Benzyl Bromide → ethyl 1-benzyl-1H-pyrazole-4-carboxylate

HRID 1737197Notes

Reaction equation

HRID 1737197 reaction equation
[H-].[Na+].[CH2:3]([O:5][C:6]([C:8]1[CH:9]=[N:10][NH:11][CH:12]=1)=[O:7])[CH3:4].[CH2:13](Br)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>CN(C)C=O>[CH2:13]([N:10]1[CH:9]=[C:8]([C:6]([O:5][CH2:3][CH3:4])=[O:7])[CH:12]=[N:11]1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 24758Sodium hydrideHCID 142179ethyl 1H-pyrazole-4-carboxylate

Product 1

HCID 15237993ethyl 1-benzyl-1H-pyrazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Procedure

To a suspension of sodium hydride (containing 63%, 652 mg) in dimethylformamide (abbreviated as DMF hereinafter) was added a solution of 4-ethoxycarbonylpyrazole (2.00 g) in DMF (15 ml) at room temperature. After stirred for 30 min at room temperature, to the mixture was added benzylbromide (2.04 ml). After stirred for 30 min, the mixture was quenched by addition of water. The mixture was extracted with ethyl acetate - n-hexane. The extract was washed with a saturated aqueous solution of sodium chloride, dried over anhydrous magnesium sulfate, and evaporated. The residue was purified by silica gel column chromatography (n-hexane: ethyl acetate=3:1) to give the title compound (2.98 g) having the following physical data.

Workup

  1. stirringAfter stirred for 30 min
  2. customthe mixture was quenched by addition of water
  3. extractionThe mixture was extracted with ethyl acetate - n-hexane
  4. washThe extract was washed with a saturated aqueous solution of sodium chloride
  5. dry with materialdried over anhydrous magnesium sulfate
  6. customevaporated
  7. customThe residue was purified by silica gel column chromatography (n-hexane: ethyl acetate=3:1)

Sources & evidence

ORD record
ord-00b89705df3a42bd864baa5c730c6c9d
Source dataset
uspto-grants-1999_10
Patent number
US05962439

Reaction notes

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