Preparation method of phloroglucinol triglycidyl ether

Abstract

The invention discloses a preparation method of phloroglucinol triglycidyl ether, which comprises the following steps: (1) under the action of a catalyst and at the temperature of 100-130 DEG C, performing ring-opening reaction on phloroglucinol and epoxy chloropropane to generate tris (3-chloro-2-hydroxy propyl) phenyl ether; (2) adding water accounting for 1% of the total amount of reactants at 30-80 DEG C, adding alkali metal hydroxides in batches, and carrying out dehydrochlorination reaction; (3) dissolving the crude product obtained in the step (2) in a water-insoluble solvent, and washing with a low-concentration alkali metal hydroxide aqueous solution at 30-100 DEG C; and (4) washing with a low-concentration sodium dihydrogen phosphate solution, and carrying out reduced pressure distillation on a solvent layer to remove the solvent, thereby obtaining the phloroglucinol triglycidyl ether. By adopting the mode, the phenol type glycidyl ether with close to three functionality degrees can be synthesized.

Description

Technical Field

[0001] The invention relates to the field of preparation of polyphenol type glycidyl ether compounds, in particular to a method for preparing pyrogallol triglycidyl ether. Background Art

[0002] The preparation method of polyphenol-type glycidyl ether has been reported in a large number of literatures. It is prepared by adding an alkali metal hydroxide solid or solution to a polyphenol in excess epichlorohydrin, such as literature US2467171, US2631138, US2739160, US2801227, US2840541, US2879259, etc.

[0003] The aforementioned preparation methods, for polyphenols, typically including hydroquinone, resorcinol, catechol, bisphenol F, and bisphenol A, are characterized by a ratio of phenolic hydroxyl groups to benzene rings typically not exceeding 2. For polyphenols such as pyrogallol, which contain three phenolic hydroxyl groups per benzene ring, the aforementioned conventional preparation methods are unable to synthesize phenolic glycidyl ethers with near-trifunctionality.

[0004] Therefore, it is urgent to provide a novel preparation method of pyrogallol triglycidyl ether to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing pyrogallol triglycidyl ether, which can synthesize phenolic glycidyl ether with nearly trifunctionality.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is: providing a method for preparing pyrogallol triglycidyl ether, comprising the following steps:

[0007] (1) In the presence of a catalyst, at 100-130° C., pyrogallol and epichlorohydrin undergo a ring-opening reaction to generate tris(3-chloro-2-hydroxypropyl)phenyl ether;

[0008] (2) adding 1% of water to the total amount of the reactants at 30-100° C., and then adding alkali metal hydroxide in batches to carry out a dehydrochlorination reaction;

[0009] (3) dissolving the crude product obtained in step (2) in a non-water-soluble solvent and washing with a low-concentration alkali metal hydroxide aqueous solution at 30-100° C.;

[0010] (4) After washing with a low concentration sodium dihydrogen phosphate solution, the solvent layer is distilled under reduced pressure to remove the solvent, thereby obtaining benzyltriol triglycidyl ether.

[0011] The chemical reaction equation of the present invention is as follows:

[0012]

[0013] In a preferred embodiment of the present application, in step (1), the molar ratio of the hydroxyl groups of the epichlorohydrin to the phenol groups of the phenol trimer is in the range of 3:1 to 20:1, and the optimal range is between 5:1 and 10:1. The optimal reaction temperature is between 110 and 120℃.

[0014] Further, the phenol trimer includes one of m-phenol trimer (1,2,4-benzene trimer) and o-phenol trimer (1,3,5-benzene trimer).

[0015] In a preferred embodiment of the present application, in step (1), the catalyst includes one or more of tertiary amine, tertiary phosphine, quaternary ammonium salt, and quaternary phosphonium salt, such as triethylamine, tri-n-butylamine, dimethylbenzylamine, tributylphosphine, triphenylphosphine, tetrabutylammonium chloride, dimethylethylbenzylammonium chloride, triethylbenzylammonium chloride, tetrabutylammonium acetate, and tetrabutylphosphonium acetate, and the amount of the catalyst is 0.1-5.0% of the epichlorohydrin.

[0016] Further, the preferred amount of the catalyst is 1.0-2.0% of the epichlorohydrin.

[0017] In a preferred embodiment of the present application, in step (2), the alkali metal hydroxide is one of sodium hydroxide and potassium hydroxide, and preferably sodium hydroxide, and is added in solid form in batches or continuously dropped in solution form, and the amount is 0.95-1.05 times of the molar amount of the phenol hydroxyl groups of the phenol trimer.

[0018] In a preferred embodiment of the present application, in step (3), the non-water-soluble solvent includes one of aromatic hydrocarbon and ketone.

[0019] In a preferred embodiment of the present application, in step (3), the aqueous alkali metal hydroxide solution has a mass of 1-3 times of the mass of the crude product obtained in step (2), and a concentration of 0.1-20%, and the optimal range is 2-5%.

[0020] In a preferred embodiment of the present application, in step (4), the sodium dihydrogen phosphate solution has a mass of 1-3 times of the mass of the crude product obtained in step (2), and a concentration of 0.1-20%, and the optimal range is 2-5%.

[0021] The present application has the following beneficial effects: the present application performs ring-opening reaction of the phenol hydroxyl groups of the phenol trimer and the epoxy groups of the epichlorohydrin under the action of the catalyst to generate tri(3-chloro-2-hydroxypropyl)phenyl ether; then, under the action of a small amount of water, the solid base is added in batches to remove hydrogen chloride to generate epoxy groups, and the phenol trimer triglycidyl ether is prepared; finally, through further separation and purification, the phenol trimer triglycidyl ether with a functionality close to 3 and a low viscosity can be prepared. DETAILED DESCRIPTION

[0022] The advantages and features of the present application will be more readily understood from the detailed description of preferred embodiments of the present application given merely by way of non-limiting examples, and the scope of the protection sought for the present application will be more clearly defined from the appended claims.

[0023] The embodiments of the present application include:

[0024] Example 1

[0025] In a 500ml four-necked flask equipped with a stirring paddle and a condenser, 37.83g (0.30mol) of phloroglucinol, 416.36g (4.5mol) of epichlorohydrin, 4.16g of triethylbenzylammonium chloride were added, and the temperature was slowly raised to 115-117°C, and the reaction was carried out at this temperature for 6h. The temperature was lowered to 60°C, and 4.58g of water and 36g (0.90mol) of sodium hydroxide were added in three equal portions, one portion every 1h. After the addition was completed, the reaction was continued at 60°C for 2h. The crude phloroglucinol triglycidyl ether obtained from the above reaction was further separated and purified. The solid salt was filtered off, and the filtrate was distilled under reduced pressure to recover the excess epichlorohydrin to obtain the crude product. The crude product was added to 100g of toluene, and washed with 100g of 2% sodium hydroxide solution at 60°C for 2h. After cooling and standing, the lower water layer was separated. The upper layer was washed once with 100g of 2% sodium dihydrogen phosphate aqueous solution, and the lower water layer was separated. The upper layer was distilled under reduced pressure to remove toluene, and refined phloroglucinol triglycidyl ether was obtained.

[0026] Example 2

[0027] Phloroglucinol was replaced with o-phloroglucinol, and the other conditions were the same as in Example 1, which will not be described here.

[0028] Example 3

[0029] The amount of triethylbenzylammonium chloride was increased by 1 times, and the other conditions were the same as in Example 1, which will not be described here.

[0030] Comparative Example 1

[0031] The reaction temperature of the first step was lowered from 115-117°C to 95-100°C, and the other conditions were the same as in Example 1, which will not be described here.

[0032] Comparative Example 2

[0033] The amount of triethylbenzylammonium chloride was 0.1 times that of Example 1, and the other conditions were the same as in Example 1, which will not be described here.

[0034] The reaction conditions and the properties of the phloroglucinol triglycidyl ether obtained in the above examples are summarized in Table 1 below.

[0035] Table 1

[0036] Examples and Comparative Examples First step reaction temperature / ℃ Catalyst dosage / % Epoxy equivalent Functionality Viscosity / mPa.s,25℃ Example 1 115-117 1.0 111 2.65 6200 Example 2 115-117 1.0 115 2.55 4500 Example 3 115-117 2.0 109 2.70 6500 Comparative Example 1 95-100 1.0 173 1.70 36000 Comparative Example 2 115-117 0.10 190 1.55 54000

[0037] In the table, the catalyst dosage is calculated as a percentage based on epichlorohydrin; the epoxy equivalent weight is determined according to GB / T 4612-2008; and the functionality is the molecular weight of benzene triol triglycidyl ether (294.30) divided by the measured epoxy equivalent weight.

[0038] As can be seen from Table 1, when the catalyst dosage is 1.0-2.0% and the reaction temperature is 115°C, the epoxy functionality is close to 3, the side reaction is less, and the viscosity is also lower; when the reaction temperature is lower than 100°C, the ring-opening reaction is incomplete, the epoxy functionality is lower, the side reaction is more, and the viscosity is also larger; when the catalyst dosage is reduced to 0.10% and the reaction temperature is 115°C, the ring-opening reaction is also incomplete, the epoxy functionality is lower, the side reaction is more, and the viscosity is also larger. The full ring-opening of the epoxy requires a suitable catalyst and reaction temperature.

[0039] The embodiments are only the preferred embodiments of the present application and are not intended to limit the other forms of the present application. Any person skilled in the art can use the above content as an inspiration to make changes or modifications into equivalent embodiments with equivalent changes. Any simple modification, equivalent change and modification of the above embodiments without departing from the technical essence of the claims of the present application still falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing pyrogallol triglycidyl ether, characterized in that: The following steps are involved: (1) In the presence of a catalyst, at 100-130° C., pyrogallol and epichlorohydrin undergo a ring-opening reaction to generate tris(3-chloro-2-hydroxypropyl)phenyl ether; (2) adding 1% of water to the total amount of the reactants at 30-100° C., and then adding alkali metal hydroxide in batches to carry out a dehydrochlorination reaction; (3) dissolving the crude product obtained in step (2) in a non-water-soluble solvent and washing with a low-concentration alkali metal hydroxide aqueous solution at 30-100° C.; (4) After washing with a low concentration sodium dihydrogen phosphate solution, the solvent layer is distilled under reduced pressure to remove the solvent, thereby obtaining benzyltriol triglycidyl ether.

2. The preparation method of pyrogallol triglycidyl ether according to claim 1, wherein In step (1), the molar ratio of the hydroxyl groups of epichlorohydrin and pyrogallol is in the range of 3:1 to 20:

1.

3. The preparation method of pyrogallol triglycidyl ether according to claim 1 or 2, wherein The pyrogallol includes one of phloroglucinol and pyrogallol.

4. The preparation method of pyrogallol triglycidyl ether according to claim 1, wherein In step (1), the catalyst includes a tertiary amine, a tertiary phosphine, a quaternary ammonium salt and a quaternary phosphonium salt, such as one or more of triethylamine, tri-n-butylamine, dimethylbenzylamine, tributylphosphine, triphenylphosphine, tetrabutylammonium chloride, dimethylethylbenzylammonium chloride, triethylbenzylammonium chloride, tetrabutylammonium acetate and tetrabutylphosphonium acetate, and the amount of the catalyst used is 0.1-5.0% of the epichlorohydrin.

5. The preparation method of pyrogallol triglycidyl ether according to claim 4, wherein The preferred range of the amount of the catalyst is 1.0-2.0% of epichlorohydrin.

6. The preparation method of pyrogallol triglycidyl ether according to claim 1, wherein In step (2), the alkali metal hydroxide is one of sodium hydroxide and potassium hydroxide, added in solid form or liquid form, and the amount used is 0.95-1.05 times the molar amount of phenolic hydroxyl group of pyrogallol.

7. The preparation method of pyrogallol triglycidyl ether according to claim 1, wherein In step (3), the non-water-soluble solvent includes one of aromatic hydrocarbons and ketones.

8. The preparation method of pyrogallol triglycidyl ether according to claim 1, wherein In step (3), the mass of the alkali metal hydroxide aqueous solution is 1-3 times the mass of the crude product obtained in step (2), and the concentration is 2-5%.

9. The method for preparing pyrogallol triglycidyl ether according to claim 1, wherein In step (4), the mass of the sodium dihydrogen phosphate solution is 1-3 times the mass of the crude product obtained in step (2), and the concentration is 2-5%.

Images