Mefenpyr-diethyl impurity, preparation method and applications thereof

Abstract

The invention discloses a mefenpyr-diethyl impurity, a preparation method and applications thereof, wherein the molecular structural formula is represented by a formula I. The preparation method comprises: carrying out diazotization and a Japp-Klingemann reaction by using 2,4,-dichloroaniline, nitrite and ethyl 2-chloroacetoacetate as raw materials to obtain an intermediate, and carrying out a ring-closure reaction on the intermediate and ethyl methacrylate to obtain 1,5-bis(2,4-dichlorophenyl)-6-methyl-1H,5H-pyrazolo[5,1-c]-1,2,4-triazole-3,6,7a-triethyl tricarboxylate, wherein the yield reaches more than 40%. According to the invention, the method has advantages of mild reaction conditions, low energy consumption, high economic feasibility and high yield; and the substance has the application value in the influence on the efficacy of mefenpyr-diethyl by using the substance as the impurity and in the safety evaluation of the residual substance on agricultural products.

Description

technical field [0001] The present invention relates to the technical field of drug synthesis, in particular to a pyraclofen-ethyl impurity, its preparation method and application. The chemical name of the impurity is 1,5-bis(2,4-dichlorophenyl)-6-methyl -1H,5H-pyrazolo[5,1-c]-1,2,4-triazole-3,6,7a-tricarboxylic acid triethyl ester. Background technique [0002] Mefenpyr-diethyl (mefenpyr-diethyl) is a new herbicide safener announced by the British Brighton Plant Protection Conference in 1999. It is a pyrazole antidote developed by Aventis. It can be used together with herbicides such as methyl disulfone. Keep wheat, barley, etc. from harm. However, some impurities will inevitably be produced during the synthesis of mefenpyr-ethyl. These impurities are not only directly related to the use effect of mefenpyr-ethyl, but also have an important impact on environmental safety and agricultural product safety, thereby posing safety hazards to human health. These impurities have a...

AI Technical Summary

Problems solved by technology

However, some impurities will inevitably be produced during the synthesis of mefenpyr-ethyl. These impurities are not only directly related to the use effect of mefenpyr-ethyl, but also have an important impact on environmental safety and agricultural product safety, thereby posing safety hazards to human health. These impurities have also become one of the important indicators for judging the quality and safety of mefenpyr-ethyl products

However, because there are many types of impurities in mefenpyr-ethyl and the overall content of impurities is small, it has not been successfully separated and confirmed by people.

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