Pyrazole → Ethyl 4-(1H-pyrazol-1-YL)benzoate

HRID 1883202Notes

Reaction equation

HRID 1883202 reaction equation
[NH:1]1[CH:5]=[CH:4][CH:3]=[N:2]1.[H-].[Na+].F[C:9]1[CH:19]=[CH:18][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][CH:10]=1>CS(C)=O>[N:1]1([C:9]2[CH:19]=[CH:18][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][CH:10]=2)[CH:5]=[CH:4][CH:3]=[N:2]1

Participants

5

Reactant 3

HCID 1048PyrazoleHCID 24758Sodium hydrideHCID 67976Benzoic acid, 4-fluoro-, ethyl ester

Product 1

HCID 973146Ethyl 4-(1H-pyrazol-1-YL)benzoateYield 79.3%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

Under nitrogen atmosphere, a solution of pyrazole (2.43 g) in DMSO (90 mL) was cooled to 0° C., and thereto was added successively NaH (1.57 g, 60%), and the mixture was stirred at room temperature for 30 minutes. To the mixture was added ethyl 4-fluorobenzoate (6.00 g) and the mixture was stirred at 110-120° C. for 20 hours. The mixture was cooled to room temperature, and thereto was added ice water (150 mL). The mixture was extracted twice with ethyl acetate, and dried over MgSO4. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column (hexane/ethyl acetate=50/3→50/4) to give ethyl 4-(1H-pyrazol-1-yl)benzoate (6.12 g, 79%).

Workup

  1. stirringthe mixture was stirred at 110-120° C. for 20 hours
  2. temperatureThe mixture was cooled to room temperature
  3. extractionThe mixture was extracted twice with ethyl acetate
  4. dry with materialdried over MgSO4
  5. customThe solvent was evaporated under reduced pressure
  6. customthe residue was purified by silica gel column (hexane/ethyl acetate=50/3→50/4)

Sources & evidence

ORD record
ord-81c7eaac9b354e7fa65fc69b4f90d30e
Source dataset
uspto-grants-2004_07
Patent number
US06759429B2

Reaction notes

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