Sodium Hydroxide → 5-(3-methylbutyl)-1H-pyrazole-3-carboxylic Acid

HRID 1724757Notes

Reaction equation

HRID 1724757 reaction equation
[OH-].[Na+].C([O:5][C:6]([C:8]1[CH:12]=[C:11]([CH2:13][CH2:14][CH:15]([CH3:17])[CH3:16])[NH:10][N:9]=1)=[O:7])C>CO>[CH3:16][CH:15]([CH3:17])[CH2:14][CH2:13][C:11]1[NH:10][N:9]=[C:8]([C:6]([OH:7])=[O:5])[CH:12]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 574350915-(3-methylbutyl)-1H-pyrazole-3-carboxylic Acid Ethyl Ester

Product 1

HCID 118456535-(3-methylbutyl)-1H-pyrazole-3-carboxylic AcidYield 97.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Freshly prepared aq. NaOH (10 M in H2O, 80.85 mmol) was added to a stirring, room temperature solution of 47 (3.40 g, 16.17 mmol) in MeOH (40.4 mL, 0.4 M) under N2. The reaction was then heated to reflux until the reaction was judged complete by HPLC (6 min): The reaction was concentrated and then dissolved in 14 mL H2O. 10% aq. HCl was added dropwise until the pH=2. The white solid that precipitated from the reaction was filtered off and washed with cold H2O. The solid was dried under vacuum overnight to obtain 2.8753 g (97.6%) of 48. (Note: An undesired impurity has a retention time of 9.522 min by HPLC.) 1H (CDCl3, 400 MHz): δ 6.61(1H, s), 2.70 (2H, t, J=7.8Hz), 1.63-1.51 (3H, m), 0.94 (6H, d, J=6.3 Hz) ppm. 13C (CDCl3, 100 MHz): δ 164.35, 149.48, 143.00, 107.34 28.71, 24.69, 22.65 ppm. DEPT (CDCl3, 100 MHz): CH3 carbons: 22.65; CH2 carbons: 39.35, 24.69; CH carbons: 107.34, 28.71 ppm. HPLC: 9.522 min.

Workup

  1. temperatureThe reaction was then heated
  2. temperatureto reflux until the reaction
  3. customwas judged complete by HPLC (6 min)
  4. concentrationThe reaction was concentrated
  5. dissolutiondissolved in 14 mL H2O
  6. addition10% aq. HCl was added dropwise until the pH=2
  7. customThe white solid that precipitated from the reaction
  8. filtrationwas filtered off
  9. washwashed with cold H2O
  10. customThe solid was dried under vacuum overnight

Sources & evidence

ORD record
ord-e0de39b18ece4728b029c0246783f5a2
Source dataset
uspto-grants-2009_02
Patent number
US07488747B2

Reaction notes

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