A catalyst for the preparation of carbonic acid-2,3-butanediol ester and its use

Abstract

The embodiment of the present application discloses a catalyst for preparing carbonic acid-2,3-butanediol ester and application thereof. The catalyst is mixed by supermolecular onium salt ionic liquid solid-supported molecular sieve and titanium glycol with a mass ratio of 1:0.5-1.5. The catalyst is composed of specific amount of supermolecular onium salt ionic liquid solid-supported molecular sieve and titanium glycol, and the raw materials play a synergistic effect. The catalyst has the advantages of high catalytic activity and strong reaction selectivity in the preparation process of carbonic acid-2,3-butanediol ester, can significantly improve the yield of carbonic acid-2,3-butanediol ester, and has good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, specifically to a catalyst for the preparation of 2,3-butanediol carbonate and its application. Background Technology

[0002] 2,3-Butanediol carbonate is a colorless, transparent liquid under normal conditions. It is soluble in ethanol and ether, but insoluble in water, with a relative density of 1.424. It is mainly used in organic synthesis and chemical production processes. The structure of 2,3-Butanediol carbonate is as follows:

[0003]

[0004] Currently, 2,3-butanediol carbonate is mainly synthesized via the cycloaddition reaction of carbon dioxide and epoxides, a typical atom-economical reaction that aligns with the development direction of green chemistry. However, existing synthetic methods suffer from low catalyst activity and reaction selectivity, resulting in low yields of the target product. Summary of the Invention

[0005] Therefore, embodiments of the present invention provide a catalyst for the preparation of 2,3-butanediol carbonate and its application.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] According to a first aspect of the present invention, the present invention provides a catalyst for preparing 2,3-butanediol carbonate, which is composed of a supramolecular onium salt ionic liquid-supported molecular sieve and titanium glycol in a mass ratio of 1:0.5 to 1.5.

[0008] Furthermore, the mass ratio of the supramolecular onium salt ionic liquid-supported molecular sieve to titanium glycol is 1:1.

[0009] Furthermore, the preparation method of the supramolecular onium salt ionic liquid-supported molecular sieve is as follows:

[0010] Molecular sieves and imidazole ionic liquids were refluxed in acetonitrile, cooled to room temperature, and then acetonitrile was removed by rotary evaporation. The mixture was then removed by Soxhlet extraction with dichloromethane, filtered, and the resulting solid phase was dried in a vacuum drying oven.

[0011] Furthermore, the molecular sieve is a zeolite molecular sieve or a mesoporous molecular sieve. As an example, the zeolite molecular sieve can be type A, type Y, type X, type ZSM-5, etc., and the mesoporous molecular sieve can be SAB-15, MCM-41, etc.

[0012] Furthermore, the mass ratio of the molecular sieve to the imidazole ionic liquid is 0.8 to 1:1.

[0013] Furthermore, the condensation reflux time is 20–28 hours.

[0014] Furthermore, the extraction and impurity removal time is 20–28 hours.

[0015] Furthermore, the drying conditions are: pressure -0.09 to -0.10 MPa, temperature 50 to 70°C, and time 10 to 15 hours.

[0016] According to a second aspect of the present invention, the present invention provides the use of the catalyst described above in the preparation of 2,3-butanediol carbonate.

[0017] According to a third aspect of the present invention, the present invention provides a method for preparing 2,3-butanediol carbonate, the method comprising:

[0018] The catalyst described above and the stock solution of 2,3-butanediol carbonate were placed in a reactor. The reactor was sealed and high-purity nitrogen was introduced for purging to ensure the sealing of the reactor. 2,3-epoxybutane and carbon dioxide were introduced and reacted at a pressure of 2.0-4.0 MPa and a temperature of 200-230°C for 3-4 hours. 2,3-butanediol carbonate was obtained by separation and purification.

[0019] Further, the mass ratio of the catalyst to the 2,3-butanediol carbonate stock solution is 1:0.5-2; the mass ratio of the catalyst to 2,3-epoxybutane is 0.05-0.08:1; and the mass ratio of 2,3-epoxybutane to carbon dioxide is 1:0.7-0.9.

[0020] Furthermore, the specific process of separation and purification is as follows: the product after reaction is distilled at a pressure of -0.09 to -0.10 MPa and a temperature of 140 to 150 °C, and the obtained fraction is further distilled at a pressure of -0.09 to -0.10 MPa and a temperature of 150 to 180 °C to obtain 2,3-butanediol carbonate.

[0021] The embodiments of the present invention have the following advantages:

[0022] The catalyst of this invention consists of a specific amount of supramolecular onium salt ionic liquid-supported molecular sieve and titanium glycolate, with the raw materials exhibiting a synergistic effect. When applied to the preparation of 2,3-butanediol carbonate, this catalyst has the advantages of high catalytic activity and strong reaction selectivity, and can significantly improve the yield of 2,3-butanediol carbonate, showing good prospects for industrial application. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0024] The preparation method of the imidazole ionic liquid used in this invention can be found in the patent document CN 113578380A filed by the applicant on August 5, 2021.

[0025] As an example, the preparation method of the imidazole ionic liquid used in the following embodiments and comparative examples is as follows:

[0026] Step 1: Weigh (1.86 g, 7.10 mmol) 1,4-bis(1-chloropropoxy)benzene and dissolve it in 1.065 mol dichloromethane in a beaker. Stir and dissolve the solution, then pour the solution into the reactor.

[0027] Step 2: Add (0.132 g, 5.3 mmol) paraformaldehyde under nitrogen protection, adjust the stirring speed to 50 r / min, and stir for 1 h at room temperature (25 °C);

[0028] Step 3: Add 0.007 mmol of boron trifluoride diethyl ether to the above three-necked flask using a separatory funnel, heat to 20°C and stir for 4 hours;

[0029] Step 4: After the reaction is complete, pour the filtrate into a 0.852 mol methanol solution, filter and collect the solid, and dry it in a vacuum drying oven for 10 h to obtain a white solid;

[0030] Step 5: Add the above white solid to a three-necked flask to neutralize 71 mmol of 1-propylimidazole, adjust the rotation speed to 180 r / min, heat to 30 °C, stir for 18 h, filter and collect the filtrate;

[0031] Step 6: Pour the above filtrate into 0.852 mol diethyl ether for precipitation and purification. Repeat the washing five times to obtain a white solid, and then dry it.

[0032] The preparation method of supramolecular onium salt ionic liquid supported molecular sieves is as follows:

[0033] 400g of ZSM-5 mordenite and 400g of imidazole ionic liquid were placed in 2000ml of acetonitrile and refluxed for 24h. After cooling to room temperature, the acetonitrile was evaporated by rotary evaporation, and then Soxhlet extraction with dichloromethane was performed to remove impurities for 24h. After filtration, the resulting solid phase was placed in a vacuum drying oven and dried at -0.10Mpa and 50℃ for 12h to obtain 500g of supramolecular onium salt ionic liquid supported molecular sieve.

[0034] Example 1

[0035] This embodiment provides a catalyst, which is composed of 50g of supramolecular onium salt ionic liquid-supported molecular sieve and 50g of titanium glycol.

[0036] Example 2

[0037] This embodiment provides a catalyst, which is composed of 50g of supramolecular onium salt ionic liquid-supported molecular sieve and 25g of titanium glycol.

[0038] Example 3

[0039] This embodiment provides a catalyst that differs from Example 1 only in that it is composed of 50g of supramolecular onium salt ionic liquid-supported molecular sieve and 75g of titanium glycol.

[0040] Comparative Example 1

[0041] This comparative example provides a catalyst that differs from Example 1 in that it does not contain titanium glycol, but is only a supramolecular onium salt ionic liquid supported molecular sieve.

[0042] Comparative Example 2

[0043] This comparative example provides a catalyst that differs from Example 1 in that it does not contain supramolecular onium salt ionic liquid-supported molecular sieves, but is only titanium glycol.

[0044] Comparative Example 3

[0045] This comparative example provides a catalyst that differs from Example 1 in that the mass ratio of supramolecular onium salt ionic liquid supported molecular sieve to titanium glycol is different. In this comparative example, it is composed of 20g of supramolecular onium salt ionic liquid supported molecular sieve and 40g of titanium glycol.

[0046] Test Example 1

[0047] 24g of catalyst and 20g of 2,3-butanediol carbonate were placed in a reactor. The reactor was sealed and purged with high-purity nitrogen to ensure the reactor was airtight. 300g of 2,3-epoxybutane and 210g of carbon dioxide were sequentially introduced into the reactor using a metering pump. The temperature inside the reactor was controlled at 220℃ and the pressure at 3.0MPa. After reacting for 4 hours, distillation was carried out at -0.10MPa and 145-150℃. The distilled fraction was fed into a distillation column for rectification. The pressure in the distillation column was controlled at -0.099MPa and the temperature at 175-180℃. 2,3-butanediol carbonate was collected from the side stream.

[0048] 2,3-Butanediol carbonate was prepared using the catalysts of Examples 1-3 and Comparative Examples 1-3, respectively, according to the method described in this test example. The results are shown in Table 1 below.

[0049] Table 1

[0050]

[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing 2,3-butanediol carbonate, characterized in that, The method includes: The catalyst and the stock solution of 2,3-butanediol carbonate were placed in a reactor. The reactor was sealed and high-purity nitrogen was introduced for purging to ensure the sealing of the reactor. 2,3-epoxybutane and carbon dioxide were introduced and reacted at a pressure of 2.0-4.0 MPa and a temperature of 200-230℃ for 3-4 hours. 2,3-butanediol carbonate was obtained by separation and purification. The catalyst is composed of a mixture of supramolecular onium salt ionic liquid-supported molecular sieve and titanium glycol in a mass ratio of 1:0.5 to 1.

5. The preparation method of the supramolecular onium salt ionic liquid supported molecular sieve is as follows: Molecular sieves and imidazole ionic liquids were refluxed in acetonitrile, cooled to room temperature, and then acetonitrile was evaporated by rotary evaporation. The impurities were removed by Soxhlet extraction with dichloromethane, filtered, and the resulting solid phase was dried in a vacuum drying oven. The molecular sieves are of type A, type Y, type X, type ZSM-5, type SAB-15, and type MCM-41.

2. The method according to claim 1, characterized in that, The mass ratio of the supramolecular onium salt ionic liquid-supported molecular sieve to titanium glycol is 1:

1.

3. The method according to claim 1, characterized in that, The mass ratio of the molecular sieve to the imidazole ionic liquid is 0.8–1:1; and / or, The reflux condensation time is 20–28 hours; and / or, The extraction and impurity removal time is 20–28 hours.

4. The method according to claim 3, characterized in that, The drying conditions are: pressure -0.09 to -0.10 MPa, temperature 50 to 70°C, and time 10 to 15 hours.

5. The method according to claim 1, characterized in that, The mass ratio of the catalyst to the 2,3-butanediol carbonate stock solution is 1:0.5-2; the mass ratio of the catalyst to 2,3-epoxybutane is 0.05-0.08:1; and the mass ratio of 2,3-epoxybutane to carbon dioxide is 1:0.7-0.

9.

6. The method according to claim 1, characterized in that, The specific separation and purification process is as follows: the product after reaction is distilled at a pressure of -0.09 to -0.10 MPa and a temperature of 140 to 150 °C, and the obtained fraction is further distilled at a pressure of -0.09 to -0.10 MPa and a temperature of 150 to 180 °C to obtain 2,3-butanediol carbonate.

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