Benzyloxycarbonyl-L-proline → (S)-1-Benzyl 2-methyl pyrrolidine-1,2-dicarboxylate

HRID 1648376Notes

Reaction equation

HRID 1648376 reaction equation
[C:1]([N:11]1[CH2:18][CH2:17][CH2:16][C@H:12]1[C:13]([OH:15])=[O:14])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].O.[C:20]1(C)C=CC(S(O)(=O)=O)=CC=1>CO>[N:11]1([C:1]([O:3][CH2:4][C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=2)=[O:2])[CH2:18][CH2:17][CH2:16][C@H:12]1[C:13]([O:15][CH3:20])=[O:14]

Participants

4

Reactant 2

HCID 101987Benzyloxycarbonyl-L-prolineHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 688168(S)-1-Benzyl 2-methyl pyrrolidine-1,2-dicarboxylateYield 1,884.4%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of N-Cbz-proline (140 g, 562 mmol) in methanol (850 mL) was added p-toluenesulfonic acid monohydrate (5 g, 26 mmol). The solution was heated to reflux and stirring continued for 12 h. The heating mantle was removed, and after cooling to room temperature, the solvent was removed by rotary evaporation. The residue was dissolved in ethyl acetate (500 mL), and washed twice with saturated aqueous NaHCO3 (300 mL), twice with brine (200 mL), dried with MgSO4 filtered and concentrated to give a colorless oil (129 g, 88% yield)

Workup

  1. temperatureThe solution was heated
  2. temperatureto reflux
  3. customThe heating mantle was removed
  4. customthe solvent was removed by rotary evaporation
  5. dissolutionThe residue was dissolved in ethyl acetate (500 mL)
  6. washwashed twice with saturated aqueous NaHCO3 (300 mL), twice with brine (200 mL)
  7. dry with materialdried with MgSO4
  8. filtrationfiltered
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-a01eb31551de4c5cac81b8b5460e57a3
Source dataset
uspto-grants-1995_07
Patent number
US05436229

Reaction notes

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