Preparation method of 8-bromo-6-phenyl naphtho [2, 1-b] benzofuran

Abstract

The invention discloses a preparation method of 8-bromo-6-phenyl naphtho [2, 1-b] benzofuran, and relates to the technical field of synthesis of dibenzofuran compounds. The preparation method comprises the following steps: taking 2, 3-dihydroxy naphthalene as a raw material, and reacting with trifluoromethanesulfonic anhydride to synthesize 3-hydroxy naphthalene-2-group trifluoromethanesulfonate; taking the prepared 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate as a raw material, and carrying out a coupling reaction with phenylboronic acid to prepare 2-hydroxy-3-phenylnaphthalene; the method comprises the following steps: by taking 1, 3-dibromobenzene as a raw material, reacting lithium diisopropylamide with trimethyl borate at a low temperature to prepare 2, 6-dibromophenylboronic acid; the 8-bromine-6-phenyl naphtho [2, 1-b] benzofuran is prepared from the prepared 2-hydroxy-3-phenyl naphthalene and 2, 6-dibromophenylboronic acid through a cascade reaction of C-O coupling and intramolecular C-H / C-X cross coupling under the action of a catalyst, a ligand and alkali, and the 8-bromine-6-phenyl naphtho [2, 1-b] benzofuran is prepared from the 2-hydroxy-3-phenyl naphthalene and the 2, 6-dibromophenylboronic acid through the cascade reaction of C-O coupling and intramolecular C-H / C-X cross coupling. The invention provides a brand new synthesis route, the raw material cost is low, the total reaction yield is high, the atom utilization rate is high, the production cost is low, the process preparation flow is simple, economic and environment-friendly, and large-scale production is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of synthesis of dibenzofuran compounds, in particular to a method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. Background Art

[0002] Dibenzofuran compounds are an important class of aromatic compounds. They are oxygen-containing fused ring compounds with similar structures to carbazole nitrogen-containing compounds. They are also the core structural units of many active drug molecules and natural products. Their derivatives have potential anti-cancer, antibacterial, anti-allergic, anti-inflammatory and other biological activities. Therefore, they are widely used in the fields of medicine, disinfectants, preservatives and dyes. Compounds containing dibenzofuran skeletons have good thermal stability and photostability, and have good device luminescence performance. At the same time, they can effectively improve the efficiency and life of OLED devices, so that the driving life is greatly improved. Therefore, they have important applications in the preparation of organic phosphorus light-emitting diodes (PhOLEDs). 8-Bromo-6-phenylnaphtho[2,1-b]benzofuran is a dibenzofuran chemical intermediate with excellent optical and electrical properties. It is widely used as a synthetic intermediate for functional organic semiconductors such as organic / polymer light-emitting diodes (OLED / PLED), organic solar cells (OSC), organic field effect transistors (OFET), organic lasers and ion detection. Aromatic compounds containing dibenzofuran skeletons prepared by further modification have important applications in OLED as luminescent host and guest materials, carrier transport materials and exciton blocking materials, and have been widely concerned and studied in recent years. Therefore, studying the synthesis of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran is of great significance to the development of the OLED industry. Existing literature reports that there are mainly two types of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran analogs.

[0003] Route 1: Using naphtho[2,1-b]benzofuran as the starting material, 8-iodo-6-phenylnaphtho[2,1-b]benzofuran is prepared by three steps of butyl lithium hydrogenation to iodinate the 6th position, Suzuki coupling, and butyl lithium hydrogenation to iodinate the 8th position. For example, patent CN201911346522.6 reports a method for preparing 8-iodo-6-phenylnaphtho[2,1-b]benzofuran, which uses naphtho[2,1-b]benzofuran as a starting material, firstly extracts the 6-position hydrogen iodide of naphtho[2,1-b]benzofuran under the action of butyl lithium to prepare 6-iodonaphtho[2,1-b]benzofuran, then reacts with phenylboronic acid to prepare 6-phenylnaphtho[2,1-b]benzofuran, and finally extracts the 8-position hydrogen iodide of 6-phenylnaphtho[2,1-b]benzofuran under the action of butyl lithium to prepare 8-iodo-6-phenylnaphtho[2,1-b]benzofuran, and the total yield of the three-step reaction is 22%;

[0004]

[0005] Route 2: Using halogenated naphthalene compounds as starting materials, naphtho[2,1-b]benzofuran compounds are prepared through Suzuki coupling reaction, intramolecular nucleophilic substitution reaction or intramolecular oxidative dehydrogenation cyclization reaction, and then Suzuki coupling reaction is carried out to prepare 6-phenylnaphtho[2,1-b]benzofuran, and finally 8-iodo-6-phenylnaphtho[2,1-b]benzofuran is prepared by halogenation of the 8-position hydrogen under the action of butyl lithium. For example, patent CN202110017783.4 reports a method for preparing 8-iodo-6-phenylnaphtho[2,1-b]benzofuran, which uses 1-bromo-3-chloronaphthalene as a starting material, first reacts with o-hydroxyphenylboronic acid to prepare 2-(3-chloronaphthalene-1-yl)phenol, then prepares 6-chloronaphtho[2,1-b]benzofuran under the action of phosphorus pentoxide and trifluoromethanesulfonic acid, and then couples with phenylboronic acid to prepare 6-phenylnaphtho[2,1-b]benzofuran, and finally, butyl lithium is used to pull out the 8-position hydrogen halogen to prepare 8-iodo-6-phenylnaphtho[2,1-b]benzofuran, and the total yield of the four-step reaction is 12%;

[0006]

[0007] In the above-mentioned synthetic routes, route 1 uses naphtho[2,1-b]benzofuran as a starting material, and prepares 8-iodo-6-phenylnaphtho[2,1-b]benzofuran through two-step low-temperature hydrogenation and iodination reactions. The yield of the two-step low-temperature butyl lithium hydrogenation and iodination reactions is low, so the total yield after three steps of reaction is low; at the same time, naphtho[2,1-b]benzofuran as a reaction raw material can shorten the reaction steps, but it requires multiple steps of reaction preparation and is expensive; therefore, this route has the disadvantages of low total reaction yield, high raw material price, high production cost, poor economy, etc. Route 2 uses 1-bromo-3-chloronaphthalene as the starting material. The preparation process is carried out in four steps and the reaction conditions are relatively mild. However, it also has the shortcomings of route 1. For example, it uses expensive and difficult-to-obtain 1-bromo-3-chloronaphthalene as the reaction raw material. The process of constructing the naphtho[2,1-b]benzofuran skeleton structure by intramolecular dehydrogenation and cyclization catalyzed by phosphorus pentoxide and trifluoromethanesulfonic acid has the shortcomings of more waste, heavy pollution, strong corrosion, etc., and the final low-temperature hydrogenation iodination process to prepare 8-iodo-6-phenylnaphtho[2,1-b]benzofuran has a low yield. Therefore, this route also has the defects of low total reaction yield, high raw material price, high production equipment requirements, heavy pollution, etc., which does not meet the development requirements of green chemistry and synthetic economy.

[0008] In summary, the existing synthesis methods generally have the problems of expensive and difficult to obtain reaction raw materials, poor reaction selectivity, route and atom economy, low total reaction yield, high production cost, etc., and the existing synthesis methods are only for iodine-containing products, and there are no bromine-containing products, and bromine-containing compounds are more difficult to synthesize than iodine-containing compounds. This situation seriously restricts the industrial application of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran compounds. Therefore, it is necessary to improve the preparation method in the prior art and develop a more economical, green and efficient new synthesis route for 8-bromo-6-phenylnaphtho[2,1-b]benzofuran compounds on the basis of ensuring a higher total product yield. Summary of the invention

[0009] The purpose of the present invention is to provide a method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran, so as to provide a new synthetic route, which can make the synthetic route more economical, green and efficient under the premise of ensuring a higher total yield of the product.

[0010] To achieve the above object, the present invention provides the following technical solution: a method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran, comprising the following specific contents:

[0011] (1) 2,3-dihydroxynaphthalene is used as a raw material to react with trifluoromethanesulfonic anhydride to synthesize 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, and the reaction formula is:

[0012] (2) Using the prepared 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate as a raw material, a coupling reaction is performed with phenylboronic acid to prepare 2-hydroxy-3-phenylnaphthalene, and the reaction formula is:

[0013] (3) Using 1,3-dibromobenzene as a raw material, lithium diisopropylamide reacts with trimethyl borate at low temperature to prepare 2,6-dibromobenzene boronic acid, and the reaction formula is:

[0014] (4) Using the above-prepared 2-hydroxy-3-phenylnaphthalene and 2,6-dibromophenylboronic acid, in the presence of a catalyst, a ligand and a base, 8-bromo-6-phenylnaphtho[2,1-b]benzofuran is prepared by a CO coupling and an intramolecular CH / CX cross-coupling tandem reaction, and the reaction formula is:

[0015]

[0016] Preferably, the specific operation process in the above step (1) is: under nitrogen protection, add 2,3-dihydroxynaphthalene, a catalyst and an organic solvent to a reaction container, stir evenly and then add trifluoromethanesulfonic anhydride, and keep the temperature at 0°C to 30°C to complete the reaction; after the reaction is completed, dissolve the reaction system with saturated ammonium chloride to neutralize it, separate the liquids, wash the organic phase with water several times, dry it to remove water, and remove dichloromethane by reduced pressure distillation.

[0017] In the above preferred embodiments, the organic solvent is one or more of dichloromethane, 1,2-dichloroethane or 2-methyltetrahydrofuran, the catalyst is selected from 4-dimethylaminopyridine, triethylamine or pyridine, the molar ratio of 2,3-dihydroxynaphthalene, trifluoromethanesulfonic anhydride and the catalyst is 1:(1.05-1.10):(0.5-1.5), and the amount of the organic solvent is (0.5-1.0) mol / L according to the molar reaction concentration of 2,3-dihydroxynaphthalene.

[0018] In the preferred embodiment, when adding trifluoromethanesulfonic anhydride, the reaction vessel is placed at 0°C and added in batches. The reaction is first carried out at 0°C for a period of time to control the temperature of the system after heat release, and then the temperature is raised to 30°C to continue the reaction until completion. The reaction takes a total of 2 to 10 hours.

[0019] Preferably, the specific operation process in the above step (2) is: under nitrogen protection, add 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, catalyst, coupling base, and a mixed solvent of organic phase and water into a reaction container; stir and react at 60-90° C. for 12-24 hours; after the reaction is completed, cool to room temperature, separate the liquids, extract with n-hexane, wash the organic phase with water several times, dry to remove water, filter with silica gel, and then distill under reduced pressure to remove the organic phase.

[0020] In the above preferred embodiments, the mixed solvent is one or more of xylene / ethanol / water, toluene ethanol / water, tetrahydrofuran / water, and 2-methyltetrahydrofuran / water; the catalyst is selected from tetrakistriphenylphosphine palladium, palladium acetate, and dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II); the coupling base is selected from potassium carbonate, sodium carbonate, potassium phosphate, and sodium hydroxide; the molar ratio of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, catalyst, and coupling base is 1:(1.10-1.20):(0.001-0.02):(2-3); the amount of the organic phase in the mixed solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate.

[0021] Preferably, the specific operation process in the above step (3) is: under nitrogen protection, add 1,3-dibromobenzene and an organic solvent to a dry reaction container and stir evenly; reduce the temperature of the reaction system to -70°C, add lithium diisopropylamide to the reaction system, and after the addition is completed, maintain the system temperature at -70°C for reaction for 2 hours; then add trimethyl borate to the reaction system, maintain the system temperature at -70°C for reaction for 2 hours, naturally warm to room temperature for reaction for more than 8 hours; after the reaction is completed, add 2M hydrochloric acid aqueous solution to the system, adjust the reaction pH to acidic, stir at room temperature for 2 hours, separate the mixed solution, extract, wash the inorganic layer with ethyl acetate, extract the combined organic solution with saturated sodium chloride aqueous solution, dry, concentrate under reduced pressure to remove the organic solvent and ethyl acetate, filter and dry.

[0022] In the above preferred embodiments, tetrahydrofuran or 2-methyltetrahydrofuran is used as the organic solvent, the molar ratio of 1,3-dibromobenzene, lithium diisopropylamide and trimethyl borate is 1:(1.10-1.20):(1.2-1.5), and the amount of the organic solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 1,3-dibromobenzene.

[0023] Preferably, the specific operation process in the above step (4) is: under nitrogen protection, add 2-hydroxy-3-phenylnaphthalene, 2,6-dibromophenylboronic acid, copper salt catalyst, nitrogen heterocyclic carbene nickel salt catalyst, oxidant, methyl boronic acid additive, organic base, inorganic base and solvent to a dry reaction container; stir and react at 80-140° C. for 12-24 hours; after the coupling reaction is completed, cool to room temperature for post-treatment, filter and dilute with water and organic solvent, extract and separate with extraction solvent, dry the organic layer, filter with silica gel, and distill to obtain the product.

[0024] In the preferred embodiment, the oxidant is one or more of hydrogen peroxide, tert-butyl perbenzoate, and cumene hydroperoxide; the organic base is one or more of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), pyridine, and triethylamine; the inorganic base is one or more of sodium carbonate, potassium carbonate, and potassium phosphate; the solvent is one or more of dimethyl sulfoxide, 1,4-dioxane, N,N-dimethylformamide, or N,N-dimethylacetamide; the copper salt catalyst is one or more of copper acetate, copper trifluoromethanesulfonate, and copper acetylacetonate; the nitrogen heterocyclic carbene nickel salt catalyst is one or more of [Ni(IPr * )CpCl]、[Ni(IPr *Tol )CpCl] or [Ni(IPr *OMe )CpCl], and the corresponding structures are as follows: The organic solvent dilution and extraction solvent for post-treatment are one or more of tetrahydrofuran, ethyl acetate, 1,2-dichloroethane, and 2-methyltetrahydrofuran; the molar ratio of 2-hydroxy-3-phenylnaphthalene to 2,6-dibromophenylboric acid is 1:(1.00-1.20), the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05), and the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05). The molar ratio of hydroxy-3-phenylnaphthalene to the additive is 1:(0.10-0.50), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the oxidant is 1:(1.00-2.00), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the organic base and the inorganic base is 1:(1.50-2.00):(2.00-3.00), and the amount of the solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 2-hydroxy-3-phenylnaphthalene.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The preparation method of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran adopts 2,3-dihydroxynaphthalene and 1,3-dibromobenzene as starting materials to synthesize 2-hydroxy-3-phenylnaphthalene and 2,6-dibromophenylboronic acid respectively, and then prepares 8-bromo-6-phenylnaphtho[2,1-b]benzofuran through CO coupling and intramolecular CH / CX cross-coupling tandem reaction, which provides a new synthetic route for synthesizing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. The new route has low raw material cost, high total reaction yield, high atomic utilization rate, low production cost, simple process preparation flow, economy and environmental protection, is conducive to large-scale production, has good industrial feasibility, and provides a more feasible new idea for the material design and application of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran in the fields of optics and medicine.

[0027] 2. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran adopts a nickel / copper bimetallic coordinated catalytic series reaction of a reaction intermediate 2-hydroxy-3-phenylnaphthalene and 2,6-dibromophenylboronic acid to prepare 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. The method has the advantages of high reaction yield in the step-by-step preparation of the reaction intermediate, mild conditions and high total reaction yield. The bimetallic coordinated catalytic series reaction process generates few by-products and has high reaction selectivity, so that a higher yield of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran can be obtained.

[0028] 3. Compared with the existing synthesis method, the present invention adopts relatively cheap and easily available 2,3-dihydroxynaphthalene and 1,3-dibromobenzene as starting materials, and has the advantage of low raw material cost; the yield of the intermediate prepared by the multi-step reaction is high, which can effectively ensure that the total yield of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran prepared by the multi-step reaction is greatly improved, avoiding the shortcomings of poor selectivity and low yield of the multi-step low-temperature halogenation reaction, and at the same time avoiding the problem of low yield of the intramolecular dehydrogenation cyclization reaction of the hydroxyl-containing intermediate, effectively improving the reaction selectivity, total reaction yield and atomic utilization, effectively reducing the difficulty of product separation, greatly reducing the raw material cost and production cost, and having the characteristics of high reaction yield, economy and environmental protection.

[0029] 4. Compared with the low-temperature halogenation reaction in the existing synthesis method, the low-temperature borylation reaction in the present invention can effectively improve the selectivity and yield of the reaction, reduce the difficulty of reaction purification, and reasonably reduce the preparation cost of intermediates and target products.

[0030] 5. In the present invention, the dibenzofuran skeleton structure is constructed to reduce the steps of the hydroxyl-containing intermediates participating in the reaction, which can effectively avoid the influence of the hydroxyl group on the reaction selectivity, thereby improving the reaction selectivity and reaction yield. DETAILED DESCRIPTION

[0031] A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran comprises the following specific contents:

[0032] (1) 2,3-dihydroxynaphthalene is used as a raw material to react with trifluoromethanesulfonic anhydride to synthesize 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, and the reaction formula is:

[0033] In a preferred embodiment, the specific operation process may be: under nitrogen protection, 2,3-dihydroxynaphthalene, a catalyst and an organic solvent are added to a reaction container, and trifluoromethanesulfonic anhydride is added after stirring evenly, and the reaction is kept at 0°C to 30°C to complete the reaction; in order to obtain a better yield, it is further preferred that the reaction container is placed at 0°C and added in batches when adding trifluoromethanesulfonic anhydride, and the reaction is first carried out at 0°C for a period of time, for example, 2 hours, to control the temperature of the system after exothermic reaction, and then the temperature is raised to 30°C to continue the reaction until the end, and the reaction takes a total of 2 to 10 hours;

[0034] After the reaction is completed, the reaction system is neutralized with saturated ammonium chloride and separated. The organic phase is washed with water several times and then dried to remove water, and dichloromethane is removed by distillation under reduced pressure.

[0035] In order to obtain a better yield, for reference, the above-mentioned organic solvent is one or more of dichloromethane, 1,2-dichloroethane or 2-methyltetrahydrofuran, and the catalyst is selected from 4-dimethylaminopyridine, triethylamine or pyridine; the molar ratio of 2,3-dihydroxynaphthalene, trifluoromethanesulfonic anhydride and catalyst is 1:(1.05-1.10):(0.5-1.5), and the amount of organic solvent is (0.5-1.0) mol / L according to the molar reaction concentration of 2,3-dihydroxynaphthalene.

[0036] (2) Using the prepared 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate as a raw material, a coupling reaction is performed with phenylboronic acid to prepare 2-hydroxy-3-phenylnaphthalene, and the reaction formula is:

[0037] In a preferred embodiment, the specific operation process can be: under nitrogen protection, add 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, a catalyst, a coupling base, and a mixed solvent of an organic phase and water into a reaction vessel; stir the reaction at 60 to 90° C. for 12 to 24 hours; after the reaction is completed, cool to room temperature, separate the liquids, extract with n-hexane, wash the organic phase with water several times, dry and remove water, filter with silica gel, and then distill under reduced pressure to remove the organic phase.

[0038] For reference, the above-mentioned mixed solvent is one or more of xylene / ethanol / water, toluene ethanol / water, tetrahydrofuran / water, and 2-methyltetrahydrofuran / water; the catalyst is selected from tetrakistriphenylphosphine palladium, palladium acetate, and dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II); the coupling base is selected from potassium carbonate, sodium carbonate, potassium phosphate, and sodium hydroxide; the molar ratio of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, catalyst, and coupling base is 1:(1.10-1.20):(0.001-0.02):(2-3); the amount of organic phase in the mixed solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, which refers to the reaction concentration calculated based on the organic phase alone.

[0039] (3) Using 1,3-dibromobenzene as a raw material, lithium diisopropylamide reacts with trimethyl borate at low temperature to prepare 2,6-dibromobenzene boronic acid, and the reaction formula is:

[0040] In a preferred embodiment, the specific operation process can be: under nitrogen protection, 1,3-dibromobenzene and an organic solvent are added to a dry reaction container and stirred evenly; the temperature of the reaction system is lowered to -70°C, and lithium diisopropylamide is added dropwise to the reaction system. After the addition is completed, the system temperature is maintained at -70°C for reaction for 2 hours; then trimethyl borate is added dropwise to the reaction system, and the system temperature is maintained at -70°C for reaction for 2 hours, and the temperature is naturally raised to room temperature for reaction for more than 8 hours; after the reaction is completed, a 2M hydrochloric acid aqueous solution is added dropwise to the system, the reaction pH is adjusted to acidic, and stirred at room temperature for 2 hours, the mixed solution is separated, extracted, the inorganic layer is washed with ethyl acetate, the combined organic liquid is extracted with a saturated sodium chloride aqueous solution, dried, concentrated under reduced pressure to remove the organic solvent and ethyl acetate, and filtered and dried.

[0041] For reference, the above-mentioned organic solvent is tetrahydrofuran or 2-methyltetrahydrofuran, the molar ratio of 1,3-dibromobenzene, lithium diisopropylamide and trimethyl borate is 1:(1.10-1.20):(1.2-1.5), and the amount of organic solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 1,3-dibromobenzene.

[0042] (4) Using the above-prepared 2-hydroxy-3-phenylnaphthalene and 2,6-dibromophenylboronic acid, in the presence of a catalyst, a ligand and a base, 8-bromo-6-phenylnaphtho[2,1-b]benzofuran is prepared by a CO coupling and an intramolecular CH / CX cross-coupling tandem reaction, and the reaction formula is:

[0043]

[0044] In a preferred embodiment, the specific operation process can be: under nitrogen protection, add 2-hydroxy-3-phenylnaphthalene, 2,6-dibromophenylboronic acid, copper salt catalyst, nitrogen heterocyclic carbene nickel salt catalyst, oxidant, methyl boronic acid additive, organic base, inorganic base and solvent into a dry reaction container; stir the reaction at 80-140°C for 12-24 hours; after the coupling reaction is completed, cool to room temperature for post-treatment, filter and dilute with water and organic solvent, extract and separate the liquid with extraction solvent, dry the organic layer, filter with silica gel, and distill to obtain the product.

[0045] For reference, the above-mentioned oxidant is one or more of hydrogen peroxide, tert-butyl perbenzoate, and cumene hydroperoxide; the organic base is one or more of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), pyridine, and triethylamine; the inorganic base is one or more of sodium carbonate, potassium carbonate, and potassium phosphate; the solvent is one or more of dimethyl sulfoxide, 1,4-dioxane, N,N-dimethylformamide, or N,N-dimethylacetamide; the copper salt catalyst is one or more of copper acetate, copper trifluoromethanesulfonate, and copper acetylacetonate; the nitrogen heterocyclic carbene nickel salt catalyst is one or more of [Ni(IPr * )CpCl]、[Ni(IPr *Tol )CpCl] or [Ni(IPr *OMe )CpCl], and the corresponding structures are as follows: The organic solvent dilution and extraction solvent for post-treatment are one or more of tetrahydrofuran, ethyl acetate, 1,2-dichloroethane, and 2-methyltetrahydrofuran; the molar ratio of 2-hydroxy-3-phenylnaphthalene to 2,6-dibromophenylboric acid is 1:(1.00-1.20), the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05), and the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05). The molar ratio of hydroxy-3-phenylnaphthalene to the additive is 1:(0.10-0.50), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the oxidant is 1:(1.00-2.00), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the organic base and the inorganic base is 1:(1.50-2.00):(2.00-3.00), and the amount of the solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 2-hydroxy-3-phenylnaphthalene.

[0046] The contents of the above specific implementation modes are further described below through several embodiments, but the following embodiments are only some illustrative embodiments of the present invention, and it should not be understood that the present invention is limited to the following embodiments.

[0047] Example 1: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0048] The steps include: (1) preparation of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate: under nitrogen protection, adding 2,3-dihydroxynaphthalene (99%, 160.2 g, 1.0 mol), 4-dimethylaminopyridine (99%, 61.1 g, 0.5 mol) and 1000 mL of dichloromethane into a reaction bottle, stirring evenly, placing the reaction bottle at 0°C and adding trifluoromethanesulfonic anhydride (99%, 296.4 g, 1.05 mol) in batches, reacting at 0°C for 2 hours after the addition of trifluoromethanesulfonic anhydride, then raising the temperature of the reaction system to 30°C and continuing the reaction for 8 hours; after the reaction is completed, dissolving the reaction system with saturated ammonium chloride to neutralize the reaction system, separating the liquids, washing the organic phase with water 3 times, drying and removing water, and then distilling under reduced pressure to remove dichloromethane to obtain 263.0 g of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate;

[0049] (2) Preparation of 2-hydroxy-3-phenylnaphthalene: Under nitrogen protection, 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate (99%, 263.0 g, 0.9 mol), phenylboric acid (99%, 122.0 g, 1.0 mol), tetrakistriphenylphosphine palladium (99%, 10.4 g, 9.0 mmol), potassium carbonate (99%, 279.0 g, 1.8 mol), 1800 mL of o-xylene, 400 mL of ethanol and 400 mL of deionized water were added to a reaction flask; after the addition, the temperature was raised to 83° C., the stirring speed was 500 rpm, and the temperature was kept for 24 hours; after the reaction was completed, the mixture was cooled to room temperature, separated, extracted with n-hexane, the organic phase was washed with water three times, dried to remove water, filtered with silica gel, and then distilled under reduced pressure to remove xylene and ethanol to obtain 170.5 g of 2-hydroxy-3-phenylnaphthalene;

[0050] (3) Preparation of 2,6-dibromophenylboronic acid: Under nitrogen protection, 1,3-dibromobenzene (99%, 236.0 g, 1.0 mol) and 2000 mL of tetrahydrofuran were added to a dry reaction bottle and stirred evenly; the temperature of the reaction system was lowered to -70°C, and 550 mL of lithium diisopropylamide (2.0 mol / L, 1.1 mol) was added dropwise to the reaction system. After the addition was completed, the system temperature was maintained at -70°C for 2 hours; then trimethyl borate (98%, After the addition of 135.0g, 1.3mol) was completed, the system temperature was maintained at -70°C for 2 hours, and the temperature was naturally raised to room temperature for more than 8 hours; after the reaction was completed, a 2M hydrochloric acid aqueous solution was added dropwise to the system to adjust the reaction pH to acidic, and stirred at room temperature for 2 hours. The mixed solution was separated, extracted, and the inorganic layer was washed with ethyl acetate. The combined organic solution was extracted with a saturated sodium chloride aqueous solution and dried, and concentrated under reduced pressure to remove tetrahydrofuran and ethyl acetate. After suction filtration and drying, 251.8g of 2,6-dibromophenylboronic acid was obtained;

[0051] (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: Under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (170.5 g, 0.774 mol) and 2,6-dibromophenylboronic acid (238.2 g, 0.85 mol) prepared in steps (2) and (3), 28.1 g of copper acetate (99%, 0.155 mol), 8.30 g of [Ni(IPr * )CpCl] (99%, 7.75mmol), 131.6g of hydrogen peroxide (30%, 1.16mol), 91.8g of pyridine (99%, 1.16mol), 9.30g of methylboric acid (99%, 0.155mol), 328.6g of potassium phosphate (99%, 1.55mol) and 1500mL of N,N-dimethylformamide; after the addition, the temperature was raised to 100°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, the mixture was cooled to room temperature and filtered, water and ethyl acetate were added to the filtrate to dilute, the mixture was mixed and stirred to extract and separate the liquids, the organic layer was dried to precipitate the solid, and then it was filtered through reduced pressure silica gel, distilled to remove the solvent and dried to obtain 219.6g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. Based on 2,3-dihydroxynaphthalene as the starting material, the total yield of the reaction was 58.8%.

[0052] Example 2: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0053] The steps include: (1) preparation of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate: under nitrogen protection, adding 2,3-dihydroxynaphthalene (99%, 160.2 g, 1.0 mol), 4-dimethylaminopyridine (99%, 122.2 g, 1.0 mol) and 1000 mL of dichloromethane into a reaction bottle, stirring evenly, placing the reaction bottle at 0°C and adding trifluoromethanesulfonic anhydride (99%, 310.5 g, 1.1 mol) in batches, reacting at 0°C for 2 hours after the addition of trifluoromethanesulfonic anhydride, then raising the temperature of the reaction system to 30°C and continuing the reaction for 8 hours; after the reaction is completed, dissolving the reaction system with saturated ammonium chloride to neutralize the reaction system, separating the liquids, washing the organic phase with water 3 times, drying and removing water, and then distilling under reduced pressure to remove dichloromethane to obtain 268.8 g of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate;

[0054] (2) Preparation of 2-hydroxy-3-phenylnaphthalene: Under nitrogen protection, 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate (99%, 268.8 g, 0.92 mol), phenylboric acid (99%, 134.7 g, 1.1 mol), dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II) (99%, 3.3 g, 4.6 mmol), potassium carbonate (99%, 279.0 g, 1.8 mol), 1800 mL of o-xylene, 400 mL of ethanol and 400 mL of deionized water were added to a reaction flask; after the addition, the temperature was raised to 83° C., the stirring speed was 500 rpm, and the temperature was kept for 24 hours; after the reaction was completed, the mixture was cooled to room temperature, separated, extracted with n-hexane, the organic phase was washed with water three times, dried to remove water, filtered with silica gel, and then distilled under reduced pressure to remove xylene and ethanol to obtain 172.3 g of 2-hydroxy-3-phenylnaphthalene;

[0055] (3) Preparation of 2,6-dibromophenylboronic acid: Under nitrogen protection, 1,3-dibromobenzene (99%, 236.0 g, 1.0 mol) and 2000 mL of tetrahydrofuran were added to a dry reaction bottle and stirred evenly; the temperature of the reaction system was lowered to -70°C, and 600 mL of lithium diisopropylamide (2.0 mol / L, 1.2 mol) was added dropwise to the reaction system. After the addition was completed, the system temperature was maintained at -70°C for 2 hours; then trimethyl borate (98%, After the addition of 155.8g, 1.5mol) was completed, the system temperature was maintained at -70°C for 2 hours, and the temperature was naturally raised to room temperature for more than 8 hours; after the reaction was completed, a 2M hydrochloric acid aqueous solution was added dropwise to the system to adjust the reaction pH to acidic, and stirred at room temperature for 2 hours. The mixed solution was separated, extracted, and the inorganic layer was washed with ethyl acetate. The combined organic solution was extracted with a saturated sodium chloride aqueous solution and dried, and concentrated under reduced pressure to remove tetrahydrofuran and ethyl acetate. After suction filtration and drying, 260.1g of 2,6-dibromophenylboronic acid was obtained;

[0056] (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: Under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (172.3 g, 0.782 mol) and 2,6-dibromophenylboronic acid (260.1 g, 0.93 mol) prepared in steps (2) and (3), 71.0 g of copper acetate (99%, 0.391 mol), 41.8 g of [Ni(IPr *)CpCl] (99%, 39.1mmol), 175.5g of hydrogen peroxide (30%, 1.56mol), 123.8g of pyridine (99%, 1.56mol), 23.4g of methylboric acid (99%, 0.391mol), 497.4g of potassium phosphate (99%, 2.35mol) and 1500mL of N,N-dimethylformamide; after the addition, the temperature was raised to 120°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, it was cooled to room temperature and filtered, and the filtrate was diluted with water and ethyl acetate, mixed and stirred to extract and separate the liquids, the organic layer was dried to precipitate the solid, and then filtered through reduced pressure silica gel, distilled to remove the solvent and dried to obtain 236.4g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. Based on 2,3-dihydroxynaphthalene as the starting material, the total reaction yield was 63.3%.

[0057] Example 3: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0058] The steps include: step (1) 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, step (2) 2-hydroxy-3-phenylnaphthalene and step (3) 2,6-dibromophenylboronic acid are prepared under the same reaction conditions and treatment methods as in Example 2; (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (172.3 g, 0.782 mol) and 2,6-dibromophenylboronic acid (260.1 g, 0.93 mol) prepared in steps (2) and (3), 56.6 g of copper trifluoromethanesulfonate (99%, 0.156 mol), 18.6 g of [Ni(IPr *Tol )CpCl] (99%, 15.6mmol), 133.0g of hydrogen peroxide (30%, 1.17mol), 118.7g of triethylamine (99%, 1.17mol), 14.0g of methylboric acid (99%, 0.24mol), 331.0g of potassium phosphate (99%, 1.56mol) and 1500mL of N,N-dimethylacetamide; after the addition, the temperature was raised to 100°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, the mixture was cooled to room temperature and filtered, water and ethyl acetate were added to the filtrate to dilute, the mixture was mixed and stirred to extract and separate the liquids, the organic layer was dried to precipitate the solid, and then the solid was filtered through reduced pressure silica gel, distilled, desolventized and dried to obtain 224.7g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. The total yield of the reaction was 60.2% based on 2,3-dihydroxynaphthalene as the starting material.

[0059] Example 4: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0060] The steps include: step (1) 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, step (2) 2-hydroxy-3-phenylnaphthalene and step (3) 2,6-dibromophenylboronic acid are prepared under the same reaction conditions and treatment methods as in Example 2; (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (172.3 g, 0.782 mol) and 2,6-dibromophenylboronic acid (260.1 g, 0.93 mol) prepared in steps (2) and (3), 28.3 g of copper acetate (99%, 0.156 mol), 17.3 g of [Ni(IPr *OMe )CpCl] (99%, 15.6mmol), 133.0g of hydrogen peroxide (30%, 1.17mol), 118.7g of triethylamine (99%, 1.17mol), 14.0g of methylboric acid (99%, 0.24mol), 331.0g of potassium phosphate (99%, 1.56mol) and 1500mL of dimethyl sulfoxide; after the addition, the temperature was raised to 100°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, the reaction was cooled to room temperature and filtered, the filtrate was diluted with water and ethyl acetate, mixed and stirred, extracted and separated, the organic layer was dried to precipitate the solid, and then filtered through reduced pressure silica gel, distilled, desolventized and dried to obtain 170.2g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran, and the total yield of the reaction was 45.6% based on 2,3-dihydroxynaphthalene as the starting material.

[0061] Example 5: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0062] The steps include: step (1) 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, step (2) 2-hydroxy-3-phenylnaphthalene and step (3) 2,6-dibromophenylboronic acid are prepared under the same reaction conditions and treatment methods as in Example 2; (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (172.3 g, 0.782 mol) and 2,6-dibromophenylboronic acid (260.1 g, 0.93 mol) prepared in steps (2) and (3), 40.8 g of copper acetylacetonate (99%, 0.156 mol), 9.3 g of [Ni(IPr *Tol)CpCl] (99%, 7.8mmol), 227.3g of tert-butyl perbenzoate (98%, 1.17mol), 118.7g of triethylamine (99%, 1.17mol), 23.4g of methylboric acid (99%, 0.391mol), 331.0g of potassium phosphate (99%, 1.56mol) and 1500mL of dimethyl sulfoxide; after the addition, the temperature was raised to 140°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, it was cooled to room temperature and filtered, and the filtrate was diluted with water and ethyl acetate, mixed and stirred to extract and separate the liquids, the organic layer was dried to precipitate the solid, and then filtered through reduced pressure silica gel, distilled to remove the solvent and dried to obtain 136.2g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. Based on 2,3-dihydroxynaphthalene as the starting material, the total yield of the reaction was 36.5%.

[0063] Example 6: A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran

[0064] The steps include: step (1) 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, step (2) 2-hydroxy-3-phenylnaphthalene and step (3) 2,6-dibromophenylboronic acid are prepared under the same reaction conditions and treatment methods as in Example 2; (4) Preparation of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran: under nitrogen protection, 2-hydroxy-3-phenylnaphthalene (172.3 g, 0.782 mol) and 2,6-dibromophenylboronic acid (260.1 g, 0.93 mol) prepared in steps (2) and (3), 71.0 g of copper acetate (99%, 0.391 mol), 8.30 g of [Ni(IPr * )CpCl] (99%, 7.75mmol), 227.3g of tert-butyl perbenzoate (98%, 1.17mol), 118.7g of triethylamine (99%, 1.17mol), 23.4g of methylboric acid (99%, 0.391mol), 328.6g of potassium phosphate (99%, 1.55mol) and 1500mL of N,N-dimethylformamide; after the addition, the temperature was raised to 120°C, the stirring speed was 550rpm, and the reaction was kept warm for 24 hours; after the reaction was completed, it was cooled to room temperature and filtered, and the filtrate was diluted with water and ethyl acetate, mixed and stirred to extract and separate the liquids, the organic layer was dried to precipitate the solid, and then filtered through reduced pressure silica gel, distilled to remove the solvent and dried to obtain 229.5g of 8-bromo-6-phenylnaphtho[2,1-b]benzofuran. Based on 2,3-dihydroxynaphthalene as the starting material, the total yield of the reaction was 61.5%.

[0065] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined by the claims.

[0066] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran, characterized in that: The specific contents include: (1) 2,3-dihydroxynaphthalene is used as a raw material to react with trifluoromethanesulfonic anhydride to synthesize 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, and the reaction formula is: (2) Using the prepared 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate as a raw material, a coupling reaction is performed with phenylboronic acid to prepare 2-hydroxy-3-phenylnaphthalene, and the reaction formula is: (3) Using 1,3-dibromobenzene as a raw material, lithium diisopropylamide reacts with trimethyl borate at low temperature to prepare 2,6-dibromobenzene boronic acid, and the reaction formula is: (4) Using the above-prepared 2-hydroxy-3-phenylnaphthalene and 2,6-dibromophenylboronic acid, in the presence of a catalyst, a ligand and a base, 8-bromo-6-phenylnaphtho[2,1-b]benzofuran is prepared by a CO coupling and an intramolecular CH / CX cross-coupling tandem reaction, and the reaction formula is:

2. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 1, characterized in that: The specific operation process in the step (1) is as follows: under nitrogen protection, 2,3-dihydroxynaphthalene, a catalyst and an organic solvent are added to a reaction container, and trifluoromethanesulfonic anhydride is added after stirring evenly, and the reaction is maintained at 0°C to 30°C to complete the reaction; after the reaction is completed, the reaction system is neutralized to neutrality by dissolving with saturated ammonium chloride, and the liquids are separated, the organic phase is washed with water several times, and then dried to remove water, and dichloromethane is removed by reduced pressure distillation.

3. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 2, characterized in that: In the step (1), the organic solvent is one or more of dichloromethane, 1,2-dichloroethane or 2-methyltetrahydrofuran, the catalyst is selected from 4-dimethylaminopyridine, triethylamine or pyridine, the molar ratio of 2,3-dihydroxynaphthalene, trifluoromethanesulfonic anhydride and the catalyst is 1:(1.05-1.10):(0.5-1.5), and the amount of the organic solvent is (0.5-1.0) mol / L according to the molar reaction concentration of 2,3-dihydroxynaphthalene.

4. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 2, characterized in that: In the step (1), when adding trifluoromethanesulfonic anhydride, the reaction vessel is placed at 0°C and added in batches. During the reaction, the reaction is first carried out at 0°C for a period of time to control the temperature of the system after heat release, and then the temperature is raised to 30°C to continue the reaction until completion. The reaction takes a total of 2 to 10 hours.

5. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 1, characterized in that: The specific operation process in the step (2) is: under nitrogen protection, adding 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, catalyst, coupling base, and a mixed solvent of organic phase and water into a reaction container; stirring the reaction at 60-90° C. for 12-24 hours; after the reaction is completed, cooling to room temperature, separating the liquids, extracting with n-hexane, washing the organic phase with water for several times, drying to remove water, filtering with silica gel, and then distilling under reduced pressure to remove the organic phase.

6. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 5, characterized in that: In the step (2), the mixed solvent is one or more of xylene / ethanol / water, toluene ethanol / water, tetrahydrofuran / water, and 2-methyltetrahydrofuran / water; the catalyst is selected from tetrakistriphenylphosphine palladium, palladium acetate, and dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II); the coupling base is selected from potassium carbonate, sodium carbonate, potassium phosphate, and sodium hydroxide; the molar ratio of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate, phenylboric acid, catalyst, and coupling base is 1:(1.10-1.20):(0.001-0.02):(2-3); the amount of the organic phase in the mixed solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 3-hydroxynaphthalene-2-yl trifluoromethanesulfonate.

7. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 1, characterized in that: The specific operation process in the step (3) is as follows: under nitrogen protection, 1,3-dibromobenzene and an organic solvent are added to a dry reaction container and stirred evenly; the temperature of the reaction system is lowered to -70°C, and lithium diisopropylamide is added dropwise to the reaction system. After the addition is completed, the system temperature is maintained at -70°C for reaction for 2 hours; then trimethyl borate is added dropwise to the reaction system, and the system temperature is maintained at -70°C for reaction for 2 hours, and the temperature is naturally raised to room temperature for reaction for more than 8 hours; after the reaction is completed, a 2M hydrochloric acid aqueous solution is added dropwise to the system, the reaction pH is adjusted to acidic, and stirred at room temperature for 2 hours, the mixed solution is separated, extracted, the inorganic layer is washed with ethyl acetate, the combined organic liquid is extracted with a saturated sodium chloride aqueous solution, dried, concentrated under reduced pressure to remove the organic solvent and ethyl acetate, filtered, and dried.

8. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 7, characterized in that: In the step (3), the organic solvent is tetrahydrofuran or 2-methyltetrahydrofuran, the molar ratio of 1,3-dibromobenzene, lithium diisopropylamide and trimethyl borate is 1:(1.10-1.20):(1.2-1.5), and the amount of the organic solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 1,3-dibromobenzene.

9. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 1, characterized in that: The specific operation process in the step (4) is as follows: under nitrogen protection, 2-hydroxy-3-phenylnaphthalene, 2,6-dibromophenylboronic acid, copper salt catalyst, nitrogen heterocyclic carbene nickel salt catalyst, oxidant, methyl boronic acid additive, organic base, inorganic base and solvent are added to a dry reaction container; at 80-140° C., the reaction is stirred for 12-24 hours; after the coupling reaction is completed, the reaction is cooled to room temperature for post-treatment, filtered, diluted with water and organic solvent, extracted with an extraction solvent, dried the organic layer, filtered with silica gel, and distilled to obtain the product.

10. The method for preparing 8-bromo-6-phenylnaphtho[2,1-b]benzofuran according to claim 9, characterized in that: In the step (4), the oxidant is one or more of hydrogen peroxide, tert-butyl perbenzoate, and cumene hydroperoxide; the organic base is one or more of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), pyridine, and triethylamine; the inorganic base is one or more of sodium carbonate, potassium carbonate, and potassium phosphate; the solvent is one or more of dimethyl sulfoxide, 1,4-dioxane, N,N-dimethylformamide, or N,N-dimethylacetamide; the copper salt catalyst is one or more of copper acetate, copper trifluoromethanesulfonate, and copper acetylacetonate; the nitrogen heterocyclic carbene nickel salt catalyst is one or more of [Ni(IPr * )CpCl]、[Ni(IPr *Tol )CpCl] or [Ni(IPr *OMe )CpCl], and the corresponding structures are as follows: The organic solvent dilution and extraction solvent for post-treatment are one or more of tetrahydrofuran, ethyl acetate, 1,2-dichloroethane, and 2-methyltetrahydrofuran; the molar ratio of 2-hydroxy-3-phenylnaphthalene to 2,6-dibromophenylboric acid is 1:(1.00-1.20), the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05), and the molar ratio of 2-hydroxy-3-phenylnaphthalene to copper salt catalyst and nitrogen heterocyclic carbene nickel salt catalyst is 1:(0.05-0.50):(0.005-0.05). The molar ratio of hydroxy-3-phenylnaphthalene to the additive is 1:(0.10-0.50), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the oxidant is 1:(1.00-2.00), the molar ratio of 2-hydroxy-3-phenylnaphthalene to the organic base and the inorganic base is 1:(1.50-2.00):(2.00-3.00), and the amount of the solvent is (0.25-0.5) mol / L according to the molar reaction concentration of 2-hydroxy-3-phenylnaphthalene.

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