L-Valine → N-Carbobenzoxy-L-valine

HRID 2185659Notes

Reaction equation

HRID 2185659 reaction equation
[NH2:1][C@H:2]([C:6]([OH:8])=[O:7])[CH:3]([CH3:5])[CH3:4].[CH2:9]([O:16][C:17](Cl)=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1>[OH-].[K+]>[CH2:9]([O:16][C:17]([NH:1][C@H:2]([C:6]([OH:8])=[O:7])[CH:3]([CH3:5])[CH3:4])=[O:18])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1

Participants

4

Reactant 2

HCID 6287L-ValineHCID 10387Benzyl chloroformate

Product 1

HCID 726987N-Carbobenzoxy-L-valine

Reagents, catalysts & solvents 1

HCID 14797Potassium HydroxideSolvent2×

Conditions

Temperature
0 °C

Procedure

10 g of L-valine (85 mmol) are dissolved in 4 M KOH (40 ml) and the mixture is cooled in ice. 21.9 g of benzyloxycarbonyl chloride (128 mmol) are added thereto over 5 minutes and a white solid forms. The mixture is stirred at 0° C. for one hour, the temperature is then allowed to rise and stirring is continued for another hour at room temperature. The reaction mixture is then diluted with 4 M KOH (200 ml) and is extracted with ether (2×100 ml). The aqueous phase is then brought to an acidic pH<1 with concentrated hydrochloric acid and is then extracted with ethyl acetate (3×200 ml). The extracts are combined and dried (Na2SO4) and the solvent is evaporated off. A clear oil is obtained.

Workup

  1. temperaturethe mixture is cooled in ice
  2. stirringstirring
  3. waitis continued for another hour at room temperature
  4. extractionis extracted with ether (2×100 ml)
  5. extractionis then extracted with ethyl acetate (3×200 ml)
  6. dry with materialdried (Na2SO4)
  7. customthe solvent is evaporated off
  8. customA clear oil is obtained

Sources & evidence

ORD record
ord-a4d670abb51d42b5bc8edcd3cf9ba88d
Source dataset
uspto-grants-2002_06
Patent number
US06403561B1

Reaction notes

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