Toluene → Ethyl N-(oxomethylidene)phenylalaninate

HRID 2205426Notes

Reaction equation

HRID 2205426 reaction equation
Cl.[CH2:2]([O:4][C:5](=[O:15])[C@H:6]([CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[NH2:7])[CH3:3].[C:16](=O)(O)[O-:17].[Na+].C(Cl)(Cl)=O.C1(C)C=CC=CC=1>C(Cl)Cl>[CH2:2]([O:4][C:5](=[O:15])[CH:6]([N:7]=[C:16]=[O:17])[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[CH3:3]

Participants

6

Reactant 4

HCID 1140TolueneHCID 6371PhosgeneHCID 165085Ethyl L-phenylalaninate hydrochlorideHCID 516892Sodium Bicarbonate

Product 1

HCID 12370705Ethyl N-(oxomethylidene)phenylalaninateYield 95%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To an ice-cold suspension of L-phenylalanine ethyl ester hydrochloride (25.0 g, 109 mmol) in methylene chloride (800 mL) a saturated solution of sodium bicarbonate (800 mL) was added and the mixture was vigorously stirred at 0° C. for 30 minutes. Stirring was stopped to allow the separation of the two layers and a solution of phosgene in toluene (20%, 100 mL, 190 mmol) was added directly into the organic layer. Stirring was resumed while keeping the mixture at 0° C. for one hour and at room temperature for one additional hour. The organic layer was separated, and washed sequentially with water and a saturated solution of sodium chloride, dried with sodium sulphate, filtered and evaporated to yield a colorless oil that slowly solidifies (22.7 g, 95% yield).

Workup

  1. additionwas added
  2. stirringStirring
  3. customthe separation of the two layers
  4. stirringStirring
  5. customat 0° C.
  6. customfor one hour
  7. customat room temperature
  8. customThe organic layer was separated
  9. washwashed sequentially with water
  10. dry with materiala saturated solution of sodium chloride, dried with sodium sulphate
  11. filtrationfiltered
  12. customevaporated
  13. customto yield a colorless oil that

Sources & evidence

ORD record
ord-463d829998f442d7b9873b1e771d17af
Source dataset
uspto-grants-2016_06
Patent number
US09371299B2

Reaction notes

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