反应详情

A 40% aqueous solution of glyoxal (2.3 g, 1.8 mL, 16 mmol) was added to a solution of 2-oxopropanal ethylhydrazone (1.83 g, 16 mmol) in water (90 mL). The mixture was heated at reflux for 1 hour. The reaction was cooled to room temperature and extracted with CH2Cl2 (4×). The combined organic extracts were dried over Na2SO4, filtered and concentrated to afford 1-(1-ethyl-4-hydroxy-1H-pyrazol-3-yl)ethanone as a yellow oil (2.16 g, 87%).

1. temperatureThe mixture was heated
2. temperatureat reflux for 1 hour
3. extractionextracted with CH2Cl2 (4×)
4. dry with materialThe combined organic extracts were dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated