3-甲基-5-吡唑酮的合成研究

Study on Synthesis of 3-Methyl-5-pyrazolone

采用乙酰乙酸乙酯和水合肼为原料 ,无水乙醇为溶剂 ,对 3-甲基 - 5 -吡唑酮的合成反应进行了研究 ,在反应温度为 80°C,乙酰乙酸乙酯与水合肼摩尔比为 1∶ 1 .2 ,反应时间 3h的较佳工艺条件下 ,产物收率大于 85 % ,产物纯度大于 99.5 %。用

The synthesis of 3 methyl 5 pyrazolone from ethyl acetoacetate and hydrazine hydrate using ethanol as solvent was studied. The optimum reaction conditions were: reaction temperature, 80°C; n (3 methyl 5 pyrazolone)∶ n (hydrazine hydrate)=1∶1.2; reaction time, 3 h. The yield of the product was ≥85% and the purity was ≥99.5%.