Method for synthesizing 2-(5-fluoro-2, 4 dinitro-phenoxy) acetate

Abstract

The invention discloses a method for synthesizing 2-(5-fluoro-2, 4 dinitro-phenoxy) acetate. 2, 4-dichloro-1, 5-dinitrobenzene serves as a raw material, the 2, 4-dichloro-1, 5-dinitrobenzene and hydroxy acetate are etherified in aprotic polar solvents DMF and react under the action of acid-binding agents and catalysts to obtain 2-(5-chlorine-2, 4 dinitro-phenoxy) acetate, and the 2-(5-chlorine-2,4 dinitro-phenoxy) acetate and potassium fluoride are fluoridated to obtain 2-(5-fluorine-2, 4-dinitro-phenoxy) acetate. Reaction raw materials in all steps are easy to obtain and economical, technological conditions are mild, a line is short, operation is simple and convenient, the method is high in safety and short in reaction time, and industrial production can be popularized.

Description

technical field [0001] The invention relates to the technical field of herbicide production and preparation, in particular to a method for synthesizing 2-(5-fluoro-2,4-dinitrophenoxy) acetate. Background technique [0002] 2-(5-fluoro-2,4-dinitrophenoxy) acetate is a kind of pesticide intermediate, which can synthesize the herbicide flumechlor, which is protoporphyrinogen oxidase ( PPO) inhibitors are used to control weeds and broad-leaved weeds on many crops such as soybeans, cotton, and grapes. The chemical structure of 2-(5-fluoro-2,4-dinitrophenoxy)acetate is as follows. Its chemical structural formula is as follows: [0003] [0004] Among the various synthetic techniques that have been published so far, m-dichlorobenzene is used as a raw material, and the precursor 2-(5-fluoro-2,4-dinitrophenoxy) is obtained through nitration, fluorination, etherification and other steps. When acetic ester is fluorinated from dichloro to difluoro, the amount of tar is large and th...

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Problems solved by technology

[0004] Among the various synthetic techniques that have been published so far, there are m-dichlorobenzene as raw materials, and the precursor 2-(5-fluoro-2,4-dinitrophenoxy) is obtained through nitration, fluorination, etherification and other steps. Acetate, when dichlorofluorinated to difluoro, the amount of tar is large, the product loss is large, etherification will produce impurities that both fluorines are etherified

There is 2,4-difluoronitrobenzene as the raw material, which undergoes hydrolysis, etherification, reduction, nitration, and reduction. Although the raw material is easy to obtain in this route, the route is long and the impurities are high. At the same time, hydrogenation is required twice, and the cost is increased. , cumbersome operation

There is m-fluorophenol as the starting material, although the reaction route is not very long, but the raw material is rare and expensive, the nitration reaction conditions are severe, the ether bond is easy to break, the impurities are high, and the product yield is low

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