Methanol → (S)-Methyl 1-methylpyrrolidine-2-carboxylate

HRID 744933Notes

Reaction equation

HRID 744933 reaction equation
[CH3:1][N:2]1[CH2:9][CH2:8][CH2:7][C@H:3]1[C:4]([OH:6])=[O:5].S(Cl)(Cl)=O.[CH3:14]O>>[CH3:14][O:5][C:4](=[O:6])[C@@H:3]1[CH2:7][CH2:8][CH2:9][N:2]1[CH3:1]

Participants

4

Reactant 3

HCID 887MethanolHCID 24386Thionyl ChlorideHCID 643474N-Methyl-L-proline

Product 1

HCID 10920622(S)-Methyl 1-methylpyrrolidine-2-carboxylate

Procedure

To a solution of N-methyl (L)-proline, from step 3a, in methanol at 0° C. is added thionyl chloride (1.1 eq) dropwise, and the reaction mixture is slowly allowed to warm to room temperature. Upon completion of the reaction the solvent is removed in vacuo, and the crude product is dissolved in 10% aq. HCl and washed with ether. The aqueous layer is adjusted to pH ~12 with K2CO3 (solid) and extracted with CH2Cl2. The combined CH2Cl2 layers are dried (MgSO4) and concentrated to afford the crude product as a clear oil.

Workup

  1. customUpon completion of the reaction the solvent
  2. customis removed in vacuo
  3. dissolutionthe crude product is dissolved in 10% aq. HCl
  4. washwashed with ether
  5. extractionextracted with CH2Cl2
  6. dry with materialThe combined CH2Cl2 layers are dried (MgSO4)
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-b1a677f5d50b4e05afcb615a489fefdc
Source dataset
uspto-grants-1996_09
Patent number
US05559242

Reaction notes

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