p-Toluenesulfonic acid → 6-fluoro-2,3,4,9-tetrahydro-1H-carbazole

HRID 847779Notes

Reaction equation

HRID 847779 reaction equation
[F:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[CH:4][CH:3]=1.[C:9]1(C)[CH:14]=[CH:13][C:12](S(O)(=O)=O)=[CH:11][CH:10]=1.C1(=O)CCCCC1>C(O)C>[F:1][C:2]1[CH:8]=[C:7]2[C:5](=[CH:4][CH:3]=1)[NH:6][C:10]1[CH2:11][CH2:12][CH2:13][CH2:14][C:9]2=1

Participants

5

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 7967CyclohexanoneHCID 97314-Fluoroaniline

Product 1

HCID 50670136-fluoro-2,3,4,9-tetrahydro-1H-carbazole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

12.6 g of p-fluoroaniline was dissolved in 100 ml of ethanol and a catalytic amount of p-toluenesulfonic acid was added thereto. 9.8 g of cyclohexanone was then added dropwise to the mixture at room temperature. After completion of the addition, the mixture was stirred at room temperature for one hour and concentrated under reduced pressure. Dilute sulfuric acid prepared from 190 ml of water and 20 ml of concentrated sulfuric acid was added to the residue and the mixture was heated at 110° C. for 15 minutes on an oil bath to precipitate light orange crystals. The crystals thus formed were filtered, washed 3 times with water and dried to obtain 17.4 g of 6-fluoro-1,2,3,4-tetrahydrocarbazol which was identified by NMR spectrum.

Workup

  1. additionAfter completion of the addition
  2. concentrationconcentrated under reduced pressure
  3. customDilute sulfuric acid prepared from 190 ml of water and 20 ml of concentrated sulfuric acid
  4. additionwas added to the residue
  5. temperaturethe mixture was heated at 110° C. for 15 minutes on an oil bath
  6. customto precipitate light orange crystals
  7. customThe crystals thus formed
  8. filtrationwere filtered
  9. washwashed 3 times with water
  10. customdried

Sources & evidence

ORD record
ord-30a215f1bdf942cb995936d3e7a740c6
Source dataset
uspto-grants-1981_10
Patent number
US04293694

Reaction notes

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