Method for synthesizing Sulfentrazone

A technology of sulfentranacil and methyl, which is applied in the field of synthesizing sulfentranacil, can solve the problems of easy occurrence of steric hindrance in intermediate products, recycling of unfavorable solvents, poor positioning effect, etc., and achieve good positioning effect, small steric hindrance, Benefits of recycling

Active Publication Date: 2017-03-08
JIANGSU REPONT PESTICIDE FACTORY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The beneficial effects of the present invention are mainly reflected in: the overall process is simple, the reaction conditions are mild, the process is safe, the yield is high, the product quality is high, and it is beneficial to industrial production. Amide DMF is a solvent, which is not conducive to solvent recovery and utilization
[0010] The beneficial effects of the present invention are mainly reflected in: using catalytic hydrogenation process, nitro reduction not only has high chemical selectivity, but also is greener, more efficient, safe and reliable, and the catalyst used in the sulfonylation reaction is triphenylphosphine, polyethylene glycol Or crown ether, instead of catalysts such as DMF used before, the side reaction is less, and the yield is high; and the overall process is simple, the reaction conditions are mild, the yield is high, and the product quality is high, which is conducive to industrial production; Disadvantages: The catalyst used in the present invention has poor positioning effect, and some intermediate products need to pass a certain pressure before they can be synthesized
However, there are certain defects in this synthesis: 2,4-dichloroaniline is used as a raw material, the intermediate product is prone to steric hindrance, and the product yield is low

Method used

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  • Method for synthesizing Sulfentrazone
  • Method for synthesizing Sulfentrazone
  • Method for synthesizing Sulfentrazone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Synthesis of 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazol-5-one:

[0035] Dissolve 15g of o-chlorophenylhydrazine hydrochloride in 240g of a dilute solution of 5% potassium carbonate, and extract 2 to 3 times with 500mL of dichloromethane, and add 11g of trimethyl orthoacetate and 100mL of methanol to the extracted organic matter , Stir and reflux for 1-2 hours, then cool to 20-30°C, then add 8g of potassium cyanate and stir for 30-40min, when the temperature drops to 0-2°C, add 6g of glacial acetic acid dropwise, and under the condition of 20-30°C Stirring at low temperature for 18-20 hours, 9g of 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazol-5-one was obtained, calculated as o-chlorophenylhydrazine hydrochloride, 1-o-chlorophenyl The yield of base-3-methyl-1H-1,2,4-triazol-5-one is 51.5%; its specific reaction is as follows:

[0036]

[0037]

Embodiment 2

[0039] Synthesis of 1-o-chlorophenyl-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one:

[0040] Put 16g of 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazol-5-one into the reaction bottle A, and then add 7.3g of potassium hydroxide powder, 10.5g of tetrabutyl bromide Amine and 150mL tetrahydrofuran, stirred and reacted, and when the temperature was raised to 75-85°C, 10g of difluorochloromethane was introduced. After the reaction, cooled to room temperature, tetrahydrofuran was evaporated, then added with 60mL of water, filtered, and dried to obtain 18g of 1-o-chlorobenzene Base-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one, with 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazole Based on -5-ketone, the yield of 1-o-chlorophenyl-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one is 90.7%; its specific reaction is as follows:

[0041]

Embodiment 3

[0043] Synthesis of 1-(2,4-dichlorophenyl)-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one:

[0044] Add 30g of 1-o-chlorophenyl-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one, 150g of dichloroethane and 0.2g of composite catalyst trichloro in reaction flask B Antimony, ferric chloride and silicon dioxide, and lower the temperature to 8 ~ 10 ° C, and then react with 13g of chlorine, after the reaction, add 100mL of water to obtain 33g of 1-(2,4-dichlorophenyl)-3- Methyl-4-difluoromethyl-1,2,4-triazol-5-one, with 1-o-chlorophenyl-3-methyl-4-difluoromethyl-1,2,4-tri Based on oxazol-5-one, the yield of 1-(2,4-dichlorophenyl)-3-methyl-4-difluoromethyl-1,2,4-triazol-5-one is 97.1% ; Its specific reaction is as follows:

[0045]

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Abstract

The invention relates to a method for synthesizing Sulfentrazone. The method is characterized by comprising the steps of liberating o-chlorophenylhydrazine from o-chlorophenylhydrazine hydrochloride, which serves as a raw material, by an alkali, subjecting o-chlorophenylhydrazine to a reaction with trimethyl orthoacetate and potassium cyanate so as to obtain 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazol-5-one, and then, subjecting 1-o-chlorophenyl-3-methyl-1H-1,2,4-triazol-5-one to N-alkylation, chlorination, nitration, reduction and sulfonylation, thereby obtaining the Sulfentrazone, wherein a composite catalyst and a solvent, i.e., dichloroethane are adopted in a chlorination reaction. The method for synthesizing the Sulfentrazone, disclosed by the invention, has the advantages that the o-chlorophenylhydrazine hydrochloride serves as the raw material, so that the steric hindrance of an intermediate product can be low, and the yield of the product is increased; and meanwhile, in the chlorination reaction, the composite catalyst is adopted, thus, the orientation effect on all atoms is good, and the solvent is dichloroethane, so that the recycling of the solvent is facilitated.

Description

technical field [0001] The invention belongs to the technical field of herbicide preparation, in particular to a method for synthesizing sulfentrazone. Background technique [0002] Sulfentrazone is a herbicide belonging to difluoromethyltriazolinones, which has the characteristics of high efficiency, low toxicity and broad spectrum. Its chemical name is N-(2,4-dichloro-5(4- Difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide, the chemical structure is as follows: [0003] [0004] The domestic prior art discloses some researches on the preparation process of sulfentrazone, and the patent CN 104326992 A discloses a method for synthesizing difluoromethyltriazolinone and sulfentrazone, using 1-aryl-3 -Methyl-1H-1,2,4-triazol-5-one is used as a raw material, and is dehydrated into a salt with the aprotic solvent dimethylformamide DMF under the synergistic action of alkali metal hydroxide and alkali metal carbonate Intermediate (D), and...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D249/12
CPCC07D249/12
Inventor 步文君陈学彬秦文华荆和芳
Owner JIANGSU REPONT PESTICIDE FACTORY
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