N-Bromoacetamide → 4beta-Bromo-24,24-difluoro-25-hydroxy-5beta-cholestan-3-one

HRID 894497

Reaktionsgleichung

Reaktionsgleichung von HRID 894497
[F:1][C:2]([F:31])([CH2:7][CH2:8][C@H:9]([C@@H:11]1[C@:28]2([CH3:29])[C@H:14]([C@H:15]3[C@H:25]([CH2:26][CH2:27]2)[C@:23]2([CH3:24])[C@@H:18]([CH2:19][C@H:20]([OH:30])[CH2:21][CH2:22]2)[CH2:17][CH2:16]3)[CH2:13][CH2:12]1)[CH3:10])[C:3]([OH:6])([CH3:5])[CH3:4].[Br:32]NC(=O)C.C(OCC)(=O)C>C(O)(C)(C)C.O.Br>[Br:32][C@H:19]1[C:20](=[O:30])[CH2:21][CH2:22][C@@:23]2([CH3:24])[C@@H:18]1[CH2:17][CH2:16][C@@H:15]1[C@@H:25]2[CH2:26][CH2:27][C@@:28]2([CH3:29])[C@H:14]1[CH2:13][CH2:12][C@@H:11]2[C@H:9]([CH3:10])[CH2:8][CH2:7][C:2]([F:31])([F:1])[C:3]([OH:6])([CH3:4])[CH3:5]

Komponenten

7

Edukt 3

HCID 4353N-BromoacetamideHCID 8857Ethyl AcetateHCID 7056520124,24-Difluoro-5beta-cholestane-3alpha,25-diol

Produkt 1

HCID 705633804beta-Bromo-24,24-difluoro-25-hydroxy-5beta-cholestan-3-one

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 260Hydrogen BromideLösungsmittelHCID 962WaterLösungsmittelHCID 6386tert-ButanolLösungsmittel

Versuchsvorschrift

To a solution of 800 mg of 24,24-difluoro-5β-cholestane-3α,25-diol (Va) in 32 ml of tert-butyl alcohol, 15 ml of water, 200 μl of 48% hydrobromic acid and 800 mg of N-bromoacetamide were added. After stirring at room temperature for 3 days, ethyl acetate was added to the reaction mixture, which was then washed sequentially with 0.5% aqueous sodium thiosulfate and saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the resulting residue was purified through a short column (5 g of silica gel) to produce 950 mg of a crude product. The product was recrystallized from ether/hexane to produce 4β-bromo-24,24-difluoro-25-hydroxy-5β-cholestan-3-one.

Aufarbeitung

  1. washwas then washed sequentially with 0.5% aqueous sodium thiosulfate and saturated aqueous sodium chloride
  2. dry with materialdried over anhydrous magnesium sulfate
  3. distillationThe solvent was distilled off
  4. customthe resulting residue was purified through a short column (5 g of silica gel)
  5. customto produce 950 mg of a crude product
  6. customThe product was recrystallized from ether/hexane

Quellen und Nachweise

ORD-Eintrag
ord-c452aa94590643a2baa50b2333c11f4b
Quelldatensatz
uspto-grants-1981_08
Patentnummer
US04284577

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