Hydrogen Bromide → t-Butyl 7alpha-bromo-3-methyl-3-cephem-4carboxylate

HRID 258000Notes

Reaction equation

HRID 258000 reaction equation
N[C@@H:2]1[C:17](=[O:18])[N:4]2[C:5]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])=[C:6]([CH3:9])[CH2:7][S:8][C@H:3]12.[BrH:19].N([O-])=O.[Na+].[Cl-].[Na+]>O.C(O)C>[Br:19][C@H:2]1[C:17](=[O:18])[N:4]2[C:5]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])=[C:6]([CH3:9])[CH2:7][S:8][C@H:3]12

Participants

7

Reactant 4

HCID 260Hydrogen BromideHCID 5234Sodium ChlorideHCID 10869362t-Butyl 7beta-amino-3-methyl-3-cephem-4-carboxylateHCID 23668193Sodium Nitrite

Product 1

HCID 67656826t-Butyl 7alpha-bromo-3-methyl-3-cephem-4carboxylateYield 50%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 962WaterSolvent

Procedure

To an ice-cooled mixture of t-butyl 7β-amino-3-methyl-3-cephem-4-carboxylate (1.3 g, 0.0048 mol), ethanol (30 ml), water (8.5 ml), hydrobromic acid (48%, 5.83 ml), sodium nitrite (0.48 g, 0.00696 mol) was added portionwise over 15 minutes and the mixture was stirred at ice-temperature (-5° C.) for 3 hours, saturated with sodium chloride, extracted with ethyl acetate (3 times). The combined ethyl acetate extract was washed with water, brine, dried and concentrated to give 800 mg (50%) of pure t-butyl 7α-bromo-3-methyl-3-cephem-4-carboxylate.

Workup

  1. additionwas added portionwise over 15 minutes
  2. extractionextracted with ethyl acetate (3 times)
  3. extractionThe combined ethyl acetate extract
  4. washwas washed with water, brine
  5. customdried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-182cdb962c75484b91715d8f91ccd4cd
Source dataset
uspto-grants-1993_11
Patent number
US05264429

Reaction notes

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