2-甲基-4-三氟甲基噻唑-5-甲酰氯的制备

Preparation of 2-Methyl-4-trifluoromethyl-thiazole-5-formyl Chloride

以固体光气为氯化试剂,二氯乙烷为反应溶剂,2-甲基-4-三氟甲基噻唑-5-甲酸与固体光气发生氯化反应,得到2-甲基-4-三氟甲基噻唑-5-甲酰氯。反应中通过调节滴加固体光气二氯乙烷溶液的时间,来控制反应速度,使固体光气得到充分利用;通过热回流的方式,热解离固体光气,避免了解聚剂的引入;以蒸馏的方式回收了反应溶剂,实现了溶剂套用5次以上,收率大于99%,产品含量大于99%,副产盐酸,三废量少,已完成中试。

2-Methyl-4-trifluoromethyl-thiazole-5-formyl chloride was prepared in 99% yield(purity>99%)by reaction of 2-methyl-4-trifluoromethyl-thiazole-5-formyl acid with solid phosgene in dichloroethane.The reaction rate was controlled by adjusting the addition speed of chlorinating agent.The solid phosgene could be completely thermally decomposed under reflux,so as to avoid the introduction of de-polymerization agent.The solvent was able to be recycled by distillation and be used for six circulations.