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A kind of preparation method of fenfentrazone intermediate

A technology of fenfentrazone and its intermediates, which is applied in the field of preparation of 2,3-dimethyl-4-methylsulfonylbromobenzene, an intermediate of fenfentrazone, can solve improper operation of peracetic acid and explosion accidents and other issues, to achieve the effect of improved reaction safety, less environmental pollution, and mild reaction conditions

Active Publication Date: 2022-04-29
JIANGSU SEVENCONTINENT GREEN CHEM CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It is well known that improper operation of peracetic acid is prone to explosion accidents

Method used

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  • A kind of preparation method of fenfentrazone intermediate

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Experimental program
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Effect test

Embodiment 1

[0037] Dissolve 51.0g (0.333mol) of 2,3-dimethylanisole in 150g of 1,2-dichloroethane, add 67.4g (0.399mol) of hydrobromic acid aqueous solution with a concentration of 48% by mass, Then add 0.5g (0.00375mol) aluminum trichloride and 1g (0.003mol) sodium tungstate, start stirring, and start to drop 97.0g (0.999mol) of hydrogen peroxide with a mass percentage concentration of 35% at 20-30°C, about The dropwise addition was completed in 1 hour, and the mixture was heated to 50° C. for 3 hours, and a large amount of solid was precipitated. Suction filtration under reduced pressure, rinse the filter cake with an appropriate amount of 1,2-dichloroethane, and dry to obtain 70.2 g of 2,3-dimethyl-4-methylsulfonylbromobenzene, with a GC purity of 98.1% and a yield of 78.6 %.

Embodiment 2

[0039] Dissolve 51.0g (0.333mol) of 2,3-dimethylanisole in 200g of methanol, add 67.4g (0.399mol) of hydrobromic acid aqueous solution with a mass percent concentration of 48%, and then add 0.5g (0.00375 mol) aluminum trichloride and 1g (0.003mol) sodium tungstate, start stirring, start dropwise adding 97.0g (0.999mol) of hydrogen peroxide with a mass percentage concentration of 35% at 20-30°C, and drop it in about 1 hour. After the addition, it was heated to 50° C. for 3 hours, and a large amount of solid was precipitated. After suction filtration under reduced pressure, the filter cake was rinsed with an appropriate amount of methanol and dried to obtain 70.5 g of 2,3-dimethyl-4-methylsulfonylbromobenzene, with a GC purity of 98.5% and a yield of 79.3%.

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Abstract

The invention relates to a preparation method of a fenflumezone intermediate, in which 2,3-dimethylanisole, hydrobromic acid, and hydrogen peroxide are reacted in a solvent in the presence of a catalyst to prepare 2,3-dimethoxyanisole Methyl-4-methylsulfonylbromobenzene. The present invention adopts the raw material that is easy to buy in the market, and produces the product by "one-step method", which simplifies the operation steps, and at the same time, has mild reaction conditions, less environmental pollution, significantly improved reaction safety, and is more suitable for industrial scale production.

Description

technical field [0001] The invention belongs to the technical field of chemistry and chemical engineering, and in particular relates to a preparation method of fenfentrazone intermediate-2,3-dimethyl-4-methylsulfonylbromobenzene. Background technique [0002] Topramezon (Topramezon) is the first benzopyrazolone herbicide developed by BASF. Conducted to the top and base to the meristem, by inhibiting the 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) in the biosynthesis of plastoquinone, indirectly affecting the synthesis of carotenoids, thereby interfering with the synthesis of chloroplasts and function, eventually leading to severe bleaching. Sensitive weeds usually show whitish symptoms within 2 to 5 days after treatment, and the poisoning symptoms in the aboveground growth areas (growing points, internodes, leaves and leaf veins) are the most obvious, and the growth of weeds is inhibited at the same time. Under light, the chlorotic tissue is necrotic and the plants usuall...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C315/02C07C317/14
CPCC07C315/02C07C317/14
Inventor 陶伟叶永胜包浩顾怡丁菲
Owner JIANGSU SEVENCONTINENT GREEN CHEM CO LTD