Sodium Hydroxide → N-tert-Butyl-3,5-di(difluoromethyl)-4-pyrazolecarboxylic acid

HRID 626288Notes

Reaction equation

HRID 626288 reaction equation
C([O:3][C:4]([C:6]1[C:7]([CH:18]([F:20])[F:19])=[N:8][N:9]([C:14]([CH3:17])([CH3:16])[CH3:15])[C:10]=1[CH:11]([F:13])[F:12])=[O:5])C.[OH-].[Na+]>C(O)C>[C:14]([N:9]1[C:10]([CH:11]([F:12])[F:13])=[C:6]([C:4]([OH:5])=[O:3])[C:7]([CH:18]([F:20])[F:19])=[N:8]1)([CH3:17])([CH3:15])[CH3:16]

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 71770124N-tert-Butyl-3,5-di(difluoromethyl)-4-pyrazolecarboxylic acid ethyl ester

Product 1

HCID 71770373N-tert-Butyl-3,5-di(difluoromethyl)-4-pyrazolecarboxylic acidYield 97.4%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

N-tert-Butyl-3,5-di(difluoromethyl)-4-pyrazolecarboxylic acid ethyl ester (3.40 g, 11.5 mmol) in ethanol (23 ml) was admixed gradually with an 8N aqueous sodium hydroxide solution (4.3 ml) and stirred at room temperature for 3 h. The solvent was removed by rotary evaporation; the residue was taken up in water (40 ml) and extracted with diethyl ether (20 ml). Acidification to pH 1 with 6M HCl was followed by extraction with ethyl acetate (3×30 ml). The combined organic phases were dried over sodium sulphate and filtered, and the solvent was removed by rotary evaporation. N-tert-Butyl-3,5-di(difluoromethyl)-4-pyrazolecarboxylic acid (3.0 g, 11.2 mmol, 97%) was isolated as a pale reddish solid.

Workup

  1. customThe solvent was removed by rotary evaporation
  2. extractionextracted with diethyl ether (20 ml)
  3. extractionAcidification to pH 1 with 6M HCl was followed by extraction with ethyl acetate (3×30 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-cb0fc5017ba544bd87e323219bdac265
Source dataset
uspto-grants-2016_04
Patent number
US09309202B2

Reaction notes

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