反应详情

A mixture of ethyl acetoacetate (8.0 mL, 63 mmol) and dimethylformamide-dimethylacetal (8.3 mL, 63 mmol) is heated to reflux for 1 hour. The reaction mixture is cooled to room temperature and diluted with EtOH (70 mL). Hydrazine hydrate (3.0 mL, 63 mmol) is then added and the reaction is heated at 80° C. for 2 hours. The resultant solution is cooled to room temperature and concentrated in vacuo to afford crude 5-methyl-1H-pyrazole-4-carboxylic acid ethyl ester which is used without further purification.

1. temperatureis heated
2. temperatureto reflux for 1 hour
3. temperaturethe reaction is heated at 80° C. for 2 hours
4. concentrationconcentrated in vacuo