A process for the preparation of 1,3,2-dioxathiolane-2-oxide-4-carboxylate

Abstract

The application discloses a preparation method of 1,3,2-dioxathiolane-2-oxide-4-carboxylate, which comprises the following steps: one, mixing and stirring halogenated hydrocarbon, solvent 1 and alkali and heating, the reaction temperature is 70-80 DEG C, stirring for 2-4 hours, dropwise adding a mixed solution of solvent 1 and epoxyethyl formic acid, filtering after the reaction is completed, removing solvent 1 from the filtrate under reduced pressure to obtain the product of step one; two, putting the product of step one, solvent 2 and a catalyst into a high-pressure reaction kettle, introducing sulfur dioxide and heating, the reaction temperature is 100-120 DEG C, washing the reaction liquid with ice water after the reaction is completed, drying after adding anhydrous sodium sulfate, removing 50-70% of solvent 2 under reduced pressure, adding n-hexane to crystallize, filtering and drying to obtain the finished product. The preparation method has the advantages of simple process route, few steps, low purification difficulty, high product purity (more than 99%) and the like, and can be used as an additive of lithium ion battery electrolyte.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery electrolyte additives, specifically to a method for preparing 1,3,2-dioxane-2-oxide-4-carboxylic acid ester. Background Technology

[0002] In recent years, with the increasing awareness of environmental protection, research on high-energy chemical power sources has been deepening worldwide, focusing on green and sustainable energy development. Among these, lithium-ion batteries have become one of the most practically advantageous power sources. The electrolyte system, a crucial component of lithium-ion batteries, has also undergone continuous development. Research on these components, including lithium salts, novel organic solvents, and electrolyte additives, has been ongoing. Additives, in particular, have received widespread attention due to their significant impact on battery performance.

[0003] The increasing multifunctionality of electronic devices equipped with lithium-ion batteries leads to higher power consumption. Therefore, the demand for high-capacity lithium-ion batteries is constantly evolving, with methods such as increasing electrode density or reducing unused space within the battery reducing the volume occupied by non-aqueous electrolytes. Sulfate, as an additive in lithium-ion battery electrolytes, plays a role in suppressing the decline in initial battery capacity, increasing initial discharge capacity, reducing battery expansion after high-temperature storage, and improving charge-discharge performance and cycle life. However, existing methods for preparing sulfate suffer from drawbacks such as complex processes, numerous steps, high purification difficulty, and low product purity. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, which is a novel sulfate ester.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, characterized by comprising the following steps:

[0006] 1. Mix and heat the haloalkane, solvent 1, and base to a temperature of 70–80°C for 2–4 hours, where the mass of solvent 1 is G1. Then, add dropwise a mixture of solvent 1 and epoxy ethyl formic acid, where the mass of solvent 1 in the mixture is G2. After the reaction is complete, filter the solution and remove solvent 1 from the filtrate under reduced pressure to obtain the product from step 1. Solvent 1 is acetonitrile or THF, where THF is tetrahydrofuran. The haloalkane has the structure RX, where R is a hydrocarbon group with 1–4 carbon atoms, X is a bromine or chlorine atom, and the base is an alkali metal hydroxide.

[0007] 2. Add the product from step 1, solvent 2, and catalyst to a high-pressure reactor. Introduce sulfur dioxide and raise the temperature to 100–120°C. After the reaction is complete, wash the reaction solution with ice water, add anhydrous sodium sulfate to dry, and then remove 50–70% of solvent 2 under reduced pressure. Add n-hexane to crystallize, filter, and dry to collect the finished product. The catalyst is a quaternary ammonium salt, and solvent 2 is a water-incompatible solvent with a boiling point of 100–150°C. The structure of 1,3,2-dioxane-2-oxide-4-carboxylic acid ester is as follows:

[0008] R is a hydrocarbon group with 1 to 4 carbon atoms.

[0009] Furthermore, in the aforementioned method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, the total amount of solvent 1 used is 2 to 4 times the mass of epoxy ethyl formic acid, and the mass ratio of G1 to G2 is 1:(2 to 5).

[0010] Furthermore, in the aforementioned method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, the base is sodium hydroxide or potassium hydroxide, and the amount used is 1.05 to 1.15 of the molar amount of epoxyethylformic acid.

[0011] Furthermore, in the aforementioned method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, the amount of the halohydrocarbon used is 1.05 to 1.15 of the molar amount of epoxyethylformic acid.

[0012] Furthermore, in the aforementioned method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, the amount of sulfur dioxide used is 1.01 to 1.025 of the molar amount of epoxyethylformic acid.

[0013] Furthermore, in the aforementioned method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, solvent 2 is toluene or xylene, preferably toluene, and the amount used is 2 to 4 times the mass of epoxyethylformic acid.

[0014] Furthermore, in the aforementioned method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, the catalyst is one of tetraethylammonium bromide, tetraethylammonium chloride, or tetrabutylammonium bromide, and the amount used is 0.01 to 0.025 of the molar amount of epoxyethylformic acid.

[0015] The advantages of this invention are: the preparation method has a simple process route, few steps, low purification difficulty, and high product purity, which can reach more than 99%, and can be used as an additive for lithium-ion battery electrolytes. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to specific embodiments.

[0017] Example 1

[0018] I. 120g of bromoethane, 100g of acetonitrile, and 44g of sodium hydroxide were mixed and stirred until the temperature reached 80℃. The mixture was stirred for 2 hours. A mixture of 88g of epoxy ethyl formic acid and 252g of acetonitrile was added dropwise. After the addition was complete, the mixture was stirred for another 2 hours. The mixture was then filtered and the acetonitrile was removed under reduced pressure to obtain ethyl epoxy formic acid. II. ethyl epoxy formic acid, 352g of toluene, and 2.1g of tetraethylammonium bromide were added to a high-pressure reactor and stirred. 65g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 100℃. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 60% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization. 153g of the product was collected, with a purity of 99.5% and a yield of 85%. The product structure is as follows:

[0019]

[0020] Example 2

[0021] I. 125g of bromoethane, 50g of acetonitrile, and 64g of potassium hydroxide were mixed and stirred until the temperature reached 70°C. The mixture was stirred for 2 hours. A mixture of 88g of epoxy ethyl formic acid and 252g of acetonitrile was added dropwise. After the addition was complete, the mixture was stirred for another 2 hours. The mixture was then filtered and the acetonitrile was removed under reduced pressure to obtain ethyl epoxy formic acid. II. ethyl epoxy formic acid, 264g of xylene, and 4.1g of tetraethylammonium chloride were added to a high-pressure reactor and stirred. 66g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 120°C. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 50% of the xylene was removed under reduced pressure. Hexane was added to induce crystallization. 157g of the product was collected, with a purity of 99.4% and a yield of 86%. The product structure is as follows:

[0022]

[0023] Example 3

[0024] I. 120g of bromoethane, 50g of THF (tetrahydrofuran), and 42g of sodium hydroxide were mixed and stirred until the temperature reached 80°C. The mixture was stirred for 4 hours. A mixture of 88g of epoxyethyl formic acid and 200g of THF was added dropwise. After the addition was complete, the mixture was stirred for 2 hours. The mixture was then filtered and the THF was removed under reduced pressure to obtain ethyl epoxyformate. II. ethyl epoxyformate, 176g of toluene, and 3.2g of tetrabutylammonium bromide were added to a high-pressure reactor and stirred. 66g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 120°C. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 70% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization. 148g of the product was collected, with a purity of 99.6% and a yield of 82%. The product structure is as follows:

[0025]

[0026] Example 4

[0027] I. 125g of bromopropyne, 100g of THF (tetrahydrofuran), and 59g of potassium hydroxide were mixed and heated to 80℃ for 4 hours. A mixture of 88g of epoxyethyl formic acid and 200g of THF was added dropwise, and the mixture was stirred for 2 hours after the addition was complete. The mixture was then filtered and the THF was removed under reduced pressure to obtain epoxyethyl formic acid propyne ester. II. Epoxyethyl formic acid propyne ester, 264g of toluene, and 3.2g of tetrabutylammonium bromide were added to a high-pressure reactor and stirred. 66g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 120℃. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 60% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization, and 167g of the product was collected with a purity of 99.2% and a yield of 88%. The product structure is as follows:

[0028]

[0029] Example 5

[0030] I. 57.5g of chloromethane, 100g of THF (tetrahydrofuran), and 64g of potassium hydroxide were mixed and stirred until the temperature reached 80°C. The mixture was stirred for 2 hours. A mixture of 88g of epoxyethyl formic acid and 200g of THF was added dropwise. After the addition was complete, the mixture was stirred for another 2 hours. The mixture was then filtered and the THF was removed under reduced pressure to obtain epoxyethyl formic acid propargyl ester. II. Epoxyethyl formic acid propargyl ester, 264g of toluene, and 3.2g of tetrabutylammonium bromide were added to a high-pressure reactor and stirred. 66g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 120°C. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 60% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization. 133g of the product was collected, with a purity of 99.5% and a yield of 80%. The product structure is as follows:

[0031]

[0032] Example 6

[0033] I. 99g of chloroprene, 100g of acetonitrile, and 62g of potassium hydroxide were mixed and stirred until the temperature reached 70℃. The mixture was stirred for 2 hours. A mixture of 88g of epoxy ethyl formic acid and 252g of acetonitrile was added dropwise. After the addition was complete, the mixture was stirred for another 2 hours. The mixture was then filtered and the acetonitrile was removed under reduced pressure to obtain epoxy ethyl formic acid butylene ester. II. Epoxy ethyl formic acid butylene ester, 352g of toluene, and 2.8g of tetrabutylammonium chloride were added to a high-pressure reactor and stirred. 65g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 120℃. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 60% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization. 161g of the product was collected, with a purity of 99.4% and a yield of 78%. The product structure is as follows:

[0034]

[0035] Example 7

[0036] I. 97g of bromobutane, 100g of acetonitrile, and 51g of sodium hydroxide were mixed and stirred until the temperature reached 70°C. The mixture was stirred for 2 hours. A mixture of 88g of epoxy ethyl formic acid and 252g of acetonitrile was added dropwise. After the addition was complete, the mixture was stirred for another 2 hours. The mixture was then filtered and the acetonitrile was removed under reduced pressure to obtain epoxy ethyl formic acid butylene ester. II. Epoxy ethyl formic acid butylene ester, 352g of toluene, and 2.8g of tetrabutylammonium chloride were added to a high-pressure reactor and stirred. 65g of sulfur dioxide was introduced into the high-pressure reactor to raise the temperature to 100°C. After the reaction was complete, the reaction solution was washed with ice water, dried with anhydrous sodium sulfate, and 60% of the toluene was removed under reduced pressure. Hexane was added to induce crystallization. 175g of the product was collected, with a purity of 99.2% and a yield of 84%. The product structure is as follows:

[0037]

[0038] The advantages of the present invention obtained from the above embodiments are: simple process route, few steps, low purification difficulty, high product purity, which can reach more than 99%, and can be used as an additive for lithium-ion battery electrolyte.

Claims

1. A method for preparing 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester, characterized in that: Includes the following steps:

1. Mix and heat the haloalkane, solvent 1, and base to a temperature of 70–80°C for 2–4 hours, where the mass of solvent 1 is G1. Then, add dropwise a mixture of solvent 1 and epoxy ethyl formic acid, where the mass of solvent 1 in the mixture is G2. After the reaction is complete, filter the solution and remove solvent 1 from the filtrate under reduced pressure to obtain the product from step 1. Solvent 1 is acetonitrile or THF, the haloalkane has the structure RX, where R is a hydrocarbon group with 1–4 carbon atoms, X is a bromine or chlorine atom, and the base is an alkali metal hydroxide.

2. Add the product from step 1, solvent 2, and catalyst to a high-pressure reactor. Introduce sulfur dioxide and raise the temperature to 100–120°C. After the reaction is complete, wash the reaction solution with ice water, add anhydrous sodium sulfate to dry, and then remove 50–70% of solvent 2 under reduced pressure. Add n-hexane to crystallize, filter, and dry to collect the finished product. The catalyst is a quaternary ammonium salt, and solvent 2 is a water-incompatible solvent with a boiling point of 100–150°C. The structure of 1,3,2-dioxane-2-oxide-4-carboxylic acid ester is as follows: R is a hydrocarbon group with 1 to 4 carbon atoms.

2. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1, characterized in that: The total amount of solvent 1 used is 2 to 4 times the mass of epoxy ethyl carboxylic acid, and the mass ratio of G1 to G2 is 1:(2 to 5).

3. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: The alkali is sodium hydroxide or potassium hydroxide, and the amount used is 1.05 to 1.15 of the molar amount of epoxy ethyl carboxylic acid.

4. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: The amount of the halohydrocarbon used is 1.05 to 1.15 of the molar amount of epoxy ethyl carboxylic acid.

5. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: The amount of sulfur dioxide used is 1.01 to 1.025 of the molar amount of epoxy ethylformic acid.

6. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: Solvent 2 is toluene or xylene, and the amount used is 2 to 4 times the mass of epoxy ethyl carboxylic acid.

7. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 6, characterized in that: Solvent 2 is toluene.

8. The method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: The catalyst is one of tetraethylammonium bromide, tetraethylammonium chloride, and tetrabutylammonium bromide, and the amount used is 0.01 to 0.025 of the molar amount of epoxy ethylformic acid.

9. A method for preparing a 1,3,2-dioxathiacyclopentane-2-oxide-4-carboxylic acid ester according to claim 1 or 2, characterized in that: In step two, 60% of the solvent 2 is removed under reduced pressure.

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