微反应器内FOX-7的连续合成工艺

Continuous Synthesis of FOX⁃7 in Microreactor System

研究以2-甲基-4,6-嘧啶二酮(MPO)为原料,在微通道反应器中探索了与硝硫混酸的硝化反应规律,并进一步通过水解反应来制备1,1-二氨基-2,2-二硝基乙烯(FOX-7)。研究通过引入惰性溶剂正辛烷,使反应体系呈弹状流,反应发生于分散液滴内部,解决了硝化中间体2-(二硝基亚甲基)-5,5-二硝基嘧啶-4,6-二酮(TNMPO)在微通道反应器中的堵塞难题,实现了过程强化和连续化;并研究了反应温度、停留时间、物料配比、水解条件等因素对产品收率的影响,提出了微反应器与搅拌釜串联的反应工艺。结果表明,在硝酸与MPO摩尔比为4.4,微反应器中停留时间3 min,反应温度30 oC时,串联搅拌釜保温反应30 min后,用冰水水解开环2 h,FOX-7收率可达90.1%,纯度高于99%。

The study investigated the nitration of 2⁃methyl⁃4,6⁃pyrimidinone(MPO)with nitrate sulfur mixed acid in a micro⁃channel reactor,and further prepared 1,1⁃diamino⁃2,2⁃dinitroethylene(FOX⁃7)through hydrolysis reaction.N⁃octane was in⁃troduced as an inert solvent to generate slug flow for the reaction system.The reaction occurred inside disperse droplets,thus solving the problem of clogging of nitration intermediates in the microchannel reactor and achieving process intensification and continuous operation.The effects of reaction temperature,residence time,material ratio,and hydrolysis conditions on the prod⁃uct yield were investigated.The combination of microreactor and stirred reactor was proposed.At the molar ratio of nitric acid to MPO of 4.4,reaction temperature of 30℃,and residence time of 3 min in the microreactor followed by a 30 min insulation re⁃action in a stirred kettle,and the ring⁃opening realized by the hydrolysis with ice water for 2 h,the yield of FOX⁃7 could reach 90.1%,with a purity of over 99%.