羧酸开环法合成1,1-二氨基-2,2-二硝基乙烯的研究

Study on Ring Cleavage of 2-(Dinitromethylene)-4,5-imidazolidinyldione to 1,1-Diamino-2,2-dinitroethylene by Carboxylic Acids

对2 甲基咪唑为反应底物制备1,1 二氨基2,2 二硝基乙烯(FOX 7)的合成方法进行了实验研究,找到了一种新的合成FOX 7的方法,该方法首次采用低碳有机羧酸与硝化中间体2 (二硝基亚甲基) 4,5 咪唑烷二酮1的反应实现FOX 7的合成,对产物结构进行了表征并对反应条件进行了优化。开环试剂为甲酸时,最优条件下两步反应(收率分别为20.3%和95.3%)的总收率约为19.3%,与氨水开环法(约13.1%)相比收率有较大幅度提高,通过控制反应时间和结晶时间可对FOX 7的颗粒度进行控制,同时该方法也是制备大颗粒和不同形貌特征FOX 7的有效方法。对开环反应机理进行了探讨。

1,1-Diamino-2,2-dinitroethylene (FOX-7) was synthesized using 2-methylimidazole as raw material. Ring cleavage of 2-(dinitromethylene)-4,5-imidazolidine dione was achieved by reacting with carboxylic acids, and the reaction conditions were optimized. The overall yield of nitration and ring cleavage was 19.3%(about 13% in literature) when formic acid was used. The ring cleavage by carboxylic acids, methanol, water and aqueous ammonia was compared. The particle size of FOX-7 can be controlled by adjusting the reaction and crystallization time, and it is also an efficient method for the preparation of large particle size FOX-7 with different features. The reaction mechanism of ring cleavage was discussed.