Hydrogen Bromide → 4-Bromo-1-(2,4,6-trichlorophenyl)-3-(trifluoromethyl)-1H-pyrazole

HRID 2352415Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 2352415
[Br:1][C:2](=[CH:9]OCC)[C:3](=O)[C:4]([F:7])([F:6])[F:5].[Cl:13][C:14]1[CH:19]=[C:18]([Cl:20])[CH:17]=[C:16]([Cl:21])[C:15]=1[NH:22][NH2:23].Br>C(O)C>[Br:1][C:2]1[C:3]([C:4]([F:5])([F:6])[F:7])=[N:23][N:22]([C:15]2[C:16]([Cl:21])=[CH:17][C:18]([Cl:20])=[CH:19][C:14]=2[Cl:13])[CH:9]=1

Komponenten

5

Edukt 3

HCID 260Hydrogen BromideHCID 79234(2,4,6-Trichlorophenyl)hydrazineHCID 37290783-Buten-2-one, 3-bromo-4-ethoxy-1,1,1-trifluoro-

Produkt 1

HCID 142741934-Bromo-1-(2,4,6-trichlorophenyl)-3-(trifluoromethyl)-1H-pyrazoleAusbeute 30,4 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 702EthanolLösungsmittel

Versuchsvorschrift

2.3 g (0.01 mole) of 3-bromo-4-ethoxy-1,1,1-trifluorobut-3-en-2-one are added to a solution of 4.2 g (0.02 mol) of 2,4,6-trichlorophenyl-hydrazine in 100 ml of ethanol which contains 0.01 mole hydrogen bromide. The mixture is refluxed for 5 hours and then concentrated under reduced pressure, and ice water is added to the residue. Extraction with dichloromethane, washing with saturated sodium chloride solution until neutral, clarification over anhydrous sodium sulphate and concentration gives 4.6 g of a crude product, which is chromatographed on 120 g of silica gel using toluene/petroleum ether (ratio 1:1). 1.2 g of 4-bromo-1-(2,4,6-trichloro-phenyl)-3-trifluoromethylpyrazole of melting point 93°-94° C. (from petroleum ether) are obtained.

Aufarbeitung

  1. temperatureThe mixture is refluxed for 5 hours
  2. concentrationconcentrated under reduced pressure, and ice water
  3. additionis added to the residue
  4. extractionExtraction with dichloromethane
  5. washwashing with saturated sodium chloride solution until neutral, clarification
  6. concentrationover anhydrous sodium sulphate and concentration
  7. customgives 4.6 g of a crude product, which
  8. customis chromatographed on 120 g of silica gel

Quellen und Nachweise

ORD-Eintrag
ord-e323f4fb137046658e9e11a4e3f5af54
Quelldatensatz
uspto-grants-1989_10
Patentnummer
US04876393

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