Sodium Hydroxide → 3H-Pyrazol-3-one, 2,4-dihydro-2,5-diphenyl-

HRID 1289881Notes

Reaction equation

HRID 1289881 reaction equation
F[C:2](F)(F)[C:3](=O)[CH2:4][C:5]([O:7]CC)=O.Cl[C:14]1[CH:19]=[C:18](Cl)[CH:17]=[CH:16][C:15]=1[NH:21][NH2:22].[OH-].[Na+]>C(O)(=O)C.O>[C:15]1([N:21]2[C:5](=[O:7])[CH2:4][C:3]([C:2]3[CH:18]=[CH:19][CH:14]=[CH:15][CH:16]=3)=[N:22]2)[CH:16]=[CH:17][CH:18]=[CH:19][CH:14]=1

Participants

6

Reactant 3

HCID 14798Sodium HydroxideHCID 67793Ethyl 4,4,4-trifluoroacetoacetateHCID 408929(2,4-Dichlorophenyl)hydrazine

Product 1

HCID 785593H-Pyrazol-3-one, 2,4-dihydro-2,5-diphenyl-Yield 171.5%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

To a mixture of ethyl trifluoroacetoacetate (5.0 g, 27.2 mmol) in acetic acid (50 mL) was added 2,4-dichlorophenylhydrazine (4.82 g, 27.2 mmol). The reaction mixture was refluxed for 22 hours and then was diluted with water (50 mL), neutralized with 2N NaOH and extracted with EtOAc (3×50 mL). The EtOAc extracts were combined, dried over Na2 SO4, filtered and concentrated to afford 5.51 g (70%) of 2,4-dihydro-2-(2,4-dichlorophenyl)-5-trifluoromethyl-3H-pyrazol-3-one (Formula III: R1 =2,4-Cl2 --Ph; R2 =CF3 ; R3 =H).

Workup

  1. temperatureThe reaction mixture was refluxed for 22 hours
  2. extractionextracted with EtOAc (3×50 mL)
  3. customdried over Na2 SO4
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-0509b6896ab3457e9cbb47d3aab486e4
Source dataset
uspto-grants-1998_05
Patent number
US05750550

Reaction notes

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