Cesium carbonate → 2-(4-methoxybenzylthio)-pentanoyl-(L)-homophenylalanine methyl ester

HRID 276111Notes

Reaction equation

HRID 276111 reaction equation
[CH3:1][O:2][C:3](=[O:21])[C@H:4]([CH2:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[NH:5][C:6](=[O:12])[CH:7](Br)[CH2:8][CH2:9][CH3:10].[CH3:22][O:23][C:24]1[CH:31]=[CH:30][C:27]([CH2:28][SH:29])=[CH:26][CH:25]=1.C(=O)([O-])[O-].[Cs+].[Cs+].CCCCCC.C(OCC)(=O)C>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.CN(C)C=O>[CH3:1][O:2][C:3](=[O:21])[C@H:4]([CH2:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[NH:5][C:6](=[O:12])[CH:7]([S:29][CH2:28][C:27]1[CH:30]=[CH:31][C:24]([O:23][CH3:22])=[CH:25][CH:26]=1)[CH2:8][CH2:9][CH3:10]

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 804074-Methoxy-alpha-toluenethiolHCID 21226206Ethyl acetate hexane2×HCID 229508312-bromopentanoyl-(L)-homophenylalanine methyl ester

Product 1

HCID 229508282-(4-methoxybenzylthio)-pentanoyl-(L)-homophenylalanine methyl ester

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 6228DimethylformamideSolvent

Procedure

Combine 2-bromopentanoyl-(L)-homophenylalanine methyl ester (3.6 g, 10 mmol), 4-methyoxybenzylmercaptan (3.48 mL, 25 mmol), and tetrabutylammonium iodide (about 50 mg) in dimethylformamide (10 mL). Degas by repeatedly applying vacuum and filling the vessel with nitrogen. Add cesium carbonate (4.10 g, 12.5 mmol). After 15 hours, partition the reaction mixture between water and methyl t-butyl ether, saturate the aqueous layer with sodium chloride. Extract the aqueous layer with brine, dry over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting sequentially with 4/1 hexane/ethyl acetate and then 2.5/1 hexane/ethyl acetate to give the title compound: Rf=0.44 (silica gel, 2.5/1 hexane/ethyl acetate).

Workup

  1. customDegas
  2. custompartition the reaction mixture between water and methyl t-butyl ether
  3. concentrationsaturate the aqueous layer with sodium chloride
  4. extractionExtract the aqueous layer with brine
  5. dry with materialdry over Na2SO4
  6. filtrationfilter
  7. customevaporate in vacuo
  8. customto give a residue

Sources & evidence

ORD record
ord-d1385ca9dc824c218ae0cd8094c64e04
Source dataset
uspto-grants-2002_03
Patent number
US06352976B1

Reaction notes

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