Potassium Carbonate → Indole

HRID 741554Notes

Reaction equation

HRID 741554 reaction equation
[CH:1]1[C:6](NN)=[CH:5][CH:4]=[C:3]([N:9]2[CH:13]=NN=C2)[CH:2]=1.[C:14]([O-])([O-])=O.[K+].[K+]>S(=O)(=O)(O)O>[NH:9]1[C:3]2[C:4](=[CH:5][CH:6]=[CH:1][CH:2]=2)[CH:14]=[CH:13]1

Participants

4

Reactant 2

HCID 11430Potassium CarbonateHCID 51624184-(4-hydrazinylphenyl)-4H-1,2,4-triazole

Product 1

HCID 798IndoleYield 17%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

A mixture of intermediates 1 (1.0 g, 5.71 mmol) and 2 (2.07 g, 6.86 mmol) in 4% sulphuric acid (30 ml) was heated at reflux for 48 h. The solution was cooled in an ice-bath, basified with solid K2CO3 and extracted with butan-1-ol (×3). The solvent was removed under vacuum and azeotroped with hexane (×2). The crude product was chromatographed through silica gel eluting with CH2Cl2 /MeOH/NH3 (30:8:1) to give the title-indole (282 mg, 17%). The succinate hemihydrate salt was prepared: mp 227°-228° C. (Found: C, 59.11; H, 6.58; N, 22.54.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 48 h
  3. temperatureThe solution was cooled in an ice-bath
  4. extractionextracted with butan-1-ol (×3)
  5. customThe solvent was removed under vacuum
  6. customazeotroped with hexane (×2)
  7. customThe crude product was chromatographed through silica gel eluting with CH2Cl2 /MeOH/NH3 (30:8:1)

Sources & evidence

ORD record
ord-9b6819fcdbc2497d8a0ccf83fe7f3287
Source dataset
uspto-grants-1996_09
Patent number
US05552402

Reaction notes

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