4-羟基-3-硝基吡啶的热分析

4-羟基-3-硝基吡啶(HNP)是合成4位有取代基的3-硝基吡啶的重要中间体。文献对HNP的受热行为鲜有报道。为了解其在受热时的行为,用TG-DSC法研究了HNP在加热速度为1.0~15.0℃/min,从室温到300℃的受热行为。发现在氮气氛、敞口容器中,HNP在200℃明显地失重。热分析数据证明在228~288℃之间存在几个重叠的过程。经过对比和讨论并通过升华制备的方法,证明在低于200℃时的失重是由于HNP的升华而不是分解,升华产物中HNP纯度可提高到99.9%、且为不含无机盐的高纯化合物。

Study on Thermoanalysis of 4-hydroxy-3-nitro-pyridine

4-hydroxy-3-nitro-pyridine(HNP) was used as the important intermediates of 4-substituted-3-nitro-pyridines.In order to find out the thermal behavior of HNP,TG-DSC method was carried out from room temperature to 300 ℃ with heating rate ranged on 1.0~15.0 ℃/min.The weight loss of HNP was distinctly below 200 ℃ in an open vessel and in nitrogen atmosphere.According to the data measured,it was proven that overlap processes exist in the temperature ranged from 228 to 288 ℃.After the data of the TG and DSC of HNP compared and discussed,a preparation method established on sublimation proved that the weight loss of HNP below 200 ℃ was due to sublime,but not decompose.The sublimed HNP product was inorganic salt free and highly purified to the content of 99.9%.