Benzyl Bromide → (R)-benzyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoate

HRID 2297965Notes

Reaction equation

HRID 2297965 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([C:13]([OH:15])=[O:14])[CH:10]([CH3:12])[CH3:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].C(=O)([O-])[O-].[Cs+].[Cs+].[CH2:22](Br)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1>CN(C)C=O>[CH2:22]([O:14][C:13](=[O:15])[C@@H:9]([CH:10]([CH3:11])[CH3:12])[NH:8][C:6]([O:5][C:1]([CH3:3])([CH3:2])[CH3:4])=[O:7])[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 637605(2R)-2-(((tert-butoxy)carbonyl)amino)-3-methylbutanoic acid

Product 1

HCID 11243734(R)-benzyl 2-((tert-butoxycarbonyl)amino)-3-methylbutanoateYield 98.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

N-Tert-butoxycarbonyl-D-valine (70 g, 0.32 mol) and cesium carbonate (200.2 g, 0.615 mol) were stirred in dry dimethylformamide (550 mL). Benzyl bromide (40.32 mL, 0.336 mol) was added and the reaction mixture was stirred overnight. The material was concentrated on the roto-evaporator and the residue was dissolved in methylene chloride (200 mL) and the methylene chloride layer was washed with water and brine, dried over magnesium sulfate and concentrated to give N-tert-butoxycarbonyl-D-valine benzyl ester (97 g) as a viscous oil.

Workup

  1. concentrationThe material was concentrated on the roto-evaporator
  2. dissolutionthe residue was dissolved in methylene chloride (200 mL)
  3. washthe methylene chloride layer was washed with water and brine
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-7d7c86b2a22b4ddc92f881785dfab1b5
Source dataset
uspto-grants-2002_12
Patent number
US06492394B1

Reaction notes

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