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Preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride

A technology of trifluoromethylbenzenesulfonyl chloride and difluoroethoxy, which is applied in the field of preparation of 2--6-trifluoromethylbenzenesulfonyl chloride, can solve environmental and production personnel injuries, high safety hazards, chlorine gas, and cost High-level problems, to achieve the effect of eliminating malodorous odor, high purity and yield, and improving production safety

Active Publication Date: 2018-09-14
CHANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] 2-(2,2-difluoroethoxy)-6-trifluoromethylbenzenesulfonyl chloride is the key intermediate in the preparation of penoxsulam, and the U.S. patent of Dow AgroSciences in 1999 disclosed the price of use 6-trifluoromethyl-2-fluoroaniline, which is expensive and not highly marketable, is used as a raw material to prepare 6-trifluoromethyl-2-fluorobenzenesulfonyl chloride, and the cost is relatively high
The raw materials of the preparation method disclosed in this patent are relatively simple, but in the process, dipropyl disulfide, which produces a pungent stench, and chlorine gas with high potential safety hazards are used, which bring great harm to the environment and production personnel.

Method used

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  • Preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride
  • Preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride
  • Preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0066] The synthesis route of 2-(2,2-difluoroethoxy)-6-trifluoromethylbenzenesulfonyl chloride in this example is as follows, and the specific preparation method includes the following steps:

[0067]

[0068] 1) Add m-trifluoromethylphenol 40.0g (246mmol), dichloromethane 160ml, p-toluenesulfonic acid 0.2g (1.24mmol) into the reaction flask, add 24g 3,4-dihydropyran under cooling to 0°C (295.2mmol), react at 25°C for 2h, add triethylamine to adjust the pH to neutral after the reaction, add 80ml of water after stirring for 10 minutes, let stand to separate layers, add dichloromethane (20ml*3) to extract the water layer , washed, dried over anhydrous magnesium sulfate, and the dichloromethane layer was recovered to obtain a pale yellow liquid, namely the compound represented by formula I (59.9 g, yield 99.0%). 1 H-NMR (300MHZ, CDCl3) δ7.41-7.21 (m, 4H, Ar-H), 5.46 (t, J = 3.1Hz, 1H, pyran ring hydrogen), 3.92-3.84 (m, 1H, pyran ring hydrogen), 3.66-3.60 (m, 1H, pyran ring h...

Embodiment 2

[0076] The preparation method of the present embodiment 2-(2,2-difluoroethoxy)-6-trifluoromethylbenzenesulfonyl chloride comprises the following steps:

[0077] 1) Add m-trifluoromethylphenol 32.0g (197.4mmol), 150ml tetrahydrofuran, ammonium chloride 0.21g (3.94mmol) into the reaction flask, add 3,4-dihydropyran 17.4g (207.3mmol) at room temperature , after the dropwise addition, heat up and react at 66°C for 1 hour. After the reaction, cool down to room temperature and add triethylamine to adjust the pH to neutral. After stirring for 10 minutes, evaporate tetrahydrofuran under reduced pressure, add 65ml of water, and dichloro Extracted with methane (60ml×3), washed the dichloromethane layer with water, dried over anhydrous magnesium sulfate, recovered the dichloromethane to obtain a light yellow liquid, namely the compound shown in formula I (47.1g, content 97.6%, yield 97.0%) ;

[0078] 2) Add 24g (97.2mmol) of the compound shown in Formula I, 0.574g (9.72mmol) of isopropy...

Embodiment 3

[0084] 1) Add m-trifluoromethylphenol 50.0g (308.4mmol), 500ml acetonitrile, aluminum phosphate 1.88g (15.4mmol) in the reaction flask, add 3,4-dihydropyran 129.5g (1.54mol) at room temperature, After the dropwise addition, raise the temperature to 80°C for reflux reaction for 1 hour. After the reaction, cool down to room temperature and add triethylamine to adjust the pH to neutral. After stirring for 10 minutes, evaporate acetonitrile under reduced pressure, add 100ml of water, and dichloromethane (150ml×3) extracted, washed the dichloromethane layer with water, dried over anhydrous magnesium sulfate, recovered the dichloromethane to obtain a light yellow liquid, namely the compound shown in formula I (74.4g, content 93.6%, yield 98.0%);

[0085] 2) Add 30.0g (121.8mmol) of the compound shown in Formula I, 12.3g (121.8mmol) of triethylamine, 110ml of dry cyclohexane into the reaction flask, cool down to 0°C under the protection of argon, and dropwise add 110.7 The cyclohexan...

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Abstract

The invention relates to the technical field of synthesis of pesticides and particularly relates to a preparation method of 2-(2,2-difluoroethyoxyl)-6-trifluoromethyl benzenesulfonyl chloride. The preparation method comprises the following steps: reacting m-trifluoromethylphenol with 3,4-dihydropyran to obtain a compound expressed as a formula (I), reacting the compound expressed as the formula (I) with n-butyl lithium and sulphur to obtain a compound expressed as a formula (II), reacting the compound expressed as the formula (II) under the action of an inorganic acid catalyst to obtain a compound expressed as a formula (III), reacting an alcoholic solution of elementary iodine or an alcoholic solution of iodide with the compound expressed as the formula (III) to obtain a compound expressed as a formula (IV), then reacting the compound expressed as the formula (IV) with carbonate and p-toluenesulfonate difluoroethanol sulfonate to obtain a compound expressed as a formula (V), and reacting the compound expressed as the formula (V) with a chlorination reagent and an oxidation reagent to obtain a final product. Through the preparation method, the generation of foul odor in the conventional synthesis process is avoided; chlorine gas with high risk is not used as the chlorination reagent; the safety in production is greatly improved.

Description

technical field [0001] The invention relates to the technical field of pesticide synthesis, in particular to a preparation method of 2-(2,2-difluoroethoxy)-6-trifluoromethylbenzenesulfonyl chloride. Background technique [0002] Penoxsulam is a post-emergence herbicide developed by Dow AgroSciences. It is a triazolopyrimidine sulfonamide herbicide that inhibits acetolactate synthase (ALS). Works, broad-spectrum weed control. Penoxsulam can not only control a variety of paddy field weeds, but also has a good control effect on barnyardgrass that is resistant to herbicides including sulfonylureas and acetyl-CoA carboxylase inhibitors. With the increasing resistance of aquatic weeds year by year, the application of penoxsulam has also become wider and is favored by users. [0003] 2-(2,2-difluoroethoxy)-6-trifluoromethylbenzenesulfonyl chloride is the key intermediate in the preparation of penoxsulam, and the U.S. patent of Dow AgroSciences in 1999 disclosed the price of use ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C309/87C07C303/16C07C319/02C07C319/24C07C319/22C07C323/20C07D309/12
CPCC07C303/16C07C319/02C07C319/22C07C319/24C07D309/12C07C323/20C07C309/87
Inventor 徐德锋管静
Owner CHANGZHOU UNIV
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