A method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene

Abstract

The present invention relates to a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene. The preparation scheme comprises the following steps: reacting phenol, terephthalaldehyde and a catalyst hindered Lewis acid-base pair in an organic solvent to obtain 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene. The present invention uses a hindered Lewis acid-base pair (FLP) to catalyze the reaction of phenol and terephthalaldehyde, and after reacting for 10 h-16 h, water is added for pulping to obtain a pure product with a purity of more than 98%, further optimizing the post-processing, and the catalyst can be recovered, thereby reducing the cost.

Description

Technical Field

[0001] The invention relates to the technical field of organic chemistry, in particular to a method for preparing 1,4-di[bis(4'-hydroxyphenyl)methyl]benzene. Background Art

[0002] 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, abbreviated as C 32 H 26 O4 is a highly symmetrical polyphenol. It has special functions such as anti-UV penetration, fluorescence generation and adaptation to automatic optical inspection (AOI), and is an important basic material for the electronics industry. It is mainly used in the synthesis of special epoxy resins, photoresists, electronic packaging materials, hydroxy COF (covalent organic framework) ligands, etc. With the development of the electronics industry, especially the semiconductor industry, the demand for 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene will continue to increase, and the requirements for product quality will be further improved. At present, there are few reports on the synthesis of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene in China. Therefore, it is of great significance to develop a preparation and purification method for 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene suitable for industrial production.

[0003] At present, the synthesis of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene and its homologues mainly uses phenol and terephthalaldehyde as raw materials. Under the catalysis of acidic catalysts, Lewis acid additives, cation exchange resins, and ionic liquids, an industrial production scale of milligrams to hundreds of kilograms has been achieved, and the yield can reach 90%. However, there is still no report of an industrial solution to the problem of many by-products and difficult treatment. When strong acids such as hydrochloric acid, phosphoric acid, and sulfuric acid are used directly as catalysts, the reaction rate becomes faster, but it is difficult to control the heat release of the reaction, and it causes serious corrosion to the equipment. Cation exchange resins contain strong acidic groups, such as -SO3H, which dissociate a large amount of H + , and then catalyze the reaction; however, as the ion exchange resin is used, its ion exchange capacity gradually decreases until it is lost, and strong acid is needed for reactivation. Ionic liquid is a room temperature molten salt, which is regarded as a "green solvent" because it is non-volatile; however, the recovery process of ionic liquids requires additional extraction, distillation and other processes, and many ionic liquids are biologically toxic, so there are potential risks in large-scale industrial applications.

[0004] Hindered Lewis acid-base pair (FLP) refers to the phenomenon that the interaction between Lewis acid and Lewis base with certain steric hindrance can activate hydrogen and various small molecules. Because its activation conditions are mild and do not even require the participation of metals, it is currently a cutting-edge research topic in the field of chemistry. Due to widespread attention, FLP catalysts have achieved rapid development in recent years. Its composition sources cover almost the entire periodic table, and the reaction types have also expanded from the initial activation of small molecules such as hydrogen and carbon dioxide to the activation of carbon-hydrogen bonds of a wide range of substrates and asymmetric catalysis. The reaction modes also include thermal catalysis, photocatalysis and electrocatalysis.

[0005] Supramol. Chem., 2005, 17, 17 reported a method for synthesizing pentaphenol in glacial acetic acid and concentrated hydrochloric acid. After the reaction, column separation and purification were used to obtain a product below the gram level with a yield of 50%. No purity data was provided. The reaction equation of the specific reaction is as follows:

[0006]

[0007] Patent US5012016 reports a synthesis method using an acidic cationic resin as a catalyst at 80°C, but does not provide purity data. The reaction equation for the specific reaction is as follows:

[0008]

[0009] In the prior art, the strong acid catalytic system is difficult to control heat release and corrodes the equipment; the catalysts such as ion exchange resins need to be recovered and reactivated; and the excess raw materials make it difficult to purify the product. Therefore, it is urgent to provide a preparation method of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene with high yield and purity and reusable catalysts. Summary of the invention

[0010] In order to solve the above technical problems, the present invention provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene. By reacting phenol, terephthalaldehyde and a catalyst hindered Lewis acid-base pair in an organic solvent, 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene with high yield and high purity is prepared. The hindered Lewis acid-base pair (FLP) used in the present invention can be recycled and reused, thereby reducing the preparation cost.

[0011] The present invention is achieved through the following technical solutions:

[0012] The object of the present invention is to provide a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, comprising the following steps:

[0013] Phenol, terephthalaldehyde and a catalyst hindered Lewis acid-base pair are reacted in an organic solvent to obtain 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene.

[0014] In one embodiment of the present invention, the organic solvent is selected from one or more of acetonitrile, DMSO and DMF.

[0015] In one embodiment of the present invention, the mass of the organic solvent is 10%-50% of phenol; preferably 15%-20%.

[0016] In one embodiment of the present invention, the molar ratio of phenol to terephthalaldehyde is 4:1-20:1, preferably 4.2:1.

[0017] In one embodiment of the present invention, the structural formula of the hindered Lewis acid-base pair is:

[0018] .

[0019] In one embodiment of the present invention, the added amount of the hindered Lewis acid-base pair is 0.5%-1% equivalent.

[0020] In one embodiment of the present invention, the reaction temperature is 20°C-25°C;

[0021] And / or, the reaction time is 10 h-16 h.

[0022] In one embodiment of the present invention, the reaction further comprises the steps of adding water, stirring, crystallization, filtering and drying.

[0023] In one embodiment of the present invention, the yield of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene is greater than 90%.

[0024] In one embodiment of the present invention, the purity of the 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene is greater than 97.4%.

[0025] The structure of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene in the present invention is as follows:

[0026]

[0027] In one embodiment of the present invention, the preparation method of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene is specifically as follows:

[0028] (1) Phenol and acetonitrile are added into a reaction kettle, followed by terephthalaldehyde and hindered Lewis acid-base pair (FLP), and then the mixture is kept warm for reaction, and water is added for crystallization and filtration to obtain pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene and a mother liquor containing (FLP);

[0029] (2) The mother liquor can be washed with alkali, washed with water, and concentrated and crystallized to recover the hindered Lewis acid-base pair (FLP);

[0030] In step (2), the alkaline washing is to add a certain volume ratio of alkaline solution, stir for a period of time, and then separate the liquids. The certain volume ratio refers to the volume ratio of the alkaline solution to the mother liquor being 0.1-0.5:1, stirring for a period of time up to 10 min-2 h; the alkaline solution is saturated NaHCO3, saturated Na2CO3, 0.02-0.2 M NaOH solution, 0.02-0.2 M KOH solution, etc.

[0031] The above technical solution of the present invention has the following advantages compared with the prior art:

[0032] The present invention provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene. The present invention uses a hindered Lewis acid-base pair (FLP) as a catalyst to catalyze the reaction of phenol and terephthalaldehyde to obtain 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene with a yield of 90% and a purity of more than 97.4%. Compared with other catalysts, the hindered Lewis acid-base pair (FLP) used in the present invention has more advantages, and the catalyst can be recovered, thereby reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0034] Figure 1 is the NMR image of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene prepared in Example 1 of the present invention;

[0035] Figure 2 This is a liquid phase diagram of 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0037] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0038] The synthesis of hindered Lewis acid-base pairs (FLPs) can be found in J. Am. Chem. Soc. 2020, 142, 34,14427–14431. The synthesis route is as follows:

[0039]

[0040] The CAS numbers of the reagents used in the present invention are shown in the table below:

[0041] Table 1

[0042] Example 1

[0043] This embodiment provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, which is as follows:

[0044] Phenol (1.4 kg, 14.9 mol, 4 eq), acetonitrile (1200 mL), and hindered Lewis acid-base pair (FLP) (9.74 g, 18.6 mmol, 0.5% eq) were added to a four-necked flask. Terephthalaldehyde (500 g, 3.73 mol, 1 eq) was added at room temperature and kept at 25°C for 10 h. The reaction was complete after HPLC detection, and 8000 mL of tap water was added dropwise and stirred for 3 h. The crystals were filtered and dried to obtain 1.65 kg of pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene and a mother liquor containing (FLP). The obtained pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene was characterized by NMR and detected by HPLC. The NMR spectrum is shown in Figure 1 As shown in the HPLC diagram Figure 2 The yield is 93% and the purity is 98.5%. The mother liquor is extracted with dichloromethane, concentrated and then recrystallized with n-hexane to recover the hindered Lewis acid-base pair (FLP).

[0045] NMR data: H NMR (CDOD): δ 6.99 (s, 4H), 6.90 (m, 8H), 6.71 (m, 8H), 5.34 (s, 2H). Example 2

[0046] This embodiment provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, which is as follows:

[0047] Phenol (2.1 kg, 22.4 mol, 6 eq), acetonitrile (1200 mL), and hindered Lewis acid-base pair (FLP) (19.5 g, 37.2 mmol, 1% eq) were added to a four-necked flask. Terephthalaldehyde (500 g, 3.73 mol, 1 eq) was added at room temperature and kept at 25°C for 10 h. The reaction was complete after HPLC detection, and 8000 mL of tap water was added dropwise and stirred for 3 h. Crystallization was filtered and dried to obtain 1.66 kg of pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene and a mother liquor containing (FLP). The obtained pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene was characterized by nuclear magnetic resonance and detected by HPLC; the yield was 93.5% and the purity was 98.3%. The obtained mother liquor was extracted with dichloromethane, concentrated, and recrystallized with n-hexane to recover the hindered Lewis acid-base pair (FLP). Example 3

[0048] This embodiment provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, which is as follows:

[0049] Phenol (1.4 kg, 14.9 mol, 4 eq), DMSO (1200 mL), and hindered Lewis acid-base pair (FLP) (9.74 g, 18.6 mmol, 0.5% eq) were added to a four-necked flask. Terephthalaldehyde (500 g, 3.73 mol, 1 eq) was added at room temperature and kept at 25°C for 10 h. The reaction was complete after HPLC detection, and 8000 mL of tap water was added dropwise and stirred for 3 h. The crystals were filtered and dried to obtain 1.65 kg of pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene and a mother liquor containing (FLP). The obtained pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene was characterized by NMR and detected by HPLC. The NMR spectrum is shown as follows: Figure 1 As shown in the HPLC diagram Figure 2 As shown; the yield is 90% and the purity is 97.4%. The obtained mother liquor is extracted with dichloromethane, the organic phase is washed three times with purified water, concentrated and then recrystallized with n-hexane to recover the hindered Lewis acid-base pair (FLP). Comparative Example 1

[0050] This comparative example provides a method for preparing 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene, which is as follows: phenol (384 g, 4 mol, 4 eq), acetonitrile (200 mL), p-aminobenzoic acid (2.75 g, 0.02 mol, 2% eq), and scandium trifluoromethanesulfonate (9.84 g, 0.02 mol, 2% eq) are added to a four-necked flask. At room temperature, terephthalaldehyde acetonitrile solution (135 g terephthalaldehyde dissolved in 200 mL acetonitrile) is added dropwise, and the addition is completed in 30 min. The temperature is raised to 85°C and the reaction is kept warm for 10 h. The reaction is detected to be complete, 300 mL of solvent is concentrated by rotary evaporation, and the crude 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene liquid is filtered out. Add 500 mL of ethyl acetate to the mother liquor, slowly add saturated NaHCO3 solution to the stirring rack until the solution is weakly alkaline (pH 8-9); separate the liquids, add 500 mL of deionized water to the organic phase and stir for 30 min, separate the liquids; remove the solvent from the organic phase by rotary evaporation to obtain crude 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene. Add the crude 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene obtained twice (483 g in total) to a three-necked flask, add 500 mL of a 1:1 mixed solution of ethyl acetate and dichloromethane, and stir at 35°C for 18 h. Filter and dry to obtain 209.0 g of pure 1,4-di[bis(4′-hydroxyphenyl)methyl]benzene, with a yield of 44% and a purity of 93.2%. Comparative Example 2

[0051] This comparative example provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, which is similar to comparative example 1, except that:

[0052] Scandium trifluoromethanesulfonate was not added, and the other conditions were the same as those in Comparative Example 1. The yield was 17%, the purity was 84.5%, and the product contained unreacted phenol. Comparative Example 3

[0053] This comparative example provides a method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, which is similar to that of Example 1, except that the catalyst used is concentrated sulfuric acid; the yield of the obtained product is 51.1% and the purity is 91.4%.

[0054] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for preparing 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene, characterized in that: The following steps are involved: Phenol, terephthalaldehyde and a catalyst hindered Lewis acid-base pair are reacted in an organic solvent to obtain 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene; The structural formula of the hindered Lewis acid-base pair is: 。 2. The preparation method according to claim 1, characterized in that: The organic solvent is selected from one or more of acetonitrile, DMSO and DMF.

3. The preparation method according to claim 1, characterized in that: The mass of the organic solvent is 10%-50% of phenol.

4. The preparation method according to claim 1, characterized in that: The molar ratio of the phenol to terephthalaldehyde is 4:1-20:

1.

5. The preparation method according to claim 1, characterized in that: The added amount of the hindered Lewis acid-base pair is 0.5%-1% equivalent.

6. The preparation method according to claim 1, characterized in that: The reaction temperature is 20°C-25°C; And / or, the reaction time is 10 h-16 h.

7. The preparation method according to claim 1, characterized in that: After the reaction, the method further comprises the steps of adding water, stirring, crystallization, filtering and drying.

8. The preparation method according to claim 1, characterized in that: The yield of the 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene is more than 90%.

9. The preparation method according to claim 1, characterized in that: The purity of the 1,4-bis[bis(4′-hydroxyphenyl)methyl]benzene is greater than 97.4%.

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