L-Methionine → Cbz-L-methionine methyl ester

HRID 2371332Notes

Reaction equation

HRID 2371332 reaction equation
[NH2:1][C@H:2]([C:7]([OH:9])=[O:8])[CH2:3][CH2:4][S:5][CH3:6].[C:10](=O)(O)O.[Na].Cl[C:16]([O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=[O:17]>CCOC(C)=O.O>[CH3:10][O:8][C:7](=[O:9])[C@@H:2]([NH:1][C:16]([O:18][CH2:19][C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1)=[O:17])[CH2:3][CH2:4][S:5][CH3:6]

Participants

6

Reactant 3

HCID 6137L-MethionineHCID 10387Benzyl chloroformateHCID 24192197Carbonic acid, sodium salt

Product 1

HCID 11141035Cbz-L-methionine methyl ester

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8857Ethyl AcetateSolvent

Procedure

L-methionine (3.70 g, 18.5 mmol) was dissolved in a biphasic mixture of EtOAc (75 mL) and water (75 mL). This was cooled in ice and sodium hydrogen bicarbonate (7.78 g, 5 equiv) and benzyl chloroformate (2.98 mL, 1.1 equiv) were added. This was stirred in ice for one h and then at rt for a further eighteen h before the mixture was allowed to partition. The organic phase was washed sequentially with 1M hydrochloric acid, saturated aqueous sodium hydrogen bicarbonate and brine before being dried (MgSO4), filtered and concentrated in vacuo to afford a yellow oil, 5.40 g, 98%.

Workup

  1. temperatureThis was cooled in ice
  2. customat rt
  3. customto partition
  4. washThe organic phase was washed sequentially with 1M hydrochloric acid, saturated aqueous sodium hydrogen bicarbonate and brine
  5. dry with materialbefore being dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customto afford a yellow oil, 5.40 g, 98%

Sources & evidence

ORD record
ord-7e458bc07f8e4fd492e5bf2c3483b50d
Source dataset
uspto-grants-2014_04
Patent number
US08710178B2

Reaction notes

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