Preparation method of triazine derivatives

Abstract

The present invention provides a preparation method of a triazine derivative. The preparation method comprises the following steps: subjecting p-nitroaniline to a substitution reaction with compound A to form intermediate B; and subjecting intermediate B to a hydrogenation reduction alkylation reaction with compound C to obtain the triazine derivative. The above method provided by the present invention prepares the triazine derivative by a two-step method of substitution first and then hydrogenation reduction alkylation, which not only has a high product yield, but also greatly shortens the process flow. At the same time, this method effectively avoids the generation of by-products of disubstituted p-phenylenediamine in the traditional process, makes the product separation easy, greatly reduces the cost, has no pollution, has high product quality, and is easy to realize industrialization.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and in particular, to a method for preparing a triazine derivative. Background Art

[0002] Triazine derivatives having the following structure are an important class of substances (where the R group is an alkyl group having 3 to C 10 ). They are a class of compounds formed by substituting and connecting N-substituted p-phenylenediamine at the 1, 3, and 5 carbon atoms of triazine.

[0003]

[0004] For example, 2,4,6-tris(N-1,4-dimethylpentyl-p-phenylenediamine)-1,3,5-triazine (abbreviated as TMPPD) is an important one among triazine derivatives and is also a new type of rubber antioxidant, also known as TAPDT or DURAZONE37. Antioxidant TMPPD is a new type of green and pollution-free antioxidant, mainly used to protect unsaturated synthetic rubbers and elastomers from aging and cracking by oxygen and ozone. It has super static ozone protection function and excellent dynamic anti-aging function, and is not prone to migration during use.

[0005] Regarding the preparation methods of TMPPD compounds, they are all reported in US Patents USP4794134, USP4794135, USP4972010, USP5047530, USP5120844. Generally, they use trichlorotriazine (cyanuric chloride) and N-(1,4-dimethylpentyl)-p-phenylenediamine (abbreviated as 7PD) as raw materials, and use the amino nitrogen atom to replace the chlorine atom in trichlorotriazine to generate the target product TMPPD. Among them, the preparation of N-(1,4-dimethylpentyl)-p-phenylenediamine (abbreviated as 7PD) usually uses p-phenylenediamine or aniline or p-nitrochlorobenzene and 5-methyl-2-hexanone as starting materials, but inevitably, the by-product N,N'-bis(1,4-dimethylpentyl)p-phenylenediamine (77PD) will be formed during the synthesis process, which brings a lot of trouble to the subsequent product separation, and the synthesis route is long and the overall yield is not high.

[0006] Similar to the rubber antioxidant TMPPD, the current synthesis processes of such triazine derivatives all have the defects of low yield and long route. Summary of the Invention

[0007] The main object of the present invention is to provide a method for preparing a triazine derivative to solve the problems of low yield and long route existing in the synthesis of triazine derivatives in the prior art.

[0008] To achieve the above object, according to one aspect of the present invention, a method for preparing a triazine derivative is provided, wherein the structural formula of the triazine derivative is as follows:

[0009]

[0010] The preparation method includes the following steps: subjecting p-nitroaniline to a substitution reaction with compound A to form intermediate B; subjecting intermediate B to a hydrogenation reductive alkylation reaction with compound C to obtain the triazine derivative; wherein, compound A has the structure shown in formula I, intermediate B has the structure shown in formula II, and compound C has the structure shown in formula III, and formula I, formula II and formula III are as follows:

[0011]

[0012] Wherein, the R group is an alkyl group with C3 to C 10 and X is a halogen atom.

[0013] Further, in the step of the substitution reaction, the molar ratio of p-nitroaniline to compound A is 3 to 10:1, preferably 3 to 6:1, and more preferably 3 to 4:1.

[0014] Further, the substitution reaction is carried out in an organic solvent, and the organic solvent is selected from one or more of 1,4-dioxane, N,N-dimethylformamide, n-hexane, tetrahydrofuran, toluene and isobutane; preferably, the water content in the organic solvent is 0 to 5 wt%, more preferably 0 to 1 wt%, and further preferably 0 to 0.5 wt%.

[0015] Further, in the step of the substitution reaction, the reaction is first carried out at a temperature of 0 to 5 °C and then heated to the reflux state for reaction.

[0016] Further, in the step of the hydrogenation reductive alkylation reaction, the molar ratio of intermediate B to compound C is 1:10 to 60, preferably 1:20 to 60.

[0017] Further, in the step of the hydrogenation reductive alkylation reaction, hydrogen is used as a reducing agent and the reaction is carried out under the action of a hydrogenation catalyst; wherein, the hydrogenation catalyst includes an active component, and the active component is one or more of platinum, palladium, nickel and copper.

[0018] Further, the hydrogenation catalyst is one or more of Pt / C catalyst, Pd / C catalyst, Raney nickel catalyst, supported nickel catalyst, amorphous nickel catalyst, CuO / ZnO / Al2O3 catalyst and CuO / CrO / Al2O3 catalyst.

[0019] Further, when the hydrogenation catalyst is a Pt / C catalyst, the dosage of the hydrogenation catalyst is 2-10% of the weight of p-nitroaniline; when the hydrogenation catalyst is a Pd / C catalyst, the dosage of the hydrogenation catalyst is 3-10% of the weight of p-nitroaniline; when the hydrogenation catalyst is one or more of Raney nickel catalyst, supported nickel catalyst and amorphous nickel catalyst, the dosage of the hydrogenation catalyst is 10-20% of the weight of p-nitroaniline; when the hydrogenation catalyst is a CuO / ZnO / Al2O3 catalyst and / or a CuO / CrO / Al2O3 catalyst, the dosage of the hydrogenation catalyst is 30-40% of the weight of p-nitroaniline.

[0020] Further, in the step of the hydrogenation reductive alkylation reaction, the reaction temperature is 80-200°C, preferably 80-160°C; the reaction pressure is 1-10 MPa, preferably 1-6 MPa, more preferably 1-3 MPa.

[0021] Further, after the step of the hydrogenation reductive alkylation reaction, it further includes: filtering the reaction solution after the hydrogenation reductive alkylation reaction to obtain a filtrate; distilling the filtrate to obtain the triazine derivative.

[0022] Applying the technical solution of the present invention, by using the substitution reaction of p-nitroaniline and compound A, the amino group in p-nitroaniline can replace X in compound A to form a trisubstituted triazine, that is, intermediate B. Then, by using the hydrogenation reductive alkylation reaction of compound C ketone compound and intermediate B, the hydrogenation reduction of the nitro group in intermediate B and the R group substitution are completed to obtain the target product triazine derivative. The two-step method for preparing triazine derivatives by substitution first and then hydrogenation reduction provided by the present invention not only has a high product yield, but also greatly shortens the process flow. At the same time, this method effectively avoids the generation of by-products of disubstituted p-phenylenediamine in the traditional process, makes the product separation easy, greatly reduces the cost, has no pollution, has high product quality, and is easy to realize industrialization. Specific Embodiments

[0023] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0024] As described in the background art section, there are problems of low yield and long route in the existing synthesis processes of triazine derivatives. To solve this problem, the inventors of the present invention provide a preparation method of triazine derivatives, and the structural formula of the triazine derivative is as follows:

[0025]

[0026] The preparation method comprises the following steps: subjecting p-nitroaniline and compound A to a substitution reaction to form intermediate B; subjecting intermediate B and compound C to a hydrogenation reduction alkylation reaction to obtain a triazine derivative; wherein, compound A has the structure shown in formula I, intermediate B has the structure shown in formula II, and compound C has the structure shown in formula III, and formula I, formula II and formula III are as follows:

[0027]

[0028] Wherein, the R group is an alkyl group having 3 to C 10 and X is a halogen atom.

[0029] In the above preparation method provided by the present invention, by subjecting p-nitroaniline and compound A to a substitution reaction, the amino group in p-nitroaniline can replace X in compound A to form a trisubstituted triazine, that is, intermediate B. Then, by subjecting the ketone compound of compound C and intermediate B to a hydrogenation reduction alkylation reaction, the hydrogenation reduction of the nitro group of intermediate B and the substitution of the R group are completed to obtain the target product triazine derivative. The two-step method for preparing triazine derivatives by substitution first and then hydrogenation reduction provided by the present invention not only has a high product yield, but also greatly shortens the process flow. At the same time, this method effectively avoids the generation of by-products of disubstituted p-phenylenediamine in the traditional process, makes the product separation easy, greatly reduces the cost, has no pollution, has high product quality, and is easy to realize industrialization.

[0030] Different R groups correspond to different triazine derivatives. Correspondingly, as long as compound C is replaced with the corresponding R-group ketone, the corresponding triazine derivative can be obtained. Preferably, R is 5-methyl-2-hexyl, 4-methyl-2-pentyl, 2-octyl, cyclohexyl, isopropyl, butyl, 2-pentyl or 2-decyl. The corresponding ketones of these R groups and intermediate B have better hydrogenation reduction reaction ability, and the reaction efficiency and yield of the obtained triazine derivatives are higher.

[0031] According to the reaction principle of the raw materials, those skilled in the art can adjust the dosage relationship between the reaction raw materials. In a preferred embodiment, in the step of the substitution reaction, the molar ratio of p-nitroaniline to compound A is 3 to 10:1, preferably 3 to 6:1, more preferably 3 to 4:1. Controlling the molar ratio of p-nitroaniline to compound A within the above range is beneficial to increasing the content of intermediate B in the reaction product on the one hand, reducing the content of mono-substituted or di-substituted by-products, and on the other hand, is also beneficial to reducing the reaction energy consumption and saving costs. Thereby, it is beneficial to further improve the yield of the target product.

[0032] In a preferred embodiment, in the step of hydroreductive alkylation reaction, the molar ratio of intermediate B to compound C is 1:10 to 60, preferably 1:20 to 60. Similarly, controlling the dosage relationship between intermediate B and compound C within the above range is beneficial to improving the yield of the triazine derivative and reducing the occurrence of side reactions.

[0033] In a preferred embodiment, the substitution reaction is carried out in an organic solvent, and the organic solvent is one or more of 1,4-dioxane, N,N-dimethylformamide, n-hexane, tetrahydrofuran, toluene and isobutane. The above several organic solvents have good compatibility with the reaction raw materials and can provide a stable reaction environment, thus maintaining the stability of the substitution reaction.

[0034] The water content of the organic solvent used in the reaction also has a great influence on the progress of the substitution reaction. The water content of the organic solvent in the substitution reaction is generally controlled at 0 to 5%, preferably 0 to 1%, and more preferably 0 to 0.5%. When the water content in the organic solvent is too high, compound A is more likely to undergo side reactions such as hydrolysis, which is not conducive to the main reaction and further affects the purity and yield of the target product. By controlling the water content within the above range, both the purity and yield of the target product are further improved.

[0035] The overall reaction conditions of the preparation method provided by the present invention are relatively mild. In a preferred embodiment, in the step of the substitution reaction, the reaction is first carried out at a temperature of 0 to 5°C and then heated to the reflux state for reaction. Since cyanuric chloride has relatively high activity, controlling the reaction temperature at 0 to 5°C can appropriately reduce the reaction activity of cyanuric chloride, thereby better controlling the substitution reaction between p-nitroaniline and compound A; when two aromatic amines are substituted on the triazine ring, due to the conjugated electron-donating effect of the aromatic amine, the activity of the third chlorine atom decreases rapidly, and it is necessary to gradually heat up to the reflux state to generate more trisubstituted products. Under such temperature conditions, the purity and yield of intermediate B are higher.

[0036] The purpose of the above hydroreductive alkylation reaction is the hydrogenation reduction of the nitro group of intermediate B and the substitution of the R group. In a preferred embodiment, this step of the hydroreductive alkylation reaction is carried out with hydrogen as the reducing agent under the action of a hydrogenation catalyst; wherein, the hydrogenation catalyst includes an active component, and the active component is one or more of platinum, palladium, nickel and copper. Using one or more of platinum, palladium, nickel and copper as the active component of the hydrogenation catalyst can improve the catalytic efficiency of the catalyst, thereby improving the efficiency of the hydroreductive reaction.

[0037] Specifically, as long as one or more of platinum, palladium, nickel, and copper are used as the active components of the hydrogenation catalyst, the catalytic efficiency of the catalyst can be effectively improved. In a preferred embodiment, the hydrogenation catalyst is one or more of Pt / C catalyst, Pd / C catalyst, Raney nickel catalyst, supported nickel catalyst, amorphous nickel catalyst, CuO / ZnO / Al2O3 catalyst, and CuO / CrO / Al2O3 catalyst. These catalysts have high catalytic efficiency. At the same time, the catalysts have high stability, good reusability, and a long active retention time.

[0038] When using different catalysts for the hydrogenation reduction alkylation reaction, the dosage can be adjusted according to their different catalytic efficiencies. In a preferred embodiment, when the hydrogenation catalyst is Pt / C catalyst, the dosage of the hydrogenation catalyst is 2-10% of the weight of p-nitroaniline; when the hydrogenation catalyst is Pd / C catalyst, the dosage of the hydrogenation catalyst is 3-10% of the weight of p-nitroaniline; when the hydrogenation catalyst is one or more of Raney nickel catalyst, supported nickel catalyst, and amorphous nickel catalyst, the dosage of the hydrogenation catalyst is 10-20% of the weight of p-nitroaniline; when the hydrogenation catalyst is CuO / ZnO / Al2O3 catalyst and / or CuO / CrO / Al2O3 catalyst, the dosage of the hydrogenation catalyst is 30-40% of the weight of p-nitroaniline. In this way, it is beneficial to further improve the reaction rate and reduce the generation of side reactions.

[0039] Based on the special two-step reaction principle, the process conditions for preparing triazine derivatives in the present invention are relatively mild. In a preferred embodiment, in the step of the hydrogenation reduction alkylation reaction, the reaction temperature is 80-200 °C, preferably 80-160 °C; the reaction pressure is 1-10 MPa, preferably 1-6 MPa, more preferably 1-3 MPa.

[0040] In the actual operation process, after the substitution reaction, it is preferred to continue to add an acid-binding agent (such as sodium bicarbonate or sodium hydroxide) to the reaction system and react for a period of time to absorb the acid generated in the reaction.

[0041] In addition, in a preferred embodiment, after the step of the hydrogenation reduction alkylation reaction, it further includes: filtering the reaction solution after the hydrogenation reduction alkylation reaction to obtain a filtrate; distilling the filtrate to obtain a triazine derivative. Specifically, vacuum distillation is carried out. First, the unreacted compound C and a small amount of low-boiling impurities are rectified and recovered at a lower temperature, then a small amount of mono-substituted and higher-boiling impurities are recovered at a higher temperature, and finally the remaining liquid obtained is the target product triazine derivative.

[0042] The following further describes the present application in detail with specific examples, and these examples should not be construed as limiting the scope claimed by the present application.

[0043] Example 1

[0044] (a) Substitution reaction

[0045] 0.3 mol of p-nitroaniline and 225 mL of 1,4-dioxane were added to a 1000 mL four-necked flask. The temperature was lowered to 0 - 5 °C, and a cyanuric chloride solution (0.06 mol of cyanuric chloride dissolved in 180 mL of 1,4-dioxane) was slowly added dropwise. After the addition was complete, the reaction was continued at this temperature for 1 h, then heated under reflux for 1 h, and then sodium bicarbonate was added and the reaction was continued for 2 h. After the reaction was completed, the reaction mixture was washed and filtered to obtain the yellow intermediate 2,4,6-tris(4-nitroaniline)-1,3,5-triazine (Intermediate B). The reaction conversion rate was 99.5%, the reaction selectivity was 98%, and the product purity was 98.5%.

[0046] (b) Hydrogenation reduction alkylation reaction

[0047] 29 g (0.06 mol) of 2,4,6-tris(4-nitroaniline)-1,3,5-triazine, 405 g (3.55 mol) of 5-methyl-2-hexanone, and 3 g of 3% Pt / C catalyst (relative to the weight of p-nitroaniline) were charged into a 1 L autoclave at one time. After being replaced with N2 and H2 three times respectively, stirring was started at a stirring speed of 900 r / min, and then heating was started to raise the temperature. The reaction was maintained at a temperature of 160 °C and a reaction pressure of 1.0 - 1.5 MPa until no hydrogen was consumed, and the reaction was continued for 3 h. After the intermediate was completely converted, the reaction was ended, the temperature was lowered, the pressure was released, the autoclave was opened, and the product was discharged. The reaction mixture was filtered through a fritted funnel, the catalyst was recovered and reused, and the reaction solution was sampled for analysis. The reaction conversion rate was 100%, the reaction selectivity was over 95%, and the product purity was 92%.

[0048] (c) Post-treatment of hydrogenation solution

[0049] The filtered hydrogenation reduction solution was added to a 1000 mL four-necked flask for vacuum distillation. At a vacuum degree ≥ -0.099 MPa, first, at a kettle temperature of 150 °C, 5-methyl-2-hexanone (MIAK) and a small amount of low-boiling impurities were recovered by rectification; then, at a kettle temperature of 200 - 260 °C, a small amount of mono-substituted and a small amount of higher-boiling impurities were recovered. Finally, the kettle liquid obtained was the product TMPPD, and the purity of the product was 93.5% by HPLC relative area analysis.

[0050] The NMR detection results of the product are as follows: 11H NMR (400 MHz, DMSO-d6): δ 8.51 (s, 3H), δ 7.36 (d, 6H), δ 6.46 (d, 6H), δ 4.98 (s, 3H), δ 3.29 (m, 3H), δ 1.51 (m, 3H), δ 1.35 (m, 6H), δ 1.23 (m, 6H), δ 1.08 (d, 9H), δ 0.87 (d, 18H).

[0051] Example 2

[0052] (a) Substitution reaction

[0053] 0.12 mol of p-nitroaniline and 200 mL of N,N-dimethylformamide were added to a 1000 mL four-necked flask. The temperature was lowered to 0 - 5 °C, and then a cyanuric chloride solution (0.04 mol of cyanuric chloride dissolved in 100 mL of N,N-dimethylformamide) was slowly added dropwise. After the addition was complete, the reaction was continued at this temperature for 1 h. Then, the reaction was heated to reflux for 1 h, and sodium bicarbonate was added and the reaction continued for 2 h. After the reaction ended, the reaction mixture was washed and filtered to obtain the yellow intermediate 2,4,6-tris-(4-nitroaniline)-1,3,5-triazine. The reaction conversion rate was 99%, the reaction selectivity was 98.6%, and the product purity was 97.5%.

[0054] (b) Hydrogenation reduction alkylation reaction

[0055] 19.6 g (0.04 mol) of the intermediate 2,4,6-tris-(4-nitroaniline)-1,3,5-triazine, 270 g (2.36 mol) of 5-methyl-2-hexanone, and 6 g of 3% Pd / C catalyst (relative to the weight of p-nitroaniline) were charged into a 1 L autoclave at one time. After being replaced with N2 and H2 three times respectively, stirring was started at a stirring speed of 900 r / min, and then heating was started to raise the temperature. The reaction was maintained at 80 °C and a reaction pressure of 1.0 - 1.5 MPa until no hydrogen was consumed, and the reaction was continued for 3 h. After the intermediate was completely converted, the reaction ended, and the temperature was lowered, the pressure was released, the autoclave was opened, and the product was discharged. The reaction mixture was filtered through a sintered glass funnel, and the catalyst was recovered for reuse. The reaction mixture was sampled for analysis. The reaction conversion rate was 100%, the reaction selectivity was over 90%, and the product purity was 90.2%.

[0056] (c) Post-treatment of the hydrogenation solution

[0057] The filtered hydrogenation reduction solution was added to a 1000 mL four-necked flask for vacuum distillation. At a vacuum degree ≥ -0.099 MPa, first, at a kettle temperature of 150 °C, 5-methyl-2-hexanone (MIAK) and a small amount of low-boiling impurities were recovered by rectification; then, at a kettle temperature of 200 - 260 °C, a small amount of monosubstituted products and a small amount of higher-boiling impurities were recovered. Finally, the kettle liquid obtained was the product TMPPD. The purity of the product was 92.9% analyzed by HPLC relative area.

[0058] Examples 3 to 7

[0059] The triazine derivative was prepared using the same raw materials and process conditions as in Example 2, except that the dosage relationship between the raw materials was different and some catalysts were different. The specific dosage relationship and product conditions are as follows:

[0060]

[0061]

[0062] Examples 8 to 12

[0063] The triazine derivative was prepared using the same dosage relationship of raw materials as in Example 2, except that Compound A, Compound C, and the solvent were different. Specifically as follows:

[0064]

[0065] Examples 10 to 12

[0066] The triazine derivative was prepared using the same raw materials and dosage relationship of raw materials as in Example 2, except that the process conditions were different. Specifically as follows:

[0067]

[0068] Examples 13 to 16

[0069] The triazine derivative was prepared using the same raw materials and the ratio relationship between the raw materials as in Example 2, except that the water content of the organic solvent used in the substitution reaction was different. Specifically as follows:

[0070]

[0071] It can be seen from Examples 13 to 16 that when the water content of the solvent is controlled below 0.5%, the content of the product TMPPD can reach more than 90%; as the water content of the solvent increases, side reactions such as hydrolysis are aggravated and more by-products are generated. It can be seen from Examples 10 to 12 that cyanuric chloride has a relatively high reaction activity and is prone to deliquescence in air. In particular, the first chlorine on its triazine ring is easily substituted to form other impurities. In the process of synthesizing TMPPD, first controlling the reaction temperature to 0 - 5°C can reduce the reaction activity of cyanuric chloride, so that groups with weaker nucleophilicity than the amino group in p-nitroaniline in the reaction system cannot react with it, thus being more conducive to the substitution reaction between p-nitroaniline and cyanuric chloride; subsequently, gradually heating up to the reflux state can generate more trisubstituted products. It can be seen from Examples 1 to 7 that controlling the raw material ratio within a specific range is beneficial to further improving the yield and purity of the target product.

[0072] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0073] Using the two-step method of first substitution and then hydrogenation reduction of the present invention to prepare triazine derivatives not only has a high product yield, but also greatly shortens the process flow. At the same time, this method effectively avoids the generation of by-products of disubstituted p-phenylenediamine in the traditional process, makes the product separation easy, greatly reduces the cost, has no pollution, has high product quality, and is easy to realize industrialization.

[0074] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a triazine derivative, characterized in that, The structural formula of the triazine derivative is as follows: ； The preparation method comprises the following steps: Performing a substitution reaction on p-nitroaniline and compound A to form intermediate B; the molar ratio of p-nitroaniline to compound A is 3-4:1; in the step of the substitution reaction, first reacting at a temperature of 0-5°C and then heating to the reflux state for reaction; the substitution reaction is carried out in an organic solvent, and the water content in the organic solvent is 0-5 wt%; Performing a hydro-reductive alkylation reaction on the intermediate B and compound C to obtain the triazine derivative; the molar ratio of the intermediate B to compound C is 1:10-60; Wherein, compound A has the structure shown in formula I, intermediate B has the structure shown in formula II, compound C has the structure shown in formula III, and formula I, formula II and formula III are as follows: ， Among them, the R group is an alkyl group with C3 to C 10 ; the X is a halogen atom; in the step of the hydrogenation reduction alkylation reaction, hydrogen is used as a reducing agent and the reaction is carried out under the action of a hydrogenation catalyst; among them, the hydrogenation catalyst is one or more of a Pt / C catalyst, a Pd / C catalyst, a Raney nickel catalyst, a supported nickel catalyst, an amorphous nickel catalyst, a CuO / ZnO / Al2O3 catalyst and a CuO / CrO / Al2O3 catalyst; when the hydrogenation catalyst is the Pt / C catalyst, the dosage of the hydrogenation catalyst is 2 to 10% of the weight of the p-nitroaniline; when the hydrogenation catalyst is the Pd / C catalyst, the dosage of the hydrogenation catalyst is 3 to 10% of the weight of the p-nitroaniline; when the hydrogenation catalyst is one or more of the Raney nickel catalyst, the supported nickel catalyst and the amorphous nickel catalyst, the dosage of the hydrogenation catalyst is 10 to 20% of the weight of the p-nitroaniline; when the hydrogenation catalyst is the CuO / ZnO / Al2O3 catalyst and / or the CuO / CrO / Al2O3 catalyst, the dosage of the hydrogenation catalyst is 30 to 40% of the weight of the p-nitroaniline; in the step of the hydrogenation reduction alkylation reaction, the reaction temperature is 80 to 200 °C; the reaction pressure is 1 to 10 MPa.

2. The preparation method according to claim 1, characterized in that, The organic solvent is selected from one or more of 1,4-dioxane, N,N-dimethylformamide, n-hexane, tetrahydrofuran, toluene and isobutane.

3. The preparation method according to claim 1, characterized in that, The water content in the organic solvent is 0-1 wt%.

4. The preparation method according to claim 1, characterized in that, The water content in the organic solvent is 0-0.5 wt%.

5. The preparation method according to any one of claims 1 to 4, characterized in that, In the step of the hydro-reductive alkylation reaction, the molar ratio of the intermediate B to compound C is 1:20-60.

6. The preparation method according to claim 1, wherein In the step of the hydro-reductive alkylation reaction, the reaction temperature is 80-160°C; the reaction pressure is 1-6 MPa.

7. The preparation method according to claim 6, characterized in that, In the step of the hydro-reductive alkylation reaction, the reaction pressure is 1-3 MPa.

8. The preparation method according to claim 7, characterized in that, After the step of the hydro-reductive alkylation reaction, it further includes: Filtering the reaction solution after the hydro-reductive alkylation reaction to obtain a filtrate; Distilling the filtrate to obtain the triazine derivative.

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