Methyl iodide → 1-Methyl-5-phenylpyrazole

HRID 1432717Notes

Reaction equation

HRID 1432717 reaction equation
[H-].[Na+].[C:3]1([C:9]2[CH:13]=[CH:12][NH:11][N:10]=2)[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.IC.[CH3:16]N1C=CC(C2C=CC=CC=2)=N1>C1COCC1.O>[CH3:16][N:10]1[C:9]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][CH:8]=2)=[CH:13][CH:12]=[N:11]1

Participants

7

Reactant 4

HCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 1379461-Methyl-3-phenyl-1H-pyrazoleHCID 178420101HCID 178420101, compound

Product 1

HCID 1379471-Methyl-5-phenylpyrazoleYield 95%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

Sodium hydride (60% dispersion in mineral oil, 0.83 g, 20.8 mmol) is suspended in THF (45 ml) and stirred under a nitrogen atmosphere. 3-Phenyl pyrazole (2.5 g, 17.3 mmol dissolved in THF, 15 ml) is added slowly, stirred for 30 minutes then iodomethane (1.3 ml, 20.8 mmol) added and stirred for 3 hrs. The reaction is added to water and extracted twice with ethyl acetate. The combined organic extracts are ished with brine, dried over Na2SO4, filtered and concentrated. The crude product is purified by chromatography using a hexane-ethyl acetate gradient (100% hexane to 40% ethyl acetate in hexane) to elute the title compound. Obtained is a mixture of 1-methyl-3-phenyl-1H-pyrazole and 1-methyl-5-phenyl-1H-pyrazole (2.6 g, 95% yield).

Workup

  1. stirringstirred for 30 minutes
  2. stirringstirred for 3 hrs
  3. extractionextracted twice with ethyl acetate
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe crude product is purified by chromatography
  8. washto elute the title compound
  9. customObtained

Sources & evidence

ORD record
ord-7a834988ac38408f9e6d9892cde779fe
Source dataset
uspto-grants-2009_11
Patent number
US07612067B2

Reaction notes

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