Preparation method for 1,2-benzo isothiazolinone

A technology of benzisothiazolinone and o-chlorobenzonitrile, applied in 1 field, can solve the problems of expensive raw materials, long process route, poor production environment and the like

Inactive Publication Date: 2013-06-26
DAFENG YUELONG CHEM
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  • Abstract
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Problems solved by technology

The raw materials of the above first method are relatively expensive, the process route is long, and the cost of industrial production is rel...

Method used

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preparation example Construction

[0026] The invention proposes a preparation method of 1,2-benzisothiazolinone, which includes the following steps or operations.

[0027] Step 1, adding sodium sulfide and sulfur into water to prepare disodium disulfide solution through reaction.

[0028] In one embodiment, this step can be specifically performed as follows: add sodium sulfide to water to make an aqueous solution with a mass percentage of 20%-50%; add equimolar sulfur, heat and stir at 70-100°C until the sulfur is completely dissolved The solution was transparent, and finally a disodium disulfide solution was obtained.

[0029] Step 2, dissolving o-chlorobenzonitrile in an organic solvent to form an o-chlorobenzonitrile solution.

[0030] In one embodiment, this step can be specifically performed as follows: dissolve o-chlorobenzonitrile in an organic solvent to form a 20%-70% o-chlorobenzonitrile solution by mass, and the organic solvent is toluene, chlorobenzene and any one of dichloroethane.

[0031] In ...

Embodiment 1

[0039] Add 0.55 moles of sodium sulfide solid into 100 ml of water to form an aqueous solution with a mass percentage of 30%, stir and heat to 80°C, add 18 grams of sulfur to react, it can be seen that the amount of sulfur and sodium sulfide is equal, continue Heated to 90°C for 2 hours. The resulting solution was transparent and clear.

[0040] Dissolve 1.0 moles of o-chlorobenzonitrile in 300 ml of toluene to form a solution of o-chlorobenzonitrile with a mass percentage of 46.51%, add 6.0 g of catalyst, stir and heat to 100°C, and dropwise add the above-mentioned prepared two Disodium sulfide solution was added in about 2 hours. After the dropwise addition was completed, the reaction was continued for 1 hour. When the o-chlorobenzonitrile content is less than 1.5% when detected by liquid chromatography, the reaction ends. The system was allowed to stand for stratification, the lower water layer was discharged, and the upper layer was bisthiobenzonitrile toluene solution....

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Abstract

The invention discloses a preparation method for 1,2-benzo isothiazolinone, which comprises the following steps of adding sodium sulphide and sulphur into water and reacting so as to prepare sodium disulfide solution; dissolving chlorobenzonitrile into organic solvent so as to prepare chlorobenzonitrile solution; adding a catalyst into the chlorobenzonitrile solution, then dropping the sodium disulfide solution for reaction, and standing for layering, wherein the oil phase product is double sulfo-cyanophenyl solution; and adding water into the double sulfo-cyanophenyl solution for cooling, then aerating oxidant for reacting, heating at the later stage of the reaction, and finally preparing the product of 1,2-benzo isothiazolinone. According to the preparation method for 1,2-benzo isothiazolinone, one the one hand, the production cost for 1,2-benzo isothiazolinone is lowered, on the other hand, the production environment is improved and the preparation method is beneficial to environment protection.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of 1,2-benzisothiazolinone. Background technique [0002] 1,2-Benzisothiazolinone is a broad-spectrum, high-efficiency industrial antifungal and fungicide, which is widely used in the field of coatings. In the past, there were mainly two industrial production processes. One was to use o-aminobenzoic acid as the starting material to produce dithiohydrobenzoic acid, and then to produce 1,2-benzoic acid through acid chloride, chlorination and amination. Isothiazolinone; the other is o-chlorobenzonitrile or o-chlorobenzaldehyde as the starting material, reacted with mercaptan, and then oxidized and cyclized to obtain 1,2-benzisothiazolinone. Above first method raw material is more expensive, process route is long, and industrial production cost is higher, and second method is owing to will use mercaptan raw material, because mercaptan has stench, so pro...

Claims

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Application Information

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IPC IPC(8): C07D275/04
Inventor 卢孔燎陆华
Owner DAFENG YUELONG CHEM
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