4-Toluenesulfonyl chloride → 1-(toluene-4-sulfonyl)-1H-pyrazole-4-carboxylic acid ethyl ester

HRID 1698228Notes

Reaction equation

HRID 1698228 reaction equation
[NH:1]1[CH:5]=[C:4]([C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH:3]=[N:2]1.[H-].[Na+].[C:13]1([CH3:23])[CH:18]=[CH:17][C:16]([S:19](Cl)(=[O:21])=[O:20])=[CH:15][CH:14]=1>C1COCC1.[NH4+].[Cl-]>[CH2:9]([O:8][C:6]([C:4]1[CH:5]=[N:1][N:2]([S:19]([C:16]2[CH:17]=[CH:18][C:13]([CH3:23])=[CH:14][CH:15]=2)(=[O:21])=[O:20])[CH:3]=1)=[O:7])[CH3:10]

Participants

6

Reactant 3

HCID 73974-Toluenesulfonyl chlorideHCID 24758Sodium hydrideHCID 142179ethyl 1H-pyrazole-4-carboxylate

Product 1

HCID 216282771-(toluene-4-sulfonyl)-1H-pyrazole-4-carboxylic acid ethyl ester

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 25517Ammonium ChlorideSolvent

Procedure

To a solution of ethyl 1H-pyrazole-4-carboxylate (4.50 g, 32.11 mmol) in THF was added 60% NaH (1.60 g, 40.00 mmol) in mineral oil. After 20 minutes, p-toluenesulfonyl chloride was added. After 3 hours, the mixture was diluted with saturated aqueous NH4Cl and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulfate and concentrated in vacuo. The residue was purified by silica gel chromatography eluting with 30-50% ethyl acetate in heptane. The major fractions were combined and the solvent was concentrated in vacuo to afford 1-(toluene-4-sulfonyl)-1H-pyrazole-4-carboxylic acid ethyl ester.

Workup

  1. waitAfter 3 hours
  2. extractionextracted with ethyl acetate
  3. washThe combined organic layers were washed with brine
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated in vacuo
  6. customThe residue was purified by silica gel chromatography
  7. washeluting with 30-50% ethyl acetate in heptane
  8. concentrationthe solvent was concentrated in vacuo

Sources & evidence

ORD record
ord-9a46e27047a14552b9aff93c77300e72
Source dataset
uspto-grants-2012_04
Patent number
US08163918B2

Reaction notes

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