Acetic Acid → 1-[4-hydroxy-1-(3-methoxyphenyl)-1H-pyrazol-3-yl]ethanone

Participants

Reaction Steps

A mixture of 2-oxopropanal (3-methoxyphenyl)hydrazone (2.88 g, 14.5 mmol), acetic acid (20 mL) and glyoxal (6.3 g, 5.0 mL, 43 mmol) were heated at reflux overnight. The reaction was cooled to room temperature, diluted with EtOAc and washed with saturated aqueous NaCl. The black sludge was removed by decantation and the filtrate was washed with more saturated aqueous NaCl, dried over MgSO4, filtered and concentrated. Purify by CombiFlash (80 g column, 0-50% heptane/EtOAc gradient) to afford 1-[4-hydroxy-1-(3-methoxyphenyl)-1H-pyrazol-3-yl]ethanone (330 mg, 10%).

Provenance & Evidence