Pyrazole → 1-(2-fluoro-4-nitrophenyl)-1H-pyrazole

HRID 56131Notes

Reaction equation

HRID 56131 reaction equation
F[C:2]1[CH:7]=[CH:6][C:5]([N+:8]([O-:10])=[O:9])=[CH:4][C:3]=1[F:11].C([O-])([O-])=O.[K+].[K+].[NH:18]1[CH:22]=[CH:21][CH:20]=[N:19]1>CS(C)=O.O>[F:11][C:3]1[CH:4]=[C:5]([N+:8]([O-:10])=[O:9])[CH:6]=[CH:7][C:2]=1[N:18]1[CH:22]=[CH:21][CH:20]=[N:19]1

Participants

6

Reactant 3

HCID 1048PyrazoleHCID 11430Potassium CarbonateHCID 1230531,2-Difluoro-4-nitrobenzene

Product 1

HCID 107035141-(2-fluoro-4-nitrophenyl)-1H-pyrazoleYield 80%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 962WaterSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of 1,2-difluoro-4-nitrobenzene (3.18 g, 20 mmol) in DMSO (35 mL) were added K2CO3 (6.08 g, 44 mmol) and pyrazole (1.50 g, 22 mmol) with stirring. The reaction mixture was heated at 90° C. for 18 h, and cooled to rt. The mixture was diluted with water (50 mL) and filtered. The filtrate was extracted with DCM (50 mL×3), the combined organic phases were concentrated in vacuo. The crude product was purified by a silica gel column chromatography (PE/CH2Cl2 (V/V)=1:1) to give the title compound as a yellow solid (3.31 g, 80%).

Workup

  1. temperaturecooled to rt
  2. filtrationfiltered
  3. extractionThe filtrate was extracted with DCM (50 mL×3)
  4. concentrationthe combined organic phases were concentrated in vacuo
  5. customThe crude product was purified by a silica gel column chromatography (PE/CH2Cl2 (V/V)=1:1)

Sources & evidence

ORD record
ord-b6fe01eba5e24354a7698f59db67fedf
Source dataset
uspto-grants-2016_09
Patent number
US09434695B2

Reaction notes

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