Lithium Hydroxide → 3-tert-butyl-1-(2-(dimethylamino)ethyl)-1H-pyrazole-5-carboxylic acid

HRID 1930344Notes

Reaction equation

HRID 1930344 reaction equation
[C:1]([C:5]1[CH:9]=[C:8]([C:10]([O:12]CC)=[O:11])[N:7]([CH2:15][CH2:16][N:17]([CH3:19])[CH3:18])[N:6]=1)([CH3:4])([CH3:3])[CH3:2].[Li+].[OH-]>C1COCC1>[C:1]([C:5]1[CH:9]=[C:8]([C:10]([OH:12])=[O:11])[N:7]([CH2:15][CH2:16][N:17]([CH3:19])[CH3:18])[N:6]=1)([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 3939Lithium HydroxideHCID 59588870ethyl 3-tert-butyl-1-(2-(dimethylamino)ethyl)-1H-pyrazole-5-carboxylate

Product 1

HCID 667292533-tert-butyl-1-(2-(dimethylamino)ethyl)-1H-pyrazole-5-carboxylic acidYield 29%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a solution of ethyl 3-tert-butyl-1-(2-(dimethylamino)ethyl)-1H-pyrazole-5-carboxylate (0.47 g, 1.8 mmol) in THF (10 mL) was added aqueous LiOH (0.22 g, 5.3 mmol, 5 mL) and mixture was stirred for 16 h at RT. Solvents were removed, the thick liquid was diluted with water (5 mL) and acidified with 50% aq. acetic acid solution to pH 5-6. The product was extracted with EtOAc (2×50 ml) and the combined organics were washed with brine, dried (Na2SO4) and concentrated in vacuo to afford 3-tert-butyl-1-(2-(dimethylamino)ethyl)-1H-pyrazole-5-carboxylic acid as a pasty mass (0.12 g, 29% yield). 1H NMR (400 MHz, DMSO-d6): δ 6.56 (s, 1H), 4.66 (t, J=6.0 Hz, 2H), 3.17 (t, J=6.0 Hz, 2H), 2.53 (s, 6H), 1.17 (s, 9H); MS (ESI) m/z: 240.3 (M+H+).

Workup

  1. customSolvents were removed
  2. additionthe thick liquid was diluted with water (5 mL)
  3. extractionThe product was extracted with EtOAc (2×50 ml)
  4. washthe combined organics were washed with brine
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-21abd031b2a24637a6d3051ae047cca5
Source dataset
uspto-grants-2012_05
Patent number
US08188113B2

Reaction notes

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