Methyl iodide → (+/-)-Methyl N,N'-dibenzyloxycarbonylpiperazine-2-carboxylate

HRID 618775Notes

Reaction equation

HRID 618775 reaction equation
[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][N:14]([C:17]([O:19][CH2:20][C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)=[O:18])[CH2:13][CH:12]1[C:27]([OH:29])=[O:28])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CI.[C:32](=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[CH2:1]([O:8][C:9]([N:11]1[CH2:16][CH2:15][N:14]([C:17]([O:19][CH2:20][C:21]2[CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=2)=[O:18])[CH2:13][CH:12]1[C:27]([O:29][CH3:32])=[O:28])=[O:10])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 11430Potassium CarbonateHCID 226328591,4-Bis(benzyloxycarbonyl)piperazine-2-carboxylic acid

Product 1

HCID 21847669(+/-)-Methyl N,N'-dibenzyloxycarbonylpiperazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a flask containing N,N'-dibenzyloxycarbonylpiperazine-2-carboxylic acid (Step 1, 12.83 g, 32.20 mmol) dissolved in dry DMF (50 mL) is added methyl iodide (5.6 mL, 90.00 mmol) and potassium carbonate (4.60 g, 32.20 mmol). The mixture is stirred for 4 hours at ambient temperature under an inert atmosphere. The reaction is concentrated in vacuo, diluted with ethyl acetate (150 mL), washed with water (3×50 mL) and saline, dried over MgSO4, concentrated in vacuo, and chromatographed on silica gel (70-230 mesh), eluting with hexane/ethyl acetate (50/50). The appropriate fractions are combined (Rf =0.55, TLC, hexane/ethyl acetate, 50/50) and concentrated in vacuo to give the title compound, NMR (CDCl) 7.31, 5.15, 5.12, 4.70, 4.1-2.9.

Workup

  1. concentrationThe reaction is concentrated in vacuo
  2. additiondiluted with ethyl acetate (150 mL)
  3. washwashed with water (3×50 mL) and saline
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated in vacuo
  6. customchromatographed on silica gel (70-230 mesh)
  7. washeluting with hexane/ethyl acetate (50/50)
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-e5e703e8dcc14841979d8ccbc301f65c
Source dataset
uspto-grants-1999_09
Patent number
US05955460

Reaction notes

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