]1([F:19])[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][C:5]2[CH:13]=[CH:14][CH:15]=[CH:16][C:4]=2[C:3]1([F:18])[F:17].FC(F)(F)C(O)=[O:23]>[O-2].[O-2].[O-2].[Cr+6].C(O)(=O)C>[F:1][C:2]1([F:19])[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[C:6](=[O:23])[C:5]2[CH:13]=[CH:14][CH:15]=[CH:16][C:4]=2[C:3]1([F:17])[F:18]

Participants

5

Reactant 2

HCID 6422Trifluoroacetic acidHCID 2037334410,11-dihydro-10,10,11,11-tetrafluoro-5H-dibenzo[a,d]cycloheptene

Product 1

HCID 2037337610,11-dihydro-10,10,11,11-tetrafluoro-5H-dibenzo[a,d]cyclohepten-5-one

Reagents, catalysts & solvents 2

HCID 10219390chromium (VI) trioxideCatalyst2×HCID 176Acetic AcidSolvent

Procedure

A mixture of 1.45 g. (0.00544 mole) of 10,11-dihydro-10,10,11,11-tetrafluoro-5H-dibenzo[a,d]cycloheptene, 0.73 g. (0.0073 mole) of chromium trioxide, 25 ml. of trifluoroacetic acid and 2 ml. of glacial acetic acid is stirred at reflux for 21/4 hours. During this period, almost all of the chromium trioxide dissolves. Solvents are evaporated under reduced pressure and the residue is partitioned between benzene and water. The aqueous layer is separated and re-extracted twice with benzene. The combined benzene extracts are washed thoroughly with water, dried over anhydrous magnesium sulfate, and evaporated to dryness under reduced pressure. The crude product is left as the residual oily solid and is purified by column chromatography on 75 g. of silica gel, eluting the product with 1:1 benzene-carbon tetrachloride. The fractions that show one spot of Rf 0.75 on a silica thin layer plate developed with benzene are combined. Evaporation of the solvent under reduced pressure leaves the white crystalline product, m.p. 70°-75°C.

Workup

  1. additionA mixture of 1.45 g
  2. temperatureat reflux for 21/4 hours
  3. waitDuring this period
  4. customSolvents are evaporated under reduced pressure
  5. customthe residue is partitioned between benzene and water
  6. customThe aqueous layer is separated
  7. extractionre-extracted twice with benzene
  8. washThe combined benzene extracts are washed thoroughly with water
  9. dry with materialdried over anhydrous magnesium sulfate
  10. customevaporated to dryness under reduced pressure
  11. waitThe crude product is left as the residual oily solid
  12. customis purified by column chromatography on 75 g
  13. washof silica gel, eluting the product with 1:1 benzene-carbon tetrachloride
  14. customEvaporation of the solvent under reduced pressure
  15. customleaves the white crystalline product, m.p. 70°-75°C.

Sources & evidence

ORD record
ord-65d3ff801d03407184baed9b448fa820
Source dataset
uspto-grants-1976_08
Patent number
US03972936

Reaction notes

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