Porous crosslinked benzyl alcohol resin sodium salt beta-h elimination promoter, method of making and use thereof

Abstract

The application discloses a kind of porous crosslinking benzyl alcohol resin sodium salt β-H elimination accelerant and its preparation method and application, it is related to β-H elimination accelerator technical field.The technical scheme is: S1 chloromethylated polystyrene crosslinked resin is poured into sodium carbonate saturated aqueous solution and heated to boiling, stirring reaction;S2 filter removes aqueous solution, washes sodium carbonate remaining in resin microspheres with water;S3 resin microspheres are dried, add anhydrous tetrahydrofuran and sodium hydride, after warming reaction, cool to room temperature and filter polymerization ball, respectively with methanol, tetrahydrofuran and n-hexane wash polymerization ball, polymerization ball is dried, obtain porous crosslinking benzyl alcohol resin sodium salt β-H elimination accelerant.The porous crosslinking benzyl alcohol resin sodium salt β-H elimination accelerant prepared by the application has the advantages of high metal salt content, strong alkaline, easy separation, etc., and is a kind of very industrial application prospect of auxiliary agent.

Description

Technical Field

[0001] This invention relates to the field of β-H elimination promoter technology, specifically to a porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter, its preparation method, and its application. Background Technology

[0002] In the 1980s, Burkhart first reported the carboxylation reaction of carbon dioxide with alkenes. Using carbon dioxide and styrene as raw materials, he demonstrated that carbon dioxide could be activated to generate nickel propionate lactone intermediates under the action of a nickel complex. By controlling the reaction temperature, phenylpropionic acid or cinnamic acid products could be generated. Building on this, more and more researchers have studied the catalytic carboxylation of unsaturated hydrocarbons with carbon dioxide. Carbon dioxide carboxylation reactions can be widely used to prepare bulk and fine chemicals, as well as intermediates in organic synthesis. In recent years, palladium and nickel-catalyzed reactions of alkenes and alkynes with carbon dioxide have received considerable attention among different catalytically active metals. Some reactions have been used to prepare a series of important industrial products. For example, valuable α,β-unsaturated carboxylic acids and their derivatives can be directly obtained via carbon dioxide carboxylation reactions. The carboxylation reaction of carbon dioxide with ethylene can directly synthesize acrylic acid, which can then be further processed through esterification to obtain various acrylate compounds.

[0003] The carboxylation reaction of carbon dioxide with ethylene is a direct reaction between ethylene and carbon dioxide catalyzed by a metal catalyst. The reaction mechanism is that after the metal catalyst activates carbon dioxide, it reacts with ethylene to generate a metal lactone ring intermediate of propionate. This intermediate can be hydrolyzed or undergo β-H elimination reaction under heating or acid-base conditions. At the same time, the metal catalyst leaves and re-enters the next catalytic cycle, finally yielding acrylic acid or propionic acid compounds.

[0004] From a reaction mechanism perspective, the promoter in the β-H elimination step plays a crucial role in the reaction process. Currently, most β-H elimination promoters are metal salts of acids or alcohols. When using tert-butanol metal salts as β-H elimination promoters for carbon dioxide carboxylation reactions, the reaction yield can reach over 70%. However, the amount of potassium tert-butoxide added is usually 200-1000 times that of the catalyst, generating a large amount of waste liquid. Furthermore, the unreacted tert-butanol metal salt and potassium acrylate product are difficult to separate, leading to increased separation energy consumption. Chevron Philips Chemicals has developed polyvinylphenol or phenolic resin metal salts (CN108368017A, CN111032609A) as supported β-H elimination promoters to replace tert-butanol metal salts for the carboxylation reaction of carbon dioxide and ethylene. Although these supported β-H elimination promoters are easy to separate, their basicity is weaker than that of alcohol metal salts, resulting in lower reaction efficiency. To address the above issues, it is of great significance to develop β-H elimination promoters for ethylene carboxylation reactions that are easy to separate, highly alkaline, simple to prepare, and low in cost. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter, its preparation method and application. The prepared porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter has advantages such as high metal salt content, strong alkalinity and easy separation, and is an additive with great prospects for industrial application.

[0006] The technical solution of this invention is as follows:

[0007] In a first aspect, the present invention provides a method for preparing a porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter, comprising the following steps:

[0008] S1. Pour the chloromethylated polystyrene crosslinked resin into a saturated aqueous solution of sodium carbonate, heat to boiling, and stir to react for 5-7 hours.

[0009] S2 filtration removes the sodium carbonate residue from the aqueous solution, and then the resin microspheres are washed with water.

[0010] S3 dried the washed resin microspheres, then added anhydrous tetrahydrofuran, and added sodium hydride in batches. After the addition was complete, the reaction system was heated to react. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed with methanol, tetrahydrofuran and n-hexane respectively. The washed polymerized microspheres were dried to obtain the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter.

[0011] Preferably, in step S1, the amount of sodium carbonate added accounts for 20-40% of the total mass of sodium carbonate and chloromethylated polystyrene crosslinking resin.

[0012] Preferably, in step S3, the amount of sodium hydride added is 10-15% of the mass of the resin microspheres.

[0013] Preferably, in step S3, the amount of sodium hydride added is 15% of the mass of the resin microspheres.

[0014] Preferably, in step S3, the reaction temperature is 60-80℃ and the reaction time is 8-10h.

[0015] Preferably, in step S3, the drying temperature is 80-100℃ and the drying time is 2-5h.

[0016] Secondly, the present invention provides a porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter prepared by the above preparation method, with the following structural formula:

[0017]

[0018] n = 500 - 2000.

[0019] Thirdly, the present invention provides the application of the above-mentioned porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter, in which ethylene and carbon dioxide react to produce acrylic acid under the catalytic action of a catalyst composed of nickel compound, phosphine ligand and porous cross-linked benzyl alcohol resin metal salt β-H elimination promoter.

[0020] Preferably, nickel compounds, phosphine ligands, and sodium salt β-H elimination promoters of porous crosslinked benzyl alcohol resin are added to a reaction vessel, sealed, and then an appropriate amount of carbon dioxide with a mass purity of 90-100% is introduced. Then, the reaction vessel is filled with ethylene to a specified pressure to carry out the reaction, wherein the mass purity of ethylene is 90-100%. This reaction is a heterogeneous reaction carried out in a batch reactor.

[0021] Preferably, the nickel compound is bis-(1,5-cyclooctadiene)nickel; the phosphine ligand is a bidentate phosphine ligand, preferably 1,2-bis(dicyclohexylphosphine)ethane or 1,4-bis(dicyclohexylphosphine)butane; the molar ratio of the nickel compound, the phosphine ligand and the porous crosslinked benzyl alcohol resin metal salt β-H elimination promoter is 1:(1-2.5):(200-800).

[0022] Preferably, the reaction temperature is 140-160℃ and the reaction time is 8-24h; preferably, the reaction temperature is 140-150℃ and the reaction time is 8-14h.

[0023] In this invention, the TON of the carbon dioxide carboxylation reaction is calculated as: the number of moles of sodium acrylate produced by the reaction / the number of moles of catalyst (i.e., nickel compound and phosphine ligand) added.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter prepared by the present invention has an exchange capacity of not less than 4 mmol / g, the amount added during the reaction is further reduced, and it has the characteristic of high temperature resistance, and can be used at reaction temperatures above 140°C.

[0026] 2. The porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter of the present invention is more basic than sodium phenolate and has a faster reaction efficiency. Furthermore, using the porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter of the present invention facilitates separation from reactants and products, reducing separation energy consumption. Therefore, the porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter prepared by the present invention has advantages such as high metal salt content, strong basicity, and easy separation, making it a promising additive for industrial application. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0028] Example 1

[0029] The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter in this embodiment includes the following steps:

[0030] In a 250mL round-bottom flask, add 20g of chloromethylated polystyrene crosslinking resin, 6g of sodium carbonate and 200mL of deionized water, heat to boiling and stir thoroughly for 5 hours.

[0031] S2 stopped the reaction and cooled to room temperature. The sodium carbonate aqueous solution was separated by filtration using a Buchner funnel. At the same time, the resin microspheres were washed with deionized water until the pH of the washed aqueous phase was neutral.

[0032] S3 placed the washed resin microspheres in an oven and dried at 110℃ for 6 hours to obtain porous cross-linked benzyl alcohol resin. 20g of the porous cross-linked benzyl alcohol resin was placed in a 250mL round-bottom flask, and 150mL of anhydrous tetrahydrofuran was added. 2g of sodium hydride was slowly poured into the reaction system in 4 batches, and the reaction was carried out at 60℃ for 8 hours. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed three times each with methanol, tetrahydrofuran, and n-hexane. The washed polymerized microspheres were placed in a vacuum drying oven and dried at 80℃ for 2 hours to obtain the β-H elimination promoter of the sodium salt of porous cross-linked benzyl alcohol resin. The sodium benzyl alcohol content was 4.3mmol / g, and the conversion rate was 77%.

[0033] Example 2

[0034] The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter in this embodiment includes the following steps:

[0035] In a 250mL round-bottom flask, add 20g of chloromethylated polystyrene crosslinking resin, 8g of sodium carbonate and 200mL of deionized water, heat to boiling and stir thoroughly for 7 hours.

[0036] S2 stopped the reaction and cooled to room temperature. The sodium carbonate aqueous solution was separated by filtration using a Buchner funnel. At the same time, the resin microspheres were washed with deionized water until the pH of the washed aqueous phase was neutral.

[0037] S3 placed the washed resin microspheres in an oven and dried at 110℃ for 6 hours to obtain porous cross-linked benzyl alcohol resin. 20g of the porous cross-linked benzyl alcohol resin was placed in a 250mL round-bottom flask, and 150mL of anhydrous tetrahydrofuran was added. 2g of sodium hydride was slowly poured into the reaction system in 4 batches, and the reaction was carried out at 60℃ for 10 hours. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed three times each with methanol, tetrahydrofuran, and n-hexane. The washed polymerized microspheres were placed in a vacuum drying oven and dried at 80℃ for 5 hours to obtain the β-H elimination promoter of the sodium salt of porous cross-linked benzyl alcohol resin. The sodium benzyl alcohol content was 4.7mmol / g, and the conversion rate was 86%.

[0038] Example 3

[0039] The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter in this embodiment includes the following steps:

[0040] In a 250mL round-bottom flask, add 20g of chloromethylated polystyrene crosslinking resin, 6g of sodium carbonate and 200mL of deionized water, heat to boiling and stir thoroughly for 7 hours.

[0041] S2 stopped the reaction and cooled to room temperature. The sodium carbonate aqueous solution was separated by filtration using a Buchner funnel. At the same time, the resin microspheres were washed with deionized water until the pH of the washed aqueous phase was neutral.

[0042] S3 placed the washed resin microspheres in an oven and dried at 110℃ for 6 hours to obtain porous cross-linked benzyl alcohol resin. 20g of porous cross-linked benzyl alcohol resin was placed in a 250mL round-bottom flask, and 150mL of anhydrous tetrahydrofuran was added. 3g of sodium hydride was slowly poured into the reaction system in 4 batches, and the reaction was carried out at 80℃ for 8 hours. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed three times each with methanol, tetrahydrofuran, and n-hexane. The washed polymerized microspheres were placed in a vacuum drying oven and dried at 100℃ for 5 hours to obtain a porous cross-linked benzyl alcohol resin sodium salt β-H elimination promoter with a benzyl alcohol sodium content of 4.5mmol / g and a conversion rate of 80%.

[0043] Example 4

[0044] The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter in this embodiment includes the following steps:

[0045] In a 250mL round-bottom flask, add 20g of chloromethylated polystyrene crosslinking resin, 8g of sodium carbonate and 200mL of deionized water, heat to boiling and stir thoroughly for 6 hours.

[0046] S2 stopped the reaction and cooled to room temperature. The sodium carbonate aqueous solution was separated by filtration using a Buchner funnel. At the same time, the resin microspheres were washed with deionized water until the pH of the washed aqueous phase was neutral.

[0047] S3. The washed resin microspheres were placed in an oven and dried at 110℃ for 6 hours to obtain porous cross-linked benzyl alcohol resin. 20g of porous cross-linked benzyl alcohol resin was placed in a 250mL round-bottom flask, and 150mL of anhydrous tetrahydrofuran was added. 3g of sodium hydride was slowly poured into the reaction system in 4 batches, and the reaction was carried out at 70℃ for 9 hours. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed three times each with methanol, tetrahydrofuran, and n-hexane. The washed polymerized microspheres were placed in a vacuum drying oven and dried at 90℃ for 4 hours to obtain the β-H elimination promoter of the sodium salt of porous cross-linked benzyl alcohol resin. The sodium benzyl alcohol content was 4.9mmol / g, and the conversion rate was 96%.

[0048] Examples 5-11

[0049] In a 150 mL high-pressure reactor, under nitrogen protection, 0.1 mmol of a metal compound, 0.1 mmol of bisphosphine ligand, 30 mmol of β-H elimination promoter, and 60 mL of solvent were added sequentially. The reactor was sealed, and the gas inside was replaced with carbon dioxide three times. Carbon dioxide was then introduced until the reactor pressure reached 1 MPa, followed by the introduction of ethylene until the reactor pressure reached 5 MPa. The temperature was slowly increased to 140 °C under temperature control, and the reaction was carried out for 8 hours. After cooling to room temperature, the reactor was removed, the β-H elimination promoter was filtered, and the resulting liquid was analyzed. The raw materials and reaction parameters for Examples 5-11 are shown in Table 1.

[0050] Table 1

[0051]

[0052] Examples 12-14

[0053] In a 150 mL high-pressure reactor, under nitrogen protection, 0.1 mmol of bis-(1,5-cyclooctadiene)nickel, 1,2-bis(dicyclohexylphosphine)ethane, 30 mmol of β-H elimination promoter, and 60 mL of N-methylpyrrolidone were added sequentially. The reactor was sealed, and after purging with carbon dioxide three times, carbon dioxide was added until the reactor pressure reached 1 MPa. Ethylene was then added until the reactor pressure reached 5 MPa. The temperature was slowly increased to 140 °C under temperature control, and the reaction was carried out for 8 hours. After cooling to room temperature, the reactor was removed, the β-H elimination promoter was filtered, and the resulting liquid was analyzed. The raw materials and reaction parameters for Examples 12-14 are shown in Table 2.

[0054] Table 2

[0055]

[0056] Examples 15-18

[0057] In a 150 mL high-pressure reactor, under nitrogen protection, 0.1 mmol of bis-(1,5-cyclooctadiene)nickel, 0.15 mmol of 1,2-bis(dicyclohexylphosphine)ethane, 30 mmol of β-H elimination promoter, and 60 mL of N-methylpyrrolidone were added sequentially. The reactor was sealed, and after purging with carbon dioxide three times, carbon dioxide was added until the reactor pressure reached 1 MPa. Ethylene was then added until the gas pressure inside the reactor reached 5 MPa. The temperature was slowly increased to the set temperature and the reaction was carried out for the set time using a temperature controller. After the reaction was completed, the reactor was cooled to room temperature, removed from the reactor, and the β-H elimination promoter was filtered. The resulting liquid was analyzed. The raw materials and reaction parameters for Examples 15-18 are shown in Table 3.

[0058] Table 3

[0059]

[0060] Comparative Examples 1-3

[0061] In a 150 mL high-pressure reactor, under nitrogen protection, 0.1 mmol of bis-(1,5-cyclooctadiene)nickel, 0.15 mmol of 1,2-bis(dicyclohexylphosphine)ethane, 30 mmol of β-H elimination promoter, and 60 mL of N-methylpyrrolidone were added sequentially. The reactor was sealed, and after purging with carbon dioxide three times, carbon dioxide was added until the reactor pressure reached 1 MPa. Ethylene was then added until the reactor pressure reached 5 MPa. The temperature was slowly increased to 140 °C under temperature control, and the reaction was carried out for 14 h. After cooling to room temperature, the reactor was removed, and the resulting liquid was analyzed. The raw materials and relevant reaction parameters for Comparative Examples 1-3 are shown in Table 4.

[0062] Table 4

[0063]

[0064] Compared with the three β-H elimination promoters used in Comparative Examples 1-3, the sodium alkoxide salt in the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter of the present invention has a stronger basicity than the general sodium carboxylate and sodium phenolate salts. After the reaction, the resin microspheres can be separated from the water-soluble sodium acrylate product by simple vacuum filtration. The used resin microspheres can be reacted with sodium hydride to obtain the sodium alkoxide salt β-H elimination promoter again, which has good recycling performance.

Claims

1. A method for preparing a β-H elimination accelerator from sodium salt of porous crosslinked benzyl alcohol resin, characterized in that, Includes the following steps: S1. Pour the chloromethylated polystyrene crosslinked resin into a saturated aqueous solution of sodium carbonate, heat to boiling, and stir to react for 5-7 hours. S2 filtration removes the sodium carbonate residue from the aqueous solution, and then the resin microspheres are washed with water. S3 dried the washed resin microspheres, then added anhydrous tetrahydrofuran, and added sodium hydride in batches. After the addition was complete, the reaction system was heated to react. After the reaction was completed, the system temperature was cooled to room temperature and the polymerized microspheres were filtered. The polymerized microspheres were washed with methanol, tetrahydrofuran and n-hexane respectively. The washed polymerized microspheres were dried to obtain the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter.

2. The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 1, characterized in that, In step S1, the amount of sodium carbonate added accounts for 20-40% of the total mass of sodium carbonate and chloromethylated polystyrene crosslinking resin.

3. The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 1, characterized in that, In step S3, the amount of sodium hydride added is 10-15% of the mass of the resin microspheres.

4. The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 1, characterized in that, In step S3, the amount of sodium hydride added is 15% of the mass of the resin microspheres.

5. The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 1, characterized in that, In step S3, the reaction temperature is 60-80℃ and the reaction time is 8-10h.

6. The preparation method of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 1, characterized in that, In step S3, the drying temperature is 80-100℃ and the drying time is 2-5 hours.

7. The porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter prepared by the preparation method according to any one of claims 1-6.

8. The application of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 7, characterized in that, Ethylene and carbon dioxide react to form acrylic acid under the catalysis of a catalyst composed of nickel compounds, phosphine ligands, and a porous cross-linked benzyl alcohol resin metal salt β-H elimination promoter.

9. The application of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 8, characterized in that, The nickel compound is bis-(1,5-cyclooctadiene)nickel; the phosphine ligand is a bidentate phosphine ligand, preferably 1,2-bis(dicyclohexylphosphine)ethane or 1,4-bis(dicyclohexylphosphine)butane; the molar ratio of the nickel compound, the phosphine ligand and the porous crosslinked benzyl alcohol resin metal salt β-H elimination promoter is 1:(1-2.5):(200-800).

10. The application of the porous crosslinked benzyl alcohol resin sodium salt β-H elimination promoter as described in claim 8, characterized in that, The reaction temperature is 140-160℃ and the reaction time is 8-24h; preferably, the reaction temperature is 140-150℃ and the reaction time is 8-14h.

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