Acetic Acid → 5-(4-Chlorophenyl)-2-methyl-2,4-dihydro-3H-pyrazol-3-one

HRID 1599980Notes

Reaction equation

HRID 1599980 reaction equation
[CH3:1][NH:2][NH2:3].[Cl:4][C:5]1[CH:18]=[CH:17][C:8]([C:9]([CH2:11][C:12](OCC)=[O:13])=O)=[CH:7][CH:6]=1.C(O)(=O)C.CCOCC>O>[Cl:4][C:5]1[CH:18]=[CH:17][C:8]([C:9]2[CH2:11][C:12](=[O:13])[N:2]([CH3:1])[N:3]=2)=[CH:7][CH:6]=1

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 3283Diethyl EtherHCID 6061MethylhydrazineHCID 101336Ethyl 3-(4-chlorophenyl)-3-oxopropanoate

Product 1

HCID 151450175-(4-Chlorophenyl)-2-methyl-2,4-dihydro-3H-pyrazol-3-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

71.2 g (1.55 mol) of methylhydrazine were added dropwise over the course of40 minutes to a suspension of 267 g (1.19 mol) of ethyl 4-chlorobenzoylacetate in 1.5 1 of acetic acid, the temperature rising to 50° C. The reaction solution was stirred at 100° C. for 2 hours and cooled, and then about 1.5 1 each of ether and water were added.The precipitate formed (66.5 g) was filtered off and washed with petroleum ether/ether (1:1). The organic phase was washed four times with saturated sodium hydrogen carbonate solution and concentrated, and the residue was taken up in water. Once again the precipitate formed was filtered off and washed with petroleum ether/ether (1:1). Overall yield: 171 g; m.p. 189° C.

Workup

  1. customrising to 50° C
  2. temperaturecooled
  3. customformed (66.5 g)
  4. filtrationwas filtered off
  5. washwashed with petroleum ether/ether (1:1)
  6. washThe organic phase was washed four times with saturated sodium hydrogen carbonate solution
  7. concentrationconcentrated
  8. customOnce again the precipitate formed
  9. filtrationwas filtered off
  10. washwashed with petroleum ether/ether (1:1)

Sources & evidence

ORD record
ord-6364ae8ec8bb483385a0c375f39656c4
Source dataset
uspto-grants-1998_04
Patent number
US05744426

Reaction notes

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