Triethylamine → 2-Tert-butoxycarbonylamino-4-oxo-butyric acid benzyl ester

HRID 433823Notes

Reaction equation

HRID 433823 reaction equation
[CH2:1]([O:8][C:9](=[O:22])[CH:10]([NH:14][C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:11][CH2:12][OH:13])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(N(CC)CC)C.S(=O)(=O)=O.N1C=CC=CC=1>CS(C)=O>[CH2:1]([O:8][C:9](=[O:22])[CH:10]([NH:14][C:15]([O:17][C:18]([CH3:20])([CH3:19])[CH3:21])=[O:16])[CH2:11][CH:12]=[O:13])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 8471TriethylamineHCID 168533Sulfur trioxide-pyridineHCID 113473932-Tert-butoxycarbonylamino-4-hydroxy-butyric acid benzyl ester

Product 1

HCID 143577952-Tert-butoxycarbonylamino-4-oxo-butyric acid benzyl ester

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

A dimethyl sulfoxide (10 mL) solution of 2-tert-butoxycarbonylamino-4-hydroxy-butyric acid benzyl ester (13.58 g, 43.9 mmol) and triethyl amine (18.35 mL, 131.7 mmol) was cooled to 0° C. Pyridine sulfur trioxide (21.0 g. 131.7 mmol) in dimethyl sulfoxide (80 mL) was added in a steady stream. The cooling bath was removed and the reaction stirred 1.5 hours. The reaction was poured into 130 mL ice water and extracted with diethyl ether (2×180 mL and 100 mL). The combined organic portion was washed sequentially with saturated sodium bicarbonate, water, brine and dried over magnesium sulfate. The solvent was removed in vacuo and the crude product was chromatographed on silica gel (900 mL) eluting with ethyl acetate/hexanes (1:4), to give the title compound as a clear, colorless oil (9.20 g, 70%). MS (CI) m/z 208.0 (M−99).

Workup

  1. customThe cooling bath was removed
  2. additionThe reaction was poured into 130 mL ice water
  3. extractionextracted with diethyl ether (2×180 mL and 100 mL)
  4. washThe combined organic portion was washed sequentially with saturated sodium bicarbonate, water, brine
  5. dry with materialdried over magnesium sulfate
  6. customThe solvent was removed in vacuo
  7. customthe crude product was chromatographed on silica gel (900 mL)
  8. washeluting with ethyl acetate/hexanes (1:4)

Sources & evidence

ORD record
ord-ee4ee3388bc34b7c8c85e3d0a2397968
Source dataset
uspto-grants-2003_12
Patent number
US06668527B2

Reaction notes

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