Diflufenican synthesis method

A technology of diflufenapyr and a synthesis method, applied in the field of fenflufen synthesis, can solve the problems of unfavorable fenflufen production yield, increased production cost and high production cost of diflufen The effect of purification treatment, increasing reaction rate and ensuring product purity

Pending Publication Date: 2021-12-24
江苏禾裕泰化学有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] There is 2-chloro-(2,4-difluorophenyl)-nicotinamide in the existing process synthesis route (1), which is easy to hydrolyze, and other impurities will be generated in the reaction, which is not conducive to improving the production yield of diflufenamide , and the post-purification process will increase the production cost of diflufenamide; and in the existing process synthesis route (1) and synthetic route (2), m-trifluoromethylphenol is used as raw material to prepare diflufenamide, and the production cost higher

Method used

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  • Diflufenican synthesis method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Put 42g (0.3mol) of 2-hydroxynicotinic acid into a 500mL four-neck flask, add 200mL of toluene, stir and raise the temperature, add 43g (0.36mol) of thionyl chloride dropwise at 80°C, drop it for 1 hour, and react under reflux 1h, distill off 100mL of solvent to obtain 2-hydroxynicotinyl chloride solution for use;

[0045]Put 38.7g (0.297mol) of 2,4-difluoroaniline and 160mL of toluene into a 500mL four-neck flask, stir and heat to 50°C, add the prepared 2-hydroxynicotinoyl chloride solution dropwise, and control the dropping temperature at 50°C. After 30 minutes of dripping, keep the temperature at 60°C for 1 hour, heat up and reflux for 1.5 hours, after the reaction is over, cool down to 100°C, add 42.8g of potassium carbonate and 0.5g of polyethylene glycol, heat up and reflux for dehydration, and add m-trifluoromethyl after the dehydration is completed Chlorobenzene 56.6g (0.31mol), reflux reaction at 110°C for 2.5 hours, after the reaction was completed, heat filte...

Embodiment 2

[0047] Put 42g (0.3mol) of 2-hydroxynicotinic acid into a 500mL four-neck flask, add 200mL of toluene, stir and raise the temperature, add 43g (0.36mol) of thionyl chloride dropwise at 70°C, drop it for 1 hour, and react under reflux 1.5h, sampling analysis, 2-hydroxynicotinic acid 0.4%, acid chloride content 99.2%, distill off 100mL of solvent to obtain 2-hydroxynicotinyl chloride solution for use;

[0048] Put 38.7g (0.297mol) of 2,4-difluoroaniline and 160mL of toluene into a 500mL four-neck flask, stir and heat to 55°C, add the prepared 2-hydroxynicotinoyl chloride solution dropwise, and control the dropping temperature at 55°C. After 30 minutes of dripping, keep warm at 60°C for 1 hour, heat up and reflux for 2 hours, the material is transparent liquid, sample analysis, N-(2,4-difluorophenyl)-2-hydroxy-nicotinamide content is 98.5%, the reaction is over, cool down To 100°C, add 41.5g (0.3mol) of potassium carbonate and 0.5g of polyethylene glycol, heat up and reflux for d...

Embodiment 3

[0050] Put 42g (0.3mol) of 2-hydroxynicotinic acid into a 500mL four-neck flask, add 200mL of toluene, stir and raise the temperature, add 43g (0.36mol) of thionyl chloride dropwise at 85°C, drop it for 1 hour, and react under reflux 2h, distill off 100mL of solvent to obtain 2-hydroxynicotinyl chloride solution for use;

[0051] Put 38.7g (0.297mol) of 2,4-difluoroaniline and 160mL of toluene into a 500mL four-neck flask, stir and heat to 60°C, add the prepared 2-hydroxynicotinoyl chloride solution dropwise, and control the dropping temperature at 60°C. After 30 minutes of dripping, keep warm at 60°C for 1 hour, heat up and reflux for 2.5 hours, the material is transparent liquid, after the reaction is completed, cool down to 100°C, add 46.8g of potassium carbonate and 0.5g of polyethylene glycol, heat up and reflux for dehydration, and add m-trifluoromethylchlorobenzene 56.6g (0.31mol), 110 ℃ reflux reaction for 3.5h, the reaction is completed, hot filtration, the filtrate i...

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Abstract

The invention provides a diflufenican synthesis method, which comprises the following steps of taking 2-hydroxy nicotinic acid as a raw material, carrying out chlorination reaction on the raw material and thionyl chloride to obtain 2-hydroxy nicotinoyl chloride, carrying out amination reaction on the 2-hydroxy nicotinoyl chloride and 2, 4-difluoroaniline to obtain N-(2, 4-difluorophenyl)-2-hydroxy-nicotinamide, and carrying out etherification reaction onN-(2, 4-difluorophenyl)-2-hydroxy-nicotinamide andm-trifluoromethyl benzene halide. Compared with the prior art, the synthesis method has the advantages that the raw material used in the etherification reaction is the m-trifluoromethyl benzene halide, the raw material used in the etherification reaction in the prior art is the m-trifluoromethyl phenol, the m-trifluoromethyl benzene halide is easier to obtain than the m-trifluoromethyl phenol, and the cost is low; according to the method, the production input cost is reduced while high yield and high content of diflufenican are kept; the synthesis method provided by the invention avoids main side reactions in diflufenican synthesis in the prior art.

Description

technical field [0001] The invention relates to the field of synthesis of diflufenamide, in particular to a method for synthesizing diflufenamide. Background technique [0002] Picolinafen, a compound with a pyridine amide structure, is the first herbicide developed by BASF; Picolinafen has excellent inhibitory and control effects on a variety of weeds; [0003] The mechanism of action of diflufenamide is: diflufenamide belongs to carotenoid biosynthesis inhibitors, and carotenoid biosynthesis inhibitors are called bleaching herbicides. Albino leaves, leading to plant death; the main cause of plant death: (1) flumezamid inhibits the synthesis of carotenoids in plants; (2) flumezamid inhibits the synthesis of chlorophyll in plants; It can inhibit the synthesis of carotenoids, and by inhibiting the activity of phytoene desaturase in plants, the chlorophyll of weed cells will be destroyed, the cells will rupture, and the weeds will die; [0004] Flupyramid has broad applicati...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D213/82
CPCC07D213/82
Inventor 岳晟马正杨胡月赞胡慧琳吴荛正丁露
Owner 江苏禾裕泰化学有限公司
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