低固废氰乙酸乙酯合成工艺研究
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摘要
采用先酯化后氰化的方法将氯乙酸先酯化为氯乙酸乙酯,然后在相转移催化剂作用下,氯乙酸乙酯发生氰化反应制得氰乙酸乙酯。优化后的最佳反应条件为:酯化回流时间为3.5h,氯乙酸与乙醇物质的量比为1∶2.0;氰化反应时间为6.0h,反应温度为60℃,催化剂为聚乙二醇与四丁基溴化铵的复配物(m(聚乙二醇)∶m(四丁基溴化铵)=1∶0.4)。在此条件下,氰乙酸乙酯的总收率达到89.58%(以氰乙酸计)。该方法反应步骤少,氰乙酸乙酯含量高,解决了先氰化后酯化固废量大,成本较高的问题。
Using late-cyanation method,chloroacetic acid was esterified into ethyl chloroacetate,and then cyanation was used to prepare ethyl cyanoacetate under phase transfer catalyst.The optimized reaction conditions were as follows:the esterification reflux reaction time was 3.5 h,chloroacetic acid and alcohol mole ratio of 1∶2.0,cyanide for 6.0 hreaction time,reaction temperature was 60℃,the catalyst was a complex formulation of polyethylene glycol and tetrabutyl ammonium bromide(m(polyethylene glycol)∶m(tetrabutyl ammonium bromide)is 1∶0.4).The total yield of ethyl cyanoacetate was 89.58% under optimized preparation conditions.This method solved the problem of large amount of solid waste,high cost in late-esterification.
Using late-cyanation method,chloroacetic acid was esterified into ethyl chloroacetate,and then cyanation was used to prepare ethyl cyanoacetate under phase transfer catalyst.The optimized reaction conditions were as follows:the esterification reflux reaction time was 3.5 h,chloroacetic acid and alcohol mole ratio of 1∶2.0,cyanide for 6.0 hreaction time,reaction temperature was 60℃,the catalyst was a complex formulation of polyethylene glycol and tetrabutyl ammonium bromide(m(polyethylene glycol)∶m(tetrabutyl ammonium bromide)is 1∶0.4).The total yield of ethyl cyanoacetate was 89.58% under optimized preparation conditions.This method solved the problem of large amount of solid waste,high cost in late-esterification.
引文
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[2]杨英,李德臣.α-氰基丙烯酸酯生产新工艺[J].中国胶黏剂,2004,13(5):46-47.
[3]王克钦,徐阵,林卿云,等.α-氰基丙烯酸酯生产新工艺[J].辽宁化工,1984,(6):46-47.
[4]尚会建,康丽娜,赵叶,等.杂多酸催化合成氰乙酸乙酯的研究[J].精细石油化工,2012,29(3):48-51.
[5]刘旭,尹国华,王金花,等.一种氰乙酸乙酯合成的新方法[J].精细与专用化学品,2016,24(1):35-37.
[6]周学永.氯乙酸基础研究与应用[M].北京:中国科学技术出版社,2006:211.
[7]司航.化工产品手册,有机化工原料[M].北京:化学工业出版社,2001:498-499.