CN104817517B - The synthetic method of BIT - Google Patents

Abstract

The synthetic method of 1,2-benzisothiazoline-3-ketone of the present invention, it is to adopt benzamide and sodium thiosulfate to generate 1,2-benzene and isothiazolin-3-one method. The synthesis method of 1,2-benzisothiazolin-3-one of the present invention has the advantages of low cost, few steps, high yield and high environmental protection.

Description

1, the synthetic method of 2-benzisothiazolin-3-ketone

technical field

The invention belongs to the field of fine chemicals, and in particular relates to a synthesis method of 1,2-benzisothiazolin-3-one.

Background technique

Existing 1,2-benzisothiazolin-3-one synthesis techniques mainly contain two kinds: one is to use anthranilic acid as raw material to make bisthiobenzoic acid, and then undergo acyl chloride, chlorination 1,2-benzisothiazolinone is obtained by ammoniation; the other is made of o-aminobenzonitrile or o-chlorobenzaldehyde, reacted with mercaptan, and then oxidized and cyclized to obtain 1,2-benzene and isothiazolinones.

The first process uses chlorine gas as the oxidant. Chlorine gas is a highly toxic gas with high operational requirements. Leakage can easily cause casualties, which puts high demands on the management level and safety measures of the enterprise. The second process uses sodium methyl mercaptan as a raw material. This substance has a foul smell, and the requirements for transportation and use are extremely high. Moreover, the residual methyl mercaptan and the methyl mercaptan released during the production process are very toxic and extremely harmful to the human body. Big.

The types of raw materials for these two processes are complex, and the market price of raw materials is relatively high, which is not conducive to reducing costs and increasing corporate profits. Moreover, multi-step synthesis is adopted, the post-treatment process is complicated, and the amount of waste water is large, which is easy to cause environmental pollution.

Contents of the invention

The technical problem to be solved by the present invention is to provide a synthesis method of 1,2-benzisothiazolin-3-one with low cost, few synthesis steps and simple post-treatment process. .

In order to solve the above-mentioned technical problems, the present invention provides the following technical scheme: a kind of synthetic method of 1,2-benzisothiazolin-3-one, which comprises:

(1) Cyclodextrin, benzamide and water are added in the reaction kettle, stirred evenly after heating, and continue to add catalyst and sodium thiosulfate in the reaction kettle;

(2) feed into air to react, adopt HPLC to detect, when product transformation rate reaches more than 99%, stop feeding into air and heating;

(3) The reaction solution is introduced into the extraction kettle, the reaction solution is extracted with an organic solvent, and the organic phase and the aqueous solution are separated;

(4) Combine the organic phases obtained by the two extractions, and evaporate the organic solvent therein under reduced pressure to obtain the product 1,2-benzisothiazolin-3-one;

(5) The aqueous solution is refluxed in the reactor, and benzamide and sodium thiosulfate are added in the same proportion;

(6) Repeat step (2) to step (6).

As a preferred embodiment of the synthesis method of 1,2-benzisothiazolin-3-one of the present invention, wherein the aqueous solution needs to be cooled after being used twice for each set, and the inorganic salt sodium sulfate is filtered off, to continue to apply.

As a preferred embodiment of the synthetic method of 1,2-benzisothiazolin-3-one of the present invention, wherein said step (1) comprises:

Add cyclodextrin and benzamide with a molar ratio of 0.01:1-0.05:1 into the reactor, and then add water whose mass fraction is 4-10 times the amount of benzamide;

Heat to 40-100°C and stir for half an hour;

The catalyst and sodium thiosulfate are added with a mass fraction of 1%-10% of the amount of benzamide, wherein the molar ratio of sodium thiosulfate to benzamide is 1.2:1.

As a preferred embodiment of the synthesis method of 1,2-benzisothiazolin-3-one in the present invention, wherein the cyclodextrin includes α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin Dextrin and cyclodextrin derivatives.

As a preferred embodiment of the synthetic method of 1,2-benzisothiazolin-3-one of the present invention, wherein said catalyst includes ferrous chloride, ferrous sulfate, ferrous acetate, ferrous nitrate, iodine Cuprous chloride, cuprous acetate, palladium dichloride.

As a preferred embodiment of the synthesis method of 1,2-benzisothiazolin-3-one in the present invention, the step (3) includes: introducing the reaction solution into an extraction kettle and heating to 40-80°C , using 3 times the amount of organic solvent to extract the reaction solution twice, and separate the organic phase and the aqueous solution;

As a preferred embodiment of the synthesis method of 1,2-benzisothiazolin-3-one of the present invention, wherein the organic solvent includes ethyl acetate, butyl acetate, dichloromethane, chloroform and the like.

As a preferred embodiment of the synthesis method of 1,2-benzisothiazolin-3-one in the present invention, wherein said step (4) includes: combining the organic phase obtained by two extractions, heating to 50-90 After ℃, the organic solvent was distilled off under reduced pressure to obtain the product 1,2-benzisothiazolin-3-one.

Compared with the prior art, the present invention has the following beneficial effects:

1. The cost is low, the price of the raw material is cheap, and the cyclodextrin and the catalyst can be recycled, and only the reaction raw material is consumed without additional consumption of other materials.

2. Less steps, one-step reaction instead of multi-step reaction, reducing process difficulty.

3. High environmental protection, using air as the oxidant, no pollution, the amount of post-treatment wastewater is reduced, and the environmental protection pressure of enterprises is reduced.

4. High yield and single-step reaction reduce the invisible consumption of materials.

detailed description

The present invention is described in further detail below in conjunction with embodiment.

Reference herein to "one embodiment" or "an embodiment" refers to a particular feature, structure or characteristic that can be included in at least one implementation of the present invention. "In one embodiment" appearing in different places in this specification does not all refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

The reaction formula of 1,2-benzisothiazolin-3-ketone of the present invention is

Embodiment one:

(1) Add 11.35g of α-cyclodextrin and 105g of benzamide into 420g of water and raise the temperature to 40°C and stir for 30min.

Add catalyst ferrous chloride 6.3g and 189.6g sodium thiosulfate.

(2) insulation feeds air, and HPLC detects, and product transformation rate reaches more than 99%, stops ventilating air.

(3) heat preservation at 40° C., extract the reaction solution twice with three times the amount of solvent ethyl acetate, and separate the organic phase.

(4) The organic phases obtained by the two extractions were combined, kept at 20° C., and the solvent was distilled off under reduced pressure to obtain 142.7 g of the product with a yield of 94.5%.

Embodiment two:

(1) Add 56.75g of β-cyclodextrin and 105g of benzamide into 1000g of water and heat up to 80°C for 30min.

Add catalyst cuprous iodide 9.5g and 189.6g sodium thiosulfate.

(2) insulation feeds air, and HPLC detects, and product transformation rate reaches more than 99%, stops ventilating air.

(3) The temperature was lowered to 40° C., and the reaction solution was extracted twice with three times the amount of solvent ethyl acetate, and the organic phase was separated.

(4) The organic phases obtained by the two extractions were combined, kept at 20° C., and the solvent was distilled off under reduced pressure to obtain 142.7 g of the product with a yield of 94.5%.

Embodiment three:

(1) Add 28.4g of γ-cyclodextrin and 105g of benzamide into 1500g of water and raise the temperature to 60°C and stir for 30min.

8.8 g of catalyst palladium dichloride and 189.6 g of sodium thiosulfate were added.

(2) insulation feeds air, and HPLC detects, and product transformation rate reaches more than 99%, stops ventilating air.

(3) The temperature was lowered to 40° C., and the reaction solution was extracted twice with three times the amount of solvent ethyl acetate, and the organic phase was separated.

(4) The organic phases obtained by the two extractions were combined, kept at 20° C., and the solvent was distilled off under reduced pressure to obtain 142.7 g of the product with a yield of 94.5%.

The above description has fully disclosed the specific implementation manners of the present invention. It should be pointed out that any changes made by those skilled in the art to the specific embodiments of the present invention will not depart from the scope of the claims of the present invention. Accordingly, the scope of the claims of the present invention is not limited only to the foregoing specific embodiments.

Claims (7)

1. a synthetic method for BIT, comprising:

(1) cyclodextrin, benzamide and water are added in reactor, stir after heating, continue to add the one in catalyst ferrous chloride, ferrous sulfate, Ferrous acetate, ferrous nitrate, Hydro-Giene (Water Science)., cuprous acetate, palladium chloride and sodium thiosulfate in reactor；

(2) it is passed through air to react, uses HPLC detection, when conversion rate of products reaches more than 99%, stop being passed through air and heating；

(3) reactant liquor is imported in extraction kettle, with organic solvent, reactant liquor is extracted, isolate organic facies and aqueous solution；

(4) merge the organic facies being obtained by extraction for twice, remove organic solvent therein under reduced pressure, obtain product BIT；

(5) aqueous solution is back in reactor, adds benzamide and sodium thiosulfate in proportion；

(6) step (2) to step (6) is repeated.

The synthetic method of BIT the most according to claim 1, it is characterised in that: described aqueous solution needs to lower the temperature after often applying mechanically 2 times, filters off inorganic salt sodium sulfate therein, could continue to apply mechanically.

The synthetic method of BIT the most according to claim 1, it is characterised in that: described step (1) including:

Cyclodextrin and benzamide that mol ratio is 0.01:1-0.05:1 are added in reactor, then the water of the 4-10 times amount that mass fraction is benzamide amount is added reactor；

It is heated to 40-100 DEG C, stirs half an hour；

Adding mass fraction is the one in the catalyst ferrous chloride of 1%-10% of benzamide amount, ferrous sulfate, Ferrous acetate, ferrous nitrate, Hydro-Giene (Water Science)., cuprous acetate, palladium chloride and sodium thiosulfate, and wherein sodium thiosulfate is 1.2:1 with the mol ratio of benzamide.

The synthetic method of BIT the most according to claim 3, it is characterised in that: described cyclodextrin includes alpha-cyclodextrin, beta-schardinger dextrin-, gamma-cyclodextrin and cyclodextrin derivative.

The synthetic method of BIT the most according to claim 1, it is characterised in that: described step (3) including:

Reactant liquor is imported in extraction kettle, be heated to 40-80 DEG C, at twice reactant liquor is extracted with the organic solvent of 3 times amount, isolate organic facies and aqueous solution.

The synthetic method of BIT the most according to claim 5, it is characterised in that: described organic solvent includes ethyl acetate, butyl acetate, dichloromethane, chloroform.

The most according to claim 11, the synthetic method of 2-benzisothiazole-3-ketone, it is characterized in that: described step (4) including: merge the organic facies being obtained by extraction for twice, after being heated to 50-90 DEG C, remove organic solvent therein under reduced pressure, obtain product BIT.