Allyl bromide → (R)-3-Allylsulfanyl-2-tert-butoxycarbonylamino-propionic acid methyl ester

HRID 58369Notes

Reaction equation

HRID 58369 reaction equation
[CH3:1][O:2][C:3](=[O:15])[C@H:4]([CH2:13][SH:14])[NH:5][C:6]([O:8][C:9]([CH3:12])([CH3:11])[CH3:10])=[O:7].C(N(CC)CC)C.[CH2:23](Br)[CH:24]=[CH2:25].CCOC(C)=O>C(Cl)Cl>[CH3:1][O:2][C:3](=[O:15])[C@@H:4]([NH:5][C:6]([O:8][C:9]([CH3:12])([CH3:10])[CH3:11])=[O:7])[CH2:13][S:14][CH2:25][CH:24]=[CH2:23]

Participants

6

Reactant 4

HCID 7841Allyl bromideHCID 8471TriethylamineHCID 8857Ethyl AcetateHCID 10977409N-(tert-Butoxycarbonyl)-L-cysteine methyl ester

Product 1

HCID 86650241(R)-3-Allylsulfanyl-2-tert-butoxycarbonylamino-propionic acid methyl ester

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

N-BOC-cysteine methyl ester (obtained from Sigma-Aldrich, Auckland, New Zealand) (5.00 g, 21.2 mmol) was dissolved in anhydrous DCM (30 mL) under an atmosphere of argon. Triethylamine (3.26 mL, 23.3 mmol) and allyl bromide (2.02 mL, 23.3 mmol) were added. The reaction mixture was stirred at rt for eighteen h before being concentrated in vacuo. The residue was partitioned between EtOAc and 1M hydrochloric acid. The organic phase was washed with brine, dried (MgSO4), filtered and concentrated in vacuo. The crude material was purified by flash chromatography on silica using a gradient of EtOAc and (50/70) petroleum ether to yield a white solid, 3.22 g, 55%. Rf=0.19 (1/5 (EtOAc/(50/70) petroleum ether).

Workup

  1. concentrationbefore being concentrated in vacuo
  2. customThe residue was partitioned between EtOAc and 1M hydrochloric acid
  3. washThe organic phase was washed with brine
  4. dry with materialdried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe crude material was purified by flash chromatography on silica using a gradient of EtOAc and (50/70) petroleum ether
  8. customto yield a white solid, 3.22 g, 55%

Sources & evidence

ORD record
ord-68428e25de1344bea5eea15db92de253
Source dataset
uspto-grants-2016_09
Patent number
US09434762B2

Reaction notes

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