2-Methyl-2-butene → 1,2-dimethyl-3-oxo-5-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylic acid

HRID 1851097Notes

Reaction equation

HRID 1851097 reaction equation
[CH3:1][N:2]1[C:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[C:5]([CH:13]=[O:14])[C:4](=[O:15])[N:3]1[CH3:16].CC(=CC)C.Cl([O-])=[O:23].[Na+].P([O-])([O-])[O-].[K+].[K+].[K+]>C(O)(C)(C)C.O>[CH3:1][N:2]1[C:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)=[C:5]([C:13]([OH:23])=[O:14])[C:4](=[O:15])[N:3]1[CH3:16]

Participants

7

Reactant 4

HCID 105532-Methyl-2-buteneHCID 9837043phosphorous acid, tripotassium saltHCID 23668197Sodium ChloriteHCID 583683381,2-dimethyl-3-oxo-5-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde

Product 1

HCID 583683541,2-dimethyl-3-oxo-5-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylic acidYield 35%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 6386tert-ButanolSolvent

Procedure

1,2-Dimethyl-3-oxo-5-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde was dissolved in t-butyl alcohol (23.5 mL) and 2-methyl-2-butene (8.3 mL, 78.5 mmol) was added at 0° C. After adding an aqueous solution of sodium chlorite (80% tech, 0.95 g, 8.7 mmol) in water (10 mL) and a suspension of potassium phosphite monobasic (3.44 g, 25.3 mmol) in water (23.5 mL) to the resulting reaction mixture, the mixture was stirred at room temperature for 10 hours. After adding water to the stirred reaction mixture, the aqueous layer was extracted with ethyl acetate, dichloromethane and 10:1 dichloromethane/methanol. The organic layer was collected, dried with sodium sulfate, and then filtered. The filtrate was concentrated. The resulting residue was washed with a small volume of ethyl acetate to give the target compound as a white solid (350 mg, 1.5 mmol, 35% yield).

Workup

  1. customto the resulting reaction mixture
  2. customto the stirred reaction mixture
  3. extractionthe aqueous layer was extracted with ethyl acetate, dichloromethane and 10:1 dichloromethane/methanol
  4. customThe organic layer was collected
  5. dry with materialdried with sodium sulfate
  6. filtrationfiltered
  7. concentrationThe filtrate was concentrated
  8. washThe resulting residue was washed with a small volume of ethyl acetate

Sources & evidence

ORD record
ord-180f36689ade41aeb65c09a954826100
Source dataset
uspto-grants-2015_02
Patent number
US08957102B2

Reaction notes

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