Ethyl 4,4,4-trifluoroacetoacetate → 3H-Pyrazol-3-one, 2,4-dihydro-2,5-diphenyl-

HRID 1289859Notes

Reaction equation

HRID 1289859 reaction equation
F[C:2](F)(F)[C:3](=O)[CH2:4][C:5]([O:7]CC)=O.Cl.Cl[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][C:16]=1[NH:21][NH2:22]>C(O)(=O)C>[C:16]1([N:21]2[C:5](=[O:7])[CH2:4][C:3]([C:2]3[CH:19]=[CH:20][CH:15]=[CH:16][CH:17]=3)=[N:22]2)[CH:17]=[CH:18][CH:19]=[CH:20][CH:15]=1

Participants

4

Reactant 2

HCID 67793Ethyl 4,4,4-trifluoroacetoacetateHCID 4432872-Chlorophenylhydrazine hydrochloride

Product 1

HCID 785593H-Pyrazol-3-one, 2,4-dihydro-2,5-diphenyl-Yield 93.7%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 5 g (27.2 mmol) of ethyl trifluoroacetoacetate and 4.86 g (27.2 mmol) of 2-chlorophenylhydrazine hydrochloride in 50 ml of acetic acid was heated at 100° C. with stirring overnight. The mixture was concentrated in vacuo (70° C.), the residue was disolved in methanol and concentrated in vacuo. The residue was triturated in methylene chloride, cooled (0° C.), and the white solid was filtered to afford 3.01 g (42%) of 2,4-dihydro-2-(2-chlorophenyl)-5-trifluoromethyl-3H-pyrazol-3-one (Formula III: R1 =2-Cl--Ph; R2 =CF3 ; R3=H) as a white solid.

Workup

  1. concentrationThe mixture was concentrated in vacuo (70° C.)
  2. concentrationconcentrated in vacuo
  3. customThe residue was triturated in methylene chloride
  4. temperaturecooled (0° C.)
  5. filtrationthe white solid was filtered

Sources & evidence

ORD record
ord-4cfa821e27b14a23a677f57f507bb852
Source dataset
uspto-grants-1998_05
Patent number
US05750550

Reaction notes

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