微反应器中2-氨基-5-硝基吡啶合成的连续流工艺研究

Study on Continuous Flow Process for Synthesis of 2-amino-5-nitropyridine in Microreactor

以哈氏合金材质的微反应器板块(容积8.2 mL)为核心组件,构建2-氨基-5硝基吡啶合成的微通道反应体系。以2-氨基吡啶和发烟硝酸-硫酸混酸体系为原料,利用微反应器强传质传热的特性来提升2-氨基-5-硝基吡啶的收率,并研究工艺温度、反应原料物质的量比、停留时间等因素对该硝化反应的影响。结果表明:微反应器中2-氨基-5-硝基吡啶合成的最佳工艺优化方案为反应温度为35℃,发烟硝酸/2-氨基吡啶物质的量比为1.15∶1,反应停留时间为60 s。

A microchannel reaction system for the synthesis of 2-amino-5-nitropyridine was constructed using a Hastelloy microreactor with volume of 8.2 mL as the core component.Using 2-aminopyridine and the mixed acid system of fuming nitric acid-sulfuric acid as raw materials,the strong mass transfer and heat transfer characteristics of the microreactor were utilized to enhance the yield of 2-amino-5-nitropyridine.The effects of reaction temperature,molar ratio of reactants,residence time and other factors on nitration reaction were studied.Results show that the optimal process plan for the synthesis of 2-amino-5-nitropyridine in microreactor is at the reaction temperature,the molar ratio of fuming nitric acid to 2-aminopyridine and the reaction residence time of 35℃,1.15∶1 and 60 s,respectively.