Sulfuric Acid → 5,6,7,8,9,10-Hexahydro-7,10-iminocyclohept[b]indole

HRID 1655271Notes

Reaction equation

HRID 1655271 reaction equation
[CH2:1]1[CH:8]2[NH:9][CH:3]([CH2:4][C:5]([CH2:7]2)=[O:6])[CH2:2]1.Cl.Cl.[C:12]1([NH:18]N)[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.S(=O)(=O)(O)O>C(O)C>[OH-:6].[NH4+:9].[NH:9]1[CH:8]2[C:7]3[C:17]4[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=4)[NH:18][C:5]=3[CH2:4][CH:3]1[CH2:2][CH2:1]2

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 60962Phenylhydrazine hydrochlorideHCID 130912188-Azabicyclo[3.2.1]octan-3-one hydrochloride

Product 2

HCID 14923Ammonium HydroxideHCID 151494265,6,7,8,9,10-Hexahydro-7,10-iminocyclohept[b]indoleYield 103.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent2×

Procedure

A stirred solution of 5.0 g (30.96 mmol) of nortropinone hydrochloride and 4.6 g (31.89 mmol) of phenylhydrazine hydrochloride in 20 mL of ethanol was heated at reflux for 2.5 hours. After slow dropwise addition of 5 mL of concentrated sulfuric acid, the reaction mixture was stirred and refluxed for an additional 16 hours, and then it was added to a 50 mL of ethanol and sufficient IRA-400 resin was added to bring the mixture to pH 10. Decolorizing carbon (10 g) was added and the mixture was stirred at ambient temperature for 30 minutes. The mixture was filtered through a pad of diatomaceous earth. After the filter cake was washed several times with warm ethanol, the filtrates were combined and concentrated. The residue was chromatographed on silica gel using methylene chloride: methanol: aqueous ammonium hydroxide/91.5: 7.5: 1.0 to afford 3.19 g (52%) of 5,6,7,8,9,10-hexahydro-7,10-iminocyclohept[b]indole identical with that obtained by Method A.

Workup

  1. temperatureat reflux for 2.5 hours
  2. temperaturerefluxed for an additional 16 hours
  3. additionwas added
  4. additionDecolorizing carbon (10 g) was added
  5. stirringthe mixture was stirred at ambient temperature for 30 minutes
  6. filtrationThe mixture was filtered through a pad of diatomaceous earth
  7. washAfter the filter cake was washed several times with warm ethanol
  8. concentrationconcentrated
  9. customThe residue was chromatographed on silica gel

Sources & evidence

ORD record
ord-09eab0b282d04feaa18a388840f02dcc
Source dataset
uspto-grants-1993_10
Patent number
US05250537

Reaction notes

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