Potassium Hydroxide → Antipyric acid

HRID 1662029Notes

Reaction equation

HRID 1662029 reaction equation
[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([CH:8]=[O:9])[C:4](=[O:10])[N:3]1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.[O-:17][Mn](=O)(=O)=O.[K+].[OH-].[K+]>O>[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([C:8]([OH:17])=[O:9])[C:4](=[O:10])[N:3]1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

5

Reactant 3

HCID 14797Potassium HydroxideHCID 703712,3-Dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazole-4-carbaldehydeHCID 516875Potassium Permanganate

Product 1

HCID 246564Antipyric acidYield 88.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
75 °C

Procedure

To a mixture of 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde (2 g, 9.25 mmol) in water (100 mL) at 75° C. is added a solution of KMnO4 (1.5 g, 9.49 mmol) in water (200 mL) slowly. After the addition is complete, the reaction mixture is stirred at 75° C. for another 1 hour. Solid KOH is added to make the solution alkaline and the mixture is filtered while it is hot. To the filtrate is added EtOH (10 mL) and EtOAc (50 mL). The organic phase is separated and discarded. The aqueous phase is acidified with concentrated HCl to pH 5 and extracted with EtOAc (60 mL) and DCM (60 mL). The organic phases are combined, dried, and concentrated to give the title product (1.9 g, 88.46%yield). MS (m/z): 233.1 (M+H).

Workup

  1. additionAfter the addition
  2. filtrationthe mixture is filtered while it
  3. additionTo the filtrate is added EtOH (10 mL) and EtOAc (50 mL)
  4. customThe organic phase is separated
  5. extractionextracted with EtOAc (60 mL) and DCM (60 mL)
  6. customdried
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-7573574d9f7448c488f836f38b9fd9c8
Source dataset
uspto-grants-2011_10
Patent number
US08030302B2

Reaction notes

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