Phenylhydrazine → 3,5-Dimethyl-1-phenyl-pyrazol-4-acetic acid methyl ester

HRID 615001Notes

Reaction equation

HRID 615001 reaction equation
[H-].[Na+].C(CC(=O)C)(=O)C.[H][H].COC(=O)CBr.[CH3:18][O:19][C:20](=[O:29])[CH2:21][CH:22]([C:26](=O)[CH3:27])[C:23](=O)[CH3:24].[C:30]1([NH:36][NH2:37])[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=1>CN(C)C=O.C(O)C.C(O)(=O)C>[CH3:18][O:19][C:20](=[O:29])[CH2:21][C:22]1[C:26]([CH3:27])=[N:37][N:36]([C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)[C:23]=1[CH3:24]

Participants

10

Reactant 6

HCID 7516PhenylhydrazineHCID 24758Sodium hydrideHCID 31261AcetylacetoneHCID 60984Methyl bromoacetateHCID 11469331Methyl 3-acetyl-4-oxopentanoateHCID 178418361HCID 178418361, compound

Product 1

HCID 205426823,5-Dimethyl-1-phenyl-pyrazol-4-acetic acid methyl esterYield 52%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 702EthanolSolventHCID 6228DimethylformamideSolvent

Procedure

10 grams of a 50% suspension of sodium hydride in paraffin oil were dispersed in 100 milliliters dimethyl formamide and to the dispersion, thus obtained, 20 grams acetylacetone were added drop by drop. After completion of the evolution of hydrogen, 31 grams bromoacetic acid methyl ester were added dropwise with stirring to the reaction mixture at room temperature and the mixture was stirred for another 15 hours. The solvent was then distilled off, the residue was taken up in ether, and the ether solution extracted with water. By distillation of the ether solution 26 grams of crude 3,3-diacetylpropionic acid-methyl ester having a Kp10 of 112°-117° C. were obtained. The distilled 3,3-diacetyl-propionic acid methylester was reacted with 16.5 grams phenylhydrazine and 9 grams glacial acetic acid in 100 milliliters ethanol and the reaction product was recovered by the method described in Example (1a) above. 28 grams of crude 3,5-dimethyl-1-phenyl-pyrazol-4-acetic acid methyl ester were obtained, which, after recrystallization from a mixture of ethanol and wter, melted at 63°-64° C.

Workup

  1. customthus obtained
  2. stirringthe mixture was stirred for another 15 hours
  3. distillationThe solvent was then distilled off
  4. extractionthe ether solution extracted with water
  5. distillationBy distillation of the ether solution 26 grams of crude 3,3-diacetylpropionic acid-methyl ester having a Kp10 of 112°-117° C.
  6. customwere obtained
  7. customthe reaction product was recovered by the method

Sources & evidence

ORD record
ord-1db2b6a895ef4d83b27d9e3bc2e055bf
Source dataset
uspto-grants-1979_03
Patent number
US04146721

Reaction notes

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