D-Proline → (S)-N-isobutoxycarbonylproline

HRID 1014987Notes

Reaction equation

HRID 1014987 reaction equation
Cl[C:2]([O:4][CH2:5][CH:6]([CH3:8])[CH3:7])=[O:3].[NH:9]1[CH2:16][CH2:15][CH2:14][C@@H:10]1[C:11]([OH:13])=[O:12].C(=O)(O)[O-].[Na+]>CC(C)=O.O>[CH2:5]([O:4][C:2]([N:9]1[CH2:16][CH2:15][CH2:14][C@H:10]1[C:11]([OH:13])=[O:12])=[O:3])[CH:6]([CH3:8])[CH3:7].[CH2:5]([O:4][C:2]([N:9]1[CH2:16][CH2:15][CH2:14][C@@H:10]1[C:11]([OH:13])=[O:12])=[O:3])[CH:6]([CH3:8])[CH3:7]

Participants

7

Reactant 3

HCID 8988D-ProlineHCID 62365Isobutyl chloroformateHCID 516892Sodium Bicarbonate

Product 2

HCID 774279(S)-N-isobutoxycarbonylprolineHCID 774280(R)-N-isobutoxycarbonylproline

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

A solution of isobutyl chloroformate (4.4 mL, 34.04 mmol) in acetone is added dropwise to a solution of L- or D-proline (4.0 g, 34.74 mmol) and sodium bicarbonate (10 g, 125 mmol) in water (50 mL). The mixture is stirred overnight. After removal of acetone, the aqueous solution is acidified to pH 2 with hydrochloric acid while maintaining the temperature below 20° C., and then extracted with ethyl acetate (3×25 mL). The combined organic phase is dried over anhydrous magnesium sulfate and evaporated in vacuo to give (S)-N-isobutoxycarbonylproline (from L-proline) or (R)-N-isobutoxycarbonylproline (from D-proline) correspondingly, as colorless oil.

Workup

  1. customAfter removal of acetone
  2. temperaturewhile maintaining the temperature below 20° C.
  3. extractionextracted with ethyl acetate (3×25 mL)
  4. dry with materialThe combined organic phase is dried over anhydrous magnesium sulfate
  5. customevaporated in vacuo

Sources & evidence

ORD record
ord-873579ac87c04e6b98f7008cabdddae2
Source dataset
uspto-grants-2011_07
Patent number
US07985753B2

Reaction notes

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