1,1,1-Trifluoro-2,4-pentanedione → 2-Fluoro-5-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzonitrile

HRID 1768101Notes

Reaction equation

HRID 1768101 reaction equation
[Sn](Cl)(Cl)(Cl)Cl.[F:6][C:7]1[CH:12]=[CH:11][C:10]([NH:13][NH2:14])=[CH:9][C:8]=1[C:15]#[N:16].[F:17][C:18]([F:26])([F:25])[C:19](=O)[CH2:20][C:21](=O)[CH3:22]>C(O)C>[F:6][C:7]1[CH:12]=[CH:11][C:10]([N:13]2[C:21]([CH3:22])=[CH:20][C:19]([C:18]([F:26])([F:25])[F:17])=[N:14]2)=[CH:9][C:8]=1[C:15]#[N:16]

Participants

4

Reactant 2

HCID 739431,1,1-Trifluoro-2,4-pentanedioneHCID 688056624-Fluoro-3-cyanophenylhydrazine tin chloride

Product 1

HCID 222807792-Fluoro-5-[5-methyl-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzonitrileYield 56%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a suspension of 4-fluoro-3-cyanophenylhydrazine tin chloride (20 g, 53.6 mmol) in ethanol (150 mL) was added 1,1,1-trifluoro-2,4-pentanedione (8.18 g, 53.6 mmol). The reaction was brought to reflux overnight. The next day the ethanol was evaporated and the residue partitioned between ethyl acetate and HCl (1 N). The aqueous phase was extracted with ethyl acetate (4×20 mL). The organic phase is washed with water, brine, dried over sodium sulfate, filtered and concentrated. Flash chromatography gave 1-(4-fluoro-3-cyanophenyl)-3-trifluoromethyl-5-methylpyrazole (8 g, 56% yield) as pure compound: MS (CI): 270 (M+H)+ (100%).

Workup

  1. temperatureto reflux overnight
  2. customThe next day the ethanol was evaporated
  3. customthe residue partitioned between ethyl acetate and HCl (1 N)
  4. extractionThe aqueous phase was extracted with ethyl acetate (4×20 mL)
  5. washThe organic phase is washed with water, brine
  6. dry with materialdried over sodium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-3b1cc3385b7f4384ad6dc9f54011d62a
Source dataset
uspto-grants-2007_06
Patent number
US07235575B2

Reaction notes

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