Preparation process of acifluorfen

A technology for the preparation of acifluorfen, which is applied in the field of preparation of acifluorfen, can solve the problems of low yield, harsh reaction conditions of acifluorfen, high production cost, etc., and achieve improved yield, Avoid excessive impurities and high production efficiency

Pending Publication Date: 2020-10-02
西安思科赛实业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the existing industrial production of acifluorfen has the ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The preparation process of acifluorfen is characterized in that it comprises the following steps:

[0028] (1) Pump 180L of concentrated nitric acid and 360L of concentrated sulfuric acid from the tank area to the upper tank of the workshop respectively, put them in the acid mixing kettle and stir for 20 minutes, turn off the stirring, and set aside;

[0029] (2) Add 1100L of DMSO and 500L of water to the reaction kettle, then put in 400kg of m-hydroxymethyl benzoic acid and 234kg of sodium hydroxide, stir, heat and dehydrate until the system is thick, then add 800L of dimethyl sulfoxide, and steam to After the water content of the system is qualified, add 410L of 3,4-dichlorobenzotrifluoride and 5kg of potassium carbonate, raise the temperature of the reaction system to 145°C, keep the temperature for 2h, evaporate the dimethyl sulfoxide under reduced pressure, slowly add 1500L of tap water, dropwise Add 450±50L of hydrochloric acid (6M), adjust the pH of the system to 1-2,...

Embodiment 2

[0033] (1) Pump 180L of concentrated nitric acid and 360L of concentrated sulfuric acid from the tank area to the upper tank of the workshop respectively, put them in the acid mixing kettle and stir for 20 minutes, turn off the stirring, and reserve;

[0034] (2) Add 1200L of DMSO and 500L of water to the reactor, then put in 420kg of m-hydroxymethyl benzoic acid and 250kg of sodium hydroxide, stir, heat and dehydrate until the system is viscous, then add 800L of dimethyl sulfoxide, and steam to After the water content of the system is qualified, add 410L of 3,4-dichlorobenzotrifluoride and 5kg of potassium carbonate, raise the temperature of the reaction system to 150°C, keep the temperature for 1.5h, evaporate the dimethyl sulfoxide under reduced pressure, and slowly add 1500L of tap water. Add 450±50L of hydrochloric acid (6M) dropwise, adjust the pH of the system to 1-2, add 4000L of dichloroethane to extract the stratification, the lower layer is 3-[2-chloro-4-(trifluoromethy...

Embodiment 3

[0038] (1) Pump 180L of concentrated nitric acid and 380L of concentrated sulfuric acid from the tank area to the upper tank of the workshop respectively, put them in the acid mixing kettle and stir for 20 minutes, turn off the stirring, and reserve;

[0039] (2) Add 1100L of DMSO and 500L of water to the reactor, then put in 390kg of m-hydroxymethyl benzoic acid and 234kg of sodium hydroxide, stir, heat and dehydrate until the system is viscous, then add 800L of dimethyl sulfoxide, and steam to After the water content of the system is qualified, add 410L of 3,4-dichlorobenzotrifluoride and 5kg of potassium carbonate, raise the temperature of the reaction system to 135℃, keep the temperature for 1h, evaporate the dimethyl sulfoxide under reduced pressure, slowly add 1500L of tap water, dropwise Add 450±50L of hydrochloric acid (6M), adjust the pH of the system to 1-2, add 3000L of dichloroethane for extraction and layering, and the lower layer is 3-[2-chloro-4-(trifluoromethyl)phe...

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PUM

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Abstract

The invention relates to the technical field of herbicides, and discloses a preparation process of acifluorfen, which comprises the following steps: synthesizing 3-[2-chloro-4-(trifluoromethyl) phenoxy] benzoic acid by using 3, 4-dichlorobenzotrifluoride as a raw material, and carrying out nitration reaction by using concentrated sulfuric acid and concentrated nitric acid as mixed acids to obtainacifluorfen. According to the production process disclosed by the invention, an extracted 3-[2-chloro-4-(trifluoromethyl) phenoxy] benzoic acid solution is directly conveyed to a nitration kettle fornitration reaction, the process is simpler, the production progress can be effectively accelerated, the yield can be effectively increased, the nitration reaction temperature in the process is about 40 DEG C, the reaction time is shorter, the problem of more impurities caused by high temperature and overlong reaction time can be avoided, meanwhile, the time cost can also be saved, and the preparation process has the characteristics of mild reaction conditions and high yield.

Description

Technical field [0001] The invention relates to the technical field of herbicides, in particular to a preparation process of acifluorfen. Background technique [0002] Carboxyfluorfen (5-(2-chloro-2,2,2-trifluoro-p-tolyloxy)-2-nitrobenzoic acid, CAS:50594-66-6) is a contact selective Post-emergence herbicides can be absorbed by the stems and leaves of weeds, and are not easily absorbed by roots in the soil and are easily decomposed by microorganisms. Carboxyfluorfen is safe for the growth of soybeans. As a herbicide, it is mainly used to control broadleaf weeds. Therefore, it is suitable for weed control in soybean fields, including iron-removing amaranth, amaranth, amaranth, ragweed, canola, quinoa, wild watermelon, Cantaloupe, Datura, Morning Glory, Sphaerophyllaceae, Rubiaceae, Polygonum vulgaris, Polygonum spp., Orangutan, etc. Carboxyfluorfen has a better control effect or inhibitory effect on setaria, millet, wild sorghum, sorrel, and cilantro in a specific period. Howev...

Claims

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Application Information

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IPC IPC(8): C07C201/08C07C201/16C07C205/59C07C51/367C07C51/48C07C65/24
CPCC07C201/08C07C201/16C07C51/367C07C51/48C07C65/24C07C205/59
Inventor 陈伟谢丹
Owner 西安思科赛实业有限公司
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