Hydrazine hydrate (1:1) → 5-Allyl-4-phenyl-3-p-tolyl-1H-pyrazole

HRID 1471932Notes

Reaction equation

HRID 1471932 reaction equation
[C:1]1([CH2:7][C:8]([C:10]2[CH:15]=[CH:14][C:13]([CH3:16])=[CH:12][CH:11]=2)=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[N:27]1(C(=O)CC=C)[C:31]2C=C[CH:34]=[CH:35][C:30]=2N=[N:28]1.O.NN>C1COCC1.CCO>[CH2:30]([C:31]1[NH:27][N:28]=[C:8]([C:10]2[CH:15]=[CH:14][C:13]([CH3:16])=[CH:12][CH:11]=2)[C:7]=1[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1)[CH:35]=[CH2:34]

Participants

7

Reactant 4

HCID 24654Hydrazine hydrate (1:1)HCID 2280161-(4-Methylphenyl)-2-phenylethan-1-oneHCID 2733832Lithium HexamethyldisilazideHCID 673843391-(1H-Benzo[d][1,2,3]triazol-1-yl)but-3-en-1-one

Product 1

HCID 673845665-Allyl-4-phenyl-3-p-tolyl-1H-pyrazoleYield 36%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 2-phenyl-1-p-tolylethanone (1.0 g, 4.76 mmol) in THF (10 mL) added LiHMDS (1.0 M in THF) (9.51 mL, 9.51 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 (1.068 g, 5.71 mmol) was added in one portion. The reaction was stirred at 0° C. for 30 min and then quenched with AcOH (2 mL). EtOH (30 mL) and hydrazine hydrate (0.714 g, 14.27 mmol) were added, and the reaction was heated to reflux for 30 min. The reaction was cooled to room temperature, concentrated and the residue was extracted with EtOAc/H2O, washed with brine, dried over MgSO4, and purified by column chromatography to give the title compound as clear oil (0.47 g). LCMS m/z=275.0 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 2.31 (s, 3H), 3.38-3.43 (m, 2H), 5.07-5.14 (m, 2H), 5.90-6.01 (m, 1H), 7.03-7.09 (m, 2H), 7.19-7.30 (m, 5H), 7.30-7.36 (m, 2H).

Workup

  1. stirringThe reaction was stirred at 0° C. for 30 min
  2. customquenched with AcOH (2 mL)
  3. temperaturethe reaction was heated
  4. temperatureto reflux for 30 min
  5. concentrationconcentrated
  6. extractionthe residue was extracted with EtOAc/H2O
  7. washwashed with brine
  8. dry with materialdried over MgSO4
  9. custompurified by column chromatography

Sources & evidence

ORD record
ord-84b0128d56e044d48283952a1b60458f
Source dataset
uspto-grants-2015_04
Patent number
US09012478B2

Reaction notes

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