p-Toluenesulfonic acid → 1,2,4,9-Tetrahydro-3H-carbazol-3-one

HRID 1200265Notes

Reaction equation

HRID 1200265 reaction equation
C1CO[C:3]2([CH2:15][C:14]3[C:13]4[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=4)[NH:7][C:6]=3[CH2:5][CH2:4]2)[O:2]1.C1(C)C=CC(S(O)(=O)=O)=CC=1>CC(C)=O>[CH2:5]1[C:6]2[NH:7][C:8]3[C:13](=[CH:12][CH:11]=[CH:10][CH:9]=3)[C:14]=2[CH2:15][C:3](=[O:2])[CH2:4]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 1487265HCID 1487265, compound

Product 1

HCID 108670371,2,4,9-Tetrahydro-3H-carbazol-3-one

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

165 g (0.72 mol) of 3,3-ethylenedioxy-1,2,3,4-tetrahydrocarbazole are dissolved in 2 l of acetone, and 3 g of p-toluenesulphonic acid are added. After the reaction solution has been heated under reflux for 4 h it is concentrated, 2 l of ethyl acetate are added, and the mixture is extracted 3 times with 1 l of saturated bicarbonate solution each time. The organic phase is dried with sodium sulphate and evaporated. The residue crystallizes from ether. In this way 118.7 g (89.1% of theory) of the product are obtained.

Workup

  1. temperatureAfter the reaction solution has been heated
  2. temperatureunder reflux for 4 h it
  3. concentrationis concentrated
  4. addition2 l of ethyl acetate are added
  5. extractionthe mixture is extracted 3 times with 1 l of saturated bicarbonate solution each time
  6. dry with materialThe organic phase is dried with sodium sulphate
  7. customevaporated
  8. customThe residue crystallizes from ether
  9. customIn this way 118.7 g (89.1% of theory) of the product are obtained

Sources & evidence

ORD record
ord-4a63cd3d04a14f76aab2a379cdace273
Source dataset
uspto-grants-1990_02
Patent number
US04904797

Reaction notes

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