Organic light-emitting material intermediate and preparation method therefor

Abstract

The present invention relates to the technical field of organic chemistry, and provides an organic light-emitting material intermediate and a preparation method therefor. According to the method of the present invention, by optimizing a process route, 1-naphthylamine is used as a starting material, and an organic light-emitting material intermediate is obtained by means of reactions such as substitution, deamination, and substitution. Compared with the prior art, the method has the advantages of cheap and easily available raw materials, low production costs, short process route, simple operation, mild conditions, environmental friendliness, high target product yield, and few by-products, and the method is suitable for industrial production of the organic light-emitting material intermediate.

Description

An organic luminescent material intermediate and its preparation method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. CN202310909240.2 filed on July 24, 2023. The full text of the above-mentioned Chinese patent application is hereby cited as part of this application. Technical Field

[0003] The present invention relates to the field of organic chemistry, and in particular to an organic luminescent material intermediate and a preparation method thereof. Background Art

[0004] In 1987, Tang et al. at Eastman Kodak in the United States first used 8-hydroxyquinoline aluminum as a luminescent material to create organic light-emitting diodes (OLEDs), ushering in a new era in the research of organic electroluminescent materials and devices. As a new display technology, OLEDs offer high brightness, a wide viewing angle, fast response, stable images, rich luminous colors, and high resolution. Their advantages include low driving voltage, full curing, and ultra-thin design. With technological advancements and continuous improvements in product performance, OLEDs are attracting increasing attention in flat-panel displays, lighting, and backlighting. They are now widely used in commerce, communications, computers, electronics, and transportation.

[0005] The construction of OLEDs primarily involves two components: organic materials and manufacturing processes. The advantages of OLEDs are closely tied to the properties of organic optoelectronic materials. High-performance organic materials not only enhance the various performance characteristics of OLEDs but also simplify the manufacturing process and reduce costs. Therefore, the design and synthesis of novel organic materials with superior optoelectronic properties and high thermal stability remains an important avenue for advancing OLED development and a research hotspot in this field. Currently, various organic optoelectronic materials have been synthesized and applied, but there remains a lack of organic light-emitting materials that combine the characteristics of pure luminescent color, high luminous efficiency, stable performance, ease of processing, and strong electron and hole transport capabilities.

[0006] Among the organic light-emitting materials used in OLEDs, naphthalene derivatives are key intermediates in their synthesis. Based on literature and the relationship between molecular structure and optical properties, these organic light-emitting materials have promising application prospects. However, existing synthesis processes generally require multiple steps, are complex, and have many drawbacks and limitations, including low yields of the target product, the formation of polyphenyl ring byproducts, harsh reaction conditions, and the use of hazardous reagents. Therefore, the design of new key intermediates for organic light-emitting materials and the development of new methods for synthesizing them under mild conditions remain worthy of further research.

[0007] Summary of the Invention

[0008] The above-mentioned method for preparing an organic luminescent material intermediate has the following technical problems: low yield, poor purity, complicated reaction steps, high cost, high production of three wastes, and environmental pollution. The present invention, on the one hand, provides a method for preparing an organic luminescent material intermediate. The method has the characteristics of simple operation, high yield, good product purity, low cost, good atom economy, low production of three wastes, and suitability for industrial scale-up. The present invention provides a method for preparing an organic luminescent material intermediate. An organic luminescent material intermediate, referred to as intermediate 5, has a structure as shown below:

[0009] The preparation method provided by the present invention can use the compound 1-naphthylamine as a starting material, undergo a substitution reaction to obtain intermediate 1, which is optionally post-treated; then add a halogenating agent to obtain intermediate 2, which is optionally post-treated; remove the amino group of intermediate 2 to obtain intermediate 3, which is optionally post-treated; intermediate 3 is substituted to obtain intermediate 4, which is optionally post-treated; intermediate 4 is subjected to a substitution reaction to obtain the target product, namely intermediate 5. The specific reaction route is as follows:

[0010] To achieve the above objectives, the present invention adopts the following technical solutions: On the one hand, the present invention provides a method for preparing an organic light-emitting material intermediate, comprising:

[0011] Step 1: 1-naphthylamine is reacted with a chlorinating agent in the presence of a solvent to obtain intermediate 1;

[0012] Step 2: reacting the intermediate 1 with an iodine reagent in the presence of a solvent to obtain the intermediate 2;

[0013] Step 3: reacting a first reaction system comprising the intermediate 2, a Lewis acid, a nitrite, and a solvent, and then adding the reaction liquid of the first reaction system to a solution containing a reducing agent and a first catalyst to react to obtain an intermediate 3;

[0014] Step 4: reacting the intermediate 3, a second catalyst, and a fluorination agent in the presence of a solvent to obtain the intermediate 4;

[0015] Step 5: Add a third catalyst and a third catalyst ligand to the mixture containing the intermediate 4, a boronating agent, an additive and a solvent in a protective atmosphere to react to obtain an intermediate 5.

[0016] In some embodiments, the solvent includes an organic solvent. For example, the organic solvent may include any one or more combinations of tetrahydrofuran, dichloromethane, N,N'-dimethylformamide, acetonitrile, and 1,4-dioxane, but is not limited thereto.

[0017] In some embodiments, the molar ratio of 1-naphthylamine to the chlorinating agent in step 1 is 1:0.8-1:1.2.

[0018] In some embodiments, the chlorination agent includes N-chlorosuccinimide, but is not limited thereto.

[0019] In some embodiments, after the reaction of step 1 is completed, post-treatment is optionally performed. In some embodiments, the post-treatment includes: extracting and separating the intermediate 1 from the reaction mixture.

[0020] In some embodiments, the molar ratio of intermediate 1 to iodine reagent in step 2 is 1:0.8-1:1.2.

[0021] In some embodiments, the iodine reagent includes N-iodosuccinimide or elemental iodine, but is not limited thereto.

[0022] In some embodiments, the solvent in step 2 is preferably N,N'-dimethylformamide.

[0023] In some embodiments, after the reaction of step 2 is completed, post-treatment is optionally performed. In some embodiments, the post-treatment comprises: adding sodium thiosulfate aqueous solution, stirring and crystallizing, filtering, washing and drying to obtain intermediate 2.

[0024] In some embodiments, the solvent in step 3 is preferably acetonitrile.

[0025] In some embodiments, in step 3, the molar ratio of the intermediate 2, the Lewis acid, the nitrite, the reducing agent, and the first catalyst is 1:3:1.2:20:0.05 to 1:5:1.5:20:0.05.

[0026] In some embodiments, the Lewis acid includes any one or more of boron trifluoride etherate, sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, and acetic acid, but is not limited thereto. Preferably, the Lewis acid is sulfuric acid.

[0027] In some embodiments, the nitrite includes any one or more of sodium nitrite, tert-butyl nitrite, or isoamyl nitrite.

[0028] In some embodiments, the reducing agent includes hypophosphorous acid, but is not limited thereto.

[0029] In some embodiments, the first catalyst includes cuprous oxide, but is not limited thereto.

[0030] In some embodiments, after the reaction of step 3 is completed, post-treatment is optionally performed. In some embodiments, the post-treatment includes: extraction, drying, and solvent removal to obtain intermediate 3.

[0031] In some embodiments, the second catalyst includes any one or more combinations of cuprous bromide or cuprous chloride, but is not limited thereto.

[0032] In some embodiments, the fluorination agent includes any one or more combinations of methyl fluorosulfonyldifluoroacetate, trifluoromethanesulfonyl chloride, or triethyl(trifluoromethyl)silane, but is not limited thereto.

[0033] In some embodiments, the molar ratio of the intermediate 3, the second catalyst, and the fluorination agent in step 4 is 1:0.1:1.2 to 1:1:3.

[0034] In some embodiments, the solvent in step 4 is preferably N,N'-dimethylformamide.

[0035] In some embodiments, after the reaction in step 4 is complete, post-treatment is optionally performed. In some embodiments, the post-treatment comprises: cooling the reaction solution to room temperature, filtering, adding water and petroleum ether to the filter cake, extracting, drying, and removing the solvent to obtain intermediate 4.

[0036] In some embodiments, the boronation reagent includes any one or more combinations of biboronic acid pinacol esters, but is not limited thereto.

[0037] In some embodiments, the additive includes any one or more combinations of potassium acetate, sodium bicarbonate, sodium carbonate, or potassium phosphate, and is not limited thereto.

[0038] In some embodiments, the third catalyst includes any one or more combinations of Pd2(dba)3, Pd(OAc)2, or PdCl2, but is not limited thereto.

[0039] In some embodiments, the third catalyst ligand includes any one or more combinations of S-phos, X-phos, or Xant-phos, but is not limited thereto.

[0040] In some embodiments, in step 5, the molar ratio of intermediate 4, boronation reagent, additive, third catalyst, and third catalyst ligand is 1:1.2:1:0.05:0.2 to 1:3:3:0.5:1.

[0041] In some embodiments, the solvent in step 5 is preferably 1,4-dioxane.

[0042] In some embodiments, after the reaction in step 5 is complete, post-treatment is optionally performed. In some embodiments, the post-treatment comprises: adding water and ethyl acetate, extracting, drying, and removing the solvent to obtain intermediate 5. In some embodiments, after the reaction in step 5 is complete, water and ethyl acetate are added, extracting, drying, removing the solvent, and purifying by column chromatography to obtain intermediate 5.

[0043] In some embodiments, the reaction in step 1 is carried out at 0°C to 10°C.

[0044] In some embodiments, the reaction in step 2 is carried out at 10° C. to 40° C. Preferably, the reaction in step 2 is carried out at 15° C. to 25° C.

[0045] In some embodiments, step 3 specifically includes: reacting the first reaction system at 70°C to 80°C, then adding the reaction liquid of the first reaction system to a solution containing a reducing agent and a first catalyst and reacting at -10°C to -5°C to obtain intermediate 3.

[0046] In some embodiments, the reaction in step 4 is carried out at 50° C. to 100° C. More preferably, the reaction in step 4 is carried out at 70° C. to 80° C.

[0047] In some embodiments, the reaction in step 5 is carried out at 80° C. to 120° C. More preferably, the reaction in step 5 is carried out at 90° C. to 110° C.

[0048] In some embodiments, the protective atmosphere includes any one or more combinations of nitrogen atmosphere and inert gas atmosphere, but is not limited thereto.

[0049] On the other hand, the present invention provides the following organic light-emitting material intermediate, whose structure is shown in the following formula:

[0050] Based on literature and the relationship between molecular structure and optical properties, the present invention designs and synthesizes a new type of organic light-emitting material intermediate. Due to its novel structure, the target product cannot be obtained using conventional synthesis methods. Therefore, the present invention conducts detailed process parameter exploration and improvement on the experimental method to obtain the optimal process conditions, which not only obtains high yield and product purity, but also greatly improves the reaction rate, avoids environmental pollution, and has the characteristics of green chemistry.

[0051] In summary, the present invention has the following beneficial technical effects:

[0052] 1. The present invention provides novel organic light-emitting material intermediates 2 and 5; the above intermediates are key intermediates for synthesizing naphthalene-based organic light-emitting materials and have good application prospects;

[0053] 2. The method for preparing the organic luminescent material intermediate provided by the present invention has the characteristics of simple operation, high yield, good product purity, low cost, good atom economy, less generation of three wastes, and suitability for industrial scale-up. DETAILED DESCRIPTION

[0054] For ease of understanding, the application will be described more fully below, and preferred embodiments of the application are provided. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents used or instruments that do not indicate manufacturers are conventional products that can be obtained on the market.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0056] In the present invention, min means minute; h means hour; g means gram; and ml means milliliter.

[0057] In the present invention, the reaction is considered complete when the remaining amount of the raw materials does not exceed 5%, 3%, 2%, 1% or 0.5% of the amount of the raw materials charged.

[0058] Purity detection method:

[0059] Example 1

[0060] 1-Naphthylamine (69.8 mmol) was weighed and dissolved in tetrahydrofuran (200 mL). N-chlorosuccinimide (69.8 mmol) was slowly added at 0°C and stirred at 0°C for 1 hour. After the reaction was complete, dichloromethane and water were added to the reaction mixture. The layers were separated by extraction. The organic phase was washed twice with saturated sodium carbonate and then with saturated brine, dried over anhydrous sodium sulfate, and concentrated to obtain 7.7 g of intermediate 1 in a 63% yield and 98% purity.

[0061] 1HNMR (400MHz, CDCl3): δ=7.83-7.79 (m, 2H), 7.54-7.47 (m, 2H), 7.54-7.47 (m, 2H), 7.38 (d, 1H, J=8.0Hz), 7.26 (d, 1H, J=8.0Hz), 4.58 (brs, 2H).

[0062] Example 2

[0063] Intermediate 1 (2.29 kg, 12.892 mol) and DMF (11 L) were added to a reactor, stirred, and dissolved. NIS (3.19 kg, 14.181 mol) was added portionwise, the temperature maintained at 15-25°C, and the reaction was allowed to proceed overnight at room temperature. Aqueous sodium thiosulfate solution was added to the reaction mixture, stirred, and crystallized. The filter cake was filtered, rinsed twice with water, and then directly dried to yield a purple-brown solid (3.29 kg) with a yield of 84% and a purity of 98%.

[0064] 1 H NMR (400MHz, Chloroform-d) δ8.04(d,J=8.0Hz,1H),7.95(s,1H),7.74(d,J=8.0Hz,1H),7.61-7.50(m,2H),4.64(brs,2H).

[0065] Example 3

[0066] Intermediate 2 (3.03 kg, 10 mol) and acetonitrile (12 L) were added to a reactor. 12 L of water was added and stirred thoroughly. An 80% aqueous sulfuric acid solution (10 kg) was added dropwise, maintaining the temperature below 30°C. The temperature was then lowered to -15°C. A 30% aqueous sodium nitrite solution (2.5 kg) was added dropwise, maintaining the temperature between -15°C and -10°C. The reaction solution was then added dropwise to a solution of hypophosphorous acid (10.2 kg, 80 mol) mixed with cuprous oxide (143 g, 1.0 mol). The temperature was maintained between -10°C and -5°C, and the reaction was allowed to warm naturally overnight. Petroleum ether was added for extraction, and the organic phase was washed once with water. The product was dried over anhydrous sodium sulfate and concentrated to yield a white solid (2.03 kg) with a yield of 70% and a purity of 98%.

[0067] 1 H NMR (400MHz, Chloroform-d) δ8.07 (s, 2H), 7.85 (s, 1H), 7.70 (d, J = 8.0Hz, 1H), 7.60-7.53 (m, 2H).

[0068] Example 4

[0069] Intermediate 3 (2.03 kg, 7.036 mol) was weighed and dissolved in DMF (10 L). CuI (2.01 kg, 10.554 mol) was added, and a solution of methyl fluorosulfonyldifluoroacetate (3.78 kg, 21.109 mol) in DMF (5 L) was added dropwise. The temperature was controlled at 75°C and the reaction was allowed to proceed for 48 hours. The reaction solution was cooled to room temperature, the filter cake was filtered, rinsed with water and petroleum ether, and the filtrate was added with water and extracted with petroleum ether several times. The organic phase was washed with water once more, dried over anhydrous sodium sulfate, and concentrated to obtain a crude product. The crude product was then distilled under reduced pressure to obtain a light yellow liquid (1 kg) with a yield of 61.7% and a purity of 80%.

[0070] 1 H NMR (400MHz, Chloroform-d) δ8.20 (s, 1H), 8.17 (d, J = 8.4Hz, 1H), 7.97 (s, 1H), 7.86 (d, J = 8.0Hz, 1H), 7.68-7.60 (m, 2H).

[0071] Example 5

[0072] Intermediate 4 (125 g, 545.3 mmol), pinacol diboronate (166.2 g, 654.4 mmol), potassium acetate (107 g, 1.09 mol), and 1,4-dioxane (0.75 L) were added to a reactor. The atmosphere was then replaced with nitrogen three times. Pd(dba) (10 g, 10.9 mmol) and S-phos (13.4 g, 32.7 mmol) were added under nitrogen, and nitrogen was replaced once. The temperature was raised to reflux. The reaction mixture was cooled to 60°C and quenched with water. The mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, and concentrated. The crude product was purified by column chromatography to obtain a white solid (95 g) with a yield of 54% and a purity of 99%.

[0073] 1 H NMR(400MHz,Chloroform-d)δ8.56(s,1H),8.26(s,1H),8.22(d,J=8.7Hz,1H),7 .99(d,J=8.1Hz,1H),7.69(t,J=7.7Hz,1H),7.60(t,J=7.5Hz,1H),1.43(s,12H).

Claims

1. A method for preparing an organic luminescent material intermediate, comprising the following steps: Step 1, reacting 1-naphthylamine with N-chlorosuccinimide in the presence of a solvent to obtain an intermediate 1; step 2, reacting the intermediate 1 with an iodine reagent in the presence of a solvent to obtain an intermediate 2; step 3, reacting a first reaction system comprising the intermediate 2, a Lewis acid, a nitrite and a solvent, and then adding the reaction liquid of the first reaction system to a solution containing a reducing agent and a first catalyst to react to obtain an intermediate 3; step 4, reacting the intermediate 3, a second catalyst and a fluorination reagent in the presence of a solvent to obtain an intermediate 4; step 5, adding a third catalyst and a third catalyst ligand to the intermediate 4, a boronating reagent, an additive and a solvent in a protective atmosphere to react to obtain an intermediate 5; 2. The method according to claim 1, characterized in that: The iodine reagent includes N-iodosuccinimide or elemental iodine.

3. The method according to claim 1, characterized in that The solvent includes any one or more combinations of tetrahydrofuran, dichloromethane, N,N'-dimethylformamide, acetonitrile, and 1,4-dioxane.

4. The method according to claim 1, characterized in that The Lewis acid includes any one or more combinations of boron trifluoride etherate, sulfuric acid, hydrochloric acid, p-toluenesulfonic acid, and acetic acid.

5. The method according to claim 1, characterized in that The nitrite includes any one or more combinations of sodium nitrite, tert-butyl nitrite or isoamyl nitrite.

6. The method according to claim 1, characterized in that The reducing agent is hypophosphorous acid; and / or the first catalyst is cuprous oxide.

7. The method according to claim 1, characterized in that The second catalyst includes any one or more combinations of cuprous iodide, cuprous bromide or cuprous chloride.

8. The method according to claim 1, characterized in that: The fluorination agent includes any one or more combinations of methyl fluorosulfonyldifluoroacetate, trifluoromethanesulfonyl chloride or triethyl (trifluoromethyl) silane.

9. The method according to claim 1, characterized in that: In step 4, the molar ratio of the intermediate 3, the second catalyst and the fluorination agent is 1:0.1:1.2 to 1:1:

3.

10. The method according to claim 1, characterized in that The boronating agent is pinacol borate; the additive includes any one or more combinations of potassium acetate, sodium bicarbonate, sodium carbonate or potassium phosphate.

11. The method according to claim 1, characterized in that: The third catalyst includes any one or more combinations of Pd2(dba)3, Pd(OAc)2 or PdCl2.

12. The method according to claim 1, characterized in that The third catalyst ligand includes any one or more combinations of S-phos, X-phos or Xant-phos.

13. The compound shown below:

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