第 50 卷第 6 期 Vol. 50 No. 6 2020 年 12 月 Dec 2020

所属栏目：农药及中间体 1-甲基-3-（二氟甲基）-1H-吡唑-4-羧酸的绿色合成

尚 宇，黄 艳，张 淳，郭亚飞，李 飞 （陕西省环境监测中心站，陕西 西安 710054）

摘　要：以二氟乙酸乙酯为原料，经Claisen酯缩合、乙氧亚甲基化、环化、水解反应合成了1-甲基-3-（二氟甲基）-1H-吡唑-4-羧酸，并优化了反应条件。优化反应条件下，总收率≥44%，纯度≥99%。中间体及产物结构经1H NMR、MS确认。该工艺操作简单，条件温和。

关键词：1-甲基-3-（二氟甲基）-1H-吡唑-4-羧酸；二氟乙酸乙酯；合成

中图分类号：S482.2　　文献标识码：A　　文章编号：1009-9212（2020）06-0025-04

A Green Route for the Synthesis of 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid

SHANG Yu, HUANG Yan, ZHANG Chun, GUO Ya-fei, LI Fei (Shaanxi Environmental Monitoring Center, Xi′an 710054, China)

Abstract：3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid was prepared using ethyl difluoroacetate as starting material through a series of reactions including ester condensation reaction, ethoxylation, cyclization, and hydrolysis reaction. Its structure was conformed by 1H NMR and MS. Under the optimal reaction conditions, the total yield was over 44% based on the amount of ethyl difluoroacetate used while the purity was up to 99%. This process is simple, warm and economical.

Key words：3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid; ethyl difluoroacetate; synthesis

作者简介：尚 宇（1983—），男，辽宁抚顺人，工程师，主要从事环境监测工作（E-mail：523588666@qq.com）。

收稿日期：2020-11-23