Hydrochloric Acid → 3-Phenyl-4,5-dihydro-1H-pyrazole-5-carboxylic acid

HRID 27447Notes

Reaction equation

HRID 27447 reaction equation
[C:1]([CH:9]=[CH:10][C:11]([OH:13])=[O:12])(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[NH2:14][NH2:15].[OH-].[K+].Cl>C(O)C>[C:2]1([C:1]2[CH2:9][CH:10]([C:11]([OH:13])=[O:12])[NH:15][N:14]=2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 9321HydrazineHCID 14797Potassium HydroxideHCID 94714Beta-benzoylacrylic acid

Product 1

HCID 131023953-Phenyl-4,5-dihydro-1H-pyrazole-5-carboxylic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 10.0 g of 3-benzoylacrylic acid, 1.8 g of hydrazine, and 3.7 g of potassium hydroxide in 30 ml. of aqueous ethanol (1:1) is stirred and heated at reflux for 2 hours. The cooled solution is treated with 5 ml of concentrated hydrochloric acid to pH 4.0 to precipitate 7.1 g of solid, melting point 180°-182° C. This material is dissolved in 40 ml of warm dimethylformamide and treated wit 140 ml of methanol to crystallize 3.9 g of the title compound, melting point 199°-201° C.

Workup

  1. temperatureheated
  2. temperatureat reflux for 2 hours
  3. customto precipitate 7.1 g of solid, melting point 180°-182° C
  4. dissolutionThis material is dissolved in 40 ml of warm dimethylformamide
  5. additiontreated wit 140 ml of methanol
  6. customto crystallize 3.9 g of the title compound, melting point 199°-201° C.

Sources & evidence

ORD record
ord-d22c92c21305491290c1eb55e997b07c
Source dataset
uspto-grants-1980_09
Patent number
US04221804

Reaction notes

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