Hydrogen Bromide → 7alpha-Bromo-3-methyl-3-cephem-4-carboxylic acid

HRID 257804

Reaktionsgleichung

Reaktionsgleichung von HRID 257804
[CH3:1][C:2]1[CH2:11][S:10][C@@H:5]2[C@H:6](N)[C:7](=[O:8])[N:4]2[C:3]=1[C:12]([OH:14])=[O:13].C(O)C.[BrH:18].N([O-])=O.[Na+]>O>[Br:18][C@H:6]1[C:7](=[O:8])[N:4]2[C:3]([C:12]([OH:14])=[O:13])=[C:2]([CH3:1])[CH2:11][S:10][C@H:5]12

Komponenten

6

Edukt 4

HCID 260Hydrogen BromideHCID 702EthanolHCID 334987-Aminodeacetoxycephalosporanic acidHCID 23668193Sodium Nitrite

Produkt 1

HCID 152807947alpha-Bromo-3-methyl-3-cephem-4-carboxylic acidAusbeute 75,5 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 962WaterLösungsmittel

Versuchsvorschrift

To an ice-cooled mixture of 7-ADCA (10.0 g, 0.4667 mol), ethanol (270 ml), water (83 ml) and hydrobromic acid (48%, 56.7 ml), sodium nitrite (4.67 g, 0.6769 mol) was added in small portions over 25 minutes and the mixture was stirred for 2.5 hours at ice-temperature. Ethanol was removed under reduced pressure and the residual mass was diluted with methylene chloride, washed with water. The aqueous washings were saturated with brine and re-extracted with methylene chloride. The combined organic layer was washed with brine, dried over anhydrous sodium sulfate and concentrated to give 9.8 g (75.5%) of 7α-bromo-3-methyl-3-cephem-4-carboxylic acid. This crude acid was directly used for the next step without further purification.

Aufarbeitung

  1. additionwas added in small portions over 25 minutes
  2. customEthanol was removed under reduced pressure
  3. additionthe residual mass was diluted with methylene chloride
  4. washwashed with water
  5. extractionre-extracted with methylene chloride
  6. washThe combined organic layer was washed with brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationconcentrated

Quellen und Nachweise

ORD-Eintrag
ord-2d0721bf2ad44643826c3111c603ab86
Quelldatensatz
uspto-grants-1993_11
Patentnummer
US05264430

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