Study On The Synthesis Of 1-methyl-2,4,5-trinitroimidazoles

Polynitroimidazoles have been investigated mostly due to their properties as antibiotics,radiosensitizers and anti-protozoans and mainly used in medicinal chemistry. However, quiterecently, nitroimidazole compounds were found to have good explosive properties, thesenitroimidazoles, so it were incorporated into“high energy density materials”. In order to finda kind of high energy and insensitive explosive, people pay attention to the polynitroimidazo-les derivatives which have good prospect.1-Methyl-2,4,5-Trinitroimidazole is the polynitroimidazoles derivatives and is a is a highenergy, insensitivity and low melting point explosives. The explosive properties wereequivalented to RDX and the sensitivity close to the B explosive. In this paper, designed twosynthetic routes: （1） Starting from the N-methlyimidazole, and then nitration （2）1-Methyl-2,4,5-Trinitroimidazol（eMTNI）is synthesized starting from imidazole with aqueousalkaline iodine further methylation using iodomethane and nitration.Synthetic method （1）: the synthetic process was optimized by single factor which arereaction time and reaction temperature, but it merely get 4,5-MTNI. Then extracted theby-product and the single crystal structure was characterized by X-ray. The result shows thatthe by-product is 1-Methyl-5-nitroimidazole, Dc=1.566 g/cm³, Orthorhombic, Z=8, a =5.323（3） , b = 12.664（6） , c = 15.993（8）。Synthetic method （2）: 1-Methyl-2,4,5-Trinitroimidazole（MTNI）is synthesized startingfrom imidazole with aqueous alkaline iodine further methylation using iodomethane andnitration. The structure of MDNI was characterized by ESI-MS, IR and Elemental analysis.TII was synthesized and product yield up to 95.41%, and the melting point （m.p.） was190℃-192℃，its purity is more than 98%. Synthetic process of TII was optimized by singlefactor and the orthogonal experiments. An optional production condition was obtained: reaction at room temperature, reaction time16h , the ratio of n（I₂）:n（C₃H₄N₂）=4.17.MTII was synthesized and product yield up to 94.32%, and the melting point （m.p.） was150℃-152℃，its purity is more than 99%. Synthetic process of MTII was optimized by singlefactor. An optional production condition was obtained: reaction at room temperature, reactiontime 4h, the ratio of n（CH₃I）:n（TII）=1.75, n（NaOH）:n（TII）=3.6.MTNI was synthesized and the product yield is 36.52%, and the melting point （m.p.） was82℃-84℃，its purity is more than 98%. Synthetic process of MTNI was optimized by singlefactor and the orthogonal experiments. An optional production condition was obtained:reaction at room temperature, reactiontime 2.5h, reaction temperature is 80℃, theconcentrion of HNO3is 100%.