Preparation method of mesosulfuron

A technology for the synthesis of methylsulfuron-methyl, which is applied in the field of pesticide chemistry, can solve the problems of cumbersome synthesis steps, cumbersome and complicated operations, and difficult availability of raw materials, and achieve the effects of cheap and easy-to-obtain raw materials, simple operation, and low equipment requirements

CN106243046AActive Publication Date: 2016-12-21NANJING UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2016-12-21

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Abstract

The invention discloses a synthesis method of mesosulfuron, and belongs to the fields of pesticide chemistry. The synthesis method is characterized in that mesosulfuron is prepared from 4-chloro-2-aminobenzoic acid through esterification, diazotization, sulfur dioxide introduction, oxychlorination, ammonification cyclization, nitrogen methylation, cyanidation, reduction, ring opening, mesylation and condensation. The method for synthesizing mesosulfuron has the advantages of cheap and easily available raw material, simplicity in operation, mild conditions, low device requirements, high yield, suitableness for industrial production, and strong practicality.
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Description

technical field

[0001] The invention relates to the field of pesticide chemistry, in particular to a method for synthesizing disulfuron-methyl, and the disulfuron-methyl prepared by the invention is particularly suitable for use in pesticides and herbicides. Background technique

[0002] Mesosulfuron-methyl is a new type of sulfonylurea herbicide developed by Bayer AG in 2002. Its common name in English is Mesosulfuron-methyl, and its chemical name is 2-[(4,6-dimethoxypyrimidine-2-aminocarbonyl )aminosulfonyl]-4-(methylsulfonylaminomethyl) methyl benzoate is a novel sulfonylurea herbicide developed by Bayer Corporation developed by Bayer Corporation, mainly used in wheat fields to prevent and control 1-year grass weeds and some broadleaf weeds. The mechanism of action of metsulfuron-methyl and other sulfonylurea herbicides is the same. It inhibits the activity of acetolactate synthase in plants and prevents the biosynthesis of branched-chain amino acids such as valine, isol...

Examples

Embodiment 1

[0051] A kind of synthetic method of methylsulfuron methyl, its steps are as follows:

[0052] 1) Preparation of 4-chloro-2-aminobenzoic acid methyl ester (2)

[0053] Add 17.1g of 4-chloro-2-aminobenzoic acid (0.1mol) and 50mL of methanol into the reaction kettle, stir to dissolve, cool to -5~10°C, slowly add 5mL of thionyl chloride dropwise, after the dropwise addition, remove Ice bath, slowly raised to room temperature, stirred for 0.5h, heated the reaction solution to reflux, reacted for 4-5h, distilled off and added 30mL of methanol, and applied mechanically next time, added the residue into ice water, added sodium bicarbonate to adjust it to neutral properties, filter, and dissolve the filter cake with 100mL of dichloromethane, filter to obtain 2g of unreacted 4-chloro-2-aminobenzoic acid, which can be directly applied to the next esterification reaction, and use 5g of anhydrous sodium sulfate for the dichloromethane layer Dry, filter, and distill off the solvent to obt...

Embodiment 2

[0072] A kind of synthetic method of methylsulfuron-methyl, the steps are as follows:

[0073] 1) Preparation of 4-chloro-2-aminobenzoic acid methyl ester (2)

[0074] Add 17.1g of 4-chloro-2-aminobenzoic acid (0.1mol) and 100mL of methanol into the reaction kettle, stir to dissolve, cool to -5~0°C, slowly add 10mL of thionyl chloride dropwise, after the dropwise addition, remove Ice bath, slowly raised to room temperature, stirred for 0.5h, heated the reaction solution to reflux, reacted for 4h, distilled off and added 70mL of methanol, and applied mechanically next time, added the residue into ice water, added sodium bicarbonate to adjust it to neutral, Filter, dissolve the filter cake with 100 mL of dichloromethane, filter to obtain 1.8 g of unreacted 4-chloro-2-aminobenzoic acid, which can be directly applied to the next esterification reaction, and dry the dichloromethane layer with 5 g of anhydrous sodium sulfate , filtered, and the solvent was distilled off to obtain 1...