反应详情

5-Amino-2H-pyrazol-3-ol (3.1 g, 31.6 mmol) were suspended in 100 ml of methanol. Then sodium methoxide (5.1 g, 95 mmol) and 2,4-dioxopentanoic acid ethyl ester (5 g, 31.6 mmol) were added, and the mixture was heated up under reflux for 12 h. The solvent was removed in a rotary evaporator, water was added to the residue, the precipitate was filtered off with suction, and the filtrate was adjusted to pH 6 with dilute hydrochloric acid. The precipitated product (both precipitates) was filtered off with suction and dried. Yield: 4.9 g (70%), M+H+: 194.09.

1. temperaturethe mixture was heated up
2. temperatureunder reflux for 12 h
3. customThe solvent was removed in a rotary evaporator, water
4. additionwas added to the residue
5. filtrationthe precipitate was filtered off with suction
6. customThe precipitated product (both precipitates)
7. filtrationwas filtered off with suction
8. customdried