Ethyl benzoylacetate → 2-(3,5-Dichloro-phenyl)-5-phenyl-2,4-dihydro-pyrazol-3-one

HRID 2187398Notes

Reaction equation

HRID 2187398 reaction equation
[C:1]([CH2:9][C:10]([O:12]CC)=O)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl.[Cl:16][C:17]1[CH:18]=[C:19]([NH:24][NH2:25])[CH:20]=[C:21]([Cl:23])[CH:22]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)C>[Cl:16][C:17]1[CH:18]=[C:19]([N:24]2[C:10](=[O:12])[CH2:9][C:1]([C:2]3[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=3)=[N:25]2)[CH:20]=[C:21]([Cl:23])[CH:22]=1

Participants

5

Reactant 3

HCID 7170Ethyl benzoylacetateHCID 521998p-Toluenesulfonic acid monohydrateHCID 2723913(3,5-Dichlorophenyl)hydrazine monohydrochloride

Product 1

HCID 120499692-(3,5-Dichloro-phenyl)-5-phenyl-2,4-dihydro-pyrazol-3-oneYield 57%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethyl benzoylacetate (0.192 g, 1.00 mmol), 3,5-dichlorophenylhydrazine hydrochloride (0.235 g, 1.10 mmol), and p-toluenesulfonic acid monohydrate (0.019 g, 0.10 mmol) in ethanol (10 mL) was heated at reflux for 24 hours. The reaction solution was concentrated and the resulting residue was partitioned between ethyl acetate and aqueous 1N hydrochloric acid solution. The organic layer was further washed with water and brine, dried (sodium sulfate) and concentrated to afford a yellow solid. The crude product was triturated with hexanes and collected by suction filtration. Air drying afforded 0.174 g (57%) of product as a bright yellow solid: 1H NMR (DMSO-d6) δ12.60-12.40 (br s, 1H), 7.92 (s, 2H), 7.87-7.83 (d, 2H), 7.50 (s, 1H), 7.44-7.38 (m, 2H), 7.36-7.31 (m, 1H), 6.02 (s, 1H) ppm.

Workup

  1. temperatureat reflux for 24 hours
  2. concentrationThe reaction solution was concentrated
  3. customthe resulting residue was partitioned between ethyl acetate and aqueous 1N hydrochloric acid solution
  4. washThe organic layer was further washed with water and brine
  5. dry with materialdried (sodium sulfate)
  6. concentrationconcentrated
  7. customto afford a yellow solid
  8. customThe crude product was triturated with hexanes
  9. filtrationcollected by suction filtration
  10. customAir drying

Sources & evidence

ORD record
ord-291e57aaa3304f20bada8d4c01da3006
Source dataset
uspto-grants-2002_06
Patent number
US06410533B1

Reaction notes

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