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

HRID 1880328

Reaction equation

HRID 1880328 reaction equation
[C:1]1([NH:7][N:8]=[CH:9][C:10](=[O:12])[CH3:11])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH:13]([CH:15]=O)=[O:14]>C(O)(=O)C>[OH:12][C:10]1[C:9]([C:13](=[O:14])[CH3:15])=[N:8][N:7]([C:1]2[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=2)[CH:11]=1

Participants

4

Reactant 2

HCID 7860GlyoxalHCID 2204342-Oxopropanal phenylhydrazone

Product 1

HCID 134133951-(4-hydroxy-1-phenyl-1H-pyrazol-3-yl)ethanoneYield 43.4%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To 2-oxopropanal phenylhydrazone (5.00 g, 30.8 mmol) in acetic acid (60 mL) was added a 40% aqueous solution of glyoxal (5.9 g, 4.6 mL, 30.8 mmol) and the mixture was heated at reflux for 45 minutes. The acetic acid was removed under reduced pressure. The resultant mixture was diluted with ethyl acetate (100 mL), washed with NaHCO3 and sat. aq. NaCl. Solids were removed by filtration, the filtrate was dried over Na2SO4, filtered and concentrated. The crude material was purified by CombiFlash (180 g column, 0-20 EtOAc/heptane gradient) to afford 1-(4-hydroxy-1-phenyl-1H-pyrazol-3-yl)ethanone as a yellow solid (2.70 g, 43%).

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 45 minutes
  3. customThe acetic acid was removed under reduced pressure
  4. additionThe resultant mixture was diluted with ethyl acetate (100 mL)
  5. washwashed with NaHCO3 and sat. aq. NaCl
  6. customSolids were removed by filtration
  7. dry with materialthe filtrate was dried over Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customThe crude material was purified by CombiFlash (180 g column, 0-20 EtOAc/heptane gradient)

Sources & evidence

ORD record
ord-4685bdcabab04375a1f86305a6097dba
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Linked notes

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