Study On Utilizing Of Dinitromethane,the By-product Of FOX-7 Prepared By 4,6-Dihydroxy-2-methylpyrimidine

1,1-Diamino-2,2-dinitroethylene(FOX-7)is an excellent insensitive high explosive.The preparation process of FOX-7 from 4,6-dihydroxy-2-methylpyrimidine has reached the kilogram level,which is in the key stage of expanding its application.Further optimization of the process is beneficial to solve these problems,such as the high cost of raw materials and unstable by-product.Study on recycling dinitromethane,the by-product of the manufacturing process of FOX-7,is not only eliminating the hidden danger and reducing the production cost,but also promoting the application and development of the gem-dinitro compounds.Via recycling dinitromethane,the by-product of the manufacturing process of FOX-7,dinitromethane potassium salt(KDNM),stable enough to store for weeks,was obtained by neutralizing it with aqueous potassium hydroxide.The synthesis process of KDNM was optimized and its stability was investigated.And then,the KDNM as raw materials,2,2-dinitro-1,3-propanediol and 1,3,5,5-tetranitro-hexahydropyrimidine(DNNC)were synthesized,and 1,3,3-trinitroazocytane(TNAZ)was also tried to synthesize by various synthetic routes.Among them,DNNC was prepared via Mannich reaction using KDNM,formaldehyde and tert-butylamine as materials,and then nitrified with concentrated sulfuric acid and nitric acid with total yield was 78.9%(Calculated by KDNM).Compared with the synthesis process of DNNC that prepared via Mannich reaction using 2,2-dinitro-1,3-propanediol and then nitrified,this process without constructing gem-dinitro groups and no need for intermediate 2,2-dinitro-1,3-propanediol,was not only shorten the process,but also greatly improved the yield that made it a great application value of amplification.KATNP was stable enough to store for weeks.And if FOX-7 and KDNM could obtain by hydrolysis of it,the occurrence of dinitromethane will be avoided and it will become intermediate and be applied in commercial process of FOX-7.On the other hand,it can also be used as a high-energy oxidant in rocket propellants and missiles.The reaction products were characterized by 1HNMR,IR and MS.Meanwhile,the synthesis process of 2,2-dinitro-1,3-propanediol and DNNC by using KDNM as raw materials were optimized,and the best reaction conditions were obtained.