摘要
以氯乙酸为原料,在微反应器中经酯化和氰化两步合成了氰乙酸乙酯,氯乙酸与乙醇经浓硫酸催化条件下在微反应器中酯化得到氯乙酸乙酯,氯乙酸乙酯进一步与氰化钠溶液在微反应器中发生氰化反应制备了氰乙酸乙酯,考察了两步反应过程中停留时间、反应温度、物质的量比例对氰乙酸乙酯收率的影响,优化反应条件为:酯化反应停留时间为167s,氯乙酸与乙醇物质的量比为1∶5,反应温度75℃,氰化反应停留时间为124s,反应温度为70℃。制备过程总收率为84.9%,实现了先氰化后酯化连续反应,解决了工业化生产固废量大,成本较高问题。
Using chloroacetic acid as raw materials,ethyl cyanoacetate was synthesized through esterification and cyanide reaction in microreactor,first,ethyl chloroacetate was synthesized by chloroacetic acid and ethanol in micro reactor under the condition of the sulfuric acid catalysis,ethyl chloroacetate further reacted with sodium cyanide solution in the micro reactor to prepare ethyl cyanoacetate,the conditions of residence time,reaction temperature,proportion of substance in the process of two step reaction influenced the yield of ethyl cyanoacetate was examined,the optimizing reaction conditions as follows:esterification reaction residence time 167 s,mole ratio of chloroacetic acid and ethanol 1∶5,reaction temperature 75℃,cyanide reaction residence time 124 s,reaction temperature 70℃.The total yield of the preparation process was 84.9%.the continuous reaction of cyanation and esterification is realized in the microreactor,and the problem of high solid waste and high cost in industrial production is solved.
引文
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