Preparation method of trifloxystrobin intermediate (E)-2-(2-bromomethyl phenyl)-2-methoxylimidomethyl acetate

Abstract

The invention discloses a preparation method of a trifloxystrobin intermediate (E)-2-(2-bromomethyl phenyl)-2-methoxylimidomethyl acetate. According to the preparation method, the (E)-2-(2-bromomethyl phenyl)-2-methoxylimidomethyl acetate, which is obtained by performing chlorination, cyanation, hydrolyzation, esterification and oximation through O-methylbenzoic acid, is used as raw material; through analysis of a bromination reaction process, hydrogen bromide released in a bromination reaction process is converted to bromine by using an oxidizing agent; the bromine continuously takes part in reaction; and a synthetic process condition is optimized, so that the utilization rate of bromine atoms is improved, a content and a yield of bromide product are improved, the quality of trifloxystrobin product is improved, the discharge of bromide-containing wastewater is reduced, the corrosion to equipment and the pollution to the environment are reduced and the production cost is reduced.

Description

Technical field [0001] The invention belongs to the technical field of chemical synthesis, and specifically relates to a preparation method of trifloxystrobin intermediate (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester. Background technique [0002] Trifloxystrobin broad-spectrum fungicides are a new class of fluorine-containing fungicides successfully developed from the natural product strobilurins as the lead fungicide compound. They are highly efficient, broad-spectrum, protective, curative, eradicating, penetrating, systemic activity, and rain-resistant. Washout, long lasting and other properties. [0003] There are currently few literature reports on the synthesis of trifloxystrobin. Among them, the preparation methods of intermediate (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester are all based on liquid bromine or NBS is a bromination reagent that performs bromination reactions under the trigger of AIBN, BPO or light. Since the ...

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Problems solved by technology

[0003] At present, there are few bibliographical reports on the synthesis of trifloxystrobin, and the preparation methods of the intermediate (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester are all based on liquid bromine or NBS is a bromination reagent, and the bromination reaction is carried out under the trigger of AIBN, BPO or light. Since the bromination reaction will generate hydrogen bromide, the utilization rate of bromine atoms is only 50% at most, so the utilization rate of bromine atoms is low, and its atom economy and the reaction selectivity is poor, the yield of the intermediate (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester generated by the bromination reaction and the quality of the product The level will directly affect the quality of trifloxystrobin; and a large amount of bromine-containing wastewater produced in the bromination reaction process is difficult to handle, causing serious environmental pollution, which does not conform to the development trend of modern organic synthesis green chemistry, nor does it meet the actual industrial use needs

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