反应详情

A suspension of ethyl 5-amino-1-(2-pyridinyl)-1H-pyrazole-4-carboxylate (27.9 g, 120 mmol) in 4N sodium hydroxide (300 mL) solution was heated under reflux for 1 hour. The mixture was cooled to room temperature, neutralized with conc. hydrochloric acid, and made acidic with acetic acid. The resulting crystals were collected by filtration, washed with ethanol, and air dried. The crystals was subjected to heat at a temperature of 200° C., and then washed with diethylether to give the title compound (6.02 g, 31% yield).

1. temperaturewas heated
2. temperatureunder reflux for 1 hour
3. filtrationThe resulting crystals were collected by filtration
4. washwashed with ethanol, and air
5. customdried
6. temperatureto heat at a temperature of 200° C.
7. washwashed with diethylether