Hydrochloric Acid → 1-(4-fluorophenyl)-5-methyl-1H-pyrazole-4-carboxylic acid

HRID 1748426Notes

Reaction equation

HRID 1748426 reaction equation
C(O[CH:4]=[C:5]([C:11]([CH3:13])=O)[C:6]([O:8]CC)=[O:7])C.Cl.Cl.[F:16][C:17]1[CH:22]=[CH:21][C:20]([NH:23][NH2:24])=[CH:19][CH:18]=1>C(O)C>[F:16][C:17]1[CH:22]=[CH:21][C:20]([N:23]2[C:11]([CH3:13])=[C:5]([C:6]([OH:8])=[O:7])[CH:4]=[N:24]2)=[CH:19][CH:18]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 699814-Fluorophenylhydrazine hydrochlorideHCID 97734Butanoic acid, 2-(ethoxymethylene)-3-oxo-, ethyl ester

Product 1

HCID 42702631-(4-fluorophenyl)-5-methyl-1H-pyrazole-4-carboxylic acidYield 47.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To an ethanol (75 ml) solution of ethyl 2-(ethoxymethylene)acetoacetate (28.63 g) prepared according to a method described in J. Chem. Soc. Perkin trans. I, 1875 (1988), was added 1N hydrochloric acid aqueous solution (75 ml) of 4-fluorophenylhydrazine hydrochloride (25 g) and the mixture was stirred at reflux temperature for three hours. After evaporation of ethanol, sodium hydroxide (12 g) was added to the residue and stirred at reflux temperature for three hours. After completion of the reaction, the solvent was evaporated, diluted hydrochloric acid was added to the residue, and the precipitated solid was washed with ethyl acetate to give the titled compound (16.08 g).

Workup

  1. temperatureat reflux temperature for three hours
  2. customAfter evaporation of ethanol, sodium hydroxide (12 g)
  3. additionwas added to the residue
  4. stirringstirred
  5. temperatureat reflux temperature for three hours
  6. customAfter completion of the reaction
  7. customthe solvent was evaporated
  8. additiondiluted hydrochloric acid was added to the residue
  9. washthe precipitated solid was washed with ethyl acetate

Sources & evidence

ORD record
ord-176b30626a0a42ab8ca006c646ba9deb
Source dataset
uspto-grants-2015_10
Patent number
US09150555B2

Reaction notes

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