Potassium Hydroxide → 1,5-diamino-3-(4-fluorophenyl)-1H-pyrazole
Reaction equation
[NH2:1]OS(O)(=O)=O.[NH2:7][C:8]1[NH:12][N:11]=[C:10]([C:13]2[CH:18]=[CH:17][C:16]([F:19])=[CH:15][CH:14]=2)[CH:9]=1.[OH-].[K+]>>[NH2:1][N:12]1[C:8]([NH2:7])=[CH:9][C:10]([C:13]2[CH:18]=[CH:17][C:16]([F:19])=[CH:15][CH:14]=2)=[N:11]1Participants
Conditions
- Temperature
- 80 °C
Procedure
Hydroxylamine-O-sulfonic acid (2.26 g, 20.0 mmol) was portionwise added to aqueous solution (100 mL) containing 5-amino-3-(4-fluorophenyl)-1H-pyrazole (2.0 g, 11.3 mmol) and potassium hydroxide (2.52 g, 45 mmol) while stirring at 80° C. After the mixture was stirred at 80° C. for 30 minutes, potassium hydroxide (2.52 g, 45 mmol) was added thereto, hydroxylamine-O-sulfonic acid (2.26 g, 20.0 mmol) was portionwise added, and the mixture was stirred for further 1 hour. The reaction solution was cooled down to room temperature, and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous potassium carbonate, and concentrated in vacuo. The residue was purified by a silica gel column chromatography (C-300, hexane:ethyl acetate=1:2) to obtain the title compound (324 mg, 14.9%).
Workup
- stirringAfter the mixture was stirred at 80° C. for 30 minutes
- stirringthe mixture was stirred for further 1 hour
- temperatureThe reaction solution was cooled down to room temperature
- extractionextracted with ethyl acetate
- washThe organic layer was washed with saturated brine
- dry with materialdried over anhydrous potassium carbonate
- concentrationconcentrated in vacuo
- customThe residue was purified by a silica gel column chromatography (C-300, hexane:ethyl acetate=1:2)
Sources & evidence
- ORD record
- ord-4131979826d2487cbb0c59bb833e4b86
- Source dataset
- uspto-grants-2008_04
- Patent number
- US07365079B2
Reaction notes
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