Nitric Acid → 3-(2,5-difluoro-4-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole
Reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][C:3]=1[C:9]1[CH:13]=[C:12]([C:14]([F:17])([F:16])[F:15])[N:11]([CH3:18])[N:10]=1.[N+:19]([O-])([OH:21])=[O:20]>>[F:1][C:2]1[CH:7]=[C:6]([N+:19]([O-:21])=[O:20])[C:5]([F:8])=[CH:4][C:3]=1[C:9]1[CH:13]=[C:12]([C:14]([F:16])([F:15])[F:17])[N:11]([CH3:18])[N:10]=1Participants
3
Procedure
To an ice cooled solution of 50 ml of fuming nitric acid (90%) was added slowly 8.29 g of 3-(2,5-difluorophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole. After addition, the mixture was allowed to warm to room temperature and then gently heated to 52° C. Heated for 2.5 hours, then cooled and poured onto ice. The resulting mixture was extracted with ether and the ether then washed twice with water, dried with anhydrous magnesium sulfate, filtered and the solvent removed by concentration in vacuo. The residue was purified utilizing a combination of chromatography and crystallization to give 5.62 g of 3-(2,5-difluoro-4-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole, mp 80°-81° C.
Workup
- additionAfter addition
- temperaturegently heated to 52° C
- temperatureHeated for 2.5 hours
- temperaturecooled
- additionpoured onto ice
- extractionThe resulting mixture was extracted with ether
- washthe ether then washed twice with water
- dry with materialdried with anhydrous magnesium sulfate
- filtrationfiltered
- customthe solvent removed by concentration in vacuo
- customThe residue was purified
- customa combination of chromatography and crystallization
Sources & evidence
- ORD record
- ord-695d4e4653ed43348acf51952c00994f
- Source dataset
- uspto-grants-1996_03
- Patent number
- US05496956
Reaction notes
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