Lithium Hydroxide → 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylic acid

HRID 1930338Notes

Reaction equation

HRID 1930338 reaction equation
[CH:1]([N:4]1[C:8]([C:9]([O:11]CC)=[O:10])=[CH:7][C:6]([C:14]2[S:15][CH:16]=[CH:17][CH:18]=2)=[N:5]1)([CH3:3])[CH3:2].[Li+].[OH-]>C1COCC1>[CH:1]([N:4]1[C:8]([C:9]([OH:11])=[O:10])=[CH:7][C:6]([C:14]2[S:15][CH:16]=[CH:17][CH:18]=2)=[N:5]1)([CH3:3])[CH3:2]

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 59826475ethyl 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylate

Product 1

HCID 690359331-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylic acidYield 88.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylate (0.88 g, 3.3 mmol) in THF (10 mL) was added aq. LiOH solution (0.42 g, 10 mmol, 5 mL) and the mixture was stirred for 16 h at RT. Solvents were removed and the thick liquid was diluted with water (5 mL) and acidified with 3M HCl solution to pH 4-5. The product precipitated and was filtered, washed with water and dried to afford 1-isopropyl-3-(thiophen-2-yl)-1H-pyrazole-5-carboxylic acid as a white solid (0.69 g, 88% yield).

Workup

  1. customSolvents were removed
  2. additionthe thick liquid was diluted with water (5 mL)
  3. customThe product precipitated
  4. filtrationwas filtered
  5. washwashed with water
  6. customdried

Sources & evidence

ORD record
ord-fa757c7508754405892e4d59cabf9e31
Source dataset
uspto-grants-2012_05
Patent number
US08188113B2

Reaction notes

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