Lithium Hydroxide → 5-chloro-1-[2-(2-methoxyethoxy)-ethyl]-1H-pyrazole-4-carboxylic acid

HRID 12903Notes

Reaction equation

HRID 12903 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([CH2:12][CH2:13][O:14][CH2:15][CH2:16][O:17][CH3:18])[C:10]=1[Cl:11])=[O:5])C.[OH-].[Li+]>CO.O>[Cl:11][C:10]1[N:9]([CH2:12][CH2:13][O:14][CH2:15][CH2:16][O:17][CH3:18])[N:8]=[CH:7][C:6]=1[C:4]([OH:5])=[O:3]

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 670210545-chloro-1-[2-(2-methoxyethoxy)-ethyl]-1H-pyrazole-4-carboxylic acid ethyl ester

Product 1

HCID 670209495-chloro-1-[2-(2-methoxyethoxy)-ethyl]-1H-pyrazole-4-carboxylic acidYield 86%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution of 5-chloro-1-[2-(2-methoxyethoxy)-ethyl]-1H-pyrazole-4-carboxylic acid ethyl ester (3.43 g, 12.39 mmol) in methanol (12 mL) and water (12 mL) was added lithium hydroxide (415 mg, 17.3 mmol). The reaction mixture was stirred at reflux for 3 h, and then the solution was concentrated under reduced pressure to remove the methanol. The residue was then acidified carefully with 6.0 N aqueous HCl. The resulting mixture was extracted with methylene chloride (3×50 mL). The combined organic extracts were dried over anhydrous Na2SO4, filtered and concentrated in vacuo to provide 5-chloro-1-[2-(2-methoxyethoxy)-ethyl]-1H-pyrazole-4-carboxylic acid as a white solid (2.65 g, 86%). Mass spectrum: m/z: 249.0 (M+1).

Workup

  1. temperatureat reflux for 3 h
  2. concentrationthe solution was concentrated under reduced pressure
  3. customto remove the methanol
  4. extractionThe resulting mixture was extracted with methylene chloride (3×50 mL)
  5. dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-acf29b7818fc4efe8cc6442094fd10f1
Source dataset
uspto-grants-2010_06
Patent number
US07728029B2

Reaction notes

Loading…