A method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane

Abstract

This invention relates to the field of compound synthesis technology, specifically to a method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane, comprising the following steps: adding an alkaline solution to a hexahydrol and stirring to disperse, obtaining a first solution; adding acrylonitrile and a phase transfer catalyst dropwise to the first solution to react, obtaining a second solution after the reaction is complete; filtering, washing, and drying the second solution to obtain the 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane product, wherein the phase transfer catalyst is an onium salt catalyst. This invention utilizes the conjugate addition reaction between hexahydrol and acrylonitrile under the synergistic catalysis of an alkaline solution and a phase transfer catalyst. The cation in the phase transfer catalyst combines with the hexahydrol oxygen anion through ion exchange to form an ion pair that readily combines with organic matter. This structure attacks acrylonitrile to undergo an addition reaction, improving reaction efficiency while effectively reducing side reactions resulting from incomplete substitution of the hydroxyl group, thus reducing the difficulty of product purification and increasing product yield.

Description

Technical Field

[0001] This invention relates to the field of compound synthesis technology, specifically to a method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane. Background Technology With the increasingly widespread application of lithium-ion batteries, the requirements for their energy density, cycle life, and safety performance are constantly increasing. As a core component of lithium-ion batteries, the performance optimization of the electrolyte is key to breaking through the battery performance bottleneck. Although electrolyte additives are used in trace amounts, they can significantly improve the overall battery performance, becoming one of the core directions for the technological upgrade of lithium-ion batteries.

[0002] 1,2,3,4,5,6-Hexa(2-cyanoethoxy)hexane, as a novel electrolyte additive for lithium-ion batteries, exhibits excellent electrochemical performance and interface regulation capabilities due to its unique molecular structure. Adding an appropriate amount of this compound to lithium-ion battery electrolytes can optimize multiple performance aspects: Firstly, it can specifically stabilize transition metals on the surface of the positive electrode active material of lithium-ion batteries, effectively reducing the oxidizability of high-valence transition metals, preventing electrode structure damage caused by the dissolution of transition metal ions, and reducing side reactions between the electrode and the electrolyte. Secondly, this compound preferentially undergoes oxidation on the electrode surface, forming a dense, stable, and highly conductive solid electrolyte interface film. Combined with its stabilizing effect on transition metals, this forms a dual protection mechanism for the electrode. This dual protection effectively inhibits electrolyte decomposition and high-temperature gas generation, significantly improving the high-temperature storage, cycling, float charging, and overcharge performance of lithium-ion batteries. It addresses the pain points of high-energy-density lithium-ion batteries, such as high-temperature gas generation, rapid cycle decay, and insufficient overcharge safety, providing a new path for the development of high-performance lithium-ion batteries.

[0003] Currently, there are few publicly available methods for synthesizing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane. Existing synthesis techniques either suffer from low reaction efficiency and low product purity, making it difficult to meet the demand for high-purity additives in industrial-scale production; or they use toxic and harmful raw materials or solvents during the synthesis process, generating a large amount of pollutants.

[0004] In summary, the demand for high-purity 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane is becoming increasingly urgent. There is a pressing need to develop a green, environmentally friendly, efficient, convenient, and cost-controllable synthesis method to solve the technical problems of low reaction efficiency, insufficient product purity, or serious pollution in existing synthesis technologies, and to realize the large-scale industrial production of this additive. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane.

[0006] This invention includes the following technical solutions: A method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane, comprising the following steps: S1 Add alkali solution to hexahydrol and stir to disperse, thus obtaining the first solution; S2. Acrylonitrile and a phase transfer catalyst are added dropwise to the first solution to carry out the reaction. After the reaction is completed, a second solution is obtained. S3 The second solution is filtered, rinsed, and dried to obtain 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane; The phase transfer catalyst is an onium salt catalyst.

[0007] Furthermore, in step S1, the mass of the alkaline solution is 50-70% of the mass of the hexahydrol.

[0008] Furthermore, in step S2, the amount of acrylonitrile added is 8 to 10 eq of the molar amount of the hexahydrol.

[0009] Furthermore, the amount of phase transfer catalyst added is 0.5% to 1% eq of the molar amount of the hexahydrol.

[0010] Furthermore, the phase transfer catalyst is any one of benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, tetrabutylammonium bromide, and trioctylmethylammonium chloride.

[0011] Furthermore, the hexahydrol is selected from any one of sweet alcohol, sorbitol, and mannitol.

[0012] Furthermore, the alkaline solution comprises an alkaline compound and a solvent, wherein the alkaline compound is selected from at least one of potassium hydroxide, lithium hydroxide, sodium hydroxide, and calcium hydroxide; and the solvent is a mixture of water and a hydroxyl-containing solvent.

[0013] Furthermore, the amount of the basic compound added is 15% to 20% eq of the molar amount of the hexahydrol.

[0014] Furthermore, the reaction temperature in step S2 is 10~20℃.

[0015] Furthermore, the solvent used for rinsing in step S3 is an ester-based organic solvent or an ether-based organic solvent.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1) This invention utilizes the conjugate addition reaction between hexahydrol and acrylonitrile under the synergistic catalysis of alkaline solution and phase transfer catalyst. The onium salt phase transfer catalyst (typically with the structure Q) + X -The cation (Q) in ) + Because of the presence of four tunable organic pairs, it can more precisely adapt to the complex spatial environment of hexahydrols, which is beneficial for binding with hexahydrol anions, which are easily soluble in alkaline water, through ion exchange. Furthermore, compared to crown ether phase transfer catalysts that rely on structural cavities to recognize specific ions, onium salt phase transfer catalysts rely on charge attraction to form an ion pair that easily binds to organic matter. + ][ - [O-hexahydrols], this approach is better suited to the complex results of hexahydrols. Ion pairs [Q + ][ - [O-hexahydrol] then attacks acrylonitrile to undergo an addition reaction, forming a cation again (Q). + The repeated cycles improve reaction efficiency while effectively reducing side reactions where hydroxyl groups are not completely replaced, thus reducing the difficulty of product purification and increasing product yield.

[0017] 2) By controlling the quality of the alkaline solution, this invention effectively avoids the problem of excessive solvent causing oxygen anions in the solvent to compete with catalyst cations and affect the process of catalyst cations combining with hexahydrol oxygen anions, thereby improving product yield.

[0018] 3) This invention prepares 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane by controlling the reaction temperature at a low temperature (10~20℃). The low temperature condition can effectively suppress side reactions such as acrylonitrile hydrolysis, self-polymerization and incomplete substitution, greatly reduce the generation of impurities, thereby significantly reducing the difficulty of product purification and efficiently preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane with high yield and high purity. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 protection scope of the present invention.

[0020] This invention provides a method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane, comprising the following steps: S1 Add alkali solution to hexahydrol and stir to disperse, thus obtaining the first solution; S2. Acrylonitrile and a phase transfer catalyst are added dropwise to the first solution to carry out the reaction. After the reaction is completed, a second solution is obtained. S3 The second solution is filtered, rinsed, and dried to obtain 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane; The phase transfer catalyst is an onium salt catalyst.

[0021] This invention utilizes a conjugate addition reaction between hexahydrol and acrylonitrile under alkaline conditions and a phase transfer catalyst to prepare 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane. The alkaline solution, acting as the alkaline medium of the reaction system, deprotonates the hydroxyl groups in the hexahydrol molecule, generating a strongly nucleophilic oxygen anion, providing a key active species for the subsequent addition reaction. The phase transfer catalyst acts as an important interfacial bridge; its cations can form stable ion pairs with the hexahydrol oxygen anion in the aqueous phase through ion exchange. These ion pairs are both hydrophilic and hydrophobic, enabling them to successfully cross the water-organic phase interface, allowing the oxygen anion, which would otherwise be difficult to enter the organic phase, to fully contact acrylonitrile. Subsequently, the oxygen anion, acting as a nucleophile, actively attacks the electrophilic carbon-carbon double bond in the acrylonitrile molecule, undergoing a nucleophilic addition reaction, gradually replacing all the hydroxyl groups in the hexahydrol molecule to generate the target product, 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane.

[0022] When conventional addition reactions are performed without catalysis or with only base catalysis, the two-phase reaction between the aqueous hexaol and the organic acrylonitrile exhibits low mass transfer efficiency and is prone to side reactions involving incomplete substitution of hydroxyl groups, resulting in low product purity and significant purification difficulties. This invention employs onium salt catalysts, specifically onium salt phase transfer catalysts (typically with a Q... + X - The cation (Q) in ) + Because of the presence of four tunable organic pairs, it can more precisely adapt to the complex spatial environment of hexahydrols, which is beneficial for binding with hexahydrol anions, which are easily soluble in alkaline water, through ion exchange. Furthermore, compared to crown ether phase transfer catalysts that rely on structural cavities to recognize specific ions, onium salt phase transfer catalysts rely on charge attraction to form an ion pair that easily binds to organic matter. + ][ - [O-hexahydrols], this approach is better suited to the complex results of hexahydrols. Ion pairs [Q + ][ - [O-hexahydrol] then attacks acrylonitrile to undergo an addition reaction, forming a cation again (Q). + The repeated cycles improve reaction efficiency while effectively reducing side reactions where hydroxyl groups are not completely replaced, thus reducing the difficulty of product purification and increasing product yield.

[0023] Specifically, in some embodiments of the present invention, the onium salt catalyst includes at least one of benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, tetrabutylammonium bromide, and trioctylmethylammonium chloride.

[0024] Specifically, in some embodiments of the present invention, in step S1, the mass of the alkaline solution is 50-70% of the mass of the hexahydrol. More specifically, the mass of the alkaline solution is a range of 50%, 52%, 54%, 55%, 57%, 59%, 60%, 62%, 64%, 65%, 67%, 69%, 70% of the mass of the hexahydrol, or any combination thereof. By controlling the mass of the alkaline solution, the amount of solvent added can be controlled, effectively avoiding the situation where excessive solvent causes oxygen anions in the solvent to compete with catalyst cations, affecting the process of the combination of catalyst cations and hexahydrol oxygen anions, thus improving the product yield.

[0025] Specifically, in some embodiments of the present invention, in step S2, the amount of acrylonitrile added is 8 to 10 eq of the molar amount of hexahydrol; eq represents molar equivalent, and 1 eq represents the amount of substance equivalent to the substrate; that is, the molar amount of acrylonitrile is 8 to 10 times the molar amount of hexahydrol. More specifically, the amount of acrylonitrile added is a range of 8 eq, 8.2 eq, 8.4 eq, 8.5 eq, 8.7 eq, 9 eq, 9.2 eq, 9.4 eq, 9.5 eq, 9.7 eq, 9.9 eq, 10 eq of the molar amount of hexahydrol, or any combination thereof.

[0026] Specifically, in some embodiments of the present invention, the amount of phase transfer catalyst added is 0.5% to 1% eq of the molar amount of hexahydrol; eq represents molar equivalent, and 1 eq represents an amount equivalent to the substrate; that is, the molar amount of the phase transfer catalyst is 0.5% to 1% of the molar amount of hexahydrol. More specifically, the amount of phase transfer catalyst added is a range of 0.5% eq, 0.6% eq, 0.7% eq, 0.8% eq, 0.9% eq, 1% eq, or any combination thereof of the molar amount of hexahydrol.

[0027] Specifically, in some embodiments of the present invention, the reaction in step S2 is monitored using liquid chromatography-mass spectrometry (LC-MS) to determine whether the reaction has ended. More specifically, the reaction is considered complete when the product purity in the system reaches 80%.

[0028] Specifically, in some embodiments of the present invention, the hexahydrol is selected from at least one of sweet alcohol, sorbitol, and mannitol.

[0029] Specifically, in some embodiments of the present invention, the alkaline solution comprises an alkaline compound and a solvent, wherein the alkaline compound is selected from at least one of potassium hydroxide, lithium hydroxide, sodium hydroxide, and calcium hydroxide; and the solvent is a mixture of water and a hydroxyl-containing solvent. By selecting a mixture of water and a hydroxyl-containing solvent, the present invention reduces the amount of water solvent used, thereby reducing the probability of the cyanohydrolysis side reaction of acrylonitrile. Simultaneously, the use of an organic solvent allows for recovery and reuse after distillation, reducing costs. Preferably, the solvent is a mixture of water and methanol or water and ethanol.

[0030] Specifically, in some embodiments of the present invention, the amount of the basic compound added is 15% to 20% eq of the molar amount of the hexahydrol; eq represents molar equivalent, and 1 eq represents an amount equivalent to the substrate; that is, the molar amount of the basic compound accounts for 15% to 20% of the molar amount of the hexahydrol. More specifically, the amount of the basic compound added is a range of 15% eq, 16% eq, 17% eq, 18% eq, 19% eq, 20% eq of the molar amount of the hexahydrol, or any combination thereof.

[0031] Specifically, in some embodiments of the present invention, the reaction temperature in step S2 is 10-20°C. Low-temperature control effectively avoids the hydrolysis reaction of acrylonitrile to generate byproducts such as acrylamide and acrylic acid, and also inhibits side reactions such as acrylonitrile self-polymerization, hexahydrol oxyanion polymerization, and incomplete hydroxyl substitution, thereby significantly improving reaction efficiency, reducing impurity formation, lowering the difficulty of product purification, and ultimately effectively improving product yield and purity. More specifically, the reaction temperature is within the range of 10°C, 12°C, 14°C, 15°C, 17°C, 19°C, 20°C, or any combination thereof. Preferably, the reaction temperature is 15-20°C.

[0032] Specifically, in some embodiments of the present invention, in step S3, the drying temperature is 100~200℃. Specifically, the drying temperature is a range of 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, or any combination thereof.

[0033] Specifically, in some embodiments of the present invention, the solvent used for rinsing in step S3 is an ester-based organic solvent or an ether-based organic solvent.

[0034] Preferably, the solvent used for rinsing is selected from at least one of dimethyl carbonate and ethylene glycol dimethyl ether. This invention uses dimethyl carbonate as the rinsing solvent, which can be recycled after distillation, reducing production costs; simultaneously, dimethyl carbonate is a commonly used solvent in electrolytes, and its introduction will not introduce exogenous impurities. Given that 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane is mainly used in battery electrolytes, this selection significantly reduces the adverse effects on the quality of the final product.

[0035] In some embodiments of the present invention, taking a sweet alcohol as an example, the sweet alcohol reacts with acrylonitrile as follows: Under alkaline conditions, the hydroxyl group of selenool is deprotonated to form a selenool anion; catalyzed by onmium salt catalysts, its cation (Q... + ) undergoes ion exchange with the sweet alcohol oxygen anion in the aqueous phase to form a lipid-soluble ion pair [Q + ][ - [O-Sweet Alcohol], this ion undergoes a conjugate addition reaction to attack the α,β-unsaturated double bond of acrylonitrile; by controlling the low-temperature reaction, the cyano hydrolysis side reaction of acrylonitrile is avoided; at the same time, the phase transfer effect of the phase-shifting catalyst is used to solve the mass transfer barrier of the two-phase reaction, which greatly improves the reaction efficiency, effectively reduces the side reaction of incomplete substitution of hydroxyl groups, reduces the difficulty of product purification, and significantly improves the yield and purity of the target product.

[0036] The preparation method of 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane of the present invention will be further described below with reference to specific embodiments.

[0037] Example 1 The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane in this embodiment includes the following steps: S1 Add 0.1 mol of sodium hydroxide to an aqueous solution containing 40% ethanol, dissolve 91 g (0.5 mol) of sweet alcohol in 56 g of sodium hydroxide solution containing 40% ethanol, and start stirring (15°C) to obtain the first solution; S2 Slowly add 212g (4mol) of acrylonitrile to the first solution, then add 0.5eq% (1.01g) of trioctylmethylammonium chloride, which accounts for 0.5 eq% of the molar amount of sweet alcohol. Control the reaction temperature at 20℃ and monitor the reaction process using LC-MS. After the reaction is completed, the second solution is obtained. S3 The second solution is filtered, and the filtrate is washed twice with dimethyl carbonate. The crude product is then filtered a second time, and the filter cake is dried at 150°C to obtain 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane.

[0038] In this embodiment, the purity of the 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane product was 99.9%, and the yield was 94.5%.

[0039] Examples 2-22 and Comparative Examples 1-5 The preparation methods of 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane in this embodiment and the comparative example include most of the operation steps in Example 1 above, the difference being the different parameters in Tables 1-4.

[0040] The 1,2,3-tris(cyanoethoxy)propane prepared in the examples and comparative examples was tested, and the results are shown in Tables 1-4.

[0041] Table 1 shows some parameters and test results of Examples 1-14 and Comparative Examples 1-2. The only difference between Examples 2-14, Comparative Examples 1-2 and Example 1 is the parameters in Table 1.

[0042] Table 1 Note: The acrylonitrile addition (eq) and phase transfer catalyst addition (eq) in the table refer to their proportion relative to the molar amount of hexahydrol. " / " indicates that the item is not included.

[0043] As can be seen from the test results in Table 1, the method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane of the present invention, through the conjugate addition reaction of hexahydrol and acrylonitrile under the synergistic catalysis of alkaline solution and onium salt phase transfer catalyst, can effectively reduce the occurrence of side reactions resulting in incomplete substitution of hydroxyl groups, thereby reducing the difficulty of product purification and improving product yield. If only alkaline solution catalysis or only phase transfer catalyst is used, the two-phase reaction mass transfer efficiency between the aqueous phase hexahydrol and the organic phase acrylonitrile is low, and side reactions of incomplete substitution of hydroxyl groups are prone to occur, resulting in low product purity and high purification difficulty.

[0044] Meanwhile, the test results of Examples 1-5 and Examples 6-9 show that when the mass of the alkaline solution is further limited to 50-70% of the mass of hexahydrol or the amount of alkaline compound added is 15-20% eq of the molar mass of hexahydrol, the process of the catalyst cation combining with the hexahydrol oxygen anion due to excessive solvent can be effectively avoided, thus improving the product yield. The test results of Examples 1-5 and Examples 10-13 show that when the amount of acrylonitrile added is further limited to 8-10 eq of the molar mass of hexahydrol or the amount of phase transfer catalyst added is 0.5-1% eq of the molar mass of hexahydrol, the catalysis of the conjugate addition reaction by the onium salt catalyst can be fully realized, and the product yield and purity are further improved.

[0045] As can be seen from the test results of Examples 1-5 and Example 14, the reaction temperature is controlled at 10~20℃. Low temperature conditions can effectively avoid the generation of by-products and the occurrence of side reactions, thereby significantly improving reaction efficiency, reducing impurity generation, reducing the difficulty of product purification, and ultimately effectively improving product yield and purity.

[0046] Table 2 shows some parameters and test results of Examples 1 and 15-16. The only difference between Examples 15-16 and Example 1 is the type of hexahydrol.

[0047] Table 2 As can be seen from the test results in Table 2, the method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane of the present invention, through the conjugate addition reaction of hexahydrol and acrylonitrile under the synergistic catalysis of alkaline solution and onium salt phase transfer catalyst, can produce high-purity and high-yield 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane products for different types of hexahydrols, indicating that the preparation method of the present invention is universally applicable to different hexahydrols.

[0048] Table 3 shows some parameters and test results of Examples 1 and 17-19. The only difference between Examples 17-19 and Example 1 is the type of hexahydrol.

[0049] Table 3 As can be seen from the test results in Table 3, the method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane of the present invention, which is prepared by conjugate addition reaction of hexahydrol and acrylonitrile under the synergistic catalysis of alkaline solution and onium salt phase transfer catalyst, can produce high-purity and high-yield 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane products for different types of basic compounds, indicating that the preparation method of the present invention is universally applicable to different basic compounds.

[0050] Table 4 shows some parameters and test results of Examples 1, 20-22, and Comparative Examples 3-5. The only difference between Examples 20-22, Comparative Examples 3-5 and Example 1 is the type of phase transfer catalyst.

[0051] Table 4 As shown in Table 4, the preparation method of 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane of the present invention, through the conjugate addition reaction of hexahydrol and acrylonitrile under the synergistic catalysis of alkaline solution and onmium salt phase transfer catalyst, yields high-purity and high-yield 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane for different types of onmium salt catalysts, indicating that the preparation method of the present invention is universally applicable to different onmium salt catalysts. The test results of Examples 1, 20-22, and Comparative Examples 3-5 show that, compared with onmium salt catalysts, other types of phase transfer catalysts have poor catalytic effects on the reaction of hexahydrol and acrylonitrile in the preparation method of the present invention, resulting in more side reactions and byproducts, and reduced product purity and yield.

[0052] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane, characterized in that, Includes the following steps: S1 Add alkali solution to hexahydrol and stir to disperse, thus obtaining the first solution; S2. Acrylonitrile and a phase transfer catalyst are added dropwise to the first solution to carry out the reaction. After the reaction is completed, a second solution is obtained. S3 The second solution is filtered, rinsed, and dried to obtain 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane; The phase transfer catalyst is an onium salt catalyst.

2. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, In step S1, the mass of the alkaline solution is 50-70% of the mass of the hexahydrol.

3. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, In step S2, the amount of acrylonitrile added is 8 to 10 eq of the molar amount of the hexahydrol.

4. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The amount of phase transfer catalyst added is 0.5% to 1% eq of the molar amount of the hexahydrol.

5. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The phase transfer catalyst is any one of benzyltriethylammonium chloride, tetrabutylammonium bisulfate, tetrabutylammonium bromide, and trioctylmethylammonium chloride.

6. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The hexahydrol is selected from any one of sweet alcohol, sorbitol, and mannitol.

7. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The alkaline solution comprises an alkaline compound and a solvent, wherein the alkaline compound is selected from at least one of potassium hydroxide, lithium hydroxide, sodium hydroxide, and calcium hydroxide; and the solvent is a mixture of water and a hydroxyl-containing solvent.

8. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 7, characterized in that, The amount of the basic compound added is 15% to 20% eq of the molar amount of the hexahydrol.

9. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The reaction temperature in step S2 is 10~20℃.

10. The method for preparing 1,2,3,4,5,6-hexa(2-cyanoethoxy)hexane according to claim 1, characterized in that, The solvent used for rinsing in step S3 is an ester-based organic solvent or an ether-based organic solvent.

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