A method for preparing 3,3'-diaryl-1,1'-bi-2-naphthol compounds

Abstract

The application provides a preparation method of 3,3'-diaryl-1,1'-bi-2-naphthol compounds, which comprises the following steps: (1) 1,3-diarylpropanone is reacted with trialkyl orthoformate to obtain 3-aryl-beta-naphthol ether compounds; (2) the 3-aryl-beta-naphthol ether compounds are reacted with a dealkylation reagent to obtain 3-aryl-beta-naphthol compounds; (3) the 3-aryl-beta-naphthol compounds are subjected to coupling reaction under the catalysis of a copper catalyst to obtain the 3,3'-diaryl-1,1'-bi-2-naphthol compounds. The preparation method has the advantages of mild reaction conditions, cheap and easily available orthoformate, wide reaction substrate range, good functional group tolerance, simple steps, simple operation, high total yield and suitability for large-scale industrial production.

Description

Technical Field

[0001] This invention belongs to the field of organic compound synthesis technology, and relates to a method for preparing 3,3′-diaryl-1,1′-bi-2-naphthol compounds. Background Technology

[0002] Binaphthols are an important class of organic compounds with wide applications, such as drug synthesis, synthetic catalysts, and ligand precursors. Therefore, developing an efficient method for preparing binaphthol derivatives with multiple functional groups is of great significance for the chemical industry and scientific research.

[0003] Among them, ligand compounds with a 3,3′-diaryl-1,1′-bi-2-naphthol skeleton (as shown in Formula A) have unique steric hindrance and electronic effects when coordinating with metals due to the presence of a benzene ring at the C3-position of binaphthol, which can efficiently control the selectivity of the hydroformylation reaction.

[0004]

[0005] Although there are many methods for preparing 3,3′-diaryl-1,1′-bi-2-naphthol compounds, these methods usually use transition metal-catalyzed coupling reactions for synthesis, which often face problems such as the pre-introduction of functional groups, cumbersome substrate synthesis, the need for noble metal catalysts, high cost, complex ligand design, and harsh operating conditions.

[0006] Literature review found that 3-aryl-β-naphthol, a precursor of binaphthol, can be synthesized using indanone as a simple starting material. Although the synthesis of this type of compound does not require complex ligands / metals, the synthesis of 3-aryl-β-naphthol alone requires seven steps (as shown in the reaction flow below), which limits the application of this type of ligand in synthesis.

[0007] Summary of the Invention

[0008] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing 3,3′-diaryl-1,1′-bi-2-naphthol compounds.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] On one hand, the present invention provides a method for preparing 3,3′-diaryl-1,1′-bi-2-naphthol compounds, the preparation method comprising the following steps:

[0011] (1) The 1,3-diarylacetone shown in Formula a reacts with the trialkyl orthoformate shown in Formula I to obtain the 3-aryl-β-naphthalene ether compound shown in Formula b.

[0012] (2) The 3-aryl-β-naphthyl ether compound shown in formula b reacts with a dealkylating agent to obtain the 3-aryl-β-naphthol compound shown in formula c;

[0013] (3) The 3-aryl-β-naphthol compound shown in formula c undergoes a coupling reaction under the catalysis of a copper catalyst to obtain the 3,3′-diaryl-1,1′-bi-2-naphthol compound shown in formula d.

[0014] In this invention, the reaction formula for the preparation process is as follows:

[0015]

[0016] Wherein Ar1 and Ar2 are substituted or unsubstituted aryl groups, and R is a C1-C4 alkyl group; the substituents in the substituted aryl group are selected from C1-C4 alkyl groups or halogens.

[0017] In this invention, ligand precursor polysubstituted naphthol compounds are synthesized by using 1,3-diarylacetone as the starting material and sequentially undergoing cyclization, dealkylation, and copper-catalyzed coupling reactions.

[0018] Preferably, the aryl group is phenyl.

[0019] In this invention, the halogen is F, Cl, Br or I.

[0020] In this invention, the C1-C4 alkyl group can be C1, C2, C3 or C4 alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, etc.

[0021] Preferably, the trialkyl orthoformate in step (1) is selected from trimethyl orthoformate or triethyl orthoformate.

[0022] Preferably, the molar ratio of 1,3-diarylacetone (formula a) to trialkyl orthoformate (formula I) in step (1) is 1:1-9, for example, 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6, 1:6.5, 1:7, 1:7.5, 1:8, 1:8.5 or 1:9.

[0023] Preferably, the reaction in step (1) is carried out in the presence of sulfonic acid compounds.

[0024] Preferably, the sulfonic acid compound is selected from any one or a combination of at least two of trifluoromethanesulfonic acid, methanesulfonic acid, or p-toluenesulfonic acid.

[0025] Preferably, the molar ratio of the sulfonic acid compound to 1,3-diarylacetone shown in formula a is 0.2-5:1, for example 0.2:1, 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 or 5:1.

[0026] Preferably, the reaction in step (1) is carried out in an organic solvent.

[0027] Preferably, the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate, or trifluoromethanesulfonic acid, with dichloromethane being the most preferred.

[0028] Preferably, the reaction temperature in step (1) is 15-100℃, for example 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃ or 100℃, and the reaction time is 1-24h, for example 1h, 3h, 5h, 8h, 10h, 12h, 15h, 18h, 20h, 22h or 24h.

[0029] Preferably, the dealkylating agent in step (2) is selected from BBr3.

[0030] Preferably, the molar ratio of the dealkylating agent in step (2) to the 3-aryl-β-naphthalene ether compound shown in formula b is 1-5:1, for example 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1 or 5:1.

[0031] Preferably, the reaction in step (2) is carried out in an organic solvent.

[0032] Preferably, the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate, or trifluoromethanesulfonic acid, with dichloromethane being the most preferred.

[0033] Preferably, the reaction temperature in step (2) is -30℃ to 40℃, for example -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃ or 40℃, and the reaction time is 6h to 36h, for example 6h, 8h, 10h, 13h, 15h, 18h, 20h, 25h, 28h, 30h, 33h or 36h.

[0034] Preferably, the copper catalyst in step (3) is selected from at least one of copper chloride, cuprous iodide, copper bromide or copper acetate.

[0035] Preferably, the molar ratio of the copper catalyst in step (3) to the 3-aryl-β-naphthol compound shown in formula c is 0.1-2:1, for example 0.1:1, 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1.

[0036] Preferably, the coupling reaction in step (3) is carried out in the presence of an organic base.

[0037] Preferably, the organic base is selected from at least one of triethylamine, pyridine, or tetramethylethylenediamine.

[0038] Preferably, the molar ratio of the organic base to the 3-aryl-β-naphthol compound shown in formula c is 1-4:1, for example 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1, 2.5:1, 2.8:1, 3:1, 3.3:1, 3.6:1, 3.8:1 or 4:1.

[0039] Preferably, the coupling reaction in step (3) is carried out in an organic solvent.

[0040] Preferably, the organic solvent is selected from at least one of methanol, ethanol, toluene, or tetrahydrofuran.

[0041] Preferably, the temperature of the coupling reaction in step (3) is 15℃-60℃, for example 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃ or 60℃, and the reaction time is 6h-36h, for example 6h, 8h, 10h, 13h, 15h, 18h, 20h, 25h, 28h, 30h, 33h or 36h.

[0042] As a preferred technical solution, the preparation method of the 3,3′-diaryl-1,1′-bi-2-naphthol compound includes the following steps:

[0043] (1) 1,3-diarylacetone of Formula a and trialkyl orthoformate of Formula I are reacted in an organic solvent at 15-100°C for 1-24 h in the presence of a sulfonic acid compound to obtain a 3-aryl-β-naphthalene ether compound of Formula b; wherein the trialkyl orthoformate is selected from trimethyl orthoformate or triethyl orthoformate, the sulfonic acid compound is selected from any one or a combination of at least two of trifluoromethanesulfonic acid, methanesulfonic acid or p-toluenesulfonic acid, the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, trichloromethane, acetonitrile, toluene, trimethyl orthoformate or trifluoromethanesulfonic acid, the molar ratio of 1,3-diarylacetone of Formula a to trialkyl orthoformate of Formula I is 1:1-9, and the molar ratio of the sulfonic acid compound to 1,3-diarylacetone of Formula a is 0.2-5:1.

[0044] (2) The 3-aryl-β-naphthyl ether compound shown in formula b is reacted with the dealkylating agent BBr3 in an organic solvent at -30℃ to -40℃ for 6h to 36h to obtain the 3-aryl-β-naphthol compound shown in formula c; wherein the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, trichloromethane, acetonitrile, toluene, trimethyl orthoformate or trifluoromethanesulfonic acid, and the molar ratio of the dealkylating agent to the 3-aryl-β-naphthyl ether compound shown in formula b is 1-5:1;

[0045] (3) The 3-aryl-β-naphthol compound shown in formula c is coupled in an organic solvent at 15℃-60℃ for 6h-36h under the catalysis of a copper catalyst and in the presence of an organic base to obtain the 3,3′-diaryl-1,1′-bi-2-naphthol compound shown in formula d. The copper catalyst is selected from at least one of copper chloride, cuprous iodide, copper bromide or copper acetate. The organic base is selected from at least one of triethylamine, pyridine or tetramethylethylenediamine. The organic solvent is selected from methanol. The molar ratio of the copper catalyst to the 3-aryl-β-naphthol compound shown in formula c is 0.1-2:1, and the molar ratio of the organic base to the 3-aryl-β-naphthol compound shown in formula c is 1-4:1.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The preparation method of this invention has mild reaction conditions, and the orthoformate ester is inexpensive and readily available. It can be used as both an alkylating agent and a carbon source for extending one carbon chain. It has a wide range of reaction substrates and good functional group tolerance. The steps are simple, the operation is convenient, and the overall yield is high, making it suitable for large-scale industrial production. It avoids the need for pre-preparation of complex substrates in traditional reactions and uses synthetic ligands as precursors, which can be widely applied to the hydroformylation of olefins. Detailed Implementation

[0048] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0049] The data and purity of the new compounds presented in the following examples were determined by nuclear magnetic resonance.

[0050] Example 1

[0051] Preparation of (±)-3,3'-diphenyl-1,1′-bi-2-naphthol:

[0052]

[0053] Step 1: In a reaction flask (250 mL), add 1,3-diphenylacetone (2.1 g, 10 mmol), trimethyl orthoformate (3.18 g, 30 mmol), and dichloromethane (60 mL) sequentially. Then, add trifluoromethanesulfonic acid (9.0 g, 40 mmol). After sealing the reaction tube, stir thoroughly until homogeneous. Monitor the reaction process by thin-layer chromatography. The reaction is complete after 4 hours.

[0054] After the reaction was complete, dichloromethane (20 mL) was first added to the reaction tube to dilute the reaction solution, and then triethylamine (10 mL) was added dropwise to quench the reaction. The mixture was stirred for another 10 min, and then the organic solvent was removed by rotary evaporation. The residue was purified by column chromatography (petroleum ether / ethyl acetate = 30 / 1) to obtain a colorless oily liquid in 86% yield.

[0055] The 1H NMR spectrum data of the obtained product are as follows:

[0056] 1 H NMR (400MHz, CDCl3): δ7.93-7.90(m,3H),7.77(s,2H),7.59-7.50(m,5H),7.35-7.34(m,1H),4.02(s,3H).

[0057] The carbon NMR spectrum data of the obtained product are as follows:

[0058] 13 C NMR (100MHz, CDCl3): δ155.2,138.3,133.9,132.3,129.9,129.7(2C),128.8,127.9(2C),127.6,127.2,126.3(2C),123.8,105.6,55.4.

[0059]

[0060] Step 2: Add 2.34 g (10 mmol) of 3-phenyl-β-naphthol and 100 mL of dichloromethane to a reaction flask (250 mL) and stir until homogeneous. Add BBr3 (18 mL, 18 mmol, 1 mol / L dichloromethane solution) sequentially in an ice-salt bath at -30 °C, stirring continuously for 1 h, then transfer to room temperature and react for 24 h.

[0061] After the reaction was complete, ice water (20 mL) was added to quench the reaction. Then, dichloromethane (3 x 20 mL) was added to extract the organic phase, and finally, the mixture was dried over anhydrous sodium sulfate and the organic solvent was evaporated. The residue was subjected to column chromatography (petroleum ether / dichloromethane = 3 / 2) to give a white solid in 95% yield.

[0062] The 1H NMR spectrum data of the obtained product are as follows:

[0063] 1 H NMR (400MHz, CDCl3): δ7.74-7.71(m,1H),7.68(s,1H),7.67-7.64(m,1H),7.52-7.49(m, 2H),7.46-7.42(m,2H),7.41-7.34(m,2H),7.31-7.27(m,1H),7.25(s,1H),5.36(s,1H).

[0064] The carbon NMR spectrum data of the obtained product are as follows:

[0065] 13 C NMR (100MHz, CDCl3): δ150.7,136.9,134.2,130.4,129.5,129.3(2C),129.1(2C),128.9,128.0,127.7,126.4,126.1,123.8,110.2.

[0066]

[0067] Step 3: In a reaction flask (250 mL), 3-phenyl-β-naphthol (2.2 g, 10 mmol), copper chloride (1.33 g, 10 mmol), tetramethylethylenediamine (2.32 g, 20 mmol), and finally methanol (100 mL) were added sequentially. The resulting mixture was stirred at room temperature for 12 h. Then, ethyl acetate (3 x 20 mL) was added to extract the organic phase, and the mixture was dried over anhydrous sodium sulfate and the organic solvent was evaporated. The residue was subjected to column chromatography (petroleum ether / ethyl acetate = 6 / 1) to give a white solid in 93% yield.

[0068] The 1H NMR spectrum data of the obtained product are as follows:

[0069] 1 H NMR (400MHz, CDCl3): δ8.02(s,2H),7.93-7.91(m,2H),7.75-7.72(m,4H),7.51-7 .47(m,4H),7.43-7.36(m,4H),7.34-7.29(m,2H),7.25-7.22(m,2H),5.36(s,2H).

[0070] The carbon NMR spectrum data of the obtained product are as follows:

[0071] 13C NMR (100MHz, CDCl3): δ150.1(2C),137.4(2C),133.0(2C),131.4(2C),130.7(2C),129.6 (4C),129.4(2C),128.5(6C),127.7(2C),127.3(2C),124.3(2C),124.2(2C),112.4(2C).

[0072] It can be seen that the product obtained is (±)-3,3'-diphenyl-1,1′-bi-2-naphthol.

[0073] Example 2

[0074] Synthesis of (±)-7,7'-dimethyl-3,3'-bis(4-tolyl)-1,1′-bi-2-naphthol:

[0075]

[0076] Step 1: In a reaction flask (250 mL), add 1,3-bis(4-tolyl)acetone (2.38 g, 10 mmol), trimethyl orthoformate (3.18 g, 30 mmol), and dichloromethane (60 mL) sequentially. Then, add trifluoromethanesulfonic acid (9.0 g, 40 mmol). After sealing the reaction tube, stir thoroughly until homogeneous. Monitor the reaction process by thin-layer chromatography. The reaction is complete after 4 hours.

[0077] After the reaction was complete, dichloromethane (20 mL) was first added to the reaction tube to dilute the reaction solution, and then triethylamine (10 mL) was added dropwise to quench the reaction. The mixture was stirred for another 10 min, and then the organic solvent was removed by rotary evaporation. The residue was purified by column chromatography (petroleum ether / ethyl acetate = 30 / 1) to obtain a colorless oily liquid in 70% yield.

[0078] The 1H NMR spectrum data of the obtained product are as follows:

[0079] 1 H NMR (400MHz, CDCl3): δ7.66-7.63(m,2H),7.53(s,1H),7.50-7.47(m,2H),7.27-7.22(m,3H),7.15(s,1H),3.87(s,3H),2.47(s,3H),2.40(s,3H).

[0080] The carbon NMR spectrum data of the obtained product are as follows:

[0081] 13C NMR (100MHz, CDCl3): δ154.7,136.8,135.6,133.3,132.3,132.0,129.6(2C ),129.1,129.0,128.7(2C),128.4,126.6,126.2,105.5,55.4,21.5,21.2.

[0082]

[0083] Step 2: Add 2.62 g (10 mmol) of 6-methyl-3-(4-tolyl)-β-naphthyl methyl ether and 100 mL of dichloromethane to a reaction flask (250 mL) and stir until homogeneous. Add BBr3 (18 mL, 18 mmol, 1 mol / L dichloromethane solution) sequentially in an ice-salt bath at -30 °C, stirring continuously for 1 h, then transfer to room temperature and react for 24 h.

[0084] After the reaction was complete, ice water (20 mL) was added to quench the reaction. Then, dichloromethane (3 x 20 mL) was added to extract the organic phase, and finally, the mixture was dried over anhydrous sodium sulfate and the organic solvent was evaporated. The residue was subjected to column chromatography (petroleum ether / dichloromethane = 3 / 2) to give a white solid in 97% yield.

[0085] The 1H NMR spectrum data of the obtained product are as follows:

[0086] 1 H NMR (400MHz, CDCl3): δ7.76-7.70(m,1H),7.61(s,1H),7.51-7.46(m,1H),7.43-7.41(m,1H) ,7.37-7.34(m,2H),7.30-7.27(m,2H),7.23(s,1H),5.37(s,1H),2.53(s,3H),2.45(s,3H).

[0087] The carbon NMR spectrum data of the obtained product are as follows:

[0088] 13 C NMR (100MHz, CDCl3): δ152.7,137.9,133.2,130.6,129.7,129.5(2C),129.1(2C),128.8,128.1,127.9,126.3,126.1,123.6,111.2,22.5,21.6.

[0089]

[0090] Step 3: In a reaction flask (250 mL), 6-methyl-3-(4-tolyl)-β-naphthol (2.48 g, 10 mmol), copper chloride (1.33 g, 10 mmol), tetramethylethylenediamine (2.32 g, 20 mmol), and finally methanol (100 mL) were added sequentially. The resulting mixture was stirred at room temperature for 12 h. Then, ethyl acetate (3 x 20 mL) was added to extract the organic phase, and the mixture was dried over anhydrous sodium sulfate and the organic solvent was evaporated to dryness. The residue was subjected to column chromatography (petroleum ether / ethyl acetate = 6 / 1) to give a white solid in 96% yield.

[0091] The 1H NMR spectrum data of the obtained product are as follows:

[0092] 1 H NMR (400MHz, CDCl3): δ8.01(s,2H),7.88-7.86(m,2H),7.75-7.70(m,4H),7.51-7.46 (m,4H),7.43-7.37(m,2H),7.30-7.26(m,2H),5.32(s,2H),2.57(s,6H),2.49(s,6H).

[0093] The carbon NMR spectrum data of the obtained product are as follows:

[0094] 13 C NMR (100MHz, CDCl3): δ151.1(2C),138.4(2C),134.4(2C),132.5(2C),131.7(2C),128.5(4C),128. 4(2C),128.0(6C),127.7(2C),127.3(2C),124.3(2C),124.2(2C),112.4(2C),25.1(2C),24.2(2C).

[0095] The high-resolution mass spectrometry data of the obtained product are as follows:

[0096] HRMS (APCI): C 36 H 31 O2 + [M+H] + Calculated value: 495.2319; Test value: 495.2321.

[0097] It can be seen that the product obtained is (±)-7,7'-dimethyl-3,3'-bis(4-tolyl)-1,1′-bi-2-naphthol.

[0098] Example 3

[0099] Synthesis of (±)-7,7'-dichloro-3,3'-bis(4-chlorophenyl)-1,1′-bi-2-naphthol:

[0100]

[0101] Step 1: In a reaction flask (250 mL), add 1,3-bis(4-tolyl)acetone (2.78 g, 10 mmol), trimethyl orthoformate (3.18 g, 30 mmol), and dichloromethane (60 mL) sequentially. Then, add trifluoromethanesulfonic acid (9.0 g, 40 mmol). After sealing the reaction tube, stir thoroughly until homogeneous. Monitor the reaction process by thin-layer chromatography. The reaction is complete after 4 hours.

[0102] After the reaction was complete, dichloromethane (20 mL) was first added to the reaction tube to dilute the reaction solution, and then triethylamine (10 mL) was added dropwise to quench the reaction. The mixture was stirred for another 10 min, and then the organic solvent was removed by rotary evaporation. The residue was purified by column chromatography (petroleum ether / ethyl acetate = 30 / 1) to obtain a colorless oily liquid in 67% yield.

[0103] The 1H NMR spectrum data of the obtained product are as follows:

[0104] 1 H NMR (400MHz, CDCl3): δ7.73-7.72(m,1H),7.68-7.65(m,1H),7.59(s,1H),7.51-7.48(m,2H),7.41-7.35(m,3H),7.16(s,1H),3.89(s,3H).

[0105] The carbon NMR spectrum data of the obtained product are as follows:

[0106] 13 C NMR (100MHz, CDCl3): δ155.2,136.2,133.5,132.3,132.2,130.9(2C),129.5,129.3,128.9,128.2(2C),127.9,127.3,126.3,106.7,55.6.

[0107]

[0108] Step 2: Add 3.02 g (10 mmol) of 6-chloro-3-(4-chlorophenyl)-β-naphthyl methyl ether and 100 mL of dichloromethane to a reaction flask (250 mL) and stir until homogeneous. Add BBr3 (18 mL, 18 mmol, 1 mol / L dichloromethane solution) sequentially in an ice-salt bath at -30 °C, stirring continuously for 1 h, then transfer to room temperature and react for 24 h.

[0109] After the reaction was complete, ice water (20 mL) was added to quench the reaction. Then, dichloromethane (3 x 20 mL) was added to extract the organic phase, and finally, the mixture was dried over anhydrous sodium sulfate and the organic solvent was evaporated. The residue was subjected to column chromatography (petroleum ether / dichloromethane = 3 / 2) to give a white solid in 92% yield.

[0110] The 1H NMR spectrum data of the obtained product are as follows:

[0111] 1 H NMR (400MHz, CDCl3): δ7.75-7.73(m,1H),7.60(s,1H),7.55-7.49(m,1H),7.42 -7.39(m,1H),7.36-7.31(m,2H),7.29-7.26(m,2H),7.21(s,1H),5.33(s,1H).

[0112] The carbon NMR spectrum data of the obtained product are as follows:

[0113] 13 C NMR (100MHz, CDCl3): δ152.7,137.9,133.2,130.6,129.7,129.5(2C),129.1(2C),128.8,128.1,127.9,126.3,126.1,123.6,111.2,22.5,21.6.

[0114]

[0115] Step 3: In a reaction flask (250 mL), 6-chloro-3-(4-chlorophenyl)-β-naphthol (2.88 g, 10 mmol), copper chloride (1.33 g, 10 mmol), tetramethylethylenediamine (2.32 g, 20 mmol), and finally methanol (100 mL) were added sequentially. The resulting mixture was stirred at room temperature for 12 h. Then, ethyl acetate (3 x 20 mL) was added to extract the organic phase, and the solution was dried over anhydrous sodium sulfate and the organic solvent was evaporated to dryness. The residue was subjected to column chromatography (petroleum ether / ethyl acetate = 6 / 1) to give a white solid in 93% yield.

[0116] The 1H NMR spectrum data of the obtained product are as follows:

[0117] 1 H NMR (400MHz, CDCl3): δ8.10(s,2H),7.91-7.88(m,2H),7.73-7.68(m,4H),7.61-7.55(m,4H),7.43-7.36(m,2H),7.29-7.25(m,2H),5.29(s,2H).

[0118] The carbon NMR spectrum data of the obtained product are as follows:

[0119] 13 C NMR (100MHz, CDCl3): δ152.3(2C),138.1(2C),134.6(2C),132.2(2C),132.0(2C),129.1 (4C),128.6(2C),128.1(6C),127.3(2C),127.0(2C),124.6(2C),124.1(2C),112.3(2C).

[0120] The high-resolution mass spectrometry data of the obtained product are as follows:

[0121] HRMS (APCI): C 32 H 19 Cl4O2 + [M+H] + Calculated value: 575.0135; Test value: 575.0140.

[0122] It can be seen that the product obtained is (±)-7,7'-dimethyl-3,3'-bis(4-tolyl)-1,1′-bi-2-naphthol.

[0123] The applicant declares that the preparation method of the present invention is illustrated by the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a 3,3'-diaryl-1,1'-bi-2-naphthol compound, characterized in that, The preparation method includes the following steps: (1) The 1,3-diarylacetone shown in Formula a reacts with the trialkyl orthoformate shown in Formula I to obtain the 3-aryl-β-naphthalene ether compound shown in Formula b. (2) The 3-aryl-β-naphthyl ether compound shown in formula b reacts with a dealkylating agent to obtain the 3-aryl-β-naphthol compound shown in formula c; (3) The 3-aryl-β-naphthol compound shown in formula c undergoes a coupling reaction under the catalysis of a copper catalyst to obtain the 3,3'-diaryl-1,1'-bi-2-naphthol compound shown in formula d; The reaction formula for the preparation process is as follows: Wherein Ar1 and Ar2 are substituted or unsubstituted phenyl groups, and R is a C1-C4 alkyl group; the substituents in the substituted aryl group are selected from C1-C4 alkyl groups or halogens; The copper catalyst in step (3) is selected from at least one of copper chloride, cuprous iodide, copper bromide or copper acetate.

2. The preparation method according to claim 1, characterized in that, The halogen is F, Cl, Br or I.

3. The preparation method according to claim 1, characterized in that, The trialkyl orthoformate mentioned in step (1) is selected from trimethyl orthoformate or triethyl orthoformate.

4. The preparation method according to claim 1, characterized in that, In step (1), the molar ratio of 1,3-diarylacetone (formula a) to trialkyl orthoformate (formula I) is 1:1-9.

5. The preparation method according to claim 1, characterized in that, The reaction described in step (1) is carried out in the presence of sulfonic acid compounds.

6. The preparation method according to claim 5, characterized in that, The sulfonic acid compound is selected from any one or a combination of at least two of trifluoromethanesulfonic acid, methanesulfonic acid, or p-toluenesulfonic acid.

7. The preparation method according to claim 5, characterized in that, The molar ratio of the sulfonic acid compound to 1,3-diarylacetone shown in formula a is 0.2-5:

1.

8. The preparation method according to claim 1, characterized in that, The reaction described in step (1) is carried out in an organic solvent.

9. The preparation method according to claim 8, characterized in that, The organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate, or trifluoromethanesulfonic acid.

10. The preparation method according to claim 8, characterized in that, The organic solvent is dichloromethane.

11. The preparation method according to claim 1, characterized in that, The reaction temperature in step (1) is 15-100℃ and the reaction time is 1-24 h.

12. The preparation method according to claim 1, characterized in that, The dealkylating agent in step (2) is selected from BBr3.

13. The preparation method according to claim 1, characterized in that, The molar ratio of the dealkylating agent in step (2) to the 3-aryl-β-naphthalene ether compound shown in formula b is 1-5:

1.

14. The preparation method according to claim 1, characterized in that, The reaction described in step (2) is carried out in an organic solvent.

15. The preparation method according to claim 14, characterized in that, The organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate, or trifluoromethanesulfonic acid.

16. The preparation method according to claim 14, characterized in that, The organic solvent is dichloromethane.

17. The preparation method according to claim 1, characterized in that, The reaction temperature in step (2) is -30℃ to 40℃, and the reaction time is 6 h to 36 h.

18. The preparation method according to claim 1, characterized in that, The molar ratio of the copper catalyst in step (3) to the 3-aryl-β-naphthol compound shown in formula c is 0.1-2:

1.

19. The preparation method according to claim 1, characterized in that, The coupling reaction in step (3) is carried out in the presence of an organic base.

20. The preparation method according to claim 19, characterized in that, The organic base is selected from at least one of triethylamine, pyridine, or tetramethylethylenediamine.

21. The preparation method according to claim 19, characterized in that, The molar ratio of the organic base to the 3-aryl-β-naphthol compound shown in formula c is 1-4:

1.

22. The preparation method according to claim 1, characterized in that, The coupling reaction in step (3) is carried out in an organic solvent.

23. The preparation method according to claim 22, characterized in that, The organic solvent is selected from at least one of methanol, ethanol, toluene, or tetrahydrofuran.

24. The preparation method according to claim 1, characterized in that, The coupling reaction in step (3) is carried out at a temperature of 15℃-60℃ and for a reaction time of 6 h-36 h.

25. The preparation method according to claim 1, characterized in that, The preparation method of the 3,3'-diaryl-1,1'-bi-2-naphthol compound includes the following steps: (1) 1,3-diarylacetone of Formula a and trialkyl orthoformate of Formula I are reacted in an organic solvent at 15-100°C for 1-24 h in the presence of sulfonic acid compounds to obtain 3-aryl-β-naphthalene ether compounds of Formula b; wherein the trialkyl orthoformate is selected from trimethyl orthoformate or triethyl orthoformate, the sulfonic acid compounds are selected from any one or at least two combinations of trifluoromethanesulfonic acid, methanesulfonic acid or p-toluenesulfonic acid, the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate or trifluoromethanesulfonic acid, the molar ratio of 1,3-diarylacetone of Formula a to trialkyl orthoformate of Formula I is 1:1-9, and the molar ratio of the sulfonic acid compounds to 1,3-diarylacetone of Formula a is 0.2-5:

1. (2) The 3-aryl-β-naphthyl ether compound shown in formula b is reacted with the dealkylating agent BBr3 in an organic solvent at -30℃ to -40℃ for 6 h to 36 h to obtain the 3-aryl-β-naphthol compound shown in formula c; wherein the organic solvent is selected from at least one of 1,2-dichloroethane, dichloromethane, chloroform, acetonitrile, toluene, trimethyl orthoformate or trifluoromethanesulfonic acid, and the molar ratio of the dealkylating agent to the 3-aryl-β-naphthyl ether compound shown in formula b is 1-5:1; (3) The 3-aryl-β-naphthol compound shown in formula c undergoes a coupling reaction in an organic solvent at 15℃-60℃ for 6 h-36 h under the catalysis of a copper catalyst and in the presence of an organic base to obtain the 3,3'-diaryl-1,1'-bi-2-naphthol compound shown in formula d. The copper catalyst is selected from at least one of copper chloride, cuprous iodide, copper bromide or copper acetate. The organic base is selected from at least one of triethylamine, pyridine or tetramethylethylenediamine. The organic solvent is selected from at least one of methanol, ethanol, toluene or tetrahydrofuran. The molar ratio of the copper catalyst to the 3-aryl-β-naphthol compound shown in formula c is 0.1-2:1, and the molar ratio of the organic base to the 3-aryl-β-naphthol compound shown in formula c is 1-4:1.

Images