Lithium Hydroxide → 1-Methyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylic acid

HRID 12819Notes

Reaction equation

HRID 12819 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[N:8][N:9]([CH3:16])[C:10]=1[N:11]1[CH:15]=[CH:14][CH:13]=[CH:12]1)=[O:5])C.[Li+].[OH-]>CO.O>[CH3:16][N:9]1[C:10]([N:11]2[CH:15]=[CH:14][CH:13]=[CH:12]2)=[C:6]([C:4]([OH:5])=[O:3])[CH:7]=[N:8]1

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 2777484Ethyl 1-methyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylate

Product 1

HCID 155002461-Methyl-5-(1H-pyrrol-1-yl)-1H-pyrazole-4-carboxylic acid

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a solution of 1-methyl-5-pyrrol-1-yl-1H-pyrazole-4-carboxylic acid ethyl ester (20 g, 91.2 mmol; available from Butt Park Ltd., Camelford, Cornwall, UK) in methanol (100 mL) and water (100 mL) was added LiOH (2.4 g, 100 mmol). The reaction mixture was stirred at reflux for 4 hours and then concentrated under reduced pressure to remove the methanol. The residue was diluted with water, acidified to pH 2 with concentrated HCl (9 mL), and extracted with ethyl acetate. The combined extracts were evaporated in vacuo to give 1-methyl-5-pyrrol-1-yl-1H-pyrazole-4-carboxylic acid which was used without further purification.

Workup

  1. temperatureat reflux for 4 hours
  2. concentrationconcentrated under reduced pressure
  3. customto remove the methanol
  4. additionThe residue was diluted with water
  5. extractionextracted with ethyl acetate
  6. customThe combined extracts were evaporated in vacuo

Sources & evidence

ORD record
ord-38ba975219f44ca7a80bbe24efdc91b0
Source dataset
uspto-grants-2010_06
Patent number
US07728029B2

Reaction notes

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