A method for preparing asymmetric triazine compounds for OLED

Abstract

The invention discloses a method for preparing an asymmetric triazine compound for OLED, comprising the following steps: S1, mixing substrate A, potassium fluoride, tetrakistriphenylphosphine palladium and dioxane uniformly to form solution A; S2, mixing substrate B and dioxane uniformly to form solution B; S3, mixing substrate C, potassium fluoride and dioxane uniformly to form solution C; S4, delivering solution A to mixer A via pump A, delivering solution B to mixer A via pump B, and then delivering solution C to reactor A via mixer A for reaction; after the reaction liquid flows out of reactor A, pump C is started, solution C and reaction liquid enter mixer B together, and then enter a product tank after reaction in reactor B. The invention overcomes the shortcomings of the prior art, has a reasonable design, combines the characteristics of microchannel reaction, adopts continuous coupling reaction, avoids the preparation of Grignard reagent, simplifies the process, improves the conversion rate, is easy to purify, and synthesizes asymmetric triazines.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to a method for preparing an asymmetric triazine compound for OLED. Background Art

[0002] Triazine OLED materials have a high glass transition temperature and excellent photoelectric properties. When used as a light-emitting layer material, they can effectively improve the luminous efficiency of the device. When used as an electron transport layer and a hole transport layer material, they can significantly reduce the driving voltage of the device and improve the operating efficiency of the device. For example, patent CN 114133400 A shows the application of compounds with triazine as the skeleton in the organic light-emitting layer of an organic electroluminescent device and performs performance parameter tests. Among them, asymmetric triazine compounds are important intermediates in the synthesis process. The following are some compounds extracted from the patent:

[0003]

[0004] However, the patent mainly uses a monosubstituted triazine compound, and then synthesizes the final product by stepwise substitution (paragraph 0214 of the specification):

[0005]

[0006] The main reason is that the current preparation method of asymmetric substituted triazine compounds is limited. ) is mainly synthesized through Grignard reaction or coupling reaction, and the single-step yield is generally only 55-70%.

[0007] For example, method 1 requires two preparations of the Grignard reagent, but due to the inherent properties of the reaction, some of the raw materials will self-couple, resulting in a waste of raw materials and low yields. In addition, the moisture content is difficult to control during scale-up production, increasing operational uncertainty.

[0008]

[0009] Method 2: Two boronic acid couplings. The reaction yield is low in the first step, and there will be a large amount of residual raw materials and double substitution products, which are difficult to purify. In addition, a new catalyst needs to be added in the second step, which increases the cost.

[0010]

[0011] Regarding the multiple substitution phenomenon that occurred in the above-mentioned continuous coupling, the researchers analyzed that there are two main problems: ① Since the three substitution sites of chlorotrimethylbenzene have the same chemical environment, it is difficult to selectively replace them; ② After one site is replaced, the difficulty of replacing the other two sites will increase, but the reaction speed is slow (overnight reaction), and disubstituted impurities will be produced.

[0012] Continuous coupling is a relatively safe and convenient method for preparing asymmetric triazine compounds. If high-yield continuous coupling can be completed, it can effectively reduce the synthesis cost, simplify the process, and increase the diversity of substrates. Therefore, it is necessary to further optimize it. The current mainstream direction is to use some catalysts or modification methods to selectively replace chloro-mesitylene based on problem ①; however, the optimization is difficult and there is no obvious progress at present.

[0013] The present invention is mainly guided by problem ②, and the monosubstituted product after the reaction is completed is separated out in time to reduce the residence time of the monosubstituted product in the first step reaction.

[0014] It is difficult to complete instant separation in traditional kettle reactions, but the emerging microchannel reaction can; however, the reaction time of this process is very slow, and microchannel reactions are suitable for reactions with faster reaction speeds, while the coupling reaction of triazines is slow, so it is also necessary to increase the reaction speed, as well as the solubility of catalysts and materials, ensure good fluidity and increase mass transfer and heat transfer efficiency to speed up the reaction rate.

[0015] The invention provides a preparation process of an asymmetric triazine compound for OLED combined with microchannel technology, providing a new idea for the preparation of the asymmetric triazine compound. Summary of the invention

[0016] In order to solve the problems mentioned in the above background technology, the present invention provides a low-cost, easily industrialized method for synthesizing asymmetric triazine compounds (microchannel reaction).

[0017] In order to achieve the above object, the present invention adopts the following technical solutions:

[0018] A method for preparing an asymmetric triazine compound for OLED comprises the following steps:

[0019] S1. Mix substrate A, potassium fluoride, tetrakistriphenylphosphine palladium and dioxane to prepare solution A;

[0020] S2, mixing substrate B and dioxane evenly to prepare solution B;

[0021] S3, mixing substrate C, potassium fluoride and dioxane evenly to prepare solution C;

[0022] S4, transporting solution A to mixer A via pump A, transporting solution B to mixer A via pump B, and then transporting to reactor A via mixer A for reaction; after the reaction liquid flows out of reactor A, start pump C, and solution C and the reaction liquid enter mixer B together, and then enter the product tank after reaction in reactor B;

[0023] S5. Add water to the product tank, add toluene while stirring, stir, stand and separate the liquids, concentrate under reduced pressure, add dichloromethane, heat to dissolve and reflux, then add dropwise to n-heptane, cool to 10-15°C, stir and crystallize for 1 hour, repeat the operation once, and filter to obtain the final product, i.e., an asymmetric triazine compound.

[0024] Preferably, the molar ratio of the substrates A, B and C is (1-1.1):1:(0.9-1.1).

[0025] Preferably, the concentrations of solution A, solution B and solution C are all 1.0-2.0 mol / L.

[0026] Preferably, the mass ratio of substrate A, potassium fluoride, tetrakistriphenylphosphine palladium and dioxane in S1 is 50:(33-48):0.1:298.

[0027] Preferably, the mass ratio of substrate B to dioxane in S2 is (53-76):298.

[0028] Preferably, the mass ratio of substrate C, potassium fluoride and dioxane in S3 is (35-118): (33-48): 298.

[0029] Preferably, the structural formula of the substrate A is: ;

[0030] The structural formula of the substrate B is: ;

[0031] The structural formula of the substrate C is: ;

[0032] Wherein R1 is an aromatic heterocyclic compound or a condensed ring compound substituted with boric acid, and R2 is a benzene ring or a naphthalene ring.

[0033] Preferably, the mass ratio of toluene, dichloromethane and n-heptane is (10-20): (5-8): (10-30).

[0034] Preferably, the flow rate of the pump A is 3.0-10.0 ml / min; the flow rate of the pump B is 3.0-10.0 ml / min; and the flow rate of the pump C is 1.5-5.0 ml / min.

[0035] Preferably, the temperature of the reactor A is set to 85-95°C; the temperature of the reactor B is set to 95-105°C.

[0036] The reaction equation is:

[0037]

[0038] The R1 is an aromatic heterocyclic compound or a condensed ring compound substituted with boric acid, and R2 is a benzene ring or a naphthalene ring.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. Synthesis route: Combined with the characteristics of microchannel reaction, continuous coupling reaction is adopted to avoid the preparation of Grignard reagent, simplify the process, improve the conversion rate, facilitate purification, and synthesize asymmetric triazine.

[0041] 2. The two-step reaction only uses the amount of catalyst for one-step reaction: the amount of catalyst used is reduced, the discharge of three wastes is reduced, and the product is obtained with high yield and high stability.

[0042] 3. The synthesis process described in the present invention has a fast reaction speed, high selectivity, and low cost as a whole, is suitable for industrial scale-up production, and has high social use value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a schematic diagram of the microchannel reaction in the present invention;

[0045] Figure 2 This is the liquid phase detection spectrum of the product of Example 1 of the present invention;

[0046] Figure 3 This is an integral report of the liquid phase detection spectrum of the product of Example 1 of the present invention. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market. Example 1

[0049] Synthetic route 1:

[0050]

[0051] ① Solution preparation: Prepare solution A (substrate A: 50.00 g, potassium fluoride: 47.65 g, tetrakistriphenylphosphine palladium: 0.1 g, dioxane: 289 ml, i.e. 298 g);

[0052] Prepare solution B (substrate B: 75.62 g, dioxane 289 ml);

[0053] Prepare solution C (substrate C: 78.25 g, potassium fluoride: 47.65 g, dioxane 289 ml);

[0054] Tube diameter: 1mm;

[0055] ② Reaction: Put the feed tube of plunger pump A into solution A, set the flow rate to 3ml / min, put the feed tube of peristaltic pump B into solution B, set the flow rate to 3ml / min, connect the discharge ports of the two pumps to mixer A, and then transport to reactor A through mixer A. Set the temperature of reactor A to 90℃, the residence time to 5s, and connect reactor A to mixer B;

[0056] Set the flow rate of pump C to 1.5 ml / min. Pump C transports solution C to mixer B. Mixer B is connected to reactor B. Reactor B is set to a temperature of 100°C and a residence time of 5 s. It is connected to the product receiving tank. Start pump A and pump B at the same time. After the reaction liquid flows out of reactor A, start pump C. After the reaction liquid passes through mixer B and reactor B, it flows into the product tank.

[0057] ③ Post-treatment: add 1L of water to the product tank, add 500ml of toluene while stirring, stir and stand to separate the liquids, concentrate under reduced pressure, add 100ml of dichloromethane and heat to dissolve and reflux, directly add dropwise to 500ml of n-heptane, cool to 10-15℃, stir and crystallize for one hour, filter to obtain the final product, HPLC purity 99.85%. Example 2

[0058] Synthesis route 2:

[0059]

[0060] ① Solution preparation: Prepare solution A (A: 50.00g, potassium fluoride: 47.65g, tetrakistriphenylphosphine palladium: 0.1g, dioxane: 289ml);

[0061] Prepare solution B (B: 75.62 g, dioxane 289 ml), tube diameter 1 mm;

[0062] Prepare solution C (C: 117.74 g, potassium fluoride: 47.65 g, dioxane 289 ml);

[0063] ② Reaction: Place the feed tube of plunger pump A into solution A, set the flow rate to 5 ml / min, place the feed tube of peristaltic pump B into solution B, set the flow rate to 5 ml / min, connect the discharge ports of the two pumps to mixer A, and then transport to reactor A through mixer A. Set the temperature of reactor A to 95°C, the residence time to 5s, and connect reactor A to mixer B;

[0064] Set the flow rate of pump C to 3 ml / min. Pump C transports solution C to mixer B. Mixer B is connected to reactor B. Reactor B is set to a temperature of 105°C and a residence time of 5 s. It is connected to the product receiving tank. Start pump A and pump B at the same time. After the reaction liquid flows out of reactor A, start pump C. After the reaction liquid passes through mixer B and reactor B, it flows into the product tank.

[0065] ③ The post-treatment was the same as in Example 1, with a HPLC purity of 99.23%. Example 3

[0066] Synthetic route 3:

[0067]

[0068] ① Solution preparation: Prepare solution A (A: 50.00g, potassium fluoride: 33.78g, tetrakistriphenylphosphine palladium: 0.1g, dioxane: 289ml);

[0069] Prepare solution B (B: 53.61 g, dioxane 289 ml), tube diameter 1 mm;

[0070] Prepare solution C (C: 35.45 g, potassium fluoride: 33.78 g, dioxane 289 ml);

[0071] ② Reaction: Place the feed tube of plunger pump A into solution A, set the flow rate to 5 ml / min, place the feed tube of peristaltic pump B into solution B, set the flow rate to 5 ml / min, connect the discharge ports of the two pumps to mixer A, and then transport to reactor A through mixer A. Set the temperature of reactor A to 85°C, the residence time to 5s, and connect reactor A to mixer B;

[0072] Set the flow rate of pump C to 3 ml / min. Pump C transports solution C to mixer B. Mixer B is connected to reactor B. Reactor B is set to a temperature of 95°C and a residence time of 5 s. It is connected to the product receiving tank. Start pump A and pump B at the same time. After the reaction liquid flows out of reactor A, start pump C. After the reaction liquid passes through mixer B and reactor B, it flows into the product tank.

[0073] ③ The post-treatment was the same as in Example 1, and the purity by HPLC was 99.55%.

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 1 is that the equivalent ratio of substrate A / B / C is 1:1:1, the concentration of solution A is 1.4 mol / L, and the flow rate of pump A is 5.0 ml / min; the concentration of solution B is 1.4 mol / L, and the flow rate of pump B is 5.0 ml / min; the concentration of solution C is 1.4 mol / L, and the flow rate of pump C is 2.5 ml / min.

[0076] Comparative Example 2

[0077] The difference between this comparative example and Example 1 is that the equivalent ratio of substrate A / B / C is 1:1:0.9, the concentration of solution A is 1.4 mol / L, and the flow rate of pump A is 5.0 ml / min; the concentration of solution B is 1.4 mol / L, and the flow rate of pump B is 5.0 ml / min; the concentration of solution C is 1.27 mol / L, and the flow rate of pump C is 2.5 ml / min.

[0078] Comparative Example 3

[0079] The difference between this comparative example and Example 1 is that the equivalent ratio of substrate A / B / C is 1:1:0.9, the concentration of solution A is 1.4 mol / L, and the flow rate of pump A is 10.0 ml / min; the concentration of solution B is 1.4 mol / L, and the flow rate of pump B is 10.0 ml / min; the concentration of solution C is 1.27 mol / L, and the flow rate of pump C is 5.0 ml / min.

[0080] Comparative Example 4

[0081] The difference between this comparative example and Example 1 is that the equivalent ratio of substrate A / B / C is 1:1:0.9, the concentration of solution A is 1.4 mol / L, and the flow rate of pump A is 8.0 ml / min; the concentration of solution B is 1.4 mol / L, and the flow rate of pump B is 8.0 ml / min; the concentration of solution C is 1.27 mol / L, and the flow rate of pump C is 4.0 ml / min.

[0082] Comparative Example 5

[0083] The difference between this comparative example and Example 1 is that the equivalent ratio of substrate A / B / C is 1:1:1, the concentration of solution A is 1.4 mol / L, and the flow rate of pump A is 5.0 ml / min; the concentration of solution B is 1.4 mol / L, and the flow rate of pump B is 5.0 ml / min; the concentration of solution C is 1.4 mol / L, and the flow rate of pump C is 2.5 ml / min. The pipe diameter is 1.5 mm.

[0084] A comparative experiment was conducted between Example 1 and Comparative Examples 1-5, and the experimental results are shown in Table 1:

[0085] Table 1

[0086] test Substrate A / B / C equivalent ratio Solution A (mol / L) Pump A flow rate (ml / min) Solution B (mol / L) Pump B flow rate (ml / min) Reactor A temperature (°C) Solution C (mol / L) Pump C flow rate (ml / min) Reactor B temperature (°C) Pipe diameter (mm) Yield (%) Example 1 1：1：0.9 1.4 3.0 1.4 3.0 90 1.27 1.5 100 1 79% Comparative Example 1 1：1：1 1.4 5.0 1.4 5.0 90 1.4 2.5 100 1 65% Comparative Example 2 1：1：0.9 1.4 5.0 1.4 5.0 90 1.27 2.5 100 1 70% Comparative Example 3 1：1：0.9 1.4 10.0 1.4 10.0 90 1.27 5.0 100 1 60% Comparative Example 4 1：1：0.9 1.4 8.0 1.4 8.0 90 1.27 4.0 100 1 63% Comparative Example 5 1：1：1 1.4 5.0 1.4 5.0 90 1.4 2.5 100 1.5 43%

[0087] Through the above data screening, it can be concluded that the flow rate of the three pumps is an important parameter, among which the flow rate is controlled between 3.0-5.0, which can maintain a high yield. Increasing the pipe diameter will reduce the mixing efficiency, thereby affecting the reaction effect.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing asymmetric triazine compounds for OLED combined with microchannel technology, characterized in that: The following steps are involved: S1. Mix substrate A, potassium fluoride, tetrakistriphenylphosphine palladium and dioxane to prepare solution A; S2, mixing substrate B and dioxane evenly to prepare solution B; S3, mixing substrate C, potassium fluoride and dioxane evenly to prepare solution C; S4, transporting solution A to mixer A via pump A, transporting solution B to mixer A via pump B, and then transporting to reactor A via mixer A for reaction; after the reaction liquid flows out of reactor A, start pump C, and solution C and the reaction liquid enter mixer B together, and then enter the product tank after reaction in reactor B; S5, add water to the product tank, add toluene while stirring, stir and stand to separate the liquids, reduce pressure and concentrate, add dichloromethane and heat to dissolve and reflux, then add dropwise to n-heptane, cool to 10-15°C, stir and crystallize for 1 hour, repeat the operation once, and filter to obtain the final product, i.e., an asymmetric triazine compound; The substrate A is an aromatic heterocyclic compound or a condensed ring compound substituted with boronic acid; The structural formula of the substrate B is: ; The structural formula of the substrate C is: , R2 is a benzene ring or a naphthalene ring; The flow rate of the pump A is 3.0-10.0 ml / min; the flow rate of the pump B is 3.0-10.0 ml / min; the flow rate of the pump C is 1.5-5.0 ml / min.

2. The method for preparing an asymmetric triazine compound for OLED combined with microchannel technology according to claim 1, characterized in that: The molar ratio of the substrates A, B and C is (1-1.1):1:(0.9-1.1).

3. The method for preparing an asymmetric triazine compound for OLED combined with microchannel technology according to claim 1, characterized in that: The concentrations of solution A, solution B and solution C are all 1.0-2.0 mol / L.

4. The method for preparing an asymmetric triazine compound for OLED combined with microchannel technology according to claim 1, characterized in that: The mass ratio of substrate A, potassium fluoride, tetrakistriphenylphosphine palladium and dioxane in the S1 is 50:(33-48):0.1:

298.

5. The method for preparing an asymmetric triazine compound for OLED combined with microchannel technology according to claim 1, characterized in that: The mass ratio of substrate B to dioxane in S2 is (53-76):

298.

6. The method for preparing asymmetric triazine compounds for OLED combined with microchannel technology according to claim 1, characterized in that: The mass ratio of substrate C, potassium fluoride and dioxane in S3 is (35-118): (33-48):

298.

7. The method for preparing asymmetric triazine compounds for OLED combined with microchannel technology according to claim 1, characterized in that: The mass ratio of toluene, dichloromethane and n-heptane is (10-20): (5-8): (10-30).

8. The method for preparing asymmetric triazine compounds for OLED combined with microchannel technology according to claim 1, characterized in that: The temperature of the reactor A is set at 85-95°C; the temperature of the reactor B is set at 95-105°C.

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