Method for preparing 4,5-dinitroimidazole using microchannel reactor

Abstract

The invention discloses a method for preparing 4,5-dinitroimidazole by using a microchannel reactor. The method uses a micro-mixer to strengthen the mixing of raw materials. Unlike traditional reactors where the degree of uniformity is limited by the uneven flow field generated by stirring, the flow focusing technology adopted by the HPIMM micro-mixer can force two streams of fluid thin laminar flow Through the converging chamber, an efficient and uniform thin-layer contact reaction is produced, the stoichiometric ratio of the reactants is precisely controlled, and the amount of strong acid is reduced from the source, and the reaction is caused by the amount of acid and temperature changes in the traditional tank reactor. The generation of multi-nitration by-products eliminates mass transfer resistance and thus avoids the generation of hot spots, and solves the huge safety problem caused by the intense heat release of 4,5-dinitroimidazole in conventional reactors. The present invention utilizes the microsystem to synthesize 4-nitroimidazole and 4,5-dinitroimidazole to obtain high yields of 96.1% and 92.4%.

Description

technical field [0001] The invention belongs to the technical field of preparation of energetic compounds, and relates to a method for preparing 4,5-dinitroimidazole by using a microchannel reactor. Background technique [0002] 4,5-Dinitroimidazole (4,5-DNI) has the characteristics of high nitrogen and low carbon hydrogen due to the N-N, C-N, N-O high-energy chemical bonds contained in its structure, and the electronegativity of the nitrogen atom is high, making it A unique molecule similar to a benzene ring structure is formed, and it is an excellent high-energy and low-sensitivity compound. The new nitrogen-rich energetic compounds of 4,5-DNI mainly have high heat generation capacity, which is significantly better than the carbon skeleton oxidation capacity of traditional energetic materials. Due to the good stability of the heterocyclic molecular structure, further modification and modification can be carried out on the basis of it, and other subsidiary groups can be ad...

AI Technical Summary

Problems solved by technology

However, during the secondary feeding, adding concentrated nitric acid dropwise at a high temperature of 90°C not only greatly increases the safety hazards of the operation, but also the temperature during feeding should not be controlled, which may easily cause the formation of by-products, and the reaction time of 5.5 hours is still too long. process, which increases production costs

Patent CN200910263938.1 discloses a method for preparing 4,5-dinitroimidazole in a conventional tank reactor. However, this method will cause process safety problems due to the strong exothermic reaction. After the reaction, a large amount of waste Acid can also cause environmental pollution

[0005] Due to the enhanced mass and heat transfer characteristics of the microreactor, the safe use of harmful and dangerous reagents has been realized, and it has the potential to scale up. At present, a new process platform has been provided for organic synthesis reactions, but the use of microreactors to synthesize 4,5-dinitrate Kimidazole has not been reported yet

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