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

HRID 257807Notes

Reaction equation

HRID 257807 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 23668193Sodium NitriteHCID 67657240t-Butyl 7alpha-amino-3-methyl-3-cephem-4-carboxylate

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 7α-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-4carboxylate.

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-8e2058d19a8645c49811053e138be1e2
Source dataset
uspto-grants-1993_11
Patent number
US05264430

Reaction notes

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