Synthesis method of thiophanate-methyl
By loading modified dialkylaniline onto a lithium magnesium silicate support, the problems of catalyst dispersion and stability in the aqueous synthesis of methylthiophanate were solved, achieving efficient and stable synthesis of methylthiophanate, improving yield and purity, and demonstrating good potential for industrial application.
Patent Information
- Application Number
- CN202511658124.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2026-01-23
AI Technical Summary
Existing catalysts for the aqueous synthesis of methyl thiophanate have poor dispersibility, are prone to floating or agglomeration, resulting in low mass transfer efficiency, low reaction rate and conversion rate, and poor catalyst stability, making them easy to deactivate.
Modified dialkylaniline was used as a catalyst and supported on a lithium magnesium silicate support. Through intercalation modification and silane coupling agent modification, the specific surface area and dispersibility of the catalyst were increased to ensure sufficient contact with the reactants. By controlling the dropping method of o-phenylenediamine, side reactions were suppressed, and the selectivity and yield were improved.
It significantly improves the yield and purity of thiophanate-methyl, enhances catalytic activity, extends catalyst life, is easy to operate, and has good prospects for industrial application.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of pesticide synthesis, in particular to a synthesis method of thiophaim. BACKGROUND
[0002] Thiophaim, chemical name 1,2-di(3-methoxycarbonyl-2-thioureido) benzene, is a high-efficiency, broad-spectrum endosporal benzimidazole fungicide. It has excellent preventive and therapeutic effects on fungal diseases of various crops, such as powdery mildew, anthracnose, bunt, and so on. Although thiophaim itself does not directly have fungicidal activity, it can be rapidly metabolized into carbendazim in the plant body and external environment conditions, thereby exerting its fungicidal effect, and thus occupies an important position in agricultural production.
[0003] Thiophaim is usually prepared by reacting methyl isothiocyanate and o-phenylenediamine, and the synthesis method of methyl isothiocyanate can be mainly divided into two categories: organic solvent method and aqueous phase method. Among them, the organic solvent method has the problems of liquid-solid-solid three-phase system, which is not conducive to heat and mass transfer and post-reaction treatment, because the raw material is solid sodium thiocyanate, and sodium chloride is also generated during the reaction of generating methyl isothiocyanate.
[0004] The aqueous phase method uses water as the main reaction medium, which greatly reduces environmental pollution and production risk. At present, this process often uses organic amine compounds such as dialkyl aniline as catalysts to promote the reaction of sodium thiocyanate and methyl chloroformate to generate the key intermediate methyl isothiocyanate. Although dialkyl aniline has certain catalytic activity, there are still problems in actual application. The most important problem is poor dispersibility, and dialkyl aniline has poor solubility in aqueous phase, is easy to float or aggregate, which leads to insufficient contact with the reactants and low mass transfer efficiency, thereby affecting the reaction rate and conversion rate. In addition, the stability is poor, and the homogeneous catalyst is easy to be deactivated under the reaction conditions.
[0005] Therefore, it is urgent to develop an efficient and stable catalytic system and thiophaim synthesis method which can not only retain the environmental advantages of the aqueous phase method, but also overcome the defects of the existing catalysts. SUMMARY
[0006] The purpose of the present application is to provide a synthesis method of thiophaim, so as to improve the synthesis efficiency of thiophaim.
[0007] A synthesis method of thiophaim, comprising the following steps: S1, dissolving sodium thiocyanate into water, adding a catalyst, and dropping methyl chloroformate, and after incubating at a temperature of 10-15℃ for 30-60 min, separating the liquid to obtain methyl isothiocyanate; S2, methyl isothiocyanate is added into 1,2-dichloroethane to obtain a methyl isothiocyanate solution; o-phenylenediamine is added into 1,2-dichloroethane and stirred to dissolve, and then the o-phenylenediamine solution is added dropwise into the methyl isothiocyanate solution, and after reaction for 30-60 min, cooling and crystallization are performed to obtain the product; The catalyst comprises modified dialkylaniline; The modified dialkylaniline comprises lithium magnesium silicate as a carrier, and further comprises dialkylaniline.
[0008] By using the above technical scheme, methyl isothiocyanate, an intermediate product of thiabendazole synthesized by using an aqueous phase method, is obtained. Specifically, sodium thiocyanate is dissolved in water, a catalyst is added, and methyl chloroformate is added to react to generate methyl isothiocyanate. However, the traditional catalyst such as dialkylaniline added into the reaction system will float in the aqueous solution and not fully contact with the reactants, resulting in low catalytic efficiency and long reaction time. The modified dialkylaniline is used in the present application, that is, the dialkylaniline is loaded on the carrier lithium magnesium silicate. By this modification, the specific surface area and dispersibility of the catalyst are significantly increased, the catalyst can be uniformly suspended in the aqueous phase and fully contact with the reactants, the catalytic activity and reaction rate are greatly improved, the catalyst can be effectively prevented from aggregation and deactivation, and the service life of the catalyst is prolonged.
[0009] Subsequently, the synthesized methyl isothiocyanate is dissolved in 1,2-dichloroethane, o-phenylenediamine is also dissolved in 1,2-dichloroethane, and the o-phenylenediamine solution is added dropwise into the methyl isothiocyanate in a dropwise adding mode. This dropwise adding mode can ensure that the o-phenylenediamine is always in a relatively insufficient state, effectively inhibits excessive reaction of the o-phenylenediamine with excessive methyl isothiocyanate or self-polymerization of the o-phenylenediamine, thereby avoiding generation of the by-product carbendazim, improving the selectivity and yield of the target product thiabendazole, and finally cooling and crystallization can obtain high-purity thiabendazole.
[0010] Preferably, the mass ratio of the lithium magnesium silicate to the dialkylaniline is 1: (0.5-2).
[0011] Preferably, the preparation method of the carrier comprises the following steps: A1, lithium magnesium silicate is dispersed in deionized water, and ultrasonic treatment is performed for 20-30 min to obtain a lithium magnesium silicate dispersion liquid; A2, an intercalation modifier is dissolved in deionized water to obtain an intercalation modification solution, the intercalation modification solution is added dropwise into the lithium magnesium silicate dispersion liquid, and reaction is performed at 60-80 ℃ for 6-12 h to obtain intercalation-modified lithium magnesium silicate; A3, the intercalation-modified lithium magnesium silicate is dispersed into anhydrous toluene, a silane coupling agent is added, and reaction is performed for 12-24 h, and then filtration, washing and drying are performed.
[0012] By adopting the above technical scheme, the magnesium lithium silicate is an inorganic material with a layered structure, and the surface thereof contains rich hydroxyl groups, and has good adsorption performance and ion exchange capacity, but the interlayer force of the magnesium lithium silicate is relatively strong, and the surface is hydrophilic and oleophobic, and the effect of directly using the magnesium lithium silicate to load organic catalyst molecules is poor. The intercalation modification of the magnesium lithium silicate can not only effectively expand the sheet structure thereof and increase the internal space, but also can introduce organic long chains and improve the compatibility of the magnesium lithium silicate with the organic phase. In order to further enhance the interaction force between the carrier magnesium lithium silicate and the organic molecules of the dialkyl aniline, the intercalation modified magnesium lithium silicate is further modified by using a silane coupling agent. The silane coupling agent can be bonded with the hydroxyl groups on the surface of the magnesium lithium silicate after hydrolysis, and specific organic functional groups are introduced, so that the anchoring capacity and the loading capacity of the magnesium lithium silicate for the dialkyl aniline are significantly improved.
[0013] Preferably, the preparation method of the modified dialkyl aniline comprises the following steps. The dialkyl aniline is dispersed in a toluene solution, the carrier is added, and after stirring and reaction at 40-60 DEG C for 6-12 h, filtration, washing and drying are performed to obtain the modified dialkyl aniline.
[0014] Preferably, the mass ratio of the magnesium lithium silicate to the intercalation modifier is 1: (0.1-0.3).
[0015] Preferably, the intercalation modifier comprises hexadecyl trimethyl ammonium bromide and sodium dodecyl sulfonate.
[0016] Preferably, the addition amount of the silane coupling agent is 1%-3% of the magnesium lithium silicate; and the silane coupling agent comprises KH570, KH550 and KH560.
[0017] Preferably, the mass ratio of sodium thiocyanate, the catalyst and methyl chloroformate is 1: (0.02-0.1): (1-1.5).
[0018] Preferably, the molar ratio of methyl isothiocyanate carbamate to o-phenylenediamine is 1: (2.01-2.05).
[0019] Preferably, the temperature for cooling and crystallization is 5-10 DEG C, and the time for cooling and crystallization is 10-20 min.
[0020] The present application has the following beneficial effects: 1. The present application provides a synthesis method of thiophine, which effectively improves the yield and content of thiophine by using the catalyst prepared by the present application, and the content of thiophine is as high as 99% or more, and the reaction yield is more than 99%.
[0021] 2. The catalyst prepared by the present application successfully constructs a high-performance catalytic system by loading dialkylaniline on the carrier lithium magnesium silicate which is modified by intercalation and modified by silane coupling agent. The intercalation modification expands the interlayer spacing of the carrier, and the silane coupling agent introduces organic functional groups. The synergistic effect of the two greatly improves the dispersibility of the carrier in the aqueous phase and the compatibility with the organic active component, so that the catalytic active site is fully exposed and efficiently contacts with the reactants, thereby improving the catalytic efficiency.
[0022] 3. The synthesis process of the present application has mild process conditions, simple operation, easy control, good industrial amplification potential and wide application prospect. DETAILED DESCRIPTION
[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below.
[0024] A synthesis method of thiophanate-methyl, comprising the following steps: Dissolve sodium thiocyanate into water, add a catalyst, and drop methyl chloroformate. After incubation at a temperature of 10-15 DEG C for 30-60 min, separate the liquid to obtain methyl isothiocyanate; S2, add methyl isothiocyanate to 1, 2-dichloroethane to obtain a methyl isothiocyanate solution; add o-phenylenediamine to 1, 2-dichloroethane, stir and dissolve, then drop into the methyl isothiocyanate solution, incubate for 30-60 min, and cool and crystallize to obtain; The catalyst comprises modified dialkylaniline; The modified dialkylaniline comprises lithium magnesium silicate as a carrier, and also comprises dialkylaniline.
[0025] By adopting the above technical scheme, the intermediate product methyl isothiocyanate of thiophanate-methyl is synthesized by using an aqueous phase method. Specifically, sodium thiocyanate is dissolved in water, then a catalyst is added, and methyl chloroformate is added to react to generate methyl isothiocyanate. However, the traditional catalyst such as dialkylaniline added to the reaction system will float in the aqueous solution, and does not fully contact with the reactants, resulting in low catalytic efficiency and long reaction time. The present application uses modified dialkylaniline, that is, dialkylaniline is loaded on the carrier lithium magnesium silicate. Through this modification, the specific surface area and dispersibility of the catalyst are significantly increased, so that it can be uniformly suspended in the aqueous phase and fully contact with the reactants, thereby greatly improving the catalytic activity and reaction rate, and effectively preventing the catalyst from being deactivated due to aggregation and prolonging the service life.
[0026] Subsequently, the synthesized methyl isothiocyanate is dissolved in 1,2-dichloroethane, and o-phenylenediamine is also dissolved in 1,2-dichloroethane, and the o-phenylenediamine solution is added dropwise to the methyl isothiocyanate in a dropwise manner, which can ensure that the o-phenylenediamine is always in a relatively insufficient state, effectively inhibiting excessive reaction or self-polymerization of the o-phenylenediamine with excess methyl isothiocyanate, thereby significantly avoiding the generation of the by-product thiabendazole, improving the selectivity and yield of the target product thiabendazole, and finally cooling and crystallizing to obtain high-purity thiabendazole.
[0027] In some embodiments, the mass ratio of lithium magnesium silicate and dialkyl aniline is 1: (0.5-2), and this mass ratio can ensure that the dialkyl aniline is fully and stably loaded on the lithium magnesium silicate carrier, avoiding the problems of unstable loading or incomplete coverage of active sites caused by insufficient carriers, and preventing the dilution of active components and the increase of catalyst cost caused by excessive carriers.
[0028] In some embodiments, the preparation method of the carrier comprises the following steps: A1, dispersing lithium magnesium silicate in deionized water, ultrasonic treatment for 20-30 min to obtain a lithium magnesium silicate dispersion; A2, dissolving the intercalation modifier in deionized water to obtain an intercalation modification solution, adding the intercalation modification solution to the lithium magnesium silicate dispersion, and reacting at 60-80°C for 6-12 h to obtain intercalation modified lithium magnesium silicate; A3, dispersing the intercalation modified lithium magnesium silicate into anhydrous toluene, adding a silane coupling agent and reacting for 12-24 h, and then filtering, washing and drying to obtain the carrier.
[0029] Lithium magnesium silicate is an inorganic material with a layered structure, and its surface contains a large number of hydroxyl groups, which has good adsorption performance and ion exchange capacity. However, the interlayer force of lithium magnesium silicate is strong, and its surface is hydrophilic and oleophobic, so it is not effective to directly load organic catalyst molecules. By intercalating and modifying lithium magnesium silicate, not only can the sheet structure be effectively expanded to increase the internal space, but also organic long chains can be introduced to improve its compatibility with organic phases. In order to further enhance the interaction between the lithium magnesium silicate carrier and the organic molecules such as dialkyl aniline, the intercalation modified lithium magnesium silicate is also modified by a silane coupling agent. The silane coupling agent can bond with the hydroxyl groups on the surface of lithium magnesium silicate after hydrolysis, and introduce specific organic functional groups, thereby significantly improving the anchoring ability and loading capacity of dialkyl aniline.
[0030] In some embodiments, the preparation method of the modified dialkyl aniline comprises the following steps: Dispersing dialkyl aniline in a toluene solution, adding a carrier, stirring at 40-60°C for 6-12 h, and then filtering, washing and drying to obtain the modified dialkyl aniline.
[0031] The modified dialkylaniline can be obtained by dispersing the dialkylaniline in toluene and mixing the carrier with stirring, the catalyst obtained by this method, the dialkylaniline is fixed on the surface and interlayer of the functional carrier by physical adsorption, forming a stable and high-activity catalytic system, which not only maintains the original catalytic characteristics of the dialkylaniline, but also has the advantages of easy dispersion, easy separation and recovery and reusability brought by the carrier.
[0032] In some embodiments, the mass ratio of lithium magnesium silicate to intercalation modifier is 1:(0.1-0.3); using lithium magnesium silicate and intercalation modifier in this ratio can effectively expand the interlayer structure of lithium magnesium silicate and optimize the modification of surface properties, if the intercalation modifier is too little, the intercalation effect is not ideal, the interlayer spacing is limited; if too much, it may cause the interlayer of the modifier molecule to be over-accumulated or even blocked, which is not conducive to subsequent loading and mass transfer.
[0033] In some embodiments, the intercalation modifier includes hexadecyl trimethyl ammonium bromide and sodium dodecyl sulfonate; by using, for example, hexadecyl trimethyl ammonium bromide, the cations in the interlayer of lithium magnesium silicate can be effectively exchanged, thereby expanding the layered structure and imparting organic affinity.
[0034] In some embodiments, the amount of silane coupling agent added is 1%-3% of lithium magnesium silicate; the silane coupling agent includes KH570, KH550, and KH560; by adding the silane coupling agent, active functional groups such as unsaturated double bonds, amino groups, or epoxy groups can be introduced on the surface of the carrier, for example, the methacryloyloxy group introduced by KH570 can produce stronger interaction with the aromatic ring or alkyl chain of dialkylaniline, such as π-π stacking or hydrophobic interaction, thereby enhancing the loading effect and the stability of the catalyst.
[0035] In some embodiments, the mass ratio of sodium thiocyanate, catalyst, and methyl chloroformate is 1:(0.02-0.1):(1-1.5); using sodium thiocyanate, catalyst, and methyl chloroformate in this mass ratio can ensure that the reactants are fully converted under the effective catalysis of the catalyst, too little catalyst will cause the reaction to be slow or incomplete, and too much will cause waste and may increase the subsequent separation burden; the amount of methyl chloroformate is slightly excessive than that of sodium thiocyanate, which helps to promote the reaction in the direction of generating methyl isothiocyanate, thereby improving the conversion rate of raw materials.
[0036] In some embodiments, the molar ratio of methyl isothiocyanate to o-phenylenediamine is 1:(2.01-2.05); the molar ratio of methyl isothiocyanate to o-phenylenediamine is strictly controlled in the range of 1:(2.01-2.05), to ensure that o-phenylenediamine is slightly excessive, the purpose is to make methyl isothiocyanate can be completely reacted to generate the target product thiophanate-methyl.
[0037] In some embodiments, the temperature for cooling crystallization is 5-10℃, and the time for cooling crystallization is 10-20 min; the temperature for crystallization of thiabendazole is selected as 5-10℃, which is beneficial to the full crystallization of thiabendazole from 1,2-dichloroethane solution and inhibits the co-crystallization of impurities, so that the crystal product with uniform particle size and high purity is obtained. The crystallization time is controlled in 10-20 min, which can ensure complete crystallization.
[0038] The specific embodiments of the present application are described in detail below, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.
[0039] Preparation Example
[0040] Preparation Example 1, a modified dialkyl aniline, is prepared by the following method: A1, 1g of lithium magnesium silicate is dispersed in 100mL of deionized water, ultrasonic treatment for 30min, to obtain a lithium magnesium silicate dispersion; A2, 0.2g of hexadecyl trimethyl ammonium bromide is dissolved in 50mL of deionized water to obtain an intercalation modification solution, the intercalation modification solution is added dropwise to the lithium magnesium silicate dispersion, and the reaction is carried out at 60℃ for 8h to obtain intercalation modified lithium magnesium silicate; A3, 1g of intercalation modified lithium magnesium silicate is dispersed in 50mL of anhydrous toluene, 2% of KH570 based on the mass of lithium magnesium silicate is added, and the reaction is carried out for 12h, then filtration, washing and drying are carried out to obtain the product; A4, 0.5g of dialkyl aniline is dispersed in 30mL of toluene solution, 1g of carrier is added, and the reaction is carried out at 40℃ for 8h, then filtration, washing and drying are carried out to obtain a modified dialkyl aniline.
[0041] Preparation Example 2, a modified dialkyl aniline, is different from Preparation Example 1 only in that the addition amount of hexadecyl trimethyl ammonium bromide is 0.1g.
[0042] Preparation Example 3, a modified dialkyl aniline, is different from Preparation Example 1 only in that the addition amount of dialkyl aniline is 1g.
[0043] Preparation Example 4, a modified dialkyl aniline, is prepared by the following method: A1, 1g of lithium magnesium silicate is dispersed in 100mL of deionized water, ultrasonic treatment for 30min, to obtain a lithium magnesium silicate dispersion; A2, 0.2g of hexadecyl trimethyl ammonium bromide is dissolved in 50mL of deionized water to obtain an intercalation modification solution, the intercalation modification solution is added dropwise to the lithium magnesium silicate dispersion, and the reaction is carried out at 60℃ for 8h to obtain intercalation modified lithium magnesium silicate; A3, 0.5 g of dialkyl aniline was dispersed in 30 mL of toluene solution, 1 g of carrier was added, after stirring at 40℃ for 8 h, filtration, washing, drying to obtain a modified dialkyl aniline.
[0044] Preparation Example 5, a modified dialkyl aniline, was prepared by the following method: A1, 1 g of lithium magnesium silicate was dispersed in 100 mL of deionized water, ultrasonic treatment for 30 min to obtain a lithium magnesium silicate dispersion; after adding 2% of the mass of KH570 for 12 h, filtration, washing, drying to obtain; A3, 0.5 g of dialkyl aniline was dispersed in 30 mL of toluene solution, 1 g of carrier was added, after stirring at 40℃ for 8 h, filtration, washing, drying to obtain a modified dialkyl aniline.
[0045] Preparation Example 6, a modified dialkyl aniline, is different from Preparation Example 1 only in that the addition amount of dialkyl aniline is 3 g.
[0046] Example
[0047] Example 1, a thiabendazole, was prepared by the following method: S1, 10 g of sodium thiocyanate was dissolved in water, 0.4 g of the catalyst prepared in Preparation Example 1 was added, 12 g of methyl chloroformate was slowly added, the reaction temperature was maintained at 15℃, after the addition was completed, it was kept for 30 min, after the reaction was completed, a methyl isothiocyanate was obtained by using a separatory funnel to separate; S2, 0.05 mol of methyl isothiocyanate was added to 15 g of 1,2-dichloroethane to obtain a methyl isothiocyanate solution; 0.1005 mol of o-phenylenediamine was added to 150 g of 1,2-dichloroethane and stirred to dissolve, then added to the methyl isothiocyanate solution, after the addition was completed, it was kept for 30 min, then cooled at 10℃ for 10 min to obtain a thiabendazole.
[0048] Example 2, a thiabendazole, is different from Example 1 only in that the same mass of the catalyst prepared in Preparation Example 2 is used to replace the catalyst prepared in Preparation Example 1.
[0049] Example 3, a thiabendazole, is different from Example 1 only in that the same mass of the catalyst prepared in Preparation Example 3 is used to replace the catalyst prepared in Preparation Example 1.
[0050] Comparative Example
[0051] Comparative Example 1, a thiabendazole, is different from Example 1 only in that the same mass of the catalyst prepared in Preparation Example 4 is used to replace the catalyst prepared in Preparation Example 1.
[0052] Comparative Example 2, a thiabendazole, differs from Example 1 only in that the same mass of catalyst prepared in Preparation Example 5 is used instead of the catalyst prepared in Preparation Example 1.
[0053] Comparative Example 3, a thiabendazole, differs from Example 1 only in that the same mass of catalyst prepared in Preparation Example 6 is used instead of the catalyst prepared in Preparation Example 1.
[0054] Comparative Example 4, a thiabendazole, differs from Example 1 only in that the catalyst is not modified.
[0055] Performance test
[0056] The thiabendazole prepared in Examples 1-3 and Comparative Examples 1-4 is tested for content and reaction yield of thiabendazole by liquid chromatography: Table 1. Performance test results
[0057] As can be seen from Table 1, the content of thiabendazole prepared in Examples 1-3 is all above 99%, and the reaction yield is all higher than 99%, indicating that the catalyst and synthesis method provided by the present application can efficiently and highly selectively prepare thiabendazole with high purity.
[0058] In contrast, the content and yield of thiabendazole prepared in Comparative Examples 1-4 all significantly decrease. Specifically, the results of Comparative Example 1 and Comparative Example 2 show that modification of the silane coupling agent is crucial for stable loading and improved catalytic efficiency; and the synergistic effect of intercalation and coupling can bring better results. The results of Comparative Example 3 show that excessive loading can instead lead to deterioration of the catalyst structure, which is not conducive to the reaction. The content and yield of thiabendazole in Comparative Example 4, which directly uses an unmodified catalyst, are much lower than those in Example 1, which fully shows that the catalyst system formed by loading dialkylaniline on a modified lithium magnesium silicate carrier by a specific method has obvious improvement in reaction efficiency and yield compared with the unmodified catalyst.
[0059] The above disclosure is only a few specific embodiments of the present application, but the embodiments of the present application are not limited thereto, and any changes that can be thought of by those skilled in the art shall fall within the protection scope of the present application.
Claims
1. A method of synthesizing thiophanate, characterized by, The method comprises the following steps: S1, dissolving sodium thiocyanate into water, adding a catalyst, and dropwise adding methyl chloroformate, and then keeping the temperature at 10-15 ℃ for 30-60 min to obtain methyl isothiocyanate by liquid separation; S2, adding methyl isothiocyanate into 1,2-dichloroethane to obtain a methyl isothiocyanate solution, adding o-phenylenediamine into 1,2-dichloroethane, stirring and dissolving, and then dropwise adding into the methyl isothiocyanate solution, keeping the temperature for 30-60 min, and then cooling and crystallizing to obtain the product; The catalyst comprises modified dialkylaniline. The modified dialkylaniline comprises lithium magnesium silicate as a carrier and dialkylaniline.
2. The method for synthesizing methyl thiophanate according to claim 1, characterized in that, The mass ratio of the lithium magnesium silicate and the dialkylaniline is 1: (0.5-2).
3. The method for synthesizing methyl thiophanate according to claim 1, characterized in that, The preparation method of the carrier comprises the following steps: A1, dispersing lithium magnesium silicate in deionized water, and ultrasonic treatment for 20-30 min to obtain a lithium magnesium silicate dispersion; A2, dissolving an intercalation modifier in deionized water to obtain an intercalation modification solution, and then dropwise adding the intercalation modification solution into the lithium magnesium silicate dispersion, and reacting at 60-80 ℃ for 6-12 h to obtain intercalation modified lithium magnesium silicate; A3, dispersing the intercalation modified lithium magnesium silicate in anhydrous toluene, adding a silane coupling agent, and reacting for 12-24 h, and then filtering, washing, and drying to obtain the product.
4. The method for synthesizing methyl thiophanate according to claim 1, characterized in that, The preparation method of the modified dialkylaniline comprises the following steps: dispersing dialkylaniline in a toluene solution, adding a carrier, and stirring and reacting at 40-60 ℃ for 6-12 h, and then filtering, washing, and drying to obtain the product.
5. The method for synthesizing methyl thiophanate according to claim 3, characterized in that, The mass ratio of the lithium magnesium silicate and the intercalation modifier is 1: (0.1-0.3).
6. The method for synthesizing methyl thiophanate according to claim 3, characterized in that, The intercalation modifier comprises cetyltrimethylammonium bromide and sodium dodecyl sulfonate.
7. The method for synthesizing methyl thiophanate according to claim 3, characterized in that, The addition amount of the silane coupling agent is 1%-3% of the lithium magnesium silicate; and the silane coupling agent comprises KH570, KH550, and KH560.
8. The method for synthesizing methyl thiophanate according to claim 1, characterized in that, The mass ratio of the sodium thiocyanate, the catalyst, and the methyl chloroformate is 1: (0.02-0.1): (1-1.5).
9. The method for synthesizing methyl thiophanate according to claim 1, characterized in that, The molar ratio of the methyl isothiocyanate and the o-phenylenediamine is 1: (2.01-2.05).
10. The method for synthesizing thiophanate-methyl according to claim 1, characterized in that, The cooling and crystallization temperature is 5-10 ℃, and the cooling and crystallization time is 10-20 min.