Phosphorus oxybromide → pentyl 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-1H-pyrazole-5-carboxylate

HRID 1641453

Reaktionsgleichung

Reaktionsgleichung von HRID 1641453
[Cl:1][C:2]1[C:3]([N:8]2[CH:12]([C:13]([O:15][CH2:16][CH2:17][CH2:18][CH2:19][CH3:20])=[O:14])[CH2:11][C:10](=O)[NH:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1.P(Br)(Br)([Br:24])=O.C(=O)([O-])O.[Na+]>C(#N)C>[Br:24][C:10]1[CH2:11][CH:12]([C:13]([O:15][CH2:16][CH2:17][CH2:18][CH2:19][CH3:20])=[O:14])[N:8]([C:3]2[C:2]([Cl:1])=[CH:7][CH:6]=[CH:5][N:4]=2)[N:9]=1

Komponenten

5

Edukt 3

HCID 24613Phosphorus oxybromideHCID 516892Sodium BicarbonateHCID 59549450Pentyl 2-(3-chloro-2-pyridinyl)-5-oxopyrazolidine-3-carboxylate

Produkt 1

HCID 59549455pentyl 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-1H-pyrazole-5-carboxylateAusbeute 137,5 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6342AcetonitrileLösungsmittel

Versuchsvorschrift

A mixed solution comprising 1.2 g of pentyl 2-(3-chloropyridin-2-yl)-5-oxopyrazolidine-3-carboxylate, 0.59 g of phosphorus oxybromide and 18 ml of acetonitrile was gradually heated, and 25 minutes later, the mixed solution was refluxed with heating for one hour. After the reaction liquid was stood to cool, it was slowly added to a saturated sodium hydrogen carbonate aqueous solution, followed by stirring for 5 minutes. The mixed liquid was subjected to extraction with ethyl acetate, and the organic layer was washed with a sodium chloride aqueous solution and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=9/1 to 8/2) to obtain 1.06 g of the desired product (melting point: 39 to 42° C.) in the form of pale yellow crystals.

Aufarbeitung

  1. temperaturewas gradually heated
  2. temperature25 minutes later, the mixed solution was refluxed
  3. temperaturewith heating for one hour
  4. customAfter the reaction liquid
  5. temperatureto cool
  6. extractionThe mixed liquid was subjected to extraction with ethyl acetate
  7. washthe organic layer was washed with a sodium chloride aqueous solution
  8. dry with materialdried over anhydrous sodium sulfate
  9. distillationThe solvent was distilled off under reduced pressure
  10. customthe residue was purified by silica gel column chromatography (eluent: n-hexane/ethyl acetate=9/1 to 8/2)

Quellen und Nachweise

ORD-Eintrag
ord-b47c9ea67e0f4747a6b5cd6689948e58
Quelldatensatz
uspto-grants-2012_02
Patentnummer
US08115006B2

Verknüpfte Notizen

Wird geladen…