Synthetic method of bentazone

A synthetic method, the technology of bentazone, applied in the direction of organic chemistry, etc., can solve the problems of high cost of raw materials, difficult process, heavy pollution of three wastes, etc., and achieve the effect of improving the yield of cyclization, high yield and less three wastes

Inactive Publication Date: 2010-10-20
江苏绿利来股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to seek a kind of more ideal method for synthesizing bentazone, so as to overcome the disadvantages of the above-mentioned difficult process, low yield, heavy pollution of three wastes, high cost of raw materials, etc.

Method used

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  • Synthetic method of bentazone
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  • Synthetic method of bentazone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Add 6.6g (0.044M) of phthalic anhydride into the reaction flask, add 8.6g (0.044M) of 18% ammonium hydroxide solution at about 0℃, increase the temperature to 50℃, and slowly add 5.8g of 30% sodium hydroxide solution (0.044M), the speed of adding alkali should not exceed 70℃, and the reaction solution should maintain pH 8.5-8.9, so that phthalic anhydride is completely dissolved. After adding liquid alkali, adjust the pH to 12-13, 60-70 After being kept at ℃ for half an hour, the ammonia will be exhausted (about 3.5 hours) and the amide solution will be obtained. Cool to about -10℃, add 7g (0.22M) of methanol that has been pre-cooled to -10℃, stir, add pre-cooled to -10℃ 10% sodium hypochlorite solution 32.8g (0.044M). React below 0°C for 45 minutes, gradually increase the temperature to 30°C, test with potassium iodide starch test solution, it should show a colorless reaction, add appropriate amount of sodium sulfite solution (20°C) to hydrolyze, wait for the material t...

Embodiment 2

[0023] Feeding: Put 48g of dichloroethane, 17g of triethylamine (0.168M), and 6.4g (0.042M) of methyl anthranilate into reactor B. After cooling to below 10°C, start to add 5.1g of chlorosulfonic acid ( 0.044M), the temperature is controlled below 35℃, after the addition is complete, stir for 30 minutes, then add 2.6g (0.044M) of isopropylamine, stir for 30 minutes, then add 7.1g (0.046M) phosphorus oxychloride dropwise, temperature control Below 50°C, the dropwise addition is completed and stirring is completed for 30 minutes.

[0024] Pour the reacted material in the previous step into 50 g of water, stir for 30 minutes, separate the layers, add 20 mL of dichloroethane to the water layer, and extract twice again, and combine the organic layers. Add liquid caustic soda to the water layer to recover the triethylamine and apply it again.

[0025] Add the above-mentioned organic layer to the reactor C, distill it, recover the dichloroethane, and use it in a similar way. Add 22g of ...

Embodiment 3

[0027] Feeding: Put 48g of dichloroethane, 17g (0.168M) of triethylamine, 6.4g (0.042M) of methyl anthranilate into reactor B, cool to below 10°C, start adding 5.3g of chlorosulfonic acid dropwise ( 0.045M), the temperature is controlled below 35℃, after the addition is complete, stir for 30 minutes, then add isopropylamine 2.8g (0.047M), stir for 30 minutes, then add phosphorus oxychloride 7.5g (0.049M) dropwise, temperature control Below 50°C, the dropwise addition is completed and stirring is completed for 30 minutes.

[0028] Pour the reacted material in the previous step into 50 g of water, stir for 30 minutes, separate the layers, add 20 mL of dichloroethane to the water layer, and extract twice again, and combine the organic layers. Add liquid caustic soda to the water layer to recover the triethylamine and apply it again.

[0029] Add the above-mentioned organic layer to the reactor C, distill it, recover the dichloroethane, and use it in a similar way. Add 22g of methano...

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Abstract

The invention discloses a synthetic method of bentazone, comprising the following steps: taking phthalic anhydride as a main raw material; aminating, degrading and esterifying the phthalic anhydride to obtain methyl anthranilate; taking the methyl anthranilate, chlorosulfonic acid, isopropyl amine and phosphorus oxychloride as raw materials and triethylamine as an acid binding agent to prepare o-isopropylamide sulfonamido-methyl benzoate by a one-pot method; and finally carrying out cyclization and acidizing reaction on the o-isopropylamide sulfonamido-methyl benzoate by utilizing sodium alkoxide to synthesize the bentazone. In the method, the phthalic anhydride with cheap price and wide source is taken as the raw material instead of isopropylamide sulfonyl chloride, the o-isopropylamide sulfonamido-methyl benzoate is directly synthesized by a one-step method and meanwhile a catalyst is added to improve the cyclization yield; the synthetic method has the characteristics of easy operation, less three wastes, high yield, low cost and the like; and the final bentazone product has the yield up to over 85% and the purity up to over 98%.

Description

Technical field [0001] The invention belongs to the field of pesticide synthesis, and specifically relates to a method for synthesizing imazapine. Background technique [0002] The chemical name of Bentazon is 3-isopropyl-(1H)-benzo-2,1,3-thiadiazine-4-one-2,2-dioxide, and its structural formula is [0003] [0004] According to DE2710382 and CN1063688A reports, using isatoic anhydride as a raw material to react with isopropylamine to form N-isopropylanthranilamide, then react with sulfur trioxide to form a complex, and then react with phosphorus oxychloride to obtain the product. The process has complex reactions and is difficult to control. It uses a large amount of picoline as the pyrobolic acid, which is very difficult to recycle, high in cost, and has the disadvantages of large waste water. [0005] According to DE2105687 report, the product is obtained by reacting anthranilic acid and isopropylaminosulfonyl chloride, and then ring-closing with phosgene. According to the DE235...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D285/16
Inventor 许网保魏明阳臧伟新虞国新傅俊周国平徐卫清
Owner 江苏绿利来股份有限公司
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