Synthesis method of tris (4-hydroxybiphenyl) phosphate
By modifying catalysts and using specific synthetic steps, the harsh reaction conditions and safety hazards in the synthesis of tris(4-hydroxybiphenyl) phosphates have been solved, achieving highly selective and high-yield synthesis, simplifying post-processing, and making it suitable for pesticides, flame retardant materials, polymer modification, and pharmaceutical fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HUAIHUA HENGBO SPECIAL NEW MATERIALS CO LTD
- Filing Date
- 2026-01-15
- Publication Date
- 2026-04-28
AI Technical Summary
In the existing technology, the synthesis method of tris(4-hydroxybiphenyl) phosphate has problems such as harsh reaction conditions, great safety risks, complicated post-processing, and unverified applicability to 4-hydroxybiphenyl substrates.
Phosphorylation reaction is carried out under specific conditions using an acid-binding agent and a modified catalyst, including steps such as water quenching, layering, alkali washing, water washing, and vacuum distillation. Modified aluminum/titanium loose aggregates are used to support zinc and iron ion catalysts to improve the selectivity and safety of the reaction.
The synthesis of tris(4-hydroxybiphenyl) phosphate with high selectivity and high yield was achieved, simplifying post-processing steps, reducing reaction risks, and providing a feasible solution for large-scale production.
Smart Images
Figure CN121930271A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for synthesizing tris(4-hydroxybiphenyl) phosphate. Background Technology
[0002] Phosphorus oxychloride and 4-hydroxybiphenyl have wide applications in pharmaceuticals, pesticides, electronic materials, and polymer materials, respectively. The tris(4-hydroxybiphenyl) phosphate formed by their reaction combines the properties of phosphorus and biphenyl structures, showing potential applications in pesticides, flame retardant materials, polymer modification, and pharmaceuticals. The development of this novel compound provides related industries with new material options and technological routes.
[0003] Currently, detailed methods for synthesizing tris(4-hydroxybiphenyl) phosphates have not been reported. Traditional phosphate ester synthesis methods often involve the reaction of phosphorus oxychloride (POCl3) with alcohols, but these methods have the following problems:
[0004] (1) The reaction conditions are harsh, requiring strict control of temperature and humidity;
[0005] (2) Reactions involving phosphorus oxychloride pose safety hazards; improper use may lead to an explosion.
[0006] (3) The post-reaction treatment is complicated, and the removal of excess phosphorus oxychloride requires special equipment;
[0007] (4) The applicability of existing methods to special substrates such as 4-hydroxybiphenyl has not yet been verified. Summary of the Invention
[0008] The purpose of this invention is to propose a method for synthesizing tris(4-hydroxybiphenyl) phosphate, which combines the characteristics of phosphorus and biphenyl structure, and has potential application value in the fields of pesticides, flame retardant materials, polymer modification and pharmaceuticals, providing new material choices and technical routes for related industries.
[0009] The technical solution of this invention is implemented as follows:
[0010] This invention provides a method for synthesizing tris(4-hydroxybiphenyl) phosphate, comprising the following steps:
[0011] (1) 4-hydroxybiphenyl was heated to complete the reaction under the action of an acid-binding agent, a catalyst and phosphorus oxychloride;
[0012] (2) Add water to the reaction solution in step (1) to quench, wash with water, separate into layers, use the aqueous phase to recover the acid-binding agent, and use the organic phase for subsequent steps;
[0013] (3) Add alkali solution and deionized water to the organic phase in step (2) in sequence, and perform alkali washing and water washing to remove residual unreacted raw materials and other impurities;
[0014] (4) Take the organic phase after impurity removal in step (3) and heat it under reduced pressure to distill it, recover the solvent, and obtain the distillation product. After purification, tris(4-hydroxybiphenyl) phosphate is obtained.
[0015] The reaction principle is as follows:
[0016] Under the action of an acid-binding agent and a catalyst, phosphorus oxychloride and 4-hydroxybiphenyl undergo a phosphorylation reaction to yield tris(4-hydroxybiphenyl) phosphate.
[0017] Equation (1)
[0018] Equation (2)
[0019] Equation (3)
[0020] As a further improvement of the present invention, in step (1), the catalyst is one of anhydrous aluminum trichloride, ferric chloride, zinc dichloride, titanium tetrachloride, and modified catalyst.
[0021] As a further improvement of the present invention, in step (1), the amount of catalyst used is 2%-5% of the amount of phosphorus oxychloride.
[0022] As a further improvement of the present invention, the preparation method of the modified catalyst is as follows:
[0023] S1. Add aluminum isopropoxide and tetrabutyl titanate to ethanol, stir and mix evenly, add acid and water, stir and hydrolyze, filter, wash, dry and calcine to obtain aluminum / titanium loose aggregates.
[0024] S2. Add aluminum / titanium loose aggregates to Tris-HCl solution, add dopamine hydrochloride, heat and stir to react, and obtain modified aluminum / titanium loose aggregates;
[0025] S3. Add the modified aluminum / titanium loose aggregate to water, add ferric chloride and zinc chloride, stir and impregnate, filter, wash, and dry to obtain the modified catalyst.
[0026] As a further improvement of the present invention, the mass ratio of aluminum isopropoxide, tetrabutyl titanate, acid and water in step S1 is 3-5:2-4:1-2:3-5, the acid is concentrated hydrochloric acid, and the hydrolysis time is 1-2 hours.
[0027] As a further improvement of the present invention, the pH value of the Tris-HCl solution in step S2 is 8.5-9.5, the mass ratio of the aluminum / titanium loose aggregate to dopamine hydrochloride is 10:2-3, the temperature of the heating and stirring reaction is 45-55℃, and the time is 3-5h; in step S3, the mass ratio of the modified aluminum / titanium loose aggregate, ferric chloride, and zinc dichloride is 100:3-5:2-6, and the stirring and impregnation time is 5-10h.
[0028] This invention utilizes acid-catalyzed hydrolysis of aluminum isopropoxide and tetrabutyl titanate to form a loose, granular alumina / titanium oxide composite, increasing its specific surface area. By loading a polydopamine layer onto its surface, zinc and iron ions can be effectively enriched, thereby increasing the number of active sites in the modified catalyst and significantly improving its catalytic effect, which is significantly superior to traditional catalysts.
[0029] As a further improvement of the present invention, in step (1), the temperature of the heating reaction is 120-170°C and the time is 48-72h.
[0030] As a further improvement of the present invention, in step (1), the acid-binding agent is one of pyridine, amine, or low-carbon fatty amine.
[0031] As a further improvement of the present invention, in step (1), the amount of acid-binding agent is 1-3 times the molar amount of phosphorus oxychloride.
[0032] As a further improvement of the present invention, in step (1), the molar ratio of phosphorus oxychloride to 4-hydroxybiphenyl is 1:2.9-3.1.
[0033] The present invention has the following beneficial effects:
[0034] (1) A suitable reaction system for 4-hydroxybiphenyl was developed, which improved the reaction selectivity and yield;
[0035] (2) Improved safety operating procedures reduced reaction risks;
[0036] (3) The post-processing steps have been simplified, making the product easier to purify;
[0037] (4) It provides a feasible solution for the large-scale production of tris(4-hydroxybiphenyl) phosphate. Attached Figure Description
[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0039] Figure 1 The image shows the liquid chromatography result of the product obtained in Example 1. Detailed Implementation
[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0041] Preparation Example 1
[0042] The preparation method of the modified catalyst is as follows:
[0043] S1. Add 3g aluminum isopropoxide and 2g tetrabutyl titanate to 150mL ethanol, stir and mix evenly, add 1g concentrated hydrochloric acid and 3mL water, stir and hydrolyze for 1h, filter, wash, dry, calcine at 400℃ for 2h to obtain aluminum / titanium loose aggregates.
[0044] S2. Add 10g of aluminum / titanium loose aggregate to a Tris-HCl solution with a pH of 8.5, add 2g of dopamine hydrochloride, heat to 45℃, stir and react for 3h to obtain modified aluminum / titanium loose aggregate;
[0045] S3. Add 10g of modified aluminum / titanium loose aggregate to 100mL of water, add 0.3g of ferric chloride and 0.2g of zinc chloride, stir and soak for 5h, filter, wash and dry to obtain the modified catalyst.
[0046] Preparation Example 2
[0047] The preparation method of the modified catalyst is as follows:
[0048] S1. Add 5g aluminum isopropoxide and 4g tetrabutyl titanate to 150mL ethanol, stir and mix evenly, add 2g concentrated hydrochloric acid and 5mL water, stir and hydrolyze for 2h, filter, wash, dry, calcine at 400℃ for 2h to obtain aluminum / titanium loose aggregates.
[0049] S2. Add 10g of aluminum / titanium loose aggregate to a Tris-HCl solution with a pH of 9.5, add 3g of dopamine hydrochloride, heat to 55℃, stir and react for 5h to obtain modified aluminum / titanium loose aggregate;
[0050] S3. Add 10g of modified aluminum / titanium loose aggregate to 100mL of water, add 0.5g of ferric chloride and 0.6g of zinc dichloride, stir and soak for 10h, filter, wash and dry to obtain the modified catalyst.
[0051] Preparation Example 3
[0052] The preparation method of the modified catalyst is as follows:
[0053] S1. Add 4g aluminum isopropoxide and 3g tetrabutyl titanate to 150mL ethanol, stir and mix evenly, add 1.5g concentrated hydrochloric acid and 4mL water, stir and hydrolyze for 1.5h, filter, wash, dry, calcine at 400℃ for 2h to obtain aluminum / titanium loose aggregates.
[0054] S2. Add 10g of aluminum / titanium loose aggregate to a Tris-HCl solution with a pH of 9, add 2.5g of dopamine hydrochloride, heat to 50℃, stir and react for 4h to obtain modified aluminum / titanium loose aggregate.
[0055] S3. Add 10g of modified aluminum / titanium loose aggregate to 100mL of water, add 0.4g of ferric chloride and 0.35g of zinc dichloride, stir and soak for 8h, filter, wash and dry to obtain the modified catalyst.
[0056] Comparative Preparation Example 1
[0057] The difference from Preparation Example 3 is that aluminum isopropoxide was not added in step S1.
[0058] The preparation method of the modified catalyst is as follows:
[0059] S1. Add 7g tetrabutyl titanate to 150mL ethanol, stir and mix evenly, add 1.5g concentrated hydrochloric acid and 4mL water, stir and hydrolyze for 1.5h, filter, wash, dry, calcine at 400℃ for 2h to obtain titanium loose aggregates.
[0060] S2. Add 10g of titanium loose aggregate to a Tris-HCl solution with a pH of 9, add 2.5g of dopamine hydrochloride, heat to 50℃, stir and react for 4h to obtain modified titanium loose aggregate.
[0061] S3. Add 10g of modified titanium loose aggregate to 100mL of water, add 0.4g of ferric chloride and 0.35g of zinc dichloride, stir and soak for 8h, filter, wash and dry to obtain the modified catalyst.
[0062] Comparative Preparation Example 2
[0063] The difference from Preparation Example 3 is that tetrabutyl titanate was not added in step S1.
[0064] The preparation method of the modified catalyst is as follows:
[0065] S1. Add 7g of aluminum isopropoxide to 150mL of ethanol, stir and mix evenly, add 1.5g of concentrated hydrochloric acid and 4mL of water, stir and hydrolyze for 1.5h, filter, wash, dry, calcine at 400℃ for 2h to obtain loose aluminum agglomerates.
[0066] S2. Add 10g of aluminum loose agglomerates to a Tris-HCl solution with a pH of 9, add 2.5g of dopamine hydrochloride, heat to 50℃, stir and react for 4h to obtain modified aluminum loose agglomerates.
[0067] S3. Add 10g of modified aluminum loose agglomerate to 100mL of water, add 0.4g of ferric chloride and 0.35g of zinc chloride, stir and soak for 8h, filter, wash and dry to obtain the modified catalyst.
[0068] Comparative preparation example 3
[0069] The difference from preparation example 3 is that step S2 was not performed.
[0070] The preparation method of the modified catalyst is as follows:
[0071] S1. Add 4g aluminum isopropoxide and 3g tetrabutyl titanate to 150mL ethanol, stir and mix evenly, add 1.5g concentrated hydrochloric acid and 4mL water, stir and hydrolyze for 1.5h, filter, wash, dry, calcine at 400℃ for 2h to obtain aluminum / titanium loose aggregates.
[0072] S2. Add 10g of aluminum / titanium loose aggregate to 100mL of water, add 0.4g of ferric chloride and 0.35g of zinc dichloride, stir and soak for 8h, filter, wash and dry to obtain the modified catalyst.
[0073] Test Example 1
[0074] The specific surface area of the modified catalysts prepared in Preparation Examples 1-3 and Comparative Preparation Examples 1-3 was determined using a 3-FLEX 3500 multi-station high-throughput gas adsorption analyzer.
[0075] The results are shown in Table 1.
[0076] Table 1
[0077]
[0078] As can be seen from the table above, the modified catalysts prepared in Examples 1-3 of this invention have a large specific surface area.
[0079] Example 1
[0080] The specific synthesis steps are as follows:
[0081] (1) Add 300g of ethylbenzene (excluding water) to a 500ml three-necked flask as a solvent, then add 15g of 4-hydroxybiphenyl, heat until dissolved, then add 8.63g of triethylamine as an acid-binding agent, dissolve again, and finally add 0.1g of anhydrous AlCl3 catalyst and 4.63g of POCl3, heat to 120℃, and reflux for 56h;
[0082] (2) Add 150 ml of deionized water to the reaction solution in step 1 for washing, then let it stand to separate into layers, filter, separate the filtrate into layers, collect the aqueous phase, which can be used to recover triethylamine, and the organic phase can be used for subsequent steps.
[0083] (3) Take the organic phase from step 2, add an appropriate amount of alkaline solution (5%, 100 ml), and wash with alkaline solution at 75°C for 0.5 h to remove the residual unreacted 4-hydroxybiphenyl. Then let it stand to separate into layers, filter, and use the organic layer of the filtrate for subsequent steps.
[0084] (4) Take the organic phase after alkali washing in step 3, add 150ml of deionized water for a second water wash to remove residual alkali, then let it stand to separate into layers, filter, and use the filtrate organic phase for subsequent steps.
[0085] (5) Take the organic phase after washing with water in step 4, place it in a distillation flask, and distill under high temperature and reduced pressure (120℃; -0.098Mpa) to remove ethylbenzene and obtain the final distillation product;
[0086] (6) Finally, the distillation product from step 5 was subjected to multiple purification processes in methanol, water, and ethylbenzene, respectively. Finally, it was cooled in ethylbenzene to crystallize, yielding white needle-like crystals. The liquid phase results (e.g.) Figure 1 The content can reach 99.89%.
[0087] Example 2
[0088] The difference from Example 1 is that the catalyst is ferric chloride.
[0089] Example 3
[0090] The difference from Example 1 is that the catalyst is zinc chloride.
[0091] Example 4
[0092] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Preparation Example 1.
[0093] Example 5
[0094] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Preparation Example 1.
[0095] Example 6
[0096] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Preparation Example 1.
[0097] Comparative Example 1
[0098] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Comparative Preparation Example 1.
[0099] Comparative Example 2
[0100] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Comparative Preparation Example 2.
[0101] Comparative Example 3
[0102] The difference from Example 1 is that the catalyst is the modified catalyst prepared in Comparative Preparation Example 3.
[0103] Test Example 2
[0104] The yields and purity of the tris(4-hydroxybiphenyl) phosphates obtained in Examples 1-6 and Comparative Examples 1-3 were analyzed, and the results are shown in Table 2.
[0105] Table 2
[0106]
[0107] As can be seen from the table above, the tris(4-hydroxybiphenyl) phosphates prepared in Examples 1-6 of this invention have high yields and high purity, with Examples 4-6 having even higher yields.
[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for synthesizing tris(4-hydroxybiphenyl) phosphate, characterized in that, Includes the following steps: (1) 4-hydroxybiphenyl was heated to complete the reaction under the action of an acid-binding agent, a catalyst and phosphorus oxychloride; (2) Add water to the reaction solution in step (1) to quench, wash with water, separate into layers, use the aqueous phase to recover the acid-binding agent, and use the organic phase for subsequent steps; (3) Add alkali solution and deionized water to the organic phase in step (2) in sequence, and perform alkali washing and water washing to remove residual unreacted raw materials and other impurities; (4) Take the organic phase after impurity removal in step (3) and heat it under reduced pressure to distill it, recover the solvent, and obtain the distillation product. After purification, tris(4-hydroxybiphenyl) phosphate is obtained.
2. The synthesis method according to claim 1, characterized in that, In step (1), the catalyst is one of anhydrous aluminum trichloride, ferric chloride, zinc dichloride, titanium tetrachloride, or a modified catalyst.
3. The synthesis method according to claim 1, characterized in that, In step (1), the amount of catalyst used is 2%-5% of the amount of phosphorus oxychloride.
4. The synthesis method according to claim 2, characterized in that, The modified catalyst is prepared as follows: S1. Add aluminum isopropoxide and tetrabutyl titanate to ethanol, stir and mix evenly, add acid and water, stir and hydrolyze, filter, wash, dry and calcine to obtain aluminum / titanium loose aggregates. S2. Add aluminum / titanium loose aggregates to Tris-HCl solution, add dopamine hydrochloride, heat and stir to react, and obtain modified aluminum / titanium loose aggregates; S3. Add the modified aluminum / titanium loose aggregate to water, add ferric chloride and zinc chloride, stir and impregnate, filter, wash, and dry to obtain the modified catalyst.
5. The synthesis method according to claim 1, characterized in that, In step S1, the mass ratio of aluminum isopropoxide, tetrabutyl titanate, acid, and water is 3-5:2-4:1-2:3-5, the acid is concentrated hydrochloric acid, and the hydrolysis time is 1-2 hours.
6. The synthesis method according to claim 1, characterized in that, In step S2, the pH value of the Tris-HCl solution is 8.5-9.5, the mass ratio of the aluminum / titanium loose aggregate to dopamine hydrochloride is 10:2-3, and the heating and stirring reaction temperature is 45-55℃ for 3-5 hours; in step S3, the mass ratio of the modified aluminum / titanium loose aggregate, ferric chloride, and zinc chloride is 100:3-5:2-6, and the stirring and impregnation time is 5-10 hours.
7. The synthesis method according to claim 1, characterized in that, In step (1), the heating reaction is carried out at a temperature of 120-170°C for 48-72 hours.
8. The synthesis method according to claim 1, characterized in that, In step (1), the acid-binding agent is one of pyridine, amine, or low-carbon fatty amine.
9. The synthesis method according to claim 1, characterized in that, In step (1), the amount of acid-binding agent used is 1-3 times the molar amount of phosphorus oxychloride.
10. The synthesis method according to claim 1, characterized in that, In step (1), the molar ratio of phosphorus oxychloride to 4-hydroxybiphenyl is 1:2.9-3.1.