Water → Ethyl 1-(2-methylpropyl)-1H-pyrazole-4-carboxylate

HRID 914468Notes

Reaction equation

HRID 914468 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][NH:9][CH:10]=1)=[O:5])[CH3:2].[H-].[Na+].[CH2:13](I)[CH:14]([CH3:16])[CH3:15].O>CN(C=O)C>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([CH2:13][CH:14]([CH3:16])[CH3:15])[CH:10]=1)=[O:5])[CH3:2]

Participants

6

Reactant 4

HCID 962WaterHCID 10556Isobutyl iodideHCID 24758Sodium hydrideHCID 142179ethyl 1H-pyrazole-4-carboxylate

Product 1

HCID 58333423Ethyl 1-(2-methylpropyl)-1H-pyrazole-4-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
0 °C

Procedure

1H-Pyrazole-4-carboxylic acid ethyl ester (5.0 g) was dissolved in DMF (50 mL), 60% sodium hydride (1.57 g) was added, and the mixture was stirred at 0° C. for 30 min. Then, isobutyl iodide (4.7 mL) was added, and the mixture was stirred for 14 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=8:2) to give 1-(2-methylpropyl)-1H-pyrazole-4-carboxylic acid ethyl ester (6.0 g) as an oil. The obtained compound was subjected to reactions in the same manner as in Reference Examples 17 to 18 to give the title compound.

Workup

  1. stirringthe mixture was stirred for 14 hr
  2. extractionthe mixture was extracted with ethyl acetate
  3. washThe organic layer was washed with water
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was purified by silica gel chromatography (elution solvent; hexane:ethyl acetate=8:2)

Sources & evidence

ORD record
ord-1528333c4fd342d4af83ac0505c44b54
Source dataset
uspto-grants-2011_09
Patent number
US08026370B2

Reaction notes

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