Hydrochloric Acid → N-(Carbobenzyloxy)-DL-proline

HRID 1170507Notes

Reaction equation

HRID 1170507 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[NH:12]1[CH2:16][CH2:15][CH2:14][CH:13]1[C:17]([OH:19])=[O:18].Cl>[OH-].[Na+]>[CH2:5]([O:4][C:2]([N:12]1[CH2:16][CH2:15][CH2:14][CH:13]1[C:17]([OH:19])=[O:18])=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 614proline dl-formHCID 10387Benzyl chloroformate

Product 1

HCID 232388N-(Carbobenzyloxy)-DL-prolineYield 93.1%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
0 °C

Procedure

Benzyl chloroformate (29.7 g, 174 mmol) was added dropwise to a 0° C. solution of Pyrrolidine-2-carboxylic acid (20.0 g, 174 mmol) dissolved in 1N NaOH (350 mL). The solution was stirred at 0° C. for 30 mins. The solution was allowed to equilibrate to room temperature while stirring overnight. The solution was acidified to pH=3 by addition of 1M HCl. The resulting solution was extracted with ethyl acetate (3×300 mL). The organic layers were combined, dried over MgSO4 and concentrated under vacuo to afford 40.4 g (89%) of the crude product, pyrrolidine-1,2-dicarboxylic acid 1-benzyl ester, as a colorless oil.

Workup

  1. customto equilibrate to room temperature
  2. stirringwhile stirring overnight
  3. extractionThe resulting solution was extracted with ethyl acetate (3×300 mL)
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated under vacuo

Sources & evidence

ORD record
ord-c0bf72c1d7944cf2afd66ab748724131
Source dataset
uspto-grants-2010_11
Patent number
US07825256B2

Reaction notes

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