Hydrazine hydrate (1:1) → 5-Allyl-3-(2-fluoro-4-methylphenyl)-4-phenyl-1H-pyrazole

HRID 1471927Notes

Reaction equation

HRID 1471927 reaction equation
[F:1][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[C:9](=O)[CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[N:28]1(C(=O)CC=C)[C:32]2C=C[CH:35]=[CH:36][C:31]=2N=[N:29]1.O.NN>C1COCC1.CCO>[CH2:31]([C:32]1[NH:28][N:29]=[C:9]([C:3]2[CH:4]=[CH:5][C:6]([CH3:8])=[CH:7][C:2]=2[F:1])[C:10]=1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)[CH:36]=[CH2:35]

Participants

7

Reactant 4

HCID 24654Hydrazine hydrate (1:1)HCID 2733832Lithium HexamethyldisilazideHCID 673843391-(1H-Benzo[d][1,2,3]triazol-1-yl)but-3-en-1-oneHCID 673846201-(2-Fluoro-4-methylphenyl)-2-phenylethanone

Product 1

HCID 673854125-Allyl-3-(2-fluoro-4-methylphenyl)-4-phenyl-1H-pyrazoleYield 39%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 1-(2-fluoro-4-methylphenyl)-2-phenylethanone (1.0 g, 4.38 mmol) in THF (10 mL) was added LiHMDS (1.0 M in THF) (8.76 mL, 8.76 mmol) slowly via syringe at 0° C. After stirring for 10 min, 1-(1H-benzo[d][1,2,3]triazol-1-yl)but-3-en-1-one (0.984 g, 5.26 mmol) was added in one portion. The reaction was stirred at 0° C. for 30 min before quenched with AcOH (2 mL). To the reaction were added EtOH (30 mL), hydrazine hydrate (0.658 g, 13.14 mmol), and heated to reflux for 1 h. After cooled to room temperature, the reaction was concentrated and extracted with EtOAc/H2O, washed with brine, dried over MgSO4, and purified by column chromatography to give the title compound as clear oil (0.50 g). LCMS m/z=293.2 [M+H]+; 1H NMR (400 MHz, DMSO-d6) δ ppm 2.31 (s, 3H), 3.40 (d, J=5.94 Hz, 2H), 4.94-5.08 (m, 2H), 5.88-6.00 (m, 1H), 6.92-7.31 (m, 8H).

Workup

  1. stirringThe reaction was stirred at 0° C. for 30 min
  2. custombefore quenched with AcOH (2 mL)
  3. temperatureheated
  4. temperatureto reflux for 1 h
  5. concentrationthe reaction was concentrated
  6. extractionextracted with EtOAc/H2O
  7. washwashed with brine
  8. dry with materialdried over MgSO4
  9. custompurified by column chromatography

Sources & evidence

ORD record
ord-978d93c796454a4395a63dc06f97b0f8
Source dataset
uspto-grants-2015_04
Patent number
US09012478B2

Reaction notes

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