CN111303074A - Process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide - Google Patents
Process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide Download PDFInfo
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- CN111303074A CN111303074A CN202010194095.0A CN202010194095A CN111303074A CN 111303074 A CN111303074 A CN 111303074A CN 202010194095 A CN202010194095 A CN 202010194095A CN 111303074 A CN111303074 A CN 111303074A
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- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D277/00—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings
- C07D277/60—Heterocyclic compounds containing 1,3-thiazole or hydrogenated 1,3-thiazole rings condensed with carbocyclic rings or ring systems
- C07D277/62—Benzothiazoles
- C07D277/68—Benzothiazoles with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached in position 2
- C07D277/70—Sulfur atoms
- C07D277/76—Sulfur atoms attached to a second hetero atom
- C07D277/80—Sulfur atoms attached to a second hetero atom to a nitrogen atom
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Abstract
The invention discloses a process for preparing NS by oxidizing M-tert-butylammonium salt with hydrogen peroxide, relates to a new synthesis process, particularly relates to a new process for synthesizing NS, and belongs to the technical field of chemical synthesis. The invention is characterized in that: mixing raw material M and tert-butylamine, pulping, adding a small amount of iodized salt (KI, NaI, KIO)3、I2Etc.), dropping oxidant hydrogen peroxide under the condition of stirring and heating, and obtaining the product NS after oxidation synthesis.
Description
Technical Field
The invention relates to a new synthesis process, in particular to a new process for synthesizing NS. Belongs to the technical field of chemical synthesis.
Background
NS, namely N-tertiary butyl-2-benzothiazole sulfonamide (accelerator NS or TBBS) is one of important varieties of sulfenamide vulcanization accelerators, and is a rubber vulcanization accelerator with excellent performance and has the advantages of scorch resistance and high vulcanization speed. The high-activity post-effect accelerator is widely applied to natural rubber, styrene-butadiene rubber, butadiene rubber and isoprene rubber, is a highly active post-effect accelerator in various accelerators at present, has high processing safety, and vulcanized rubber has good physical properties, mechanical properties and ageing resistance and short vulcanization time. The rubber is mainly used for manufacturing industrial rubber products such as tires, rubber tubes, rubber shoes, cables and the like, the development of the radial tire industry in China is fast, and the requirement on a vulcanization accelerator NS is more urgent.
There are four main methods for the synthesis of accelerator NS: (1) sodium hypochlorite oxidation: and (3) reacting the promoter M (2-mercaptobenzothiazole) with tert-butylamine in the presence of an oxidant sodium hypochlorite to generate NS. The disadvantages of this process are the difficulty in recovering tert-butylamine and the large amount of industrial waste water produced. (2) A catalytic oxidation method: copper acetate or cobalt phthalocyanine is used as a catalyst, and oxygen is used for oxidation. The method has the disadvantages of explosive oxygen, high technical safety difficulty, overlong reaction time or requirement of a pressure device and overlarge equipment investment. (3) Electrolytic oxidation method: and oxidizing the M and the tert-butylamine to generate the accelerator NS under the electrolytic action. The disadvantage is that the technique is not mature and is in the experimental stage. (4) Chlorine oxidation method: and (3) oxidizing the M and tert-butylamine by using chlorine as an oxidizing agent to generate NS. The defects are that the operation is difficult, the chlorine method process has serious harm to human bodies and the environment, and the treatment difficulty of the generated organic wastewater containing salt is large. The methods either cause a large amount of pollution or have overlarge equipment investment or immature technology, and the production processes do not meet the requirements of green chemical industry and clean production.
The invention content is as follows:
the invention aims to provide a novel process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide under the catalysis of iodide, which has the advantages of simple operation, mild condition, no salt generation and easy realization of industrialization. The process is clean and environment-friendly, and the product has high melting point and stable yield.
The purpose of the invention is realized by the following technical scheme:
the invention relates to a novel process for preparing NS by oxidizing M tert-butylammonium salt with iodide catalytic hydrogen peroxide, which is characterized in that: mixing raw material M and tert-butylamine, pulping, adding a small amount of iodized salt (KI, NaI, KIO)3、I2Etc.), dropwise adding an oxidant hydrogen peroxide under the condition of stirring and heating, oxidizing and synthesizing to obtain a product NS, and separating the product to obtain the tert-butylamine which can be recycled.
A process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide uses promoter M and tert-butylammonium salt as raw materials, iodide as catalyst, and hydrogen peroxide to oxidize NS.
The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide comprises the following steps:
(1) mixing M, tert-butylamine and water, pulping, stirring at a certain temperature to form M tert-butylammonium salt, detecting by TLC that no free M remains, and adding catalyst iodide;
(2) heating the mixed solution obtained in the step (1) and adding hydrogen peroxide dropwise;
(3) after the dropwise addition is finished, the reaction is carried out in a heat preservation way until no M tert-butylammonium salt is left in TLC detection, namely the end point;
(4) cooling, centrifuging, washing, drying a filter cake to obtain an NS finished product, and recycling tert-butylamine from the filtrate for reuse.
The process route is as follows:
the molar ratio of the tert-butylamine to the M in the step (1) is 1-10: 1.
More preferably, the molar ratio of tert-butylamine to M is 1.5-2.5: 1.
Preferably, the molar ratio of the water to the M in the step (1) is 0.28-2.5: 1; more preferably, the molar ratio of water to M is 0.28-1.5: 1.
Preferably, the temperature in step (1) is 20-30 ℃.
Preferably, the TLC checking method described in step (1): taking out the feed liquid, adding toluene or ethyl acetate for extraction, and carrying out TLC detection.
Preferably, the iodide salt catalyst in the step (1) is KI, NaI or KIO3、I2And the like. Further preferably, the iodized salt catalyst is KI or KIO3、I2One kind of (1).
Preferably, the mass ratio of the catalyst to the M in the step (1) is 0.0001% to 10%: 1. more preferably, the mass ratio of the catalyst to M is 0.001% to 2%: 1.
preferably, the reaction temperature in the step (2) is-10 to 30 ℃, and further preferably, the reaction temperature is 0 to 30 ℃.
Preferably, the mass concentration of hydrogen peroxide in the step (2) is 5-35%, and further preferably 10-27.5%.
Preferably, the ratio of the amount of the hydrogen peroxide species in step (2) M is 1: 1.0 to 2.0. Further preferably, the ratio of the amount of M to the amount of hydrogen peroxide species is 1: 1.0 to 1.5.
Preferably, the dropping time of the hydrogen peroxide in the step (2) is 0.5-120min, and further preferably is 0.5-30 min.
Preferably, the mass concentration of the tert-butylamine recovered in the step (4) is more than 80%.
The invention has the beneficial effects that:
the iodide catalytic mechanism is to adjust the oxidability of hydrogen peroxide, and the specific mechanism is as follows: the low-valence iodide can be oxidized into the high-valence iodide by hydrogen peroxide, so that the oxidizing property of the hydrogen peroxide is reduced, and the high-valence iodide can also play an oxidizing role and is reduced back to the low-valence iodide, so that a new round of regulation on the oxidizing property of the hydrogen peroxide is formed, and the problem of peroxidation of raw materials is solved.
The iodide used as the catalyst can be dissolved in the mother liquor, so that the catalyst separation operation can be reduced, the application of the catalyst is facilitated, the loss of the catalyst is reduced, the operation steps are simplified, and the raw material cost and the production cost are saved. And catalysts such as iron phthalocyanine and the like are insoluble in a water phase and finally enter products, so that the ash content of the products is influenced, and the service performance of downstream products is influenced. The iodide catalysis can avoid the problem, the iodide can not enter the product, and the product quality is not influenced while the catalytic effect is exerted.
The process takes M as a raw material, tert-butylamine as a raw material and water as a solvent, mother liquor is dehydrated and concentrated after the tert-butylamine is recovered, the catalyst-containing mother liquor is directly used, hydrogen peroxide is used as an oxidant, and a small amount of iodized salt is used for catalyzing to synthesize NS, so that the problems of three wastes and safety are fundamentally solved.
The process has the advantages of simple operation, mild conditions and no waste salt, the amount of the process waste water is only the raw material hydrogen peroxide water and the reaction generated water, the amount of the waste water is obviously reduced, and the industrialization is easy to realize. The process is clean and environment-friendly, and the product has high melting point and high yield.
The specific implementation mode is as follows:
example 1
167.25g of accelerator M is added into 109.71g of tert-butylamine and 20g of water for pulping, the temperature is raised to 30 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, 0.2gKI is added after TLC detection of no free M, heating is carried out to 30 ℃, and 156.4g of hydrogen peroxide with the concentration of 27.5 percent is dropwise added. Dropwise adding hydrogen peroxide for 10min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.4 ℃, purity 98.6%, yield: 98.1 percent, and the appearance of the product is white particles.
Example 2
167.25g of accelerator M is added into 182.85g of tert-butylamine and 5g of water for pulping, the temperature is raised to 20 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, and 0.01gI is added after TLC (thin layer chromatography) detection of no free M2And heating to 25 ℃, adding 156.4g of 27.5% hydrogen peroxide, dropwise adding the hydrogen peroxide for 10min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.2 ℃, purity 99.5%, yield: 98.2 percent, and the appearance of the product is white particles.
Example 3
167.25g of accelerator M is added into 167.1g of tert-butylamine and 10g of water for pulping, the temperature is raised to 30 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, 0.8g of KIO is added after TLC (thin layer chromatography) detection of free M3And continuously keeping the temperature at 30 ℃, and dropwise adding 172.1g of hydrogen peroxide with the concentration of 25.1 percent. Dropwise adding hydrogen peroxide for 30min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.6 ℃, purity 99.2%, yield: 98.6 percent, and the appearance of the product is white particles.
Example 4
167.25g of accelerator M is added into 150.2g of tert-butylamine and 15g of water for pulping, the temperature is raised to 28 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, 1gKI is added after TLC detection of no free M, the temperature is kept at 20 ℃, and 172.1g of hydrogen peroxide with the concentration of 25.1 percent is added dropwise. Dropwise adding hydrogen peroxide for 20min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.4 ℃, purity 99.2%, yield: 98.1 percent, and the appearance of the product is white particles.
Example 5
167.25g of accelerator M is added into 167.1g of recovered tert-butylamine to be pulped, the temperature is raised to 40 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, and 0.1gI is added after TLC (thin layer chromatography) detection of no free M2Heating to 30 ℃, and dropwise adding 215.1g of 20% hydrogen peroxide. Dropwise adding hydrogen peroxide for 30min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.1 ℃, purity 99.3%, yield: 98.2 percent, and the appearance of the product is white particles.
Example 6
167.25g of accelerator M is added into mother liquor containing catalyst, 155.1g of tert-butylamine is dripped into the mother liquor to be pulped, the temperature is raised to 60 ℃, stirring is carried out to ensure that all M and tert-butylamine are combined into salt, after no free M is detected, the temperature is lowered to 40 ℃, 158.2g of hydrogen peroxide with the concentration of 27 percent is added, and the heat preservation reaction is carried out until no M tert-butylammonium salt is left after TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.8 ℃, purity 99.4%, yield: 99.1%, the appearance of the product is white particles.
Example 7
167.25g of accelerator M is added into 75g of tert-butylamine and 45g of water for pulping, the temperature is raised to 20 ℃, stirring is carried out, all M and tert-butylamine are combined into salt, 0.2g of NaI is added after TLC detection of no free M, heating is carried out to 30 ℃, and 156.4g of hydrogen peroxide with the concentration of 27.5 percent is dropwise added. Dropwise adding hydrogen peroxide for 80min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.4 ℃, purity 98.6%, yield: 96.3 percent, and the appearance of the product is white particles.
Example 8
167.25g of accelerator M is added into 80g of tert-butylamine and 40g of water for pulping, the temperature is raised to 30 ℃, stirring is carried out, all M and tert-butylamine are combined into salt, 0.2gKI is added after TLC detection of no free M, the temperature is kept at 15 ℃, and 156.4g of hydrogen peroxide with the concentration of 27.5 percent is dripped. Dropwise adding hydrogen peroxide for 60min, and carrying out heat preservation reaction until no M tert-butylammonium salt is left in TLC detection. And cooling, centrifuging, washing, recovering tert-butylamine, and drying a filter cake to obtain an NS finished product. Initial melting point: 107.4 ℃, purity 97.6%, yield: 97.1 percent, and the appearance of the product is white particles.
Although the present invention has been described with reference to the specific embodiments, it is not intended to limit the scope of the present invention, and various modifications and variations can be made by those skilled in the art without inventive changes based on the technical solution of the present invention.
Claims (10)
1. A process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide is characterized in that an accelerator M and tert-butylammonium salt are used as raw materials, iodide is used as a catalyst, and NS is oxidized with hydrogen peroxide.
2. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 1, comprising the steps of:
(1) mixing M, tert-butylamine and water, pulping, stirring at 20-30 ℃ to form M tert-butylammonium salt, detecting by TLC that no free M remains, and adding catalyst iodide;
(2) heating the mixed solution obtained in the step (1) and adding hydrogen peroxide dropwise;
(3) after the dropwise addition is finished, the reaction is carried out in a heat preservation way until no M tert-butylammonium salt is left in TLC detection, namely the end point;
(4) cooling, centrifuging, washing, drying a filter cake to obtain an NS finished product, and recycling tert-butylamine from the filtrate for reuse.
3. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the molar ratio of tert-butylamine to M in step (1) is 1-10: 1; preferably, the molar ratio of the tert-butylamine to the M is 1.5-2.5: 1.
4. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the molar ratio of water to M in the step (1) is 0.28-2.5: 1; preferably, the molar ratio of water to M is 0.28-1.5: 1.
5. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 1, wherein the iodonium salt catalyst is KI, NaI, KIO3、I2One or more of the above; preferably, the iodide salt catalyst is KI or KIO3、I2One kind of (1).
6. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the mass ratio of the catalyst in the step (1) to M is 0.0001-10%: 1; preferably, the mass ratio of the catalyst to the M is 0.001-2%: 1.
7. the process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the reaction temperature in the step (2) is-10 to 30 ℃; preferably, the reaction temperature is 0 to 30 ℃.
8. The process for preparing NS by oxidizing M-tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the mass concentration of hydrogen peroxide in the step (2) is 5-35%; the preferable mass concentration of the hydrogen peroxide is 10-27.5%.
9. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the mass ratio of M to hydrogen peroxide in the step (2) is 1: 1.0 to 2.0; further preferably, the ratio of the amount of M to the amount of hydrogen peroxide species is 1: 1.0 to 1.5.
10. The process for preparing NS by oxidizing M tert-butylammonium salt with hydrogen peroxide according to claim 2, wherein the dropping time of hydrogen peroxide in the step (2) is 0.5-120 min; the preferable dropping time of the hydrogen peroxide is 0.5-30 min.
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CN115109010A (en) * | 2022-07-20 | 2022-09-27 | 聊城金歌合成材料有限公司 | Method for preparing accelerator NS by oxidizing hydrogen peroxide in organic solvent |
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CN101717380A (en) * | 2009-12-09 | 2010-06-02 | 河南省开仑化工有限责任公司 | Clean production method of rubber vulcanizing accelerator TBBS |
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Cited By (1)
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CN115109010A (en) * | 2022-07-20 | 2022-09-27 | 聊城金歌合成材料有限公司 | Method for preparing accelerator NS by oxidizing hydrogen peroxide in organic solvent |
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