Cesium carbonate → Boc-L-Lys(Z)-OMe

HRID 2118869Notes

Reaction equation

HRID 2118869 reaction equation
[C:1]([NH:8][C@H:9]([C:25]([OH:27])=[O:26])[CH2:10][CH2:11][CH2:12][CH2:13][NH:14][C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[C:28](=O)([O-])[O-].[Cs+].[Cs+]>CO.O>[CH3:28][O:26][C:25](=[O:27])[C@H:9]([CH2:10][CH2:11][CH2:12][CH2:13][NH:14][C:15]([O:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:16])[NH:8][C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2]

Participants

5

Reactant 2

HCID 10796Cesium carbonateHCID 2724765Boc-Lys(Z)-OH

Product 1

HCID 11132998Boc-L-Lys(Z)-OMe

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

Dissolve 10.45 g of Nα -Boc-Nε -Cbz-L-lysine in 125 ml methanol and 17 ml water. Neutralize the solution with 27.5 ml of 0.5M cesium carbonate solution and concentrate the resulting solution to a syrup at aspirator pressure and 35° C. Dissolve the syrup in 100 ml. dimethylformamide and concentrate; repeat once more. Dissolve the residue in 75 ml. dimethylformamide and 2.7 ml. methyl iodide. Stir the reaction mixture overnight at room temperature then remove the dimethylformamide under vacuum (oil pump). Add 250 ml. water to the residue and extract into 150 ml. ethyl acetate. Wash the ethyl acetate extract twice with 100 ml. portions of water then dry the organic phase over MgSO4. Filter and concentrate the dried solution in vacuo to obtain Nα -Boc-Nε -Cbz-L-lysine methyl ester.

Workup

  1. concentrationconcentrate the resulting solution to a syrup at aspirator pressure and 35° C
  2. dissolutionDissolve the syrup in 100 ml
  3. concentrationdimethylformamide and concentrate
  4. dissolutionDissolve the residue in 75 ml
  5. customthen remove the dimethylformamide under vacuum (oil pump)
  6. additionAdd 250 ml
  7. extractionwater to the residue and extract into 150 ml
  8. washWash the ethyl acetate
  9. extractionextract twice with 100 ml
  10. dry with materialportions of water then dry the organic phase over MgSO4
  11. filtrationFilter
  12. concentrationconcentrate the dried solution in vacuo

Sources & evidence

ORD record
ord-ebe92dd3dd4648d6a9b1b945824aa739
Source dataset
uspto-grants-1987_07
Patent number
US04680392

Reaction notes

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