Acetic Acid → 1-Methyl-3,5-diphenyl-pyrazol-4-acetic acid

HRID 615013Notes

Reaction equation

HRID 615013 reaction equation
C([O:3][C:4](=[O:23])[CH2:5][CH:6]([C:15](=O)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)[C:7](=O)[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)C.[CH3:24][NH:25][NH2:26].C(O)(=O)C.[OH-].[Na+]>O.C(O)C>[CH3:24][N:25]1[C:15]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[C:6]([CH2:5][C:4]([OH:3])=[O:23])[C:7]([C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)=[N:26]1

Participants

7

Reactant 4

HCID 176Acetic AcidHCID 6061MethylhydrazineHCID 14798Sodium HydroxideHCID 108524383,3-Dibenzoylpropionic acid ethyl ester

Product 1

HCID 205427631-Methyl-3,5-diphenyl-pyrazol-4-acetic acidYield 67%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

6.2 grams 3,3-dibenzoyl-propionic acid-ethyl ester, 1.0 gram methyl hydrazine and 4 grams glacial acetic acid were mixed and the mixture heated to the boiling temperature under reflux for 4 hours. The reaction mixture was then evaporated, the residue taken upon benzene and extracted with water. The benzene was then distilled from the benzene phase and the residue, constituting the crude ester reaction product, was heated with 2.0 grams sodium hydroxide, 20 milliliters ethanol and 20 milliliters water to the boiling temperature under reflux for 2 hours. The reaction mixture was then worked up and the reaction product was recovered by the general procedure set out in Example (2a). The recovered free acid was recrystallized from a mixture of benzene and petroleum ether boiling in a range from 50°-70° C. 3.9 grams 1-methyl-3,5-diphenyl-pyrazol-4-acetic acid, melting at 170°-172° C., were obtained, representing a yield of 67%.

Workup

  1. temperaturethe mixture heated to the boiling temperature
  2. temperatureunder reflux for 4 hours
  3. customThe reaction mixture was then evaporated
  4. extractionextracted with water
  5. distillationThe benzene was then distilled from the benzene phase
  6. customthe crude ester reaction product
  7. temperatureunder reflux for 2 hours
  8. customthe reaction product was recovered by the general procedure
  9. customThe recovered free acid was recrystallized from a mixture of benzene and petroleum ether boiling in a range from 50°-70° C

Sources & evidence

ORD record
ord-f0ad8b6f264b48e9ad5d2907c8bcbdbd
Source dataset
uspto-grants-1979_03
Patent number
US04146721

Reaction notes

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