Sodium Hydroxide → 1-Methyl-3-(difluoromethyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid

HRID 626276Notes

Reaction equation

HRID 626276 reaction equation
C([O:3][C:4]([C:6]1[C:7]([CH:16]([F:18])[F:17])=[N:8][N:9]([CH3:15])[C:10]=1[C:11]([F:14])([F:13])[F:12])=[O:5])C.[OH-].[Na+]>C(O)C>[CH3:15][N:9]1[C:10]([C:11]([F:12])([F:13])[F:14])=[C:6]([C:4]([OH:5])=[O:3])[C:7]([CH:16]([F:18])[F:17])=[N:8]1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 897336901-Methyl-3-(difluoromethyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid ethyl ester

Product 1

HCID 717702521-Methyl-3-(difluoromethyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acidYield 98%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

N-Methyl-3-difluoromethyl-5-trifluoromethyl-4-pyrazolecarboxylic acid ethyl ester (0.5 g, 1.84 mmol) in ethanol (3 ml) was admixed gradually with an 8N aqueous sodium hydroxide solution (0.7 ml) and stirred at room temperature for 3 h. The solvent was removed by rotary evaporation; the residue was taken up in water (10 ml) and extracted with diethyl ether (10 ml). Acidification to pH 1 with 1M HCl was followed by extraction with ethyl acetate (3×10 ml). The combined organic phases were dried over sodium sulphate and filtered, and the solvent was removed by rotary evaporation. N-Methyl-3-difluoromethyl-5-trifluoromethyl-4-pyrazolecarboxylic acid (0.44 g, 1.80 mmol, 98%) was isolated as a yellowish solid.

Workup

  1. customThe solvent was removed by rotary evaporation
  2. extractionextracted with diethyl ether (10 ml)
  3. extractionAcidification to pH 1 with 1M HCl was followed by extraction with ethyl acetate (3×10 ml)
  4. dry with materialThe combined organic phases were dried over sodium sulphate
  5. filtrationfiltered
  6. customthe solvent was removed by rotary evaporation

Sources & evidence

ORD record
ord-db80b35c431c48c988faccec9d67dbe9
Source dataset
uspto-grants-2016_04
Patent number
US09309202B2

Reaction notes

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