Method for preparing bis-(2-cyanoethoxy) compound

Abstract

A method for preparing a compound represented by the following chemical formula 1 according to one embodiment of the present invention comprises: a step of preparing a mixture comprising a diol (-diol) compound, acrylonitrile, and a tertiary amine as a base; and a step of heating the prepared mixture: In the above chemical formula 1, L is a divalent hydrocarbon group having 20 or fewer carbon atoms that is substituted or unsubstituted, a divalent heterohydrocarbon group in which one or more carbons in the chain of the divalent hydrocarbon group are replaced with a heteroatom of N, O, P, or S, a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons in the chain of the divalent hydrocarbon group, or a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons or heteroatoms in the chain of the divalent heterohydrocarbon group.

Description

Technology Field

[0001] The present invention relates to a method for preparing a bis-(2-cyanoethoxy) compound. Background Technology

[0003] To produce a bis-(2-cyanoethoxy)ethane (1,2-bis-(2-cyanoethoxy)ethane) compound, the conventional process involves reacting ethylene glycol with acrylonitrile under an alkali metal base catalyst, then extracting and removing the alkali metal base with water or an aqueous solution containing water, and purifying the organic layer by distillation to obtain bis-(2-cyanoethoxy)ethane (1,2-bis-(2-cyanoethoxy)ethane).

[0004] However, this existing process has a problem in that it is difficult to reduce the residual concentration of the alkali metal used as a base catalyst in the generated bis-(2-cyanoethoxy)ethane (1,2-bis-(2-cyanoethoxy)ethane) compound, and due to the reverse reaction caused by the residual alkali metal base catalyst, the bis-(2-cyanoethoxy)ethane (1,2-bis-(2-cyanoethoxy)ethane) compound is decomposed into 3-(2-hydroxyethoxy)propanenitrile during distillation purification, making it difficult to obtain a high-purity bis-(2-cyanoethoxy)ethane (1,2-bis-(2-cyanoethoxy)ethane) compound. The problem to be solved

[0006] In order to solve the above problems, as one objective of the present invention, we intend to provide a method for producing a bis-(2-cyanoethoxy) compound that has high purity and can maintain a low alkali metal content. means of solving the problem

[0008] A method for preparing a compound represented by the following chemical formula 1 according to one embodiment of the present invention comprises the steps of: preparing a mixture comprising a diol (-diol) compound, acrylonitrile, and a tertiary amine as a base; and heating the prepared mixture.

[0009] <Chemical Formula 1>

[0010]

[0011] In the above chemical formula 1, L is a divalent hydrocarbon group having 20 or fewer carbon atoms that is substituted or unsubstituted, a divalent heterohydrocarbon group in which one or more carbons in the chain of the divalent hydrocarbon group are replaced with a heteroatom of N, O, P, or S, a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons in the chain of the divalent hydrocarbon group, or a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons or heteroatoms in the chain of the divalent heterohydrocarbon group.

[0012] In one embodiment, the diol (-diol) compound is ethylene glycol, and the compound represented by Chemical Formula 1 may be 1,2-bis(2-cyanoethoxy)ethane represented by Chemical Formula 1-1 below.

[0013] <Chemical Formula 1-1>

[0014] .

[0015] In one embodiment, acrylonitrile may be included in the mixture in an amount of 2.0 equivalents or more relative to the diol compound.

[0016] In one embodiment, the tertiary amine may be one or more selected from compounds represented by the following chemical formulas A-1 to A-7.

[0017] [Chemical Formula A-1]

[0018]

[0019] [Chemical Formula A-2]

[0020]

[0021] [Chemical Formula A-3]

[0022]

[0023] [Chemical Formula A-4]

[0024]

[0025] [Chemical Formula A-5]

[0026]

[0027] [Chemical Formula A-6]

[0028]

[0029] [Chemical Formula A-7]

[0030]

[0031] In one embodiment, a method for preparing a compound represented by Chemical Formula 1 may further include the steps of: acid-treating the heated mixture; separating and removing the aqueous layer from the acid-treated mixture; and purifying the organic layer from the mixture from which the aqueous layer has been removed to obtain a product.

[0032] In one embodiment, the purity of the obtained product may be 98.0% or higher.

[0033] An electrolyte for a secondary battery according to one embodiment of the present invention may include a bis-(2-cyanoethoxy) compound produced by the above manufacturing method. Effects of the invention

[0035] As one effect of the present invention, a method for producing a bis-(2-cyanoethoxy) compound is provided, which has high purity and can maintain a low alkali metal content. Specific details for implementing the invention

[0037] Expressions such as "comprising" as used in this specification should be understood as open-ended terms implying the possibility of including other configurations.

[0038] As used herein, "preferably" and "preferably" refer to embodiments of the present invention that can provide certain advantages under certain conditions. However, it is not intended to exclude other embodiments from the scope of the present invention.

[0039] The singular form used in this specification is intended to include the plural form unless specifically indicated otherwise in the context.

[0040] The numerical ranges used in this specification include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of numerical ranges limited in different forms.

[0041] Unless otherwise specifically defined in this specification, values ​​outside the numerical range that may occur due to experimental error or rounding are also included in the defined numerical range.

[0043] Meanwhile, the technical features described below relate to an embodiment that obtains the desired effect of the present invention described above. That is, a method for producing a bis-(2-cyanoethoxy) compound according to an embodiment of the present invention can produce an effect of the present invention by including the technical features according to an embodiment described below.

[0045] The present invention relates to a method for preparing a bis-(2-cyanoethoxy) compound represented by the following chemical formula 1.

[0046] <Chemical Formula 1>

[0047]

[0048] In the above chemical formula 1, L is a divalent hydrocarbon group having 20 or fewer carbon atoms that is substituted or unsubstituted, a divalent heterohydrocarbon group in which one or more carbons in the chain of the divalent hydrocarbon group are replaced with a heteroatom of N, O, P, or S, a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons in the chain of the divalent hydrocarbon group, or a divalent organic group further comprising a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons or heteroatoms in the chain of the divalent heterohydrocarbon group.

[0049] In one embodiment, the above L may be a substituted or unsubstituted divalent hydrocarbon with 20 or fewer carbon atoms.

[0050] In this specification, "hydrocarbon group" refers to a cyclic or chain-type, straight-chain or branched-chain hydrocarbon group, which may mean a saturated hydrocarbon with a carbon-carbon single bond, an unsaturated hydrocarbon with a double or triple bond, or an aromatic hydrocarbon group, and may be, for example, alkylene, alkenylene, alkynylene, arylene, aralkylene, aralkenylene, or alkylarylene.

[0051] In another embodiment, the above L may be a divalent heterohydrocarbon in which one or more carbons in the chain of the above divalent hydrocarbon are replaced with heteroatoms of N, O, P, or S.

[0052] In another embodiment, the divalent organic group may further comprise a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to one or more carbons or heteroatoms in the chain of the divalent heterohydrocarbon group.

[0053] In another embodiment, the divalent organic group may further comprise a carbonyl group (-(C=O)-) or an ester group (-(OC=O)-) connected to any one or more carbons or heteroatoms in the chain of the divalent heterohydrocarbon group.

[0054] In this specification, the meaning of “substituted or unsubstituted” is that it is substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; halogen group; nitrile group; nitro group; hydroxyl group; carbonyl group; ester group; imide group; amino group; phosphine oxide group; alkoxy group; aryloxy group; alkyl sulfoxy group; aryl sulfoxy group; silyl group; boron group; alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; alkylaryl group; alkylamine group; aralkylamine group; heteroarylamine group; arylamine group; arylphosphine group; or heterocyclic group, or is substituted or unsubstituted with two or more of the exemplified substituents connected. For example, “a substituent with two or more connected substituents” may be a biphenyl group. That is, the biphenyl group can be an aryl group or can be interpreted as a substituent in which two phenyl groups are connected.

[0055] As an example, the above L may be an organic group of the following 2.

[0056]

[0057] More preferably, the compound represented by the above chemical formula 1 may be 1,2-bis(2-cyanoethoxy)ethane (1,2-bis(2-cyanoethoxy)ethane, DPN) represented by the following chemical formula 1-1.

[0058] <Chemical Formula 1-1>

[0059] .

[0060] To prepare the compound represented by the above chemical formula 1, a mixture comprising a diol (-diol) compound, acrylonitrile, and a tertiary amine as a base can first be prepared.

[0061] In one embodiment, the diol (-diol) compound may be a compound in which hydroxyl groups are bonded to both ends of the divalent organic group L. Examples include ethylene glycol, butylene glycol, or diethylene glycol.

[0062] In a more preferred embodiment, when the diol (-diol) compound is ethylene glycol, the compound represented by Chemical Formula 1 may be 1,2-bis(2-cyanoethoxy)ethane represented by Chemical Formula 1-1 below.

[0063] <Chemical Formula 1-1>

[0064] .

[0065] In one embodiment, acrylonitrile in the mixture may be included in an amount of 2.0 equivalents or more, 3.0 equivalents or more, 5.0 equivalents or less, or 4.0 equivalents or less relative to the diol compound.

[0066] The above tertiary amine can act as a base catalyst.

[0067] More preferably, the tertiary amine may be a cyclic tertiary amine, in which case it can further promote the reactivity of the diol (-diol) compound and acrylonitrile.

[0068] In a more preferred embodiment, the tertiary amine may be one or more selected from compounds represented by the following chemical formulas A-1 to A-7.

[0069] [Chemical Formula A-1]

[0070]

[0071] [Chemical Formula A-2]

[0072]

[0073] [Chemical Formula A-3]

[0074]

[0075] [Chemical Formula A-4]

[0076]

[0077] [Chemical Formula A-5]

[0078]

[0079] [Chemical Formula A-6]

[0080]

[0081] [Chemical Formula A-7]

[0082]

[0083] The present invention can suppress the decomposition reaction into 3-(2-hydroxyethoxy)propanenitrile and significantly reduce the metal content in the bis-(2-cyanoethoxy) produced by using a tertiary amine instead of an alkali metal base as a conventional base to carry out the reaction.

[0084] In one embodiment, the mechanism by which the decomposition reaction is suppressed by using the tertiary amine as a base catalyst can be explained by the following reaction scheme 2.

[0085] [Reaction Equation 2]

[0086]

[0087] To explain this, when using alkali metal bases such as LiOH, KOH, or t-Bu-OK, if the alkali metal base is to be removed with an acidic aqueous solution after the reaction is finished, the alkali metal base is not completely removed and some remains due to the metal chelating effect, which is an inherent characteristic of the product, bis-(2-cyanoethoxy) compound. Furthermore, when attempting to purify the obtained organic layer by distillation, the residual alkali metal base acts as a catalyst for the reverse reaction (decomposition reaction) upon heating, which causes a significant decrease in chemical purity and also causes an increase in the metal content of the final product.

[0088] However, according to one embodiment of the present invention, when a tertiary amine base is used, when the tertiary amine is to be removed with an acidic aqueous solution after the reaction is finished, the tertiary amine base is completely removed without interference from the product, bis-(2-cyanoethoxy) compound. In addition, when the obtained organic layer is to be purified by distillation, the progress of the reverse reaction (decomposition reaction) is suppressed, so a high-purity product can be obtained and a product with a significantly low metal content can be obtained.

[0089] Next, after the step of preparing the mixture, the step of heating the prepared mixture can be performed.

[0090] When the above mixture is heated, the reaction according to the following reaction scheme 1 may proceed.

[0091] [Reaction Equation 1]

[0092]

[0093] In the above reaction formula 1, L is as defined in the above chemical formula 1.

[0094] Acrylonitrile reacts with the above-mentioned diol (-diol) compound under tertiary amine base conditions to produce a compound represented by the above-mentioned chemical formula 1.

[0095] In one embodiment, the heating step may be performed at a temperature of 30°C to 100°C, more preferably 40°C to 80°C. When the reaction is carried out by heating in the above temperature range, side reactions are suppressed, the reaction rate is appropriate, and the reaction can be carried out with maximum efficiency.

[0096] In addition, as one embodiment, the heating step may be performed for 4 to 8 hours, or 5 to 6 hours.

[0097] Next, the step of acid-treating the heated mixture can be further performed.

[0098] At this time, the acid treatment can be performed by adding an aqueous solution of an organic acid or an inorganic acid.

[0099] As an example, the organic acid may be a carboxylic acid, sulfinic acid, sulfonic acid, phenol, thiophenol, oxime, enol, imide, aromatic sulfonamide, primary and secondary nitro compound, but is not particularly limited thereto.

[0100] As an example, the above inorganic acid may be hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, boric acid, hydrofluoric acid, hydrobromide, and carbonic acid, but is not specifically limited thereto.

[0101] As a more desirable example, the inorganic acid may be hydrochloric acid or sulfuric acid.

[0102] Next, a step of separating and removing the aqueous layer from the acid-treated mixture can be performed.

[0103] By the neutralization process by the above acid treatment, a tertiary amine salt compound in the form of salt is formed, and since the tertiary amine salt is dissolved in the aqueous layer, the tertiary amine salt can be removed by separating the organic layer and the aqueous layer and removing the aqueous layer.

[0104] Next, a step of purifying the organic layer from the mixture from which the above water layer has been removed to obtain a product can be performed.

[0105] In a more preferred embodiment, the purification may be purification by distillation.

[0106] In one embodiment, the purity of the obtained product may be 98.0% or more, 98.5% or more, 99.0% or more, or 99.5% or more.

[0107] In one embodiment, the purity of the compound produced above may be 98.0% or more, 98.5% or more, 99.0% or more, or 99.5% or more.

[0108] Meanwhile, in the present invention, the purity analysis method measured the purity through a GC analysis method. More specifically, it refers to the ratio of the area occupied by the substance to the total GC area of ​​the entire composition.

[0109] In one embodiment, the total content of metal included in the obtained product may be 10 ppm or less, 5 ppm or less, 3 ppm or less, 1 ppm or less, or 0.5 ppm or less relative to the total content of the obtained product.

[0110] The total content of metal included in the compound being manufactured above may be 10 ppm or less, 5 ppm or less, 3 ppm or less, 1 ppm or less, or 0.5 ppm or less relative to the total content of the compound being manufactured.

[0111] In the present invention, the metal content measurement method used ICP-MS to measure the metal content.

[0112] An electrolyte for a secondary battery according to one embodiment of the present invention may include a bis-(2-cyanoethoxy) compound produced by the above manufacturing method. The bis-(2-cyanoethoxy) compound produced in the present invention has high purity and significantly reduced metal content, so it may be useful as an additive to an electrolyte for a secondary battery.

[0114] The present invention will be explained in more detail below through examples.

[0116] [Example 1]

[0117] 100 g (1.61 mol) of ethylene glycol, 342 g (6.4 mol) of acrylonitrile, and 7.6 g (0.05 mol) of the base (DBU) of formula A-1 were mixed in a reactor and heated at 50 ℃ for 6 hours.

[0118] Next, 100 mL of 1 N concentration HCl aqueous solution was added and stirred, and the aqueous layer was separated and removed.

[0119] Next, the obtained organic layer was obtained by distilling an initial excess amount of acrylonitrile (approximately 160 g) under a vacuum system (high vacuum oil pump, 0.9 mmHg) equipped with a distillation glass set, then removing a small amount of product (130 °C) and purifying 244 g of the main product (90% yield).

[0120] The obtained product was analyzed by GC and confirmed to have a purity of 99.6%.

[0121] In addition, the metal content was analyzed using ICP-MS, and it was confirmed that the total metal content was 0.12 ppm.

[0123] [Example 2]

[0124] In the above Example 1, the process was carried out in the same manner as Example 1, using the base of Formula A-2 (DBN) instead of the base of Formula A-1 (DBU).

[0125] The obtained product was confirmed to have a yield of 91%, a purity of 99.5%, and a total metal content of 0.17 ppm.

[0127] [Example 3]

[0128] In the above Example 1, the same procedure as in Example 1 was performed using the base of Formula A-3 (DABCO) instead of the base of Formula A-1 (DBU).

[0129] The obtained product was confirmed to have a yield of 85%, a purity of 99.2%, and a total metal content of 0.25 ppm.

[0131] [Comparative Example 1]

[0132] In the above Example 1, LiOH was used instead of the base (DBU) of Formula A-1, and the process was carried out in the same manner as in Example 1.

[0133] The obtained product was confirmed to have a yield of 94%, a purity of 98.5%, and a total metal content of 11.4 ppm.

[0135] [Comparative Example 2]

[0136] In the above Example 1, KOH was used instead of the base (DBU) of Formula A-1, and the process was carried out in the same manner as in Example 1.

[0137] The obtained product was confirmed to have a yield of 91%, a purity of 97.8%, and a total metal content of 15.7 ppm.

[0139] It was confirmed that when the tertiary amine bases of Examples 1 to 3 were used, compared to when the alkali metal bases of Comparative Examples 1 to 2 were used, equivalent yield, excellent purity, and excellent metal content of the product could be obtained.

Claims

Claim 1 A method for preparing a compound represented by the following chemical formula 1-1, comprising the steps of: preparing a mixture comprising ethylene glycol, acrylonitrile, and a tertiary amine as a base; heating the prepared mixture; acid-treating the heated mixture; separating and removing an aqueous layer from the acid-treated mixture; and purifying the organic layer from the mixture from which the aqueous layer has been removed to obtain a product; wherein the tertiary amine salt is removed when separating and removing the aqueous layer from the acid-treated mixture, and the total metal content contained in the obtained product is 10 ppm or less. <Chemical Formula 1-1> . Claim 2 delete Claim 3 A method for preparing a bis-(2-cyanoethoxy) compound according to claim 1, wherein the prepared mixture contains at least 2.0 equivalents of acrylonitrile relative to ethylene glycol. Claim 4 Method for preparing a bis-(2-cyanoethoxy) compound according to claim 1, wherein the tertiary amine is one or more selected from compounds represented by the following chemical formulas A-1 to A-7: [Chemical Formula A-1] [Chemical Formula A-2] [Chemical Formula A-3] [Chemical Formula A-4] [Chemical Formula A-5] [Chemical Formula A-6] [Chemical Formula A-7] Claim 5 delete Claim 6 A method for preparing a bis-(2-cyanoethoxy) compound according to claim 1, wherein the purity of the obtained product is 98.0% or higher. Claim 7 An electrolyte for a secondary battery comprising a bis-(2-cyanoethoxy) compound produced by the manufacturing method of claim 1.

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