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Synthesis method of 1, 2-benzisothiazoline-3-ketone

A technology of benzisothiazoline and synthetic method, applied in 1 field, can solve problems such as low yield of raw materials, long reaction time, environmental pollution, etc., and achieve the effects of high yield, less equipment, and reduced production cost

Inactive Publication Date: 2021-04-09
DAFENG YUELONG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a synthetic method of 1,2-benzisothiazolin-3-one, which can solve the problem of low yield, high cost, high toxicity and low utilization rate of raw materials in the prior art, as well as cumbersome steps and reaction problems. Longer time, more by-products and greater pollution to the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0030] The present invention provides a kind of synthetic method of 1,2-benzisothiazolin-3-ketone, it comprises the following steps,

[0031] (1) At room temperature, add 1,2-dimercaptoethane and potassium carbonate to the flask at one time, stir and slowly raise the temperature to 80°C, and keep warm for 1 hour to obtain potassium mercapto salt;

[0032] (2) Add 1,2-dichloroethane as a solvent to the mercaptopotassium salt generated in step (1), then add o-chlorobenzonitrile, control the temperature below 80°C to react, and react to the liquid phase of o-chlorobenzonitrile Residual less than 1% ends;

[0033] (3) Suction filter the solution in step (2), remove excess potassium carbonate and generated potassium bicarbonate, obtain the filtrate, pass the filtrate to chlorine at 40-50°C for oxidative cyclization reaction to generate a mixture of BIT intermediate and BIT ;

[0034] (4) Heat the mixture of BIT intermediate and BIT in step (3) to 80°C, keep warm until the BIT int...

Embodiment 1

[0048] At room temperature, add 94g of 1,2-dimercaptoethane and 345g of potassium carbonate into the flask at one time, stir and slowly raise the temperature to 80°C, and generate potassium mercapto salt after keeping it for 1 hour. Then add 400g of 1,2-dichloroethane as a solvent, and add 247.5g of o-chlorobenzonitrile in 2 times on average, and control the temperature to be less than 80°C. After 4 hours, 0.84% ​​of the o-chlorobenzonitrile liquid phase remains. Excess potassium carbonate and generated potassium bicarbonate are removed by suction filtration, and the obtained filtrate is subjected to a chlorine flow reaction at 40-50° C., and the chlorine flow is stopped when the residual liquid phase of the raw material is less than 12%. Raise the temperature to 80°C for 3 hours, and then slowly cool down to 50°C to obtain the BIT product by suction filtration, rinse with 1,2-dichloroethane solvent twice the mass of the solid and filter with suction, continue to rinse with the...

Embodiment 2

[0050] Potassium carbonate and potassium bicarbonate in Example 1 were treated to obtain potassium carbonate, and the recovered 1,2-dichloroethane in Example 1 was used mechanically.

[0051] At room temperature, add 68g of 1,2-dimercaptoethane and 298g of potassium carbonate obtained after treatment into the flask at one time, stir and slowly raise the temperature to 80°C, and keep warm for 1 hour to form potassium mercapto salt. Then add 375g of 1,2-dichloroethane as a solvent, and add 247.5g of o-chlorobenzonitrile in 2 times on average, and control the temperature below 80°C. After 4 hours, 0.86% of the liquid phase of o-chlorobenzonitrile remains. Excess potassium carbonate and generated potassium bicarbonate are removed by suction filtration, and the obtained filtrate is subjected to a chlorine flow reaction at 40-50° C., and the chlorine flow is stopped when the residual liquid phase of the raw material is less than 12%. Raise the temperature to 80°C for 3 hours, and then...

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PUM

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Abstract

The invention discloses a synthesis method of 1, 2-benzisothiazoline-3-ketone, which comprises the following steps: (1) adding 1, 2-dimercaptoethane and potassium carbonate at room temperature at one time, stirring, and slowly heating to obtain a mercaptopotassium salt; (2) adding 1, 2-dichloroethane as a solvent, then adding o-chlorobenzonitrile, controlling the temperature to be less than 80 DEG C, and reacting until the liquid phase residue of o-chlorobenzonitrile is less than 1%; (3) introducing chlorine into the obtained filtrate at 40-50 DEG C, and carrying out oxidative cyclization reaction to generate a mixture of a BIT intermediate and BIT; and (4) heating the mixture to 80 DEG C, carrying out heat preservation until the BIT intermediate is completely converted into BIT, slowly cooling to 50 DEG C, carrying out suction filtration to obtain a BIT product, and carrying out suction filtration, purification and drying on the BIT product to obtain a BIT pure product. The method provided by the invention has the advantages of short production route, less equipment, simple operation, convenient management, high yield, low raw material cost, recyclable raw materials, small environmental protection pressure and the like.

Description

technical field [0001] The invention belongs to the field of chemical industry, in particular to a synthesis method of 1,2-benzisothiazolin-3-one. Background technique [0002] Now 1,2-benzisothiazolin-3-one synthesis techniques mainly contain three kinds: the first one is to prepare bisthiobenzoic acid with anthranilic acid as raw material, through acyl chloride, chlorination, ammoniation Obtain BIT; the second is to use o-chlorobenzonitrile or o-chlorobenzamide or o-chlorobenzaldehyde as a raw material, react with mercaptan, and then oxidize and cyclize to obtain 1,2-benzisothiazolinone; the second Three kinds of 1,2-benzisothiazolin-3-ones were synthesized through the cyclization reaction of 1,3-benzoxocin-4-one oxides. [0003] The existing technical process is too complicated, which makes the production route too long, requires more reactors and operators, and the reaction time becomes longer. These conditions lead to higher production costs and more problems (such as...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D275/04
CPCC07D275/04
Inventor 杨采风汤青江以桦
Owner DAFENG YUELONG CHEM
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