p-Toluenesulfonic acid → Stk074598

HRID 443597

Reaction equation

HRID 443597 reaction equation
[C:1]1([N:7]2[C:11](=[O:12])[CH:10]=[C:9]([CH3:13])[NH:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C1(C)C=CC(S(O)(=O)=O)=CC=1.[C:25](OC(=O)C)(=[O:27])[CH3:26]>>[C:1]1([N:7]2[C:11](=[O:12])[C:10]([C:25](=[O:27])[CH3:26])=[C:9]([CH3:13])[NH:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

4

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 7918Acetic AnhydrideHCID 703351H-Pyrazol-5-ol, 3-methyl-1-phenyl-

Product 1

HCID 495593Stk074598

Procedure

174 g of 1-phenyl-3-methyl-pyrazol-5-one in 700 ml of acetic anhydride, with the addition of 6 g of p-toluenesulphonic acid, are heated to the boil under reflux for 6 hours. The solvent is then distilled off under a water-pump vacuum, the residue is dissolved hot in 2 l of 5% strength sodium hydroxide solution, the solution is clarified with 8 g of active charcoal, the filtrate is acidified with hydrochloric acid at room temperature and the crystalline precipitate is filtered off, washed with water and dried in vacuo at 40° C. 183 g of 1-phenyl-3-methyl-4-acetyl-pyrazol-5-one are obtained in the form of colourless crystal needles.

Workup

  1. temperatureare heated to the boil
  2. temperatureunder reflux for 6 hours
  3. distillationThe solvent is then distilled off under a water-pump vacuum
  4. dissolutionthe residue is dissolved hot in 2 l of 5% strength sodium hydroxide solution
  5. customis acidified with hydrochloric acid at room temperature
  6. filtrationthe crystalline precipitate is filtered off
  7. washwashed with water
  8. customdried in vacuo at 40° C

Sources & evidence

ORD record
ord-123f5fbc0e454a2988b953380176fc5f
Source dataset
uspto-grants-1981_04
Patent number
US04260776

Linked notes

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