Preparation method of fused carbazole compound
Through inorganic acid catalysis and low-temperature reaction, the problems of explosive raw materials and large catalyst usage in the synthesis of fused carbazole compounds are solved, and high yield and low cost preparation of fused carbazole compounds are achieved, which is suitable for industrial production.
Patent Information
- Application Number
- CN202411333689.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2024-12-31
AI Technical Summary
In the existing synthesis methods of fused carbazole compounds, the raw material dinitrobiphenyl is prone to explosion, the catalyst triphenylphosphine is used in large amounts and a large amount of waste solids are generated, and the reaction requires high temperature reflux, which limits its application in actual production.
Inorganic acid catalysis is used, react with sodium nitrite first, and then potassium iodide is added to prepare fused carbazole compounds through low-temperature reaction, avoiding high-temperature reflux and the use of large amounts of triphenylphosphine, and simplifying the post-treatment operation.
It improves the reaction activity of fused carbazole compounds, reduces side reactions, simplifies post-treatment operations, improves yields, and makes raw materials simple and easy to obtain, low-price, and suitable for industrial production.
Smart Images
Figure CN119219633A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of organic synthesis and relates to a preparation method of a fused carbazole compound. Background Art
[0002] The structure of fused carbazole compounds is similar to that of carbazole, and they have high reactivity and are widely used organic intermediates. They react with halogenated aromatic hydrocarbons to produce a series of chemicals that show excellent application prospects in organic electroluminescent devices. At present, the method for synthesizing fused carbazole is mainly to use dinitrobiphenyl as the raw material and heat it under reflux reaction under the catalysis of triphenylphosphine, such as CN110669051A, However, in the above method, the raw material dinitrobiphenyl is prone to explosion due to collision during the reaction, the catalyst triphenylphosphine is used in a large amount, and a large amount of waste solid triphenylphosphine oxide is generated accordingly, the post-treatment is relatively troublesome, and the reaction requires high temperature reflux. The above disadvantages limit their application in actual production. Summary of the invention
[0003] The present invention aims to solve at least one of the technical problems existing in the above-mentioned prior art. To this end, the present invention provides a preparation method of a fused carbazole compound.
[0004] In one aspect, the present invention relates to a method for preparing a compound, comprising: subjecting a compound represented by formula (I) to a reaction catalyzed by an inorganic acid, and then adding sodium nitrite and potassium iodide to obtain a compound represented by formula (II);
[0005]
[0006] Among them, R 1 or R 2 Each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
[0007] Furthermore, in the preparation method of the compound provided by the present invention, after the compound represented by formula (I), solvent and inorganic acid are mixed, sodium nitrite is first added to react, and after the reaction is completed, potassium iodide is added to react to obtain the compound represented by formula (II).
[0008] Furthermore, in the method for preparing the compound provided by the present invention, the inorganic acid is at least one of hydrochloric acid, bromic acid, sulfuric acid, nitric acid, and phosphoric acid.
[0009] Furthermore, in the method for preparing the compound provided by the present invention, the molar ratio of the compound represented by formula (I), the inorganic acid, sodium nitrite and potassium iodide is 1.0:1.0-4.0:1.0-2.0:1.0-2.0.
[0010] Furthermore, in the preparation method of the compound provided by the present invention, the solvent is at least one of methanol, ethanol, isopropanol, tetrahydrofuran, toluene, xylene, ethylbenzene, cyclohexane, n-hexane, n-heptane, dichloromethane, dichloroethane, chloroform, 1,4-dioxane, acetonitrile, and water.
[0011] Furthermore, in the method for preparing the compound provided by the present invention, the molar ratio of the compound represented by formula (I) to the solvent is 1.0:5.0-30.0.
[0012] Furthermore, in the preparation method of the compound provided by the present invention, the reaction time of the preparation method is 3 to 12 hours, and the reaction temperature is 0 to 10°C.
[0013] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:
[0014] The present invention provides a method for preparing a fused carbazole compound. The starting raw material used has an alkyl group connected to the fused ring carbazole, which can improve the activity of subsequent reactions. The raw materials involved are simple and easy to obtain, low in price, low in reaction temperature, and less in side reactions. In addition, the reaction does not require a large amount of triphenylphosphine, does not produce waste solids, and the post-processing operation is relatively simple and has a high yield, making it more suitable for industrial scale-up production. The present invention experimentally verified that the compound represented by formula (I) was catalyzed by an inorganic acid, reacted with sodium nitrite first, and then potassium iodide was added to react to obtain the compound represented by formula (II). Compared with the reaction of first adding potassium iodide and then adding sodium nitrite, the yield can be increased from 35.6% to 92.5%. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solution of the present invention, the drawings involved in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the description 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.
[0016] Figure 1 This is the GC chart of the 4,4'-di-tert-butyl fused carbazole compound prepared in Example 1.
[0017] Figure 2 This is the GCMS chart of the 4,4'-di-tert-butyl fused carbazole compound prepared in Example 1.
[0018] Figure 3 The 4,4'-di-tert-butyl fused carbazole compound prepared in Example 1 1 H-NMR spectrum. DETAILED DESCRIPTION
[0019] The technical scheme of the present invention is described below in conjunction with the embodiments, but the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.
[0020] Example 1
[0021] This embodiment provides a synthesis of a 4,4'-di-tert-butyl fused carbazole compound.
[0022] Under nitrogen protection, 90.7g sodium nitrite was added to a mixture of 200g 2,2'-diamino-4,4'-di-tert-butylbiphenyl, 171.9g sulfuric acid and 3L water in 5 batches, and the mixture was kept at 0-5℃ for 3h. 218.3g potassium iodide was added in 5 batches, and the mixture was kept at 0-5℃ for 5h. The diazonium salt was completely converted using a sodium hydroxide solution of 2-naphthol, and the reaction was stopped by GC detection. The reaction solution was poured into 400mL of dichloroethane and an aqueous solution of sodium sulfite, stirred for 5min, allowed to stand for 10min, and separated. The aqueous phase was extracted once with 1000mL of dichloroethane, separated, and the organic phase was combined and washed with water until neutral. The organic phase was concentrated until no solvent was produced, and 182.49g of light yellow liquid 4,4'-di-tert-butyl fused carbazole was obtained by reduced pressure distillation with a yield of 92.5%.
[0023] MS:C 24 H 20 N 2 , m / z calculated value 292.43; measured value 292.19.
[0024] Example 2
[0025] This example provides the preparation of fused carbazole compounds under different parameters.
[0026] The compound represented by formula (II) was synthesized with reference to Example 1.
[0027]
[0028] Its structure and preparation step parameters are shown in Table 1.
[0029] Table 1: Test methods and results
[0030]
[0031] As shown in Table 1, the present invention changes the raw material structure (R 1 and R 2Substituents), solvent type, inorganic acid type and molar ratio of reactants, etc., to synthesize a variety of fused carbazole compounds. As can be seen from Example 1 and the preparation of compounds 1 to 6, the present invention provides a method for preparing fused carbazole compounds, the raw materials involved are simple and easy to obtain, low in price, low in reaction temperature, less in side reactions, the reaction does not require a large amount of triphenylphosphine, does not produce waste solids, the post-processing operation is relatively simple, and the yield is high, which is more suitable for industrial scale-up production. As can be seen from the preparation of compounds 1 and 2, the starting raw materials used have alkyl groups on the fused ring carbazole, which can improve the activity of subsequent reactions, avoid the generation of a large number of by-products, and increase the yield from 83.2% to 92.3%. From the preparation of Example 1 and Compound 7, it can be seen that the order of adding potassium iodide and sodium nitrite significantly affects the yield of the product. The compound represented by formula (I) is catalyzed by an inorganic acid and reacted with sodium nitrite first and then potassium iodide to obtain the compound represented by formula (II). Compared with the reaction of first adding potassium iodide and then adding sodium nitrite, the yield can be increased from 35.6% to 92.5%.
[0032] The above-described embodiments are part of the embodiments of the present invention, but not all of them. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but rather represents selected embodiments of the present invention. All other embodiments obtained without creative work and related deductions and substitutions made by ordinary technicians in the field under the conditions of the concept of the present invention belong to the scope of protection of the present invention.
Claims
1. A method for preparing a compound, characterized in that: include: The compound represented by formula (I) is catalyzed by an inorganic acid, and sodium nitrite and potassium iodide are added to react to obtain the compound represented by formula (II); Here, R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
2. The method for preparing the compound according to claim 1, characterized in that: After the compound represented by formula (I), solvent and inorganic acid are mixed, sodium nitrite is first added to react, and after the reaction is completed, potassium iodide is added to react to obtain the compound represented by formula (II).
3. The method for preparing the compound according to claim 1, characterized in that: The inorganic acid is at least one of hydrochloric acid, bromic acid, sulfuric acid, nitric acid and phosphoric acid.
4. The method for preparing the compound according to claim 1, characterized in that: The molar ratio of the compound represented by formula (I), the inorganic acid, sodium nitrite and potassium iodide is 1.0:1.0-4.0:1.0-2.0:1.0-2.
0.
5. The method for preparing the compound according to claim 2, characterized in that: The solvent is at least one of methanol, ethanol, isopropanol, tetrahydrofuran, toluene, xylene, ethylbenzene, cyclohexane, n-hexane, n-heptane, dichloromethane, dichloroethane, chloroform, 1,4-dioxane, acetonitrile and water.
6. The method for preparing the compound according to claim 5, characterized in that: The molar ratio of the compound represented by formula (I) to the solvent is 1.0:5.0-30.
0.
7. The method for preparing the compound according to claim 1, characterized in that: The reaction time of the preparation method is 3 to 12 hours, and the reaction temperature is 0 to 10°C.