Potassium trimethylsilanolate → 1-(4-cyanophenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid

HRID 1799437Notes

Reaction equation

HRID 1799437 reaction equation
C[Si](C)(C)[O-].[K+].[C:7]([C:9]1[CH:14]=[CH:13][C:12]([N:15]2[C:19]([C:20]([F:23])([F:22])[F:21])=[C:18]([C:24]([O:26]CC)=[O:25])[CH:17]=[N:16]2)=[CH:11][CH:10]=1)#[N:8]>C1COCC1>[C:7]([C:9]1[CH:14]=[CH:13][C:12]([N:15]2[C:19]([C:20]([F:21])([F:22])[F:23])=[C:18]([C:24]([OH:26])=[O:25])[CH:17]=[N:16]2)=[CH:11][CH:10]=1)#[N:8]

Participants

4

Reactant 2

HCID 23668039Potassium trimethylsilanolateHCID 59516077ethyl 1-(4-cyanophenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate2×

Product 1

HCID 432594381-(4-cyanophenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acidYield 73.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Potassium trimethylsilanolate (3.32 g, 23.28 mmol) was added in one portion to ethyl 1-(4-cyanophenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (Intermediate #126) (2.4 g, 7.76 mmol), in THF (50 mL), under nitrogen. The resulting suspension was stirred at room temperature for 3 hours. The reaction mixture was evaporated to dryness and redissolved in EtOAc (100 mL), and washed sequentially with 0.1M HCl (50 mL), water (50 mL), and saturated brine (50 mL). The organic layer was dried over MgSO4, filtered and evaporated to afford crude product. The crude solid was triturated with isohexane to give a solid which was collected by filtration and dried under vacuum to give 1-(4-cyanophenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acid (1.600 g, 73.3%) as a orange solid. Used directly in next stage.

Workup

  1. customThe reaction mixture was evaporated to dryness
  2. dissolutionredissolved in EtOAc (100 mL)
  3. washwashed sequentially with 0.1M HCl (50 mL), water (50 mL), and saturated brine (50 mL)
  4. dry with materialThe organic layer was dried over MgSO4
  5. filtrationfiltered
  6. customevaporated
  7. customto afford crude product
  8. customThe crude solid was triturated with isohexane
  9. customto give a solid which
  10. filtrationwas collected by filtration
  11. customdried under vacuum

Sources & evidence

ORD record
ord-84443da759354c7a92f3043ce7267fa7
Source dataset
uspto-grants-2013_01
Patent number
US08344016B2

Reaction notes

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