为了寻求新型高氮含能材料,以2,3-二氨基-2-丁烯二腈(DAMN)为原料,经过氧化缩合、叠氮反应两步法合成了 2,3,5,6-四(1H-四唑-5-基)吡嗪(H4TTP);通过傅里叶变换红外光谱(FTIR)、核磁共振、质谱、元素分析对H4TTP进行了表征.在原工艺基础上,以添加稳定剂四丁基溴化铵(TBAB)、改变最终酸度值的方法对原工艺进行改进,在单因素试验基础上,以H4TTP的得率为响应值,用响应面法优化其反应条件,研究了反应温度、反应时间、吡嗪四腈(TCP)与叠氮化钠(NaN3)的摩尔比3个因素对叠氮反应的影响,建立了 H4TTP的得率与3个相关因素的回归方程,所得模型的R2值为0.9992,证明该回归方程高度拟合.结果表明,叠氮反应较佳工艺条件为:以二甲基亚砜(DM-SO)为溶剂,TBAB为稳定剂,2,3,5,6-吡嗪四腈(TCP)与叠氮化钠的摩尔比为1∶4.4,反应温度124℃,反应时间42h、搅拌速率400r/min,H4TTP的得率为89.73%,与模型预测值90.61%基本相符,进一步验证了所选模型的合理性.与原工艺相比,工艺优化后的目标产物H4TTP得率提高7%左右.
In order to explore new high-nitrogen energetic materials,2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine(H4TTP)was synthesized by oxidative condensation and azide-cyano cyclization reaction in a two-step process using 2,3-diamino-2-butene-dicarbonitrile(DAMN)as raw material.H4TTP was characterized by Fourier transform infrared spectroscopy(FTIR),nuclear magnetic resonance(NMR),mass spectrometry and elemental analysis.Based on the original process,the process was im-proved by adding tetrabutylammonium bromide(TBAB)as stabilizer and changing the final acidity value.On the basis of the single factor test,the reaction conditions were optimized by the response surface method with the yield of H4TTP as the re-sponse value.The effects of reaction temperature,reaction time,and molar ratio of pyrazine tetracosanoic acid(TCP)and sodium azide(NaN3)on the cyclization reaction were studied.A regression equation was established between the yield of H4TTP and the three correlates.The R2 value of the resulting model is 0.9992,indicating that the regression equation is highly fitted.The optimized conditions for the cyclization reaction are as follows:dimethyl sulfoxide(DMSO)as solvent,TBAB as stabilizer,the molar ratio of TCP and NaN3 is 1∶4.4,the reaction temperature is 124 ℃,the reaction time is 42h,the stir-ring rate is 400 r/min,and the yield of H4TTP is 89.73%.The experimental yield is basically consistent with the model predic-tion value of 90.61%,and the reasonableness of the selected model is further verified.Compared with the original process,the yield of cyclization reaction of the improved process is increased by about 7%.