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

HRID 1393043Notes

Reaction equation

HRID 1393043 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 (Maybridge plc, Cornwall, UK; 20 g, 91.2 mmol) in methanol (100 mL) and water (100 mL) was added LiOH (2.4 g, 100.3 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-19c5a7ab9ab44e339c32927f6c6b21de
Source dataset
uspto-grants-2008_03
Patent number
US07345058B2

Reaction notes

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