Hydrazine hydrate (1:1) → 3-Phenyl-5-(trifluoromethyl)-1H-pyrazole

HRID 1471915Notes

Reaction equation

HRID 1471915 reaction equation
[F:1][C:2]([F:15])([F:14])[C:3](=O)[CH2:4][C:5]([C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=O.O.[NH2:17][NH2:18]>C(O)C>[C:7]1([C:5]2[CH:4]=[C:3]([C:2]([F:15])([F:14])[F:1])[NH:18][N:17]=2)[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 675894,4,4-Trifluoro-1-phenyl-1,3-butanedione

Product 1

HCID 6113223-Phenyl-5-(trifluoromethyl)-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a stirred mixture of 4,4,4-trifluoro-1-phenylbutane-1,3-dione (5.0 g, 23.13 mmol) in dry ethanol (100 mL) was added hydrazine hydrate (1.737 g, 34.7 mmol) dropwise. The resulting solution was refluxed for 16 h. The reaction was cooled to room temperature and concentrated. The oil was diluted with saturated NaHCO3 solution and extracted with EtOAc, washed with brine, dried over MgSO4 and concentrated. The residue was purified by silica gel column chromatography to give the title compound as a clear liquid which was crystallized in hexanes/ethyl acetate (3.25 g). LCMS m/z=213.1 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 6.77 (s, 1H), 7.36-7.51 (m, 3H), 7.53-7.64 (m, 2H), 11.59 (s, 1H).

Workup

  1. temperatureThe resulting solution was refluxed for 16 h
  2. concentrationconcentrated
  3. additionThe oil was diluted with saturated NaHCO3 solution
  4. extractionextracted with EtOAc
  5. washwashed with brine
  6. dry with materialdried over MgSO4
  7. concentrationconcentrated
  8. customThe residue was purified by silica gel column chromatography

Sources & evidence

ORD record
ord-3e36ca54b11744cba0a2217d7a2832bc
Source dataset
uspto-grants-2015_04
Patent number
US09012478B2

Reaction notes

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