Method for synthesizing trifloxystrobin

Abstract

The invention discloses a method for synthesizing trifloxystrobin. Liquid bromine, (E)-2-(2-methyl phenyl)-2-methoxyimno methyl acetate and sodium acetate which are taken as raw materials are subjected to catalytic reaction in a system of an organic solvent and water by taking fluorescent powder and a fluorescent lamp as light sources to form the product. The method comprises the following steps: completely dissolving the raw materials; preparing a trifloxystrobin intermediate through catalytic reaction; preparing an alkaline solution of trifluoromethylacetophenone oxime; and reacting the alkaline solution of trifluoromethylacetophenone oxime with the trifloxystrobin intermediate to obtain the target product trifloxystrobin. The invention has the advantages that the preparation method is simple, practical, high in efficiency, safe and convenient, the product is high in purity and yield, the yield of the final product is over 98 percent, and the purity of the final product is over 95 percent; during synthesis, adopted reagents are low in toxicity and high in economy and have a few side reactions; and because the solvent is recycled, the production cost and the danger coefficient are greatly reduced, the economy is high, and the trifloxystrobin is suitable for industrial large-scale production and meets the current increasing market demand.

Description

Technical field [0001] The invention relates to the preparation of fine chemical products, in particular to a synthesis method of trifloxystrobin. Background technique [0002] Trifloxystrobin: English name Trifloxystrobin, Chinese alias: trifloxystrobin, (2Z)-2-methoxyimino-2-[2-[[1-[3-(trifluoromethyl)phenyl]ethylene Amino]oxymethyl]phenyl]methyl acetate, trifluoropropyl, and hydrochloride, the chemical substance registration number (CAS number) is 141517-21-7, and the molecular formula is C 20 H 19 F 3 N 2 O 4 , molecular weight is 408.37, melting point: 72.9℃, boiling point: 312℃, structural formula is as follows: [0003] [0004] Trifloxystrobin broad-spectrum fungicides are a new class of fluorine-containing fungicides successfully developed using the natural product strobilurins as the lead fungicide compounds. They are highly efficient, broad-spectrum, protective, therapeutic, and eradicative. , penetration, systemic activity, resistance to rain erosion, lo...

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Problems solved by technology

[0007] The main method of synthesizing this compound at present is to use peroxidation reagent to catalyze the bromination process, and there are many shortcomings: 1) incomplete reaction, low product purity, difficult to purify with industrialized methods, and the crude product that this method obtains is unstable; 2 ) The bromination process is difficult to control and easily produces dibromide; 3) Due to the incomplete reaction, 18 tons of bromine-containing waste water is produced for every ton of product produced, which is difficult to treat and seriously pollutes the environment; 4) The chemical properties are unstable and heat , friction, and impact can easily cause decomposition, combustion, or even explosion. It is more unstable when dry, and it will burn when it encounters sulfuric acid. The purity requirement is high, and trace impurities will bring difficulties in reducing the yield and purity.

There are also literatures to prepare (E)-2-(2-bromomethylphenyl)-2-methoxyiminoacetic acid methyl ester under light conditions with liquid bromine, and the total yield is less than 60%. The limitations of the efficiency, the light source can not meet the reaction and other shortcomings, and it is not suitable for industrial mass production

The current trifloxystrobin production company also tried to use various light sources for research, but they all failed because the reaction efficiency of bromination reagents and raw materials was too low to be practical.

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