Carbon tetrabromide → Methyl (S)-2-(Boc-amino)-4-bromobutyrate

HRID 909197Notes

Reaction equation

HRID 909197 reaction equation
[CH3:1][O:2][C:3](=[O:16])[C@@H:4]([NH:8][C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:6]O.C(Br)(Br)(Br)[Br:18].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>ClCCl>[CH3:1][O:2][C:3](=[O:16])[C@@H:4]([NH:8][C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:6][Br:18]

Participants

5

Reactant 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 10561607Methyl N-(tert-butoxycarbonyl)-L-homoserinate

Product 1

HCID 10685328Methyl (S)-2-(Boc-amino)-4-bromobutyrateYield 76%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled (0° C.) solution of (S)-2-tert-butoxycarbonylamino-4-hydroxy-butyric acid methyl ester (28.7 g, 123 mmol) in dichloromethane (500 mL) was added CBr4 (51.0 g, 154 mmol). The mixture was stirred for 5 minutes before the portion-wise addition of triphenylphosphine (48.41 g, 185 mmol). The mixture continued to stir at 0° C. for 1 hour and was then allowed to warm to room temperature. The solvent was removed under reduced pressure and was then diluted with ether (500 mL) and stirred for 30 minutes. The mixture was filtered, and the filtrate was concentrated under reduced pressure. The residue was chromatographed eluting with ether/hexanes (1:2) to afford 27.5 g of white solid (76% yield).

Workup

  1. temperatureto warm to room temperature
  2. customThe solvent was removed under reduced pressure
  3. additionwas then diluted with ether (500 mL)
  4. stirringstirred for 30 minutes
  5. filtrationThe mixture was filtered
  6. concentrationthe filtrate was concentrated under reduced pressure
  7. customThe residue was chromatographed
  8. washeluting with ether/hexanes (1:2)

Sources & evidence

ORD record
ord-872e654fd7284595a6d3dab6cca97e21
Source dataset
uspto-grants-2011_09
Patent number
US08017641B2

Reaction notes

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