Pyridine → 2-[2-(4-Fluorophenyl)acetyl]-4-(4-nitro-phenoxycarbonyloxy)-pyrazolidine-1-carboxylic acid benzyl ester

HRID 7662

Reaktionsgleichung

Reaktionsgleichung von HRID 7662
[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH:14]([OH:16])[CH2:13][N:12]1[C:17](=[O:26])[CH2:18][C:19]1[CH:24]=[CH:23][C:22]([F:25])=[CH:21][CH:20]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl[C:28]([O:30][C:31]1[CH:36]=[CH:35][C:34]([N+:37]([O-:39])=[O:38])=[CH:33][CH:32]=1)=[O:29].N1C=CC=CC=1>ClCCl.O>[CH2:1]([O:8][C:9]([N:11]1[CH2:15][CH:14]([O:16][C:28]([O:30][C:31]2[CH:32]=[CH:33][C:34]([N+:37]([O-:39])=[O:38])=[CH:35][CH:36]=2)=[O:29])[CH2:13][N:12]1[C:17](=[O:26])[CH2:18][C:19]1[CH:24]=[CH:23][C:22]([F:25])=[CH:21][CH:20]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Komponenten

6

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

2-[2-(4-Fluorophenyl)acetyl]-4-hydroxy-pyrazolidine-1-carboxylic acid benzyl ester, 38, (366 mg, 1.02 mmol) is dissolved in dichloromethane (10 mL). The solution is cooled to 0° C. and p-nitrophenyl chloroformate (411 mg, 2.04 mmol) is added in one portion. The solution is stirred at 0° C., and pyridine (198 μL, 2.45 mmol) added. Stirring is continued at 0° C. for 1 hour followed by stirring at room temperature for 12 hours. The reaction is diluted with water (40 mL) and extracted with dichloromethane (40 mL). The organic layer is washed with 0.5 N NaOH (2×40 mL). The combined aqueous layers are back-extracted extracted with dichloromethane (30 mL). The combined organic layers are washed with brine (30 mL), dried, filtered, and concentrated in vacuo. The crude material is purified over silica (3:1 to 2:1 to 1:1 hexane/ethyl acetate) to afford 462 mg (86% yield) of the desired product as a white foam.

Aufarbeitung

  1. stirringStirring
  2. stirringby stirring at room temperature for 12 hours
  3. extractionextracted with dichloromethane (40 mL)
  4. washThe organic layer is washed with 0.5 N NaOH (2×40 mL)
  5. extractionThe combined aqueous layers are back-extracted
  6. extractionextracted with dichloromethane (30 mL)
  7. washThe combined organic layers are washed with brine (30 mL)
  8. customdried
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe crude material is purified over silica (3:1 to 2:1 to 1:1 hexane/ethyl acetate)

Quellen und Nachweise

ORD-Eintrag
ord-07899571ac004176a04f3732b5db25f0
Quelldatensatz
uspto-grants-2006_08
Patentnummer
US07087615B2

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