Citric Acid → tert-butyl N-((2S)-1-oxobutan-2-yl)carbamate

HRID 1173640

Reaction equation

HRID 1173640 reaction equation
[C:1]([O:5][C:6](=[O:13])[NH:7][C@H:8]([CH2:11][OH:12])[CH2:9][CH3:10])([CH3:4])([CH3:3])[CH3:2].C(N(CC)CC)C.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CS(C)=O>[C:1]([O:5][C:6](=[O:13])[NH:7][C@H:8]([CH:11]=[O:12])[CH2:9][CH3:10])([CH3:2])([CH3:3])[CH3:4]

Participants

5

Reactant 3

HCID 311Citric AcidHCID 8471TriethylamineHCID 11263954tert-butyl N-[(2S)-1-hydroxybutan-2-yl]carbamate

Product 1

HCID 10241556tert-butyl N-((2S)-1-oxobutan-2-yl)carbamateYield 85%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

A solution of tert-butyl[(1S)-1-(hydroxymethyl)propyl]carbamate (30.0 g) in dimethyl sulfoxide (300 mL) was ice-cooled under a nitrogen atmosphere, and triethylamine (64.4 mL) and a solution of sulfur trioxide•pyridine complex (80.7 g) in dimethyl sulfoxide (300 mL) were successively added. The mixture was stirred at the same temperature for 30 min and then at room temperature for 3 hr, 1 mol/L aqueous citric acid solution (500 mL) was added to the reaction solution, and the mixture was extracted with diethyl ether. The obtained organic layer was washed with water and saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane=0→30%) to give the title compound as a white powder (yield: 24.3 g, 85%).

Workup

  1. temperaturecooled under a nitrogen atmosphere
  2. waitat room temperature for 3 hr
  3. extractionthe mixture was extracted with diethyl ether
  4. washThe obtained organic layer was washed with water and saturated brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane=0→30%)

Sources & evidence

ORD record
ord-8cc9315d98d2401abba8f1195f84e21b
Source dataset
uspto-grants-2010_11
Patent number
US07834051B2

Linked notes

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