Glyoxal → 1-(1-benzyl-4-hydroxy-1H-pyrazol-3-yl)ethanone

HRID 1880338Notes

Reaction equation

HRID 1880338 reaction equation
[CH:1]([CH:3]=O)=[O:2].[CH2:5]([NH:12][N:13]=[CH:14][C:15](=[O:17])[CH3:16])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1>O.CO>[CH2:5]([N:12]1[CH:16]=[C:15]([OH:17])[C:14]([C:1](=[O:2])[CH3:3])=[N:13]1)[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

5

Reactant 2

HCID 7860GlyoxalHCID 669205262-Oxopropanal benzylhydrazone

Product 1

HCID 669204761-(1-benzyl-4-hydroxy-1H-pyrazol-3-yl)ethanoneYield 33%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a 40% aqueous solution of glyoxal (8.28 g, 6.55 mL, 57.1 mmol) was added a slurry of 2-oxopropanal benzylhydrazone (10.1 g, 57.1 mmol) in water (250 mL) and methanol (25 mL). The resulting mixture was heated at reflux for 3 hours before cooling to room temperature. The mixture was extracted with EtOAc (2×100 mL) and the combined organic extracts were washed with water, saturated aqueous NaCl, dried over Na2SO4, filtered and concentrated. The crude material was purified by CombiFlash (120 g column, 0-100% EtOAc/heptane gradient) to provide 1-(1-benzyl-4-hydroxy-1H-pyrazol-3-yl)ethanone (4.07 g, 33%).

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureat reflux for 3 hours
  3. extractionThe mixture was extracted with EtOAc (2×100 mL)
  4. washthe combined organic extracts were washed with water, saturated aqueous NaCl
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe crude material was purified by CombiFlash (120 g column, 0-100% EtOAc/heptane gradient)

Sources & evidence

ORD record
ord-5912bc2e12994f89ab829ab5ab074a93
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

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