农药中间体3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸的合成  

Synthesis of pesticide intermediate 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid

作　　者：戴耀 DAI Yao(Dalian Join King Fine Chemical Co.,Ltd.,Dalian 116620,Liaoning,China)

机构地区：[1]大连九信精细化工有限公司,辽宁大连116620

出　　处：《农药》2023年第8期560-564,共5页Agrochemicals

摘　　要：[目的]以丙二酸二乙酯为原料制备3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸。[方法]以丙二酸二乙酯为原料,经过酰基化、脱羧、缩合、环合、氟化及水解反应制备3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸,并进行工艺优化。[结果]最优反应条件下,工艺总收率67%,产品纯度为99.6%,异构体<0.1%。[结论]该工艺开发出一条基于丙二酸二乙酯为原料制备3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸的新方案,原料廉价易得,操作简单,适合工业化生产。[Aims]Using diethyl malonate as starting material,to synthesize 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid.[Methods]With diethyl malonate as starting material,3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid was prepared via acylation,decarboxylation,condensation,cyclization,fluorination and hydrolysis reactions.[Results]Under the best reaction conditions,the total process yield was 67%,and the product purity was 99.6%,with isomer content<0.1%.[Conclusions]A new technique was developed based on diethyl malonate as starting material for producing 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid.And the process is inexpensive and suitable for industrial manufacturing.

关 键 词：丙二酸二乙酯 脱羧 环合 3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸 

分 类 号：TQ460.3[化学工程—制药化工]