CN113999171A - Synthesis method of high-content dipyrithione - Google Patents
Synthesis method of high-content dipyrithione Download PDFInfo
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- CN113999171A CN113999171A CN202111505855.6A CN202111505855A CN113999171A CN 113999171 A CN113999171 A CN 113999171A CN 202111505855 A CN202111505855 A CN 202111505855A CN 113999171 A CN113999171 A CN 113999171A
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- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/89—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members with hetero atoms directly attached to the ring nitrogen atom
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Abstract
The invention relates to the field of preparation of dipyrithione, and discloses a synthesis method of high-content dipyrithione. The content of the dipyridyl thioketone prepared by the method is more than 98.0%, the yield is improved to more than 90%, the quality requirement of daily chemical products can be met, the process is simple, and the industrial popularization and application are easy.
Description
Technical Field
The invention relates to the field of preparation of dipyrithione, in particular to a synthetic method of high-content dipyrithione.
Background
The dipyrithione has high-efficiency broad-spectrum antibacterial and antifungal effects, is an excellent anti-dandruff and antipruritic agent, has broad-spectrum antibacterial performance, and is widely applied to the fields of transparent plastics, medical intermediates and the like. Due to the unique molecular structure of the dipyrithione, compared with the traditional dandruff remover, namely Zinc Pyrithione (ZPT), the dipyrithione greatly reduces the sensitivity of the dipyrithione to metal ions and can exist in a shampoo system more stably.
Few research reports about the synthetic method of the dipyridyl thioketone at home and abroad are reported, and the dipyridyl thioketone synthesized by the traditional process at present takes 2-mercaptopyridine nitrogen oxide as an initial raw material and is oxidized by a hydrogen peroxide urea system under the weakly acidic condition to prepare the dipyridyl thioketone. However, practice proves that when the hydrogen peroxide urea system is used as an oxidant to synthesize the dipyrithione, more byproducts are generated, so that the yield and the product content of the product are low, the yield is only about 78%, and the content of the dipyrithione is about 96%. The content of the dipyridyl thioketone in daily chemical articles is required to be more than 98%, and the quality of the dipyridyl thioketone prepared by the traditional method cannot meet the requirement.
Disclosure of Invention
The invention aims to provide a method for synthesizing high-content dipyrithione, and aims to solve the problems that the traditional method for synthesizing dipyrithione is low in product yield and content and cannot meet the requirements of daily chemical products.
In order to achieve the purpose, the invention adopts the following technical scheme: a synthesis method of high-content dipyridyl thioketone comprises the steps of dropwise adding an oxidant into a mixed system of 2-mercaptopyridine-N-oxide and an anionic surfactant, heating, preserving heat, and then carrying out suction filtration, washing, refining and drying to obtain solid dipyridyl thioketone, wherein the oxidant is hypochlorous acid-urea solution.
The principle and the advantages of the scheme are as follows: in practical application, in the technical scheme, the anionic surfactant and the oxidant are added into the 2-mercaptopyridine-N-oxide solution, and the oxidant is optimized, so that the problems that the amount of generated byproducts is large when a traditional hydrogen peroxide-urea strong oxidant system is used as the oxidant, and the problems of high raw material residue and long reaction time caused by incomplete reaction when the oxidant with low oxidability is tried are found in the process of optimizing the oxidant. In the research process, the unexpectedly found that when the hypochlorous acid-urea solution is used as the oxidant for synthesizing the dipyrithione, the sufficient oxidability can be ensured, the reaction is complete, the problem that when the traditional hydrogen peroxide-urea solution is used as the oxidant, more byproducts are generated can be avoided, and the yield and the purity of a finished product can be improved; meanwhile, the scheme uses the anionic surfactant which can promote the reaction and has the synergistic effect with the urea hypochlorite system, so that the enough high oxidability is ensured, and the raw material residue is avoided; while avoiding the formation of excessive by-products. Through practical verification, the content of the dipyridyl thioketone prepared by the technical scheme is more than 98.0%, the yield is improved to more than 90%, the quality requirement of daily chemical products can be met, the process is simple, and the industrial popularization and application are easy.
Preferably, as a refinement, the anionic surfactant is sodium dodecylbenzenesulfonate.
In the technical scheme, the sodium dodecyl benzene sulfonate is a common anionic surfactant and a commercially available finished product, is wide in source, easy to obtain and mature in application technology, and experiments prove that the sodium dodecyl benzene sulfonate has a better effect when being used as the anionic surfactant compared with other anionic surfactants such as stearic acid.
Preferably, as an improvement, the preparation method of the hypochlorous acid-urea solution comprises the steps of introducing carbon dioxide gas into a 10-15% sodium hypochlorite solution until the solution is saturated, adding 99% urea, and uniformly stirring to obtain the hypochlorous acid-urea solution.
After a hypochlorous acid-urea oxidation system is developed, the preparation method of the oxidant is designed and researched in a targeted mode, and the oxidant system prepared by the preparation method is stable in property and can meet the reaction requirement.
Preferably, as an improvement, the molar ratio of the hypochlorous acid to the urea in the hypochlorous acid-urea solution is 1.2 to 1.4: 1.0.
In the technical scheme, a hypochlorous acid-urea oxidant system has an important influence on the reaction, a byproduct is generated when the addition amount of the oxidant is too high, the purity and the yield of a product are influenced, raw material residues are caused by incomplete reaction when the addition amount of the oxidant is too low, the yield and the purity of the product are reduced, and the addition ratio is a better addition ratio.
Preferably, as an improvement, the preparation method of the 2-mercaptopyridine-N-oxide comprises the steps of adjusting the pH value of SPT to 1-3 by using concentrated hydrochloric acid, and performing suction filtration to obtain a filter cake, wherein the filter cake is the 2-mercaptopyridine-N-oxide and is directly used for synthesizing the dipyrithione.
In the technical scheme, the pH of the SPT (2-mercaptopyridine oxide sodium salt) solution can be adjusted to 1-3 by using concentrated hydrochloric acid through the method, and the filter cake obtained after suction filtration is 2-mercaptopyridine-N-oxide, so that the filter cake can be directly used for synthesizing the dipyrithione, the subsequent reaction requirements are met, the preparation process is simple, and the method is suitable for industrial popularization and application.
Preferably, as an improvement, the mixed system of the 2-mercaptopyridine-N-oxide solution and the anionic surfactant is heated to 45 ℃ before the oxidant is added dropwise.
In the technical scheme, before the oxidant is dripped, the 2-mercaptopyridine-N-oxide solution and the anionic surfactant are heated, and at the temperature, the oxidant can react with the substance after being dripped, so that the reaction speed is accelerated.
Preferably, as an improvement, the temperature is raised to 55-60 ℃ after the oxidant is dripped, and the heat preservation time is 1-3 h.
In the technical scheme, the temperature of the temperature rise is optimized, the oxidant can be decomposed when the temperature of the temperature rise is too high, the reaction is not facilitated when the temperature is too low, and the temperature range and the heat preservation time are within a proper range.
Preferably, as an improvement, the drying mode is reduced pressure drying, the drying temperature is 55 ℃, and the water content of the dried solid dipyrithione is less than 0.5%.
In the technical scheme, ethanol is adopted for refining, so that the drying requirement can be met at a lower temperature in the later period, and the operation is simple and has no residue.
Detailed Description
The following is a detailed description of the embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; the materials, reagents and the like used are all commercially available.
The scheme is summarized as follows: a method for synthesizing high-content dipyrithione comprises the following steps:
step I: performing nitrogen oxidation reaction, namely adding a solvent, a catalyst and 2-chloropyridine into a reactor, and uniformly stirring, wherein the molar ratio of the 2-chloropyridine to the catalyst is 1: 1-2, and the mass ratio of the 2-chloropyridine to the solvent is 1: 0.5-1; the solvent in this example is distilled water, and the catalyst is a titanium silicalite catalyst (IEZ-Ti-MWW catalyst); then adding hydrogen peroxide dropwise at 40-100 ℃, after the dropwise addition, keeping the temperature and reacting for 2-5h, and after the reaction is finished, cooling and filtering to obtain filtrate, namely the 2-chloropyridine nitrogen oxide solution.
Step II: and (2) carrying out sulfhydrylation reaction, namely adding a sodium hydrosulfide solution and a sodium hydroxide solution into a reaction kettle, wherein the concentration of sodium hydrosulfide is 35-45%, the concentration of sodium hydroxide is 27-32%, dropwise adding a 2-chloropyridine nitrogen oxide solution at 40-100 ℃, keeping the temperature for 1-3h, cooling to 40 ℃ after the reaction is finished, adjusting the pH value to 5-6, adding activated carbon, decoloring and filtering for 1h to obtain a 2-mercaptopyridine oxide sodium salt Solution (SPT). And (3) adjusting the pH value of the SPT to 1-3 by using concentrated hydrochloric acid, and then performing suction filtration to obtain a filter cake, wherein the filter cake is 2-mercaptopyridine-N-oxide and is directly used for synthesizing the dipyrithione.
Step III: synthesis of dipyrithione
(1) Adding 25-35% hydrogen peroxide into 99% urea, and stirring to obtain hydrogen peroxide-urea solution (oxidant).
(2) Introducing carbon dioxide gas into a sodium hypochlorite solution of 10-15% until the sodium hypochlorite solution is saturated, adding 99% urea, and uniformly stirring to obtain a hypochlorous acid-urea solution for later use (an oxidant).
(3) 2-mercaptopyridine-N-oxide, pure water and an anionic surfactant are added into a reactor, wherein the anionic surfactant in the embodiment is sodium dodecyl benzene sulfonate, and the addition amount of the anionic surfactant is 0.5-1% of the molar weight of the 2-chloropyridine-N-oxide. Stirring for dissolving, heating to 45 ℃, dropwise adding an oxidant (hydrogen peroxide-urea solution or hypochlorous acid-urea solution), heating to 55-60 ℃, keeping the temperature for 1-3 hours after dropwise adding, performing suction filtration, washing, refining with ethanol, and drying under reduced pressure at 55 ℃ to obtain a white-like solid, namely the dipyrithione.
Example 1
A method for synthesizing high-content dipyrithione comprises the following steps:
step I: performing nitrogen oxidation reaction, namely respectively adding 100g of 2-chloropyridine, 75g of distilled water and 2g of IEZ-Ti-MWW catalyst into a 500L four-neck flask, stirring, heating to 40 ℃, dropwise adding 97g of hydrogen peroxide with the mass fraction of 35%, and controlling the temperature to be between 60 and 80 ℃. After the dropwise addition, preserving heat for 4 hours, cooling to 40 ℃ after the heat preservation is finished, filtering to obtain 2-chloropyridine nitrogen oxide, and recovering a filter cake as a catalyst for later use;
step II: carrying out sulfhydrylation reaction, adding 117g of 45% sodium hydrosulfide solution and 107g of 32% sodium hydroxide solution into a 1000L four-neck flask, starting stirring and heating to 60 ℃, beginning to dropwise add the obtained filtrate 2-chloropyridine nitrogen oxide, controlling the reaction temperature to be 60-70 ℃, keeping the temperature for reaction for 3h after dropwise addition, cooling to 40 ℃ after heat preservation, dropwise adding 30% hydrochloric acid to adjust the pH value to be 5-6, adding 1g of activated carbon, stirring for 1h, filtering to obtain a filtrate 2-mercaptopyridine oxide sodium salt Solution (SPT), adjusting the pH value of the filtrate to be 1-3 by using 30% hydrochloric acid, and carrying out suction filtration to obtain 104g of filter cake, wherein the filter cake is 2-mercaptopyridine-N-oxide and has the content of 98.0%.
Step III: synthesis of dipyrithione
(1) The oxidant in this example is a hypochlorous acid-urea solution, the mole ratio of hypochlorous acid to urea is 1.2:1.0, and the preparation process is as follows: 300g of 13% sodium hypochlorite solution is weighed and saturated with carbon dioxide gas for later use. 26.5g of 99 percent urea is added into the solution and stirred evenly to obtain the hypochlorous acid-urea solution.
(2) Weighing 100g of 2-mercaptopyridine-N-oxide and 300g of pure water in a 1000ml four-neck flask for dispersion, adding 1.4g of sodium dodecyl benzene sulfonate, stirring for dissolution, heating to 45 ℃, and dropwise adding the prepared hypochlorous acid-urea solution; after the dropwise addition, the temperature is raised to 55-60 ℃, the temperature is kept for 1 hour, and the white solid dipyrithione 90.8g, the content of 99.0 percent and the yield of 92.3 percent are obtained by pumping filtration, washing, ethanol refining and reduced pressure drying at 55 ℃.
Example 2
This example differs from example 1 in that the mole ratio of hypochlorous acid to urea is 1.4: 1.0: in this embodiment, step III: the oxidant is hypochlorous acid-urea solution, and the preparation process comprises the following steps: 350g of 13% sodium hypochlorite solution is weighed and saturated with carbon dioxide gas for use. 26.5g of 99 percent urea is added into the solution and stirred evenly to obtain the hypochlorous acid-urea solution.
In the synthetic step of the dipyrithione, 100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and dispersed in a 1000ml four-neck flask, 1.4g of sodium dodecyl benzene sulfonate is added, stirred and dissolved, the temperature is raised to 45 ℃, hypochlorous acid-urea solution is dripped, after the dripping is finished, the temperature is raised to 55-60 ℃, the temperature is kept for 1 hour, the filtration, the washing and the ethanol refining are carried out, and the reduced pressure drying is carried out at 55 ℃, so that 90.3g of white-like solid dipyrithione is obtained, the content is 98.9 percent, and the yield is 91.8 percent.
Example 3
The present embodiment is different from embodiment 1 in that: in this embodiment, in step III: in the synthesis step of the dipyrithione, the addition amount of the sodium dodecyl sulfate is 2.7g, and 91.2g of white-like solid dipyrithione is obtained, the content is 99.3%, and the conversion rate is 93.1%.
Example 4
The present embodiment is different from embodiment 2 in that: in this embodiment, in step III: in the synthesis step of the dipyrithione, the addition amount of the sodium dodecyl sulfate is 2.7g, and 90.5g of the white-like solid dipyrithione is obtained, the content is 99.1%, and the yield is 92.0%.
Comparative example 1
This comparative example differs from example 1 in that: in the comparative example, hydrogen peroxide-urea solution is used as an oxidant. The preparation process of the hydrogen peroxide-urea solution is as follows: weighing 25g of pure water and 26.5g of urea, stirring for dissolving, weighing 50g of 30% hydrogen peroxide, adding into the urea solution, and uniformly mixing to obtain the urea.
Preparation of bis-pyrithione: weighing 100g of 2-mercaptopyridine-N-oxide and 300g of pure water in a 1000ml four-neck flask for dispersion, adding 1.4g of sodium dodecyl benzene sulfonate, stirring for dissolution, heating to 45 ℃, dropwise adding a hydrogen peroxide-urea solution, heating to 55-60 ℃, keeping the temperature for 1 hour after dropwise adding, carrying out suction filtration, washing, refining with ethanol, and drying under reduced pressure at 55 ℃ to obtain 86.5g of white-like solid dipyrithione, wherein the content is 97.2%, and the yield is 86.5%.
Comparative example 2
This comparative example differs from example 1 in that: no anionic surfactant was added in this comparative example.
100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and dispersed in a 1000ml four-neck flask, stirred and heated to 45 ℃, hypochlorous acid-urea solution is dripped, after the dripping is finished, the temperature is heated to 55-60 ℃, the temperature is kept for 1 hour, the solution is filtered, washed and refined by ethanol, and the solution is dried under reduced pressure at 55 ℃, so that 86.8g of white-like solid dipyrithione is obtained, the content is 97.1%, and the yield is 87.5%.
Comparative example 3
This comparative example differs from example 1 in that: the oxidant in the comparative example is hydrogen peroxide-urea solution, and no anionic surfactant is added. The preparation process of the hydrogen peroxide-urea solution is as follows: weighing 25g of pure water and 26.5g of urea, stirring for dissolving, weighing 50g of 30% hydrogen peroxide, adding into the urea solution, and uniformly mixing to obtain the urea.
Preparation of bis-pyrithione: 100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and put into a 1000ml four-neck flask to be dispersed, stirred and heated to 45 ℃, hydrogen peroxide-urea solution is dripped, after the dripping is finished, the temperature is raised to 55-60 ℃, the temperature is kept for 1 hour, the mixture is filtered, washed and refined by ethanol, and the mixture is dried under reduced pressure at 55 ℃, so that 84.4g of white-like solid dipyrithione is obtained, the content is 96.5 percent, and the yield is 83.7 percent.
Comparative example 4
This comparative example differs from example 1 in that: the oxidant in this comparative example was hypochlorous acid.
Preparation of bis-pyrithione: 100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and put into a 1000ml four-neck flask to be dispersed and stirred, 28g of hypochlorous acid is dripped at normal temperature, the temperature is raised to 55-60 ℃ after the dripping is finished, the temperature is kept for 1 hour, the filtration, the washing and the ethanol refining are carried out, and the reduced pressure drying is carried out at 55 ℃, so as to obtain 76.8g of white-like solid dipyrithione with the content of 95.4 percent and the yield of 75.3 percent.
Comparative example 5
The present embodiment is different from embodiment 1 in that: in this embodiment, in step III: in the synthesis step of the dipyrithione, the addition amount of the sodium dodecyl sulfate is 0.8g, 87.3g of the white-like solid dipyrithione is obtained, the content is 98.4%, and the yield is 88.3%.
Comparative example 6
The present embodiment is different from embodiment 1 in that: in this embodiment, in step III: in the synthesis step of the dipyrithione, the addition amount of the sodium dodecyl sulfate is 3.2g, and 90.7g of the white-like solid dipyrithione is obtained, the content is 99.1%, and the conversion rate is 92.4%.
Comparative example 7
This example differs from example 1 in that the mole ratio of hypochlorous acid to urea is 1.0: in this embodiment, step III: the preparation process comprises the following steps: 250g of 13% sodium hypochlorite solution is weighed and saturated with carbon dioxide gas for use. 26.5g of 99 percent urea is added into the solution and stirred evenly to obtain the hypochlorous acid-urea solution.
In the synthesis step of the dipyrithione, 100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and dispersed in a 1000ml four-neck flask, 1.4g of sodium dodecyl benzene sulfonate is added, stirred and dissolved, the temperature is raised to 45 ℃, hypochlorous acid-urea solution is dripped, after the dripping is finished, the temperature is raised to 55-60 ℃, the temperature is kept for 1 hour, the mixture is subjected to suction filtration, washing and ethanol refining, and the temperature is reduced and dried at 55 ℃, so that 85.7g of white-like solid dipyrithione is obtained, the content is 98.3%, and the yield is 86.6%.
Comparative example 8
This example differs from example 1 in that the mole ratio of hypochlorous acid to urea is 1.6: 1.0. In this embodiment, step III: the preparation process comprises the following steps: 400g of 13% sodium hypochlorite solution was weighed and saturated with carbon dioxide gas for use. 26.5g of 99 percent urea is added into the solution and stirred evenly to obtain the hypochlorous acid-urea solution.
In the synthesis step of the dipyrithione, 100g of 2-mercaptopyridine-N-oxide and 300g of pure water are weighed and dispersed in a 1000ml four-neck flask, 1.4g of sodium dodecyl benzene sulfonate is added, stirred and dissolved, the temperature is raised to 45 ℃, hypochlorous acid-urea solution is dripped, after the dripping is finished, the temperature is raised to 55-60 ℃, the temperature is kept for 1 hour, the filtration, the washing and the ethanol refining are carried out, and the reduced pressure drying is carried out at 55 ℃, so as to obtain 87.6g of white-like solid dipyrithione, the content is 97.4 percent, and the yield is 87.7 percent.
Examples 1 to 4 and comparative examples 1 to 8 were prepared by methods mainly different in the kinds and addition amounts of the oxidizing agent and the anionic surfactant, and for convenience of comparison, the addition amounts shown in table 1 are summarized as the addition amounts corresponding to 100g of 2-mercaptopyridine-N-oxide.
TABLE 1
The content and yield of the off-white solid-dipyrithione prepared in the above examples and comparative examples were measured by liquid phase quantitative measurement, and three parallel tests were performed for each experimental group, and the results are shown in table 2. As is clear from the data in table 2, the present invention can improve the content of dipyrithione to about 99% and the yield of dipyrithione to 90% or more by optimizing the ratio of hypochlorous acid to urea and adding an appropriate amount of surfactant, thereby satisfying the quality requirements of daily use products. The comparative example 1 adopts the traditional hydrogen peroxide-urea solution as an oxidant, so that the content and the yield of the dipyrithione are obviously reduced; comparative examples 2 and 3, in which no anionic surfactant is added, also result in significant reduction in the content and yield of dipyrithione; comparative example 4 yield of dipyrithione was only 75% using hypochlorous acid as the oxidizing agent; the ratio of hypochlorous acid and urea to be added and the amount of anionic surfactant to be added also affect the content and yield of dipyrithione.
TABLE 2
| Mass (g) of dipyrithione | Content of Bipyrithione (%) | Yield of bispyrithione (%) | |
| Example 1 | 90.8 | 99.0 | 92.3 |
| Example 2 | 90.3 | 98.9 | 91.8 |
| Example 3 | 91.2 | 99.3 | 93.1 |
| Example 4 | 90.5 | 99.1 | 92.2 |
| Comparative example 1 | 86.5 | 97.2 | 86.5 |
| Comparative example 2 | 86.8 | 97.1 | 87.5 |
| Comparative example 3 | 84.4 | 96.5 | 83.7 |
| Comparative example 4 | 76.8 | 95.4 | 75.3 |
| Comparative example 5 | 87.3 | 98.4 | 88.3 |
| Comparative example 6 | 90.7 | 99.1 | 92.4 |
| Comparative example 7 | 85.7 | 98.3 | 86.6 |
| Comparative example 8 | 87.6 | 97.4 | 87.7 |
The foregoing is merely an example of the present invention and common general knowledge in the art of designing and/or characterizing particular aspects and/or features is not described in any greater detail herein. It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several variations and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.
Claims (8)
1. A method for synthesizing high-content dipyrithione is characterized in that: and (2) dropwise adding an oxidant into a mixed system of the 2-mercaptopyridine-N-oxide and the anionic surfactant, heating, preserving heat, and then carrying out suction filtration, washing, refining and drying to obtain the solid dipyrithione, wherein the oxidant is a hypochlorous acid-urea solution.
2. The method for synthesizing high-content dipyrithione according to claim 1, wherein: the anionic surfactant is sodium dodecyl benzene sulfonate.
3. The method for synthesizing high-content dipyrithione according to claim 2, wherein: the preparation method of the hypochlorous acid-urea solution comprises the steps of introducing carbon dioxide gas into a 10-15% sodium hypochlorite solution until the solution is saturated, adding 99% urea, and uniformly stirring to obtain the hypochlorous acid-urea solution.
4. The method for synthesizing high-content dipyrithione according to claim 3, wherein: the mole ratio of the hypochlorous acid to the urea in the hypochlorous acid-urea solution is 1.2-1.4: 1.0.
5. The method for synthesizing high-content dipyrithione according to claim 1, wherein: the preparation method of the 2-mercaptopyridine-N-oxide comprises the steps of adjusting the pH value of SPT to 1-3 by using concentrated hydrochloric acid, and performing suction filtration to obtain a filter cake, wherein the filter cake is the 2-mercaptopyridine-N-oxide and is directly used for synthesizing the dipyrithione.
6. The method for synthesizing high-content dipyrithione according to claim 1, wherein: before dropping oxidant, the mixed system of 2-mercaptopyridine-N-oxide aqueous solution and anionic surfactant is heated to 45 ℃.
7. The method for synthesizing high-content dipyrithione according to claim 1, wherein: after the oxidant is dripped, the temperature is raised to 55-60 ℃, and the heat preservation time is 1-3 h.
8. The method for synthesizing high-content dipyrithione according to claim 7, wherein: the drying mode is reduced pressure drying, the drying temperature is 55 ℃, and the water content of the dried solid dipyrithione is less than 0.5%.
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|---|---|---|---|---|
| CN115784977A (en) * | 2023-02-06 | 2023-03-14 | 淄博新农基作物科学有限公司 | Synthesis process of 2-chloro-3-trifluoromethylpyridine |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102875463A (en) * | 2012-08-29 | 2013-01-16 | 滨海明鸿精细化工有限公司 | Synthesis method for high-quality and low-cost bispyrithione |
-
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102875463A (en) * | 2012-08-29 | 2013-01-16 | 滨海明鸿精细化工有限公司 | Synthesis method for high-quality and low-cost bispyrithione |
Non-Patent Citations (3)
| Title |
|---|
| LI SHU’AN 等: "Improved Preparation of 2,2-Dithiobis(Pyridine-N-Oxide)", 《ADVANCED MATERIALS RESEARCH》 * |
| SAIMA 等: "Biocatalytic synthesis of diaryl disulphides and their bio-evaluation as potent inhibitors of drug-resistant Staphylococcus aureus", 《DRUG DEV RES.》 * |
| 李树安等: "双吡啶硫酮的合成改进", 《精细石油化工》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115784977A (en) * | 2023-02-06 | 2023-03-14 | 淄博新农基作物科学有限公司 | Synthesis process of 2-chloro-3-trifluoromethylpyridine |
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