Ethyl 3-(2-fluorophenyl)-3-oxopropanoate → 2,5-bis(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one

HRID 449948Notes

Reaction equation

HRID 449948 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8](=O)[CH2:9][C:10]([O:12]CC)=O.Cl.[F:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][C:19]=1[NH:24][NH2:25]>C(O)(=O)C>[F:17][C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][C:19]=1[N:24]1[C:10](=[O:12])[CH2:9][C:8]([C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[F:1])=[N:25]1

Participants

4

Reactant 2

HCID 296342Ethyl 3-(2-fluorophenyl)-3-oxopropanoateHCID 2723910Hydrazine, (2-fluorophenyl)-, hydrochloride (1:1)

Product 1

HCID 671115152,5-bis(2-fluorophenyl)-2,4-dihydro-3H-pyrazol-3-one

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
135 °C

Procedure

Ethyl 3-(2-fluorophenyl)-3-oxopropanoate (2.5 g, 12 mmol) and 2-fluorophenyl hydrazine hydrochloride (1.5 g, 12 mmol, 1.0 equiv) were dissolved in acetic acid (24 mL) and placed into a preheated oil bath at 120° C. for 3 hours and then heated for an additional 2 hours at 135° C. The mixture was cooled to ambient temperature, concentrated in vacuo and then concentrated once from toluene (1×25 mL). The residue was suspended in dichloromethane, filtered and the solid was washed once with dichloromethane and dried in vacuo, providing the titled compound. The resulting filtrate was concentrated in vacuo and purified by silica gel gradient chromatography (100:0 to 65:35; hexanes:ethyl acetate), providing additional titled compound as a light brown solid.

Workup

  1. temperatureThe mixture was cooled to ambient temperature
  2. concentrationconcentrated in vacuo
  3. concentrationconcentrated once from toluene (1×25 mL)
  4. filtrationfiltered
  5. washthe solid was washed once with dichloromethane
  6. customdried in vacuo

Sources & evidence

ORD record
ord-8f63ecb72bec425c99891c0290a2ace5
Source dataset
uspto-grants-2013_07
Patent number
US08486946B2

Reaction notes

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