L-Methionine → Cbz-L-methionine methyl ester

HRID 58387Notes

Reaction equation

HRID 58387 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. customto partition
  3. washThe organic phase was washed sequentially with 1M hydrochloric acid, saturated aqueous sodium hydrogen bicarbonate and brine
  4. dry with materialbefore being dried (MgSO4)
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto afford a yellow oil, 5.40 g, 98%

Sources & evidence

ORD record
ord-5cb80fc450934bafb6832fa71e00a402
Source dataset
uspto-grants-2016_09
Patent number
US09434762B2

Reaction notes

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