Sulfuric Acid → 6-(trifluoromethyl)-1H-indazol-5-amine

HRID 1360837Notes

Reaction equation

HRID 1360837 reaction equation
[N+]([O-])([O-])=O.[Na+].[F:6][C:7]([F:18])([F:17])[C:8]1[CH:16]=[C:15]2[C:11]([CH:12]=[N:13][NH:14]2)=[CH:10][CH:9]=1.S(=O)(=O)(O)O.O.[NH3:25]>>[NH2:25][C:9]1[CH:10]=[C:11]2[C:15](=[CH:16][C:8]=1[C:7]([F:6])([F:17])[F:18])[NH:14][N:13]=[CH:12]2

Participants

5

Reactant 4

HCID 1118Sulfuric AcidHCID 24268Sodium NitrateHCID 12896473Azane;hydrateHCID 214555996-(trifluoromethyl)-1H-indazole

Product 1

HCID 579513676-(trifluoromethyl)-1H-indazol-5-amineYield 94%

Procedure

Under ice-cooling, 1.01 g (12.0 mmol) of sodium nitrate was added to a mixture of 1.54 g (8.29 mmol) of 6-trifluoromethylindazole and 5 ml of concentrated sulfuric acid, and the mixture was stirred for 1 hour. The reaction mixture was poured onto ice and after ammonia water was added dropwise to the mixture under ice-cooling until pH reached 10 or higher, the precipitated solid was collected by filtration and then washed with water, followed by drying. The resulting crude product was dissolved in 50 ml of methanol, activated carbon was added to the mixture, and the mixture was filtered. 0.20 g of 5% Palladium-on-carbon was added to the filtrate, and the mixture was stirred under a hydrogen atmosphere at room temperature for 14 hours. The mixture was filtered through Celite and the filtrate was concentrated under reduced pressure to give 1.57 g (yield: 94%, two steps) of 5-amino-6-trifluoromethylindazole.

Workup

  1. temperatureUnder ice-cooling
  2. additionThe reaction mixture was poured onto ice
  3. temperaturecooling until pH
  4. filtrationhigher, the precipitated solid was collected by filtration
  5. washwashed with water
  6. customby drying
  7. dissolutionThe resulting crude product was dissolved in 50 ml of methanol
  8. additionactivated carbon was added to the mixture
  9. filtrationthe mixture was filtered
  10. addition0.20 g of 5% Palladium-on-carbon was added to the filtrate
  11. stirringthe mixture was stirred under a hydrogen atmosphere at room temperature for 14 hours
  12. filtrationThe mixture was filtered through Celite
  13. concentrationthe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-fe4bce7044bb4b86bfea569bdf17a5e4
Source dataset
uspto-grants-2011_02
Patent number
US07879887B2

Reaction notes

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