Benzyl Bromide → N-(4-methoxybenzenesulfonyl)-D-valine benzyl ester

HRID 2297973Notes

Reaction equation

HRID 2297973 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([S:9]([NH:12][C@H:13]([CH:17]([CH3:19])[CH3:18])[C:14]([OH:16])=[O:15])(=[O:11])=[O:10])=[CH:5][CH:4]=1.C(=O)([O-])[O-].[Cs+].[Cs+].[CH2:26](Br)[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1>CN(C)C=O>[CH2:26]([O:15][C:14](=[O:16])[C@H:13]([NH:12][S:9]([C:6]1[CH:7]=[CH:8][C:3]([O:2][CH3:1])=[CH:4][CH:5]=1)(=[O:11])=[O:10])[CH:17]([CH3:19])[CH3:18])[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 1133588N-[4-methoxybenzenesulfonyl]-(D)-valine

Product 1

HCID 15429254N-(4-methoxybenzenesulfonyl)-D-valine benzyl esterYield 83.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 2(R)-(4-methoxybenzenesulfonylamino)-3-methylbutyric acid (40 g, 139.2 mmol) and cesium carbonate (85.7 g, 444 mmol) in dimethylformamide was added benzyl bromide (16.1 g, 135 mmol). The reaction mixture was stirred overnight. The dimethylformamide was removed on the rotoevaporator and the residue was dissolved in ethyl acetate (200 ml) and partitioned with an equal volume of water. The organic phase was collected and washed with an equal volume of brine. The aqueous phases were back extracted with ethyl acetate (2×150 ml), combined and dried over magnesium sulfate and condensed to provide 2(R)-(4-methoxybenzenesulfonylamino)-3-methylbutyric acid benzyl ester (42.6 g) as a white crystalline solid.

Workup

  1. customThe dimethylformamide was removed on the rotoevaporator
  2. dissolutionthe residue was dissolved in ethyl acetate (200 ml)
  3. custompartitioned with an equal volume of water
  4. customThe organic phase was collected
  5. washwashed with an equal volume of brine
  6. extractionThe aqueous phases were back extracted with ethyl acetate (2×150 ml)
  7. dry with materialdried over magnesium sulfate and condensed

Sources & evidence

ORD record
ord-a8a072e3ec5442fa83b137c37b0f21d6
Source dataset
uspto-grants-2002_12
Patent number
US06492394B1

Reaction notes

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