2-氯-5-氯甲基吡啶的合成研究

Research on Synthesis of 2-Chloro-5-Chloromethyl Pyridine

以2-氯-2-氯甲基-4-氰基丁醛(CCC)为原料,采用三光气作为氯化剂,通过环合反应合成了2-氯-5-氯甲基吡啶。通过单因素实验和正交优化实验确定了环合反应的工艺条件,并对环合反应的机理进行了探讨。优化后的反应条件为:以甲苯为反应溶剂,反应温度为90℃,物料滴加时间为2 h,n(CCC)∶n(三光气)∶n(DMF)=1∶0.35∶0.9,采用滴加三光气甲苯溶液的方式投料。在优化工艺条件下,反应收率为86.2%,纯度为99.2%,反应收率高于三氯氧磷工艺15%以上,废水减少80%以上,废固减少30%以上,是一条适合工业生产的工艺路线。

2-Chloro-5-chloromethyl pyridine was synthesized in a cyclization reaction process with 2-chloro-chloromethyl-4-cyan butyraldehyde（ CCC） as the material and the triphosgene as the chlorating agent. The process conditions were identified via single-factor experiment and orthogonal optimization test,and the mechanism of cyclization reaction is discussed. The reaction conditions identified through optimization are： the reaction solvent is toluene,the reaction temperature is 90 ℃,the time of adding material dropwise is2 h,n（ CCC） ： n（ triphosgene） ： n（ DMF） = 1： 0. 35： 0. 9,and the material is fed by adding the toluene solution of triphosgene dropwise. The product yield is 86. 2% and the product purity is 99. 2% at the above-mentioned process conditions with the product yield being 15% higher than that when phosphorus oxychloride process is used,the wastewater being reduced by more than 80% and waste solids being reduced by more than30%,suggesting this process is suitable for industrial production.