Recovery method of carfentrazone-ethyl

Abstract

The invention discloses a recovery method of carfentrazone-ethyl. The recovery method is characterized in that the carfentrazone-ethyl in low-boiling wastes is hydrolyzed under an alkaline condition so that high-purity 2-chloro-3-[2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxy-1H-1,2,4-triazole-1-yl]-4-fluorophenyl] propionic acid is obtained; and then the high-purity 2-chloro-3-[2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxy-1H-1,2,4-triazole-1-yl]-4-fluorophenyl] propionic acid is esterified so that the carfentrazone-ethyl is obtained; the recovery rate reaches 92% and the content of the product is more than 96%. The new recover process provided by the invention is simple and efficient, safe for operation, high in recovery rate and suitable for industrial production.

Description

technical field [0001] The invention belongs to a recovery method of chemicals, in particular to a new process for recovery of high-purity carfentrazone-ethyl. Background technique [0002] Mefentrazone-ethyl, also known as mefentrazone-ethyl, triafentrazone-ethyl, the chemical name is (RS)-2-chloro-3-[2-chloro-5-(4-difluoromethyl-4,5-di Hydrogen-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl)-4-fluorophenyl]propanoic acid ethyl ester, CAS No: 128639-02-1, was produced by FMC A high-efficiency and low-toxic triazolinone herbicide (WO9002120) developed by the company in 1988. Molecular formula: C 15 h 14 Cl 2 f 3 N 3 o 3 , relative molecular mass: 412.19, its chemical structure is as follows: The current industrial production of carfentrazone-ethyl generally adopts Meerwein arylation reaction, with acetonitrile or acetone as solvent, cuprous chloride as catalyst, sodium nitrite as diazotization reagent to 1-(5-amino-4-chloro -2-fluorophenyl)-4-(difluoromethyl)-3-methyl-1...

AI Technical Summary

Problems solved by technology

Due to the low content of carfentrazone in the low boiling matter, usually only 30-50%, it cannot be applied directly, otherwise the quality of the product will not meet the requirements, so it is generally directly incinerated, which is a waste of product and energy. consumption, and not conducive to the environment

Images