Synthetic method of cyhalofop-butyl active compound

Abstract

The invention discloses a synthetic method of a cyhalofop-butyl active compound. The method comprises the following steps of: undergoing a condensation reaction on (R)-4-hydroxyphenoxypropanoic acid and 3,4-difluorobenzonilyile serving as raw materials in an organic solvent under an alkaline catalysis condition to generate an intermediate, i.e., (R)-2-[4-(2-fluoro-4-nitrile)-phenoxyl]-propanoic acid; undergoing a photochemical reaction on the intermediate, i.e., (R)-2-[4-(2-fluoro-4-nitrile)-phenoxyl]-propanoic acid to generate an intermediate, i.e., (R)-2-[4-(2-fluoro-4-nitrile)-propionyl chloride; and undergoing a third step esterification reaction on the intermediate, i.e., (R)-2-[4-(2-fluoro-4-nitrile)-propionyl chloride and n-butyl alcohol to generate the cyhalofop-butyl active compound. The method has the advantages of simple process, low production cost, high chemical content, high optical purity and the like.

Description

technical field

[0001] The invention relates to a method for synthesizing the original drug of cyhalofop-ethyl Background technique

[0002] Cyhalofop-methyl, common name cyhalofop-butyl, other names Qianjin, cyhalofop-methyl, chemical name is (R)-2-[4-(4-cyano-2-fluorophenoxy)phenoxy] Butyl propionate. It is mainly used to control gramineous weeds, and has excellent selectivity to rice, etc. It is the only aryloxyphenoxypropionic acid herbicide with high safety to rice. Cyhalofop-ethyl is not only highly effective against various barnyardgrasses (including older barnyardgrass), but also can prevent and control Qianjinzi, crabgrass, double paspalum, foxtail, goosegrass, and kannada.

[0003] According to domestic and foreign literature reports, there are two main synthetic routes of cyhalofop-ethyl at present: (1) the intermediate 4-oxo-(2'-fluoro- 4'-cyanophenoxy)benzenediol (A); (S)-butyl lactate reacts with p-toluenesulfonyl chloride to generate intermediate (S)-2-(4-m...

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