Continuous production method for trifluoro monochloro chrysanthemic acid

Abstract

The invention discloses a continuous production method for trifluoro monochloro chrysanthemic acid. The method includes the steps of (1) performing an addition reaction to prepare 3,3-dimethyl-4,6,6-trichloro-7,7,7-trifluoro heptylic acid ester with 3,3-dimethyl-4-pentenoic acid methyl ester and trifluorotrichloroethane as initial raw materials; (2) performing a cyclization reaction with sodium tert-butoxide to generate cis(trans)-3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl cyclocarboxylate; and (3) performing a saponification reaction to prepare 3-(2-chloro-3,3,3-trifluoro-propylene-1-yl)-2,2-dimethylcyclopropane carboxylic acid, namely, the trifluoro monochloro chrysanthemic acid. In the invention, continuous control is employed in the production method, so that the method is simple in process, is high in equipment utilization, is high in yield and stable in quality of products, is low in production cost and has a wide application prospect.

Description

technical field [0001] The invention relates to a preparation method of a compound, in particular to a continuous production method of trifluoro-permethrin. Background technique [0002] Trifluorochrysanthemum acid, also known as Kungfu acid, is chemically named 3-(2-chloro-3,3,3-trifluoro-propen-1-yl)-2,2-dimethylcyclopropanecarboxylic acid. It is an important intermediate of pyrethroids such as kungfuthrin, bifenthrin, tefluthrin and seflumethrin. [0003] The structural formula is as follows: [0004] [0005] The current domestic production method is to use methyl perineate and trifluorotrichloroethane as starting materials, undergo addition, cyclization, saponification, acidification, and then extract, freeze, refine, and dry to obtain trifluoro-trifluoro- Permethrin. The domestic existing technology adopts batch synthesis process. The addition reaction uses cuprous chloride and monoethanolamine as catalysts. The addition reaction produces catalyst tar, which need...

AI Technical Summary

Problems solved by technology

The domestic existing technology adopts batch synthesis process. The addition reaction uses cuprous chloride and monoethanolamine as catalysts. The addition reaction produces catalyst tar, which needs to go through multiple processes such as layering, distillation, water washing, and distillation to obtain the adduct. Addition and cyclization reactions increase the water content of the system due to the batch method synthesis, the reaction speed is slow, the by-products increase, the product yield and quality decrease significantly, the recovered raw materials cannot be used, and the saponification reacts in the methanol system, and the saponification reaction time is long. The yield of crude trifluoro-permethrin is low, the recovery loss of methanol is large, the batch production method is adopted, the production cycle is long, the output is low, the product quality is unstable, the energy consumption is large, the unit consumption of raw materials is high, and the production cost is high, which is not conducive to large-scale production

Images