A preparation method of bi(β-naphthol)

Abstract

The invention discloses a production method of bi(β-naphthol), relates to the technical field of bi(β-naphthol) production, and comprises the following reaction steps: adding β-naphthol to an organic solvent of ferric chloride, introducing air or oxygen under stirring; after the reaction is completed, cooling, filtering and washing the reaction liquid to obtain a primary product containing bi(β-naphthol), dissolving the primary product in an alkali solution, decolorizing by adsorption with activated carbon until the solution is clear and transparent, adjusting the pH value of the solution to slightly acidic by using dilute hydrochloric acid to precipitate bi(β-naphthol), and then purifying by recrystallization to obtain a high-quality bi(β-naphthol); the method of the invention is not only simple but also can efficiently obtain high-quality bi(β-naphthol) with a purity of more than 99.5%, and at the same time, the amount of ferric chloride catalyst required for the reaction is small, which significantly reduces the generation of solid waste, and the reaction time is short, which is conducive to improving the purity and yield of the product, improving the production efficiency, and is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to a preparation technology of bi(beta-naphthol) and its derivatives, in particular to a preparation method of bi(beta-naphthol). Technical Background

[0002] Bis(β-naphthol) is a typical C 2 Axially asymmetric biphenyl aromatic molecular structures are organic chemical raw materials or reaction intermediates. Their unique stereochemical structure has a wide range of applications in asymmetric organic synthesis, molecular recognition, medicine, dyes and materials. Racemic biphenyl (β-naphthol) can be further separated into pure (S)- and (R)-biphenyl (β-naphthol) for the reaction of chiral catalyst ligands, and can also be used in the research or production of organic synthesis reactions of asymmetric compounds.

[0003] The two hydroxyl groups on β-naphthol can react with different molecules, so it is a chain extender for the production of polymer materials such as carbonate, epoxy resin, polyimide fiber, etc. Due to its good rigidity and flexibility of molecular structure, β-naphthol is also an important intermediate and modifier of an ideal functional polymer material compound. In addition, the high refractive index of β-naphthol (1.754) indicates that it has a strong ability to change the refraction of light. The polymer optical materials derived and synthesized from it have excellent resistance to moisture and heat, mechanical properties, chemical resistance, etc., as well as excellent dielectric properties and optical properties. High refractive index materials have broad application prospects in aerospace, missile warheads, optical imaging, electronic appliances, smart car manufacturing and other fields.

[0004] Document and patent report the synthesis production method of bi (beta naphthol) mainly contain liquid phase method and solid phase method two kinds (Zhang Zhanhui etc., Hebei University Journal, 2001,21,334 and Liu Huanmei etc., Chemical Engineer, 2009,9,33), wherein solid phase method is to place beta naphthol and iron trichloride oxidant in ball mill grinding reaction, and this production method is stricter to the control requirement of reaction unit and reaction temperature, and industrialized production cannot be realized so far. The liquid phase synthesis production method of bi (beta naphthol) is mainly by the oxidative coupling reaction of beta naphthol, and reaction needs to use iron trichloride oxidant far exceeding equivalent, and because excessive iron trichloride oxidant is used in the reaction process, not only production cost is increased, but also solid waste and waste water brought by reaction byproducts such as a large amount of metal salts and hydroxides are produced simultaneously. Recycling iron trichloride solid waste and waste water process is complicated, and can cause very large environmental protection and cost problem. In addition, the existing technology has defects and shortcomings such as low reaction conversion rate, slow reaction rate, high pollution, low product purity, etc., and the product quality and production cost are difficult to meet customer requirements. Summary of the invention

[0005] The purpose of the present invention is to overcome the many shortcomings of the existing production technology of bi(β-naphthol), such as low conversion rate, slow reaction rate, high pollution and low product purity. The present invention discloses a synthesis preparation method of bi(β-naphthol) with high conversion rate, fast reaction rate, low pollution and high product purity, which is suitable for industrial production.

[0006] The technical solution adopted by the present invention is as follows:

[0007] A method for preparing bi(β-naphthol) comprises the following steps:

[0008] (1) Preparing a preliminary product of bi(β-naphthol): weighing appropriate amounts of β-naphthol, ferric chloride and an organic solvent into a reaction flask; stirring a reaction mixture of β-naphthol and ferric chloride under a certain reaction temperature condition, while introducing air or oxygen; after the reaction is completed, cooling the reaction mixture to room temperature, and then filtering and washing to obtain a preliminary product of bi(β-naphthol);

[0009] (2) Crude preparation of β-naphthol: The obtained β-naphthol crude product is dissolved in an alkaline solution and decolorized by adsorption with activated carbon until the solution is clear and transparent; the solution is adjusted to slightly acidic with hydrochloric acid to precipitate β-naphthol, and then filtered, washed and dried to obtain a crude β-naphthol;

[0010] (3) Purification of β-naphthol: The crude β-naphthol is purified by recrystallization with an organic solvent and vacuum dried to obtain the fine β-naphthol.

[0011] Further settings are:

[0012] In step (1), the mass ratio of the β-naphthol, ferric chloride and organic solvent is 1:0.0005 to 0.01:5.

[0013] The organic solvent is selected from any one of o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, toluene, methanol, ethanol, isopropanol, butanol and the like.

[0014] The reaction temperature is 50-180°C, preferably 170°C

[0015] The reaction time is 0.5 to 15 hours, preferably 10 hours.

[0016] The mixed solution after the reaction was completed was cooled to room temperature and then filtered and washed with clean water.

[0017] In step (2), the crude product of di(β-naphthol) is dissolved in an alkali solution, which is an aqueous solution of 3% to 5% sodium hydroxide.

[0018] The decolorization is carried out by adsorption with activated carbon, and the temperature of the decolorization process is 50-80°C.

[0019] The activated carbon is used for adsorption and decolorization, and the amount of the activated carbon is 0.05-1% of the mass of the β-naphthol.

[0020] The solution is adjusted to be slightly acidic with dilute hydrochloric acid, and the pH value of the adjusted solution is 3.0-6.0.

[0021] In step (3):

[0022] The organic solvent is used to recrystallize the di(β-naphthol) product, and the organic solvent is any one of methanol, ethanol, isopropanol, toluene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, dichloroethane, dimethylacetamide, acetonitrile, etc.

[0023] Compared with the prior art, the present invention provides a production and preparation method of bi(β-naphthol), which has the following beneficial effects:

[0024] The production process of β-naphthol is not only simple and efficient, but also can produce high-quality β-naphthol with a purity of more than 99.5%. The production process reduces the generation of by-products, wastewater and solid waste, shortens the reaction time and improves production efficiency.

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 HPLC spectrum of the reaction product prepared in Example 1;

[0027] Figure 2 This is the HPLC spectrum of the standard sample of di(β-naphthol);

[0028] Figure 3 The reaction product prepared in Example 1 1 HNMR spectrum (solvent: CDCl 3 ). Specific implementation methods

[0029] Example 1

[0030] The production method of bi(β-naphthol) comprises the following steps:

[0031] S1: Weigh 21.63g of β-naphthol, 0.02g of ferric chloride, and 108.15g of o-dichlorobenzene in a flask; start stirring, ventilate, and heat to 170°C for 10 hours. After the reaction is completed, cool the reaction solution to room temperature, filter it, and wash it with water to obtain a preliminary product containing bi(β-naphthol);

[0032] S2: The obtained crude β-naphthol is dissolved in 4% sodium hydroxide solution, 0.26 g of activated carbon is added, and the temperature is raised to 66° C. for decolorization to obtain a light yellow transparent filtrate; the pH of the filtrate is adjusted to about 3.0 with dilute hydrochloric acid, and after the β-naphthol is completely precipitated, suction filtration is performed, washing, and drying are performed to obtain the crude β-naphthol.

[0033] S3: The crude product of β-naphthol was recrystallized with acetonitrile to obtain a fine product of β-naphthol. The product was weighed, and the yield was 95.47% and the purity was 99.95%.

[0034] Product Confirmation:

[0035] Liquid chromatography (HPLC), liquid chromatography-mass spectrometry (LC / MS) and proton nuclear magnetic resonance spectroscopy ( 1 HNMR) to identify the obtained product, and the HPLC spectrum of the product is as follows Figure 1 As shown, the product H NMR spectrum ( 1 HNMR) Figure 3 shown.

[0036] like Figure 1 Shown: Reaction product ( Figure 1 ) were similar to those of the standard sample ( Figure 2 ) had the same retention time and peak shape.

[0037] Mass spectrometry: LC / MS analysis of the obtained reaction product showed that the molecular weight (m / e) of the anion was 285, which was consistent with the chemical structure (II) of the di(β-naphthol) anion.

[0038]

[0039] H NMR ( 1 HNMR): Figure 3 As shown: The obtained reaction product was identified by hydrogen nuclear magnetic spectrum. 1 The HNMR spectrum was consistent with the chemical structure of di(β-naphthol).

[0040] Example 2: Effect of different organic solvents on yield

[0041] The preparation method is the same as that of Example 1, except that the organic solvent selection in step S1 is adjusted, and its effect on the reaction yield is detected, as shown in Table 1.

[0042] Table 1

[0043] Serial number Organic solvents Yield / % Example 2-1 Ethylene dichloride 30.5 Example 2-2 Toluene 51.6 Example 2-3 chlorobenzene 77.13 Embodiment 2-4 Trimethylbenzene 90.21 Embodiment 2-5 o-Dichlorobenzene 95.47 Embodiment 2-6 m-Dichlorobenzene 92.43 Embodiment 2-7 p-Dichlorobenzene 91.56 Embodiment 2-8 Methanol 20.1 .

[0044] As shown in Table 1: the organic reaction solvent used has a great influence on the yield of the coupling reaction to form di(β-naphthol), and it is obvious that a high boiling point organic polar solvent is beneficial to improving the yield of the reaction.

[0045] Example 3: Effect of different reaction temperatures on yield

[0046] The preparation method is the same as that of Example 1, except that the reaction temperature of step S1 is adjusted, and its effect on the reaction yield is detected, as shown in Table 2.

[0047] Table 2

[0048]

[0049]

[0050] As shown in Table 2:

[0051] Trend analysis: The results in Table 2 clearly show that the reaction temperature has a great influence on the yield of the coupling reaction to produce bi(β-naphthol). When the reaction temperature is 80°C, the reaction yield is only 30.5%, and the reaction yield improves as the reaction temperature increases. When the reaction temperature is 170°C, the reaction yield is the highest; when the temperature is 180°C, the reaction yield does not increase, but begins to decrease.

[0052] Example 4: Effect of different recrystallization processes on product purity

[0053] The preparation method is the same as that of Example 1, except that the organic solvent used for recrystallization in step S3 is adjusted, and its effect on the reaction purity is detected, as shown in Table 3.

[0054] Table 3

[0055] Serial number Organic solvent for recrystallization purity / % Example 4-1 Toluene 98.12 Example 4-2 o-Dichlorobenzene 98.32 Example 4-3 Ethylene dichloride 98.26 Example 4-4 dimethylformamide 98.75 Embodiment 4-5 dimethylacetamide 98.53 Embodiment 4-6 Methanol 99.09 Embodiment 4-7 Ethanol 99.15 Embodiment 4-8 Acetonitrile 99.95 .

[0056] As shown in Table 3: the purity of the bis(β-naphthol) product after recrystallization purification is related to the polarity and boiling point of the selected organic solvent. Methanol, ethanol and acetonitrile are suitable recrystallization solvents for the bis(β-naphthol) product.

[0057] Example 5: Effect of reaction material ratio on product yield

[0058] The preparation method is the same as that of Example 1, except that the reaction material ratio in step S1 (mass ratio of β-naphthol: ferric chloride: o-dichlorobenzene) is adjusted, and its effect on the reaction yield is detected, as shown in Table 4.

[0059] Table 4

[0060] Serial number Reaction material ratio Reaction temperature Reaction time Yield Example 5-1 1:0.0003:5 170℃ 10 hours 87.31 Example 5-2 1:0.0005:5 170℃ 10 hours 92.51 Example 5-3 1:0.0009:5 170℃ 10 hours 95.47 .

[0061] Analysis: As shown in Table 4, the amount of reaction catalyst has a significant effect on the reaction yield. When the amount of reaction catalyst increases, the reaction yield is significantly improved.

Claims

1. A method for preparing bi(β-naphthol), characterized in that: The following steps are involved: (1) Preparation of a preliminary product of bis(β-naphthol): weigh β-naphthol, ferric chloride and an organic solvent into a reaction flask; stir the reaction mixture of β-naphthol and ferric chloride under a certain reaction temperature, while introducing air or oxygen; after the reaction is completed, cool the reaction mixture to room temperature, and then filter and wash to obtain a preliminary product of bis(β-naphthol); In step (1), the mass ratio of β-naphthol, ferric chloride and organic solvent is 1:0.0005 to 0.01:5; In step (1), the organic solvent is selected from any one of o-dichlorobenzene, m-dichlorobenzene, and p-dichlorobenzene; In step (1), the reaction temperature is 160-180°C; (2) Crude preparation of β-naphthol: The obtained β-naphthol crude product is dissolved in an alkaline solution and decolorized by adsorption with activated carbon until the solution is clear and transparent; the solution is adjusted to slightly acidic with hydrochloric acid to precipitate β-naphthol, which is then filtered, washed and dried to obtain a crude β-naphthol product; (3) Purification of β-naphthol: The crude β-naphthol is recrystallized and purified with an organic solvent, and then vacuum dried to obtain the fine β-naphthol; In step (3), the di(β-naphthol) product is recrystallized using an organic solvent, and the organic solvent is any one of methanol, ethanol, and acetonitrile.

2. The method for preparing bis(β-naphthol) according to claim 1, characterized in that: In step (1), the reaction time is 0.5 to 15 hours.

3. The method for preparing bis(β-naphthol) according to claim 1, characterized in that: In step (2), the crude product of di(β-naphthol) is dissolved in an alkali solution, which is an aqueous solution of 3% to 5% sodium hydroxide.

4. The method for preparing bis(β-naphthol) according to claim 1, characterized in that: In step (2), the activated carbon is used for decolorization by adsorption, and the temperature of the decolorization process is 50 to 80°C.

5. The method for preparing bis(β-naphthol) according to claim 1, characterized in that: In step (2), the activated carbon is used for adsorption decolorization, and the amount of activated carbon used is 0.05-1% of the mass of β-naphthol.

6. The method for preparing bis(β-naphthol) according to claim 1, characterized in that: In step (2), the solution is adjusted to be slightly acidic with dilute hydrochloric acid, and the pH value of the solution after adjustment is 3.0-6.0.

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