一锅法合成3-硝基吡唑的研究

One-pot Method for Synthesis of 3-Nitropyrazole

以吡唑为原料,经发烟硝酸和醋酐体系硝化后,将反应液在水热釜中高压反应,一锅法合成了3-硝基吡唑。产物经红外光谱、熔点、高效液相色谱表征。优化反应条件为:4.0 g吡唑、4.4 m L发烟硝酸、10.7 m L醋酐在冰水浴中反应1 h,然后将得到的反应液在170℃下、在水热釜中高压密封反应3 h,3-硝基吡唑的收率达46.2%。

3-Nitropyrazole was synthesized using pyrazole as the starting material by one-pot method. In this method, pyrazole was nitrated using fuming nitric acid and acetic anhydride; Then, the obtained liquid was transferred to a hydrothermal reaction vessel and reacted under a condition of high-pressure. The target product was characterized by IR, melting point and HPLC. A typical process under the optimal reaction condition was as following： pyrazole（4.0 g） in the mixture of fuming nitric acid（4.4 mL） and acetic anhydride（10.7 mL） was nitrated for 1 h at a temperature which was controlled by an ice-water bath; then, the obtained liquid was reacted under high-pressure for 3 h at 170℃ in a hydrothermal reaction vessel. The yield rate was 46.2%.