Lithium Hydroxide → 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acid

HRID 886697Notes

Reaction equation

HRID 886697 reaction equation
[NH2:1][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][C:10]([F:13])=[CH:9][CH:8]=2)[N:5]=[CH:4][C:3]=1[C:14]([O:16]CC)=[O:15].[OH-].[Li+]>C(O)C.O>[NH2:1][C:2]1[N:6]([C:7]2[CH:8]=[CH:9][C:10]([F:13])=[CH:11][CH:12]=2)[N:5]=[CH:4][C:3]=1[C:14]([OH:16])=[O:15]

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 688689ethyl 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate

Product 1

HCID 52068325-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acidYield 95.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

To a suspension of ethyl 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate (12.1 g, 48.5 mmol) in ethanol (250 ml) was added a solution of lithium hydroxide (5.8 g, 242 mmol) in water (100 ml). The mixture was stirred at reflux for 2.5 hours. It was allowed to cool and concentrated to 50% of its volume before 5M hydrochloric acid (47 ml) was added. After stirring for 15 minutes, the resulting white solid was filtered off and further 5M hydrochloric acid (3 ml) was added to the filtrate and the resulting solid was filtered and the combined solids were washed with water and diethyl ether and then dried under vacuum to give the title compound (10.27 g).

Workup

  1. temperatureat reflux for 2.5 hours
  2. temperatureto cool
  3. concentrationconcentrated to 50% of its volume before 5M hydrochloric acid (47 ml)
  4. additionwas added
  5. stirringAfter stirring for 15 minutes
  6. filtrationthe resulting white solid was filtered off
  7. additionfurther 5M hydrochloric acid (3 ml) was added to the filtrate
  8. filtrationthe resulting solid was filtered
  9. washthe combined solids were washed with water and diethyl ether
  10. customdried under vacuum

Sources & evidence

ORD record
ord-9bccad98c3b14e1aa97e40f6a9b1dabf
Source dataset
uspto-grants-2012_08
Patent number
US08247377B2

Reaction notes

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