微反应技术合成甲硝胺的工艺优化
李 冬,刘卫孝,刘亚静,陆婷婷,陈 斌,汪营磊

(西安近代化学研究所,陕西 西安 710065)

有机化学; 甲硝胺; NMA; 微反应技术; 硝化反应; 1,3-二甲基脲; 含能增塑剂; DNDAs

Synthesis of N-Nitromethylamine via Micro-reaction Technology
LI Dong, LIU Wei-xiao, LIU Ya-jing, LU Ting-ting, CHEN Bin, WANG Ying-lei

(Xi'an Modern Chemistry Research Institute, Xi'an 710065, China)

organic chemistry; N-nitromethylamine; NMA; micro reaction; nitration reaction; 1,3-dimethylurea; energetic plasticizer; DNDAs

DOI: 10.14077/j.issn.1007-7812.202404009

备注

针对线状硝胺含能增塑剂(DNDAs)合成过程中,前驱体甲硝胺(NMA)硝化反应存在放热剧烈、在线量大、有安全隐患等问题,采用微反应技术,以1,3-二甲基脲为原料、硝硫混酸为硝化剂进行硝化反应,进一步水解合成出关键中间产物NMA,并表征了其结构,对反应条件进行了优化。结果表明,微反应技术解决了甲硝胺合成过程中硝化反应放热量大、在线量大等导致的反应难以控制、安全风险高的问题; 得到优化后的微反应器硝化反应最佳工艺条件为:温度为15℃,硝酸、硫酸、1,3-二甲基脲的摩尔比为1:0.78:0.67,平均反应时间为22.5s,甲硝胺收率达到90.7%,纯度为99.2%。表明该工艺具有反应温度高、安全性高、反应速率快、产品收率高等优点。
Aiming at the problems of nitration reaction such as intense exotherm, large volume online, and serious safety hazards during the synthesis of N-nitromethylamine(NMA), the precursor of linear nitramine energetic plasticizers(DNDAs), micro reaction technology was adopted to carry out the nitration of 1,3-dimethylurea using nitrate-sulfur mixed acid. Critical intermediate NMA was further synthesized through the hydrolysis reaction. The structure of synthesized NMA was characterized, and the reaction conditions of nitration were also optimized. The results show that micro-reaction technology can solve the problems of uncontrollability and high safety risk caused by large amounts of heat release and volume online of nitration reaction in the process of synthesizing NMA. The optimal nitration reaction temperature is 15℃, the optimal material mol ratio of nitric acid, sulfuric acid and 1,3-dimethylurea is 1:0.78:0.67, and the average residence time was 22.5s. The yields of NMA reached 90.7%, and the purity was 99.2%. This micro-reaction process has the advantages of high reaction temperature, high safety, fast reaction rate, and high product yield.
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