Potassium Hydroxide → 3-Iodo-1-methyl-1H-pyrazole-4-carboxylic acid

HRID 2246764Notes

Reaction equation

HRID 2246764 reaction equation
[I:1][C:2]1[C:6]([C:7]([O:9]CC)=[O:8])=[CH:5][N:4]([CH3:12])[N:3]=1.[OH-].[K+]>C(O)C.O>[I:1][C:2]1[C:6]([C:7]([OH:9])=[O:8])=[CH:5][N:4]([CH3:12])[N:3]=1

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 19754674HCID 19754674, compound

Product 1

HCID 114140693-Iodo-1-methyl-1H-pyrazole-4-carboxylic acidYield 73.1%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

134 g (0.478 mol) of ethyl 3-iodo-1-methyl-1H-pyrazole-4-carboxylate were initially charged in 850 ml of ethanol, and a solution of 29.5 g (0.526 mol) of KOH in 340 ml of water was added dropwise. After 2 days of stirring at room temperature, the mixture was concentrated, the residue was taken up in water and extracted with ethyl acetate and, after separation, the aqueous phase was adjusted to pH 1 using hydrochloric acid, resulting in the precipitation of a solid. Filtration with suction and 3 hours of drying under reduced pressure at 40° C. gave 88 g (70% of theory) of 3-iodo-1-methyl-1H-pyrazole-4-carboxylic acid [logP (pH 2.3)=0.57]. The aqueous phase was extracted with ethyl acetate and the organic phase was concentrated, which gave another 5.1 g (2.1% of theory) of product.

Workup

  1. concentrationthe mixture was concentrated
  2. extractionextracted with ethyl acetate
  3. customafter separation
  4. customresulting in the precipitation of a solid
  5. filtrationFiltration with suction and 3 hours
  6. customof drying under reduced pressure at 40° C.

Sources & evidence

ORD record
ord-6270d343f18d44afb80d3142d16c3a50
Source dataset
uspto-grants-2010_03
Patent number
US07687531B2

Reaction notes

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