阅读说明：本技术 双氟磺酰亚胺类化合物及其金属盐的制备方法 (Preparation method of bis-fluorosulfonyl imide compound and metal salt thereof ) 是由 董佳家 蒲小秋 江营 于 2019-07-31 设计创作，主要内容包括：本发明公开了一种双氟磺酰亚胺类化合物及其金属盐的制备方法。本发明的如式I所示的双磺酰亚胺类化合物的制备方法,包括以下步骤：将如式A所示的双磺酰亚胺盐与硫酸在溶剂中进行反应,得到式I所示的双磺酰亚胺类化合物,即可；所述溶剂的种类为能作为超临界流体的气体,所述溶剂的形态为液体或超临界流体。本发明得到的双磺酰亚胺类化合物收率高,离子含量低。<Image he="177" wi="700" file="DDA0002150724800000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention discloses a method for preparing a difluoride sulfimide compound and a metal salt thereof. The preparation method of the bissuccinimide compound shown in the formula I comprises the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I; the solvent is a gas capable of being used as a supercritical fluid, and the solvent is in the form of a liquid or a supercritical fluid. The bissulfoimide compound obtained by the method has high yield and low ion content.)

1. A preparation method of a bissuccinimide compound shown as a formula I is characterized by comprising the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I; the solvent is a gas capable of being used as a supercritical fluid, and the form of the solvent is liquid or supercritical fluid;

wherein X is an alkali metal; r¹And R²Independently F or C substituted by all F_1-12An alkyl group.

2. The process according to claim 1, wherein R in the formula A is¹And R²The same;

and/or, in the formula A, X is lithium, sodium or potassium, and is sodium or potassium;

and/or in the reaction, the solvent is carbon dioxide, sulfur dioxide, nitrogen, ethane, ethylene, propane or argon, and is also sulfur dioxide;

and/or, when said R is¹And R²Independently C substituted by all F_1-12When alkyl, said all-F substituted C_1-12Alkyl being C substituted by all F_1-6Alkyl, which is also fully F-substituted C_1-3An alkyl group;

and/or in the reaction, the sulfuric acid is 98% concentrated sulfuric acid, and the percentage is the mass percentage of the sulfuric acid in the total mass of the concentrated sulfuric acid;

and/or in the reaction, the molar ratio of the sulfuric acid to the bissulfonyl imide salt is 1-20, 1-4 and 1-2;

and/or, in the reaction, the solvent is in a liquid form;

and/or in the reaction, the temperature of the reaction is-70-50 ℃, 20-50 ℃ or 20-20 ℃;

and/or, in the reaction, the reaction is carried out in a high-pressure reaction kettle;

and/or in the reaction, the molar ratio of the solvent to the bissulfonyl imide salt is 10-300, 10-100, 100-200, 10-34 and further 17-34.

3. The method of claim 2, wherein when R is present¹And R²Independently C substituted by all F_1-3When alkyl, said all-F substituted C_1-3The alkyl is trifluoromethyl, perfluoroethyl, perfluoro-n-propyl or perfluoro-isopropyl and is trifluoromethyl;

and/or when the reaction is carried out under pressure, the pressure of the reaction is 0.01-4.00 MPa.

4. The method of claim 1, further comprising the steps of:

in the presence of an alkaline agent, SO₂F₂Ammonia gas and alkali metal fluoride salt in organic solvent to obtain the compound shown in the formulaAnd (B) bis (sulfonyl) imide salt shown as A.

5. The process according to claim 4, wherein the basic agent is a weak organic base, further triethylamine;

and/or the organic solvent is a nitrile solvent, further acetonitrile;

and/or, the ammonia gas reacts in the form of ammonia gas solution; when the ammonia gas is reacted in the form of ammonia gas solution, the ammonia gas is nitrile ammonia solution, and further ammonia acetonitrile solution;

and/or the alkali metal fluoride salt is potassium fluoride or sodium fluoride.

6. The process according to claim 1, wherein R in the formula A is¹And R²Independently F or trifluoromethyl;

in the reaction, the molar ratio of the sulfuric acid to the bissulfonyl imide salt is 1-2; the molar ratio of the solvent to the bis-sulfonyl imide salt is 17-34; the solvent is sulfur dioxide; the solvent is in the form of a liquid.

7. The production method according to any one of claims 1 to 6, further comprising a post-treatment step after the reaction is completed; the method and operation of the post-treatment is method 1 or 2:

the method comprises the following steps: the method comprises the following post-treatment steps: heating the reaction solution after the reaction to room temperature, separating out a solid after the solvent is completely volatilized, and extracting the bissulfonamide compound shown in the formula I by using an organic solvent to obtain a dissolved solution;

the method 2 comprises the following steps: the method comprises the following post-treatment steps: and cooling the reaction solution after the reaction is finished, filtering, heating the filtrate to room temperature until the solvent is completely volatilized, and distilling the filtrate.

8. The method according to claim 7, wherein in the method 1, the organic solvent is a chlorinated hydrocarbon solvent, more preferably dichloromethane;

and/or, in the method 2, the distillation is vacuum distillation.

9. A preparation method of a bis-sulfonyl imide compound metal salt shown as a formula II comprises the following steps:

the method comprises the following steps: the preparation method of the bissulfimide compound shown as the formula I comprises the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I;

step two: reacting the bissulfoimide compound shown in the formula I prepared in the step one with a metal ion source in an organic solvent to obtain a bissulfoimide compound metal salt shown in a formula II, wherein the metal ion source is metal carbonate, metal bicarbonate, metal hydroxide or metal oxide;

in the first step, the reaction conditions and operation are as defined in any one of claims 1 to 8;

in formula II, y is 1, 2 or 3; and M is metal in the metal ion source.

10. The method according to claim 9, wherein in formula II, M is lithium, sodium, potassium, , cesium, magnesium, calcium, strontium, barium, copper, zinc, palladium, nickel, rhodium, ruthenium, platinum, silver, gold, cobalt, manganese, iron, or iridium, and may be lithium, sodium, potassium, magnesium, silver, nickel, copper, or cobalt;

and/or in the second step, the molar ratio of the metal ion source to the bissulfoimide compound is 0.3-1.4, and can also be 0.3-1.2;

and/or in the second step, the molar ratio of the metal ions in the metal ion source to the bis-sulfonyl imide compound is 1.0-1.7, and can also be 1.0-1.4;

and/or, in the second step, the organic solvent is an ether solvent and/or a halogenated hydrocarbon solvent;

and/or in the second step, the metal carbonate is one or more of alkali metal carbonate, alkaline earth metal carbonate and transition metal carbonate;

and/or in the second step, the metal bicarbonate is one or more of alkali metal carbonate, alkaline earth metal bicarbonate and transition metal bicarbonate;

and/or, in the second step, the metal hydroxide is one or more of alkali metal hydroxide, alkaline earth metal hydroxide and transition metal hydroxide;

and/or in the second step, the metal oxide is one or more of alkali metal oxide, alkaline earth metal oxide and transition metal oxide;

and/or the reaction temperature is-20-40 ℃ and 0-30 ℃;

and/or after the reaction is finished, the method further comprises the following post-treatment steps: concentrating, washing, dissolving, filtering, concentrating filtrate and drying the reaction solution after the reaction is finished; the washed organic solvent is one or more of an ether solvent, an ester solvent, a nitrile solvent and a ketone solvent; the ether solvent is one or more of diethyl ether, tetrahydrofuran and tert-butyl methyl ether, and is also tert-butyl methyl ether; the ester solvent is ethyl acetate and/or butyl acetate; the nitrile solvent is acetonitrile and/or propionitrile; the ketone solvent is acetone.

11. Application of sulfur dioxide in preparation of the bis-sulfimide compound shown in the formula I as claimed in any one of claims 1 to 7.

12. The use according to claim 11, wherein the sulphur dioxide is used as a solvent.

Technical Field

The invention relates to a method for preparing a difluoride sulfimide compound and a metal salt thereof.

Background

Bis (fluorosulfonyl) imide (HN (SO)₂F)₂) Is an important strong acid containing nitrogen and has very high practical value in chemistry. For example, in electrochemistry, the method can be used as an important synthetic raw material of lithium bis (fluorosulfonyl) imide of lithium ion battery electrolyte. Lithium bis (fluorosulfonylimide) versus lithium hexafluorophosphate (LiPF)₆) Other currently available electrolyte materials have high stability and good hydrolytic stability. Lithium bis (fluorosulfonyl) imide will become an important type of electrolyte for lithium ion batteries. Also for example in organic chemistry, bis-fluorosulfonylimides can be used in acid-catalyzed reactions or in the preparation of metal catalysts. The rare earth metal salt of bis (fluorosulfonyl) imide has a weak coordination effect, so that rare earth metal ions show strong Lewis acidity and become a good acid catalyst. Compared with classical Lewis acid catalysts such as aluminum chloride or hydrofluoric acid, the catalyst has remarkable environmental friendliness.

The lithium bis (fluorosulfonyl) imide is used as an electrolyte, the purity requirement is extremely high, and the service life and safety of the battery are greatly influenced by trace anions remained in the preparation process. The method for preparing the bis-fluorosulfonyl imide and the metal salt thereof at home and abroad mainly comprises the following steps:

world patent WO2016093399A1 reported ClSO₃H and chlorosulfonyl isocyanate react to obtain dichlorosulfimide, the dichlorosulfimide is slowly dropped into an amine fluoride acetonitrile solution, the solution is removed after refluxing for two hours to obtain difluoride sulfimide ammonium salt, and the ammonium salt reacts with metal hydroxide to finally obtain the difluoride sulfimide metal salt. The metal salt produced by this method will have a small amount of chloride ions present and the method is relatively costly.

Chinese patent CN105523970A reports that the exchange of bis (fluorosulfonyl) imide metal salt with lithium perchlorate and lithium tetrafluoroborate obtains bis (fluorosulfonyl) imide lithium, and the preparation cost of bis (fluorosulfonyl) imide lithium prepared from lithium perchlorate and lithium tetrafluoroborate is high and is not beneficial to industrialization.

DesMarteau (organic chemistry 32 (1993): 5007 + 5010; organic chemistry 23 (1984); 3720 + 3723) reported that dried sodium bis (perfluoroalkylsulfonyl) imide was dissolved in concentrated sulfuric acid (100%) and placed in a sublimer under high vacuum at 60 ℃ to obtain bis (perfluoroalkylsulfonyl) imide. In the above production method, since bis (fluorosulfonyl) imide cannot be sublimed and is in a liquid state at room temperature, it cannot be used for producing bis (fluorosulfonyl) imide.

Chinese patent CN101747242A, which reports that bis-chlorosulfonyl imide is obtained by the reaction of sulfonamide with thionyl chloride and chlorosulfonic acid, and then reacted with antimony trifluoride to obtain bis-fluorosulfonyl imide, has the following disadvantages: antimony trifluoride is high in price and difficult to industrially amplify; the product has more impurities, and is difficult to purify and meets the application standard.

U.S. Pat. No. 5,591647,647 reports that fluorosulfonic acid reacts with urea to prepare bis-fluorosulfonylimide and then lithiated to obtain the product, and fluorosulfonic acid in the route is expensive, extremely corrosive to equipment and not beneficial to industrialization.

Chinese patent CN105523529A reports that potassium bis (fluorosulfonyl) imide is prepared by reacting bis (chlorosulfonyl) imide with potassium fluoride, and then reacting with sufficient amount of strong acid (perchloric acid, hydroiodic acid, fluorosulfonic acid, chlorosulfonic acid, fluorosulfonic acid, trifluoroacetic acid) in the presence of aprotic organic solvent. When the method is used for removing water and an organic solvent, with the increase of the concentration of the bis-fluorosulfonyl imide, the bis-fluorosulfonyl imide is hydrolyzed at the rectification temperature to generate HF, and the strong acting force between the HF and the bis-fluorosulfonyl imide can increase the content of fluorine ions in the bis-fluorosulfonyl imide, so that the content of the fluorine ions in lithium salt can be increased, and the performance of a battery is influenced.

World patent WO2009123328A1 reports the preparation of chlorosulfonic acid isocyanate from cyanogen chloride gas and sulfur trioxide, which is then reacted with chlorosulfonic acid to produce the bischlorosulfonimide. The route uses cyanogen chloride which is a toxic gas and is difficult to be produced in a large scale.

US20120245386a1 and US20140142338a1 report a mild process for the formation of bis-fluorosulfonylimide anions. In the patent, SO is adopted₂F₂And NH₃The method comprises the steps of taking Tetramethylpropanediamine (TMPDA) as a raw material as an alkali and acetonitrile as a solvent, reacting at 10-15 ℃, and after the reaction is finished, carrying out reduced pressure separation on low-boiling-point liquidThe viscous product was dissolved in methanol at 30 ℃ and one equivalent of aqueous tetrabutylammonium bromide was added dropwise to the methanol solution, followed by precipitation of a white solid and filtration to give tetrabutylammonium bis-fluorosulfonylimide metal salt in 84.4% yield. The method can obtain various tetra-tertiary-ammonium bis (fluorosulfonyl) imide metal salts with mild conditions, simple operation and high efficiency, but no research is carried out on further lithium salt conversion, and the used alkali TMPDA is more difficult to remove and can be wrapped in the bis (fluorosulfonyl) imide metal salts to reduce the product quality compared with low-boiling-point alkali. In addition, the tetra-tertiary ammonium bis (fluorosulfonyl) imide metal salt does not exchange with sodium hydroxide or potassium hydroxide, and thus bis (fluorosulfonyl) imide metal salt cannot be obtained.

U.S. Pat. No. 3, 2010113835, 1, reported SO₂F₂，NH₃And Et₃The mass ratio of N to acetonitrile is 2:1:3, acetonitrile is used as a solvent, triethylamine bis (fluorosulfonyl) imide metal salt and a small amount of by-products are obtained in an ice-water bath with a yield of over 90%, various metal hydroxides are slowly added into the triethylamine bis (fluorosulfonyl) imide metal salt solution, and the triethylamine is removed to obtain the product bis (fluorosulfonyl) imide metal salt. This exclusive use of SO₂F₂，NH₃And Et₃N is cheap, so that the bis (fluorosulfonyl) imide triethylamine salt is effectively synthesized, has excellent ion exchange capacity, and can be efficiently exchanged to obtain the bis (fluorosulfonyl) imide metal salt. However, excess triethylamine in the reaction promotes SO₂F₂And generating hydrolysis products of fluorosulfonic acid triethylamine salt and other byproducts. The method is directly used for preparing the lithium bis (fluorosulfonyl) imide and has high post purification treatment cost.

World patent 2010140580, reporting SO₂F₂Reacting with ammonia gas and 6 times of equivalent of villiaumite at 60 ℃ to directly generate the bis-fluorosulfonyl imide metal salt. The invention can obtain the bis-fluorosulfonyl imide metal salt without metal exchange, but 6 times of fluorine salt is required to be added in the reaction, the economy of a large amount of fluorine salt is poor, and the dissolution and stirring of the fluorine salt in acetonitrile also are great obstacles to the industrialization of the invention.

Chinese patent CN103664712B reports that concentrated sulfuric acid is used to acidify metal salts of bis-fluorosulfonyl imide, and vacuum distillation is performed to obtain bis-fluorosulfonyl imide, then further rectification and purification are performed to obtain imine with purity of more than 99%, and the imine reacts with lithium salt to obtain the product of lithium bis-fluorosulfonyl imide. The process avoids loss of lithium salts by purification of the starting materials. However, in the method, silicon dioxide is used as an additive, high temperature is used as a reaction condition, in the presence of the silicon dioxide, the bis (fluorosulfonyl) imide is partially decomposed into fluorosulfonic acid at high temperature, the boiling points of the fluorosulfonic acid and the bis (fluorosulfonyl) imide are very close, and the product inevitably contains fluorosulfonic acid in further rectification and purification; and the fluorosulfonic acid has extremely strong corrosivity and is easy to corrode reaction equipment.

Therefore, the preparation method of the bifluoro-sulfimide and the metal salt thereof with low cost, high purity and less anion residue is developed, and the application of the bifluoro-sulfimide lithium in the battery industry is facilitated.

Disclosure of Invention

The invention aims to overcome the defects of low product purity, more anion residues, inconvenient operation, harsh production conditions and the like of the existing preparation method of the fluorosulfonyl imide salt, and provides a preparation method of the difluoride sulfonyl imide compound and the metal salt thereof. The preparation method has the advantages of high yield of the prepared product, high purity, less anion residue, simple post-treatment, no side reaction, low cost and the like.

The invention provides a preparation method of a bissuccinimide compound shown as a formula I, which comprises the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I; the solvent is a gas capable of being used as a supercritical fluid, and the form of the solvent is liquid or supercritical fluid;

wherein X is an alkali metal; r¹And R²Independently F or C substituted by all F_1-12An alkyl group.

In the formula A, theR is¹And R²Preferably the same.

In formula A, X can be lithium, sodium or potassium, and can also be sodium or potassium.

In the formula A, when R is¹And R²Independently C substituted by all F_1-12When alkyl, said all-F substituted C_1-12Alkyl may be C substituted by all F_1-6Alkyl, which may also be C substituted by all F_1-3An alkyl group. Said all-F substituted C_1-3The alkyl group may be trifluoromethyl, perfluoroethyl, perfluoro-n-propyl or perfluoro-isopropyl, and may also be trifluoromethyl.

In the reaction, the bis-sulfonyl imide salt may be a salt conventional in the art, and may also be KN (SO)₂F)₂Or NaN (SO)₂F)₂。

In the reaction, the sulfuric acid can be sulfuric acid conventional in the field, and preferably 98% concentrated sulfuric acid, wherein the percentage is the mass percentage of the mass of the sulfuric acid to the total mass of the concentrated sulfuric acid.

In the reaction, the molar ratio of the sulfuric acid to the bissulfonylimide salt may be a molar ratio conventionally used in the art, and may be 1 to 20, and may also be 1 to 4, and further may be 1 to 2, such as1, and such as 2.

In the reaction, the solvent may be in the form of a liquid.

In the reaction, the solvent can be carbon dioxide, sulfur dioxide, nitrogen, ethane, ethylene, propane or argon, and can also be sulfur dioxide.

It is well known to those skilled in the art that lowering the temperature below the boiling point of the gas, or applying a certain pressure, or a combination of a certain temperature range and a certain pressure range, can cause the gas to exist in liquid form. When the temperature and pressure of the gas are both above their critical points, the state is a supercritical fluid. In the reaction, the temperature and/or pressure of the reaction may be any temperature and/or pressure that can cause the gas to be in the form of a liquid or a supercritical fluid.

In the reaction, the temperature of the reaction can be-70-50 ℃, can be-20-50 ℃, and can also be-20 ℃, for example-20 ℃.

In the reaction, the reaction can also be carried out in a high-pressure reaction kettle. When the reaction is carried out under pressure, the pressure of the reaction can be 0.01-4.00 MPa.

In the reaction, the molar ratio of the solvent to the bis-sulfonyl imide salt may be a molar ratio conventionally used in the art, and may be 10 to 300, further 10 to 100, further 100 to 200, further 10 to 34, further 17 to 34, for example 10, further 17, further 22, further 34.

After the reaction is finished, the preparation method can further comprise a post-treatment step. The method and operation of the post-treatment are preferably method 1 or 2: the method comprises the following steps: the method comprises the following post-treatment steps: and (3) heating the reaction solution after the reaction is finished to room temperature, precipitating a solid after the solvent is completely volatilized, and extracting the bissulfonyl imide compound shown as the formula I by using an organic solvent. The organic solvent may be a chlorinated hydrocarbon solvent (e.g., dichloromethane).

The method 2 comprises the following steps: the method comprises the following post-treatment steps: after the reaction, the reaction solution is cooled, filtered, and the filtrate is warmed to room temperature until the solvent is completely volatilized, and the filtrate is distilled (for example, distillation under reduced pressure).

The progress of the reaction can be monitored using detection methods conventional in the art (e.g., fluorine spectroscopy). The reaction time may be 0.5 to 5 hours, for example 1 hour.

In a preferred embodiment of the present invention, in formula A, R is¹And R²Independently F or C substituted by all F_1-3An alkyl group.

In a preferred technical scheme of the present invention, in the reaction, a molar ratio of the sulfuric acid to the bissulfonylimide salt is 1 to 4.

In a preferred technical scheme of the present invention, in the reaction, a molar ratio of the sulfuric acid to the bis-sulfonyl imide salt is 1 to 2.

In a preferred technical scheme of the present invention, in the reaction, a molar ratio of the solvent to the bis-sulfonyl imide salt is 10 to 34.

In a preferred technical scheme of the invention, in the reaction, the molar ratio of the solvent to the bis-sulfonyl imide salt is 17-34.

In a preferred embodiment of the present invention, in the reaction, the solvent is selected from carbon dioxide, sulfur dioxide, nitrogen, ethane, ethylene, propane, and argon.

In a preferred embodiment of the present invention, in the reaction, the solvent is carbon dioxide.

In a preferred embodiment of the present invention, in the reaction, the solvent is in a liquid form.

In a preferred embodiment of the present invention, in formula A, R is¹And R²Independently F or C substituted by all F_1-3An alkyl group;

in the reaction, the molar ratio of the sulfuric acid to the bissulfonyl imide salt is 1-4; the molar ratio of the solvent to the bissulfonyl imide salt is 10-34; the solvent is selected from carbon dioxide, sulfur dioxide, nitrogen, ethane, ethylene, propane or argon.

In a preferred embodiment of the present invention, in formula A, R is¹And R²Independently F or trifluoromethyl;

in the reaction, the molar ratio of the sulfuric acid to the bissulfonyl imide salt is 1-2; the molar ratio of the solvent to the bis-sulfonyl imide salt is 17-34; the solvent is sulfur dioxide; the solvent is in the form of a liquid.

The preparation method of the bis-sulfonyl imide compound shown in the formula I can further comprise the preparation of the bis-sulfonyl imide salt shown in the formula A.

The bis-sulfonyl imide salt of formula a can be prepared by any conventional method. It is known in the art that lithium bis (fluorosulfonyl) imide, as an electrolyte, has a very high purity requirement, and trace ions (especially anions, such as chloride ions) remaining in the preparation process greatly affect the life and safety of the battery. In order to reduce the content of chloride ions as much as possible or not introduce chloride ions, the bis-fluorosulfonyl imide shown in the formula I can also be prepared by the following preparation method. The preparation method of the bissuccinimide compound shown in the formula I can also comprise the following steps:

in the presence of an alkaline agent, SO₂F₂Reacting ammonia gas and alkali metal fluoride salt in an organic solvent to obtain the bissulfonylimide salt shown as the formula A.

In the reaction, the basic reagent may be a basic reagent conventional in the art, preferably an organic weak base, and further preferably triethylamine. The amount of the alkaline agent may be an amount conventional in the art, for example, the alkaline agent is used with SO₂F₂The molar ratio of (a) to (b) is 2.8.

In the reaction, the ammonia gas may also be reacted in the form of an ammonia gas solution. The ammonia may be used in amounts conventional in the art, for example, the ammonia and SO₂F₂Is 1.0. The ammonia solution is preferably a nitrile ammonia solution, and is more preferably an ammonia acetonitrile solution.

In the reaction, the alkali metal fluoride salt may be an alkali metal fluoride salt conventional in the art, such as potassium fluoride or sodium fluoride. The amount of alkali metal fluoride may be any amount conventional in the art, for example, the alkali metal fluoride may be used with SO₂F₂The molar ratio of (a) to (b) is 0.2.

In the reaction, the organic solvent may be an organic solvent conventional in the art, preferably a nitrile solvent, and more preferably acetonitrile. The amount of the organic solvent to be used is not particularly limited as long as the reaction is not affected.

The invention also provides a preparation method of the bissuccinimide compound shown in the formula I, which comprises the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I; carbon dioxide, sulfur dioxide, nitrogen, ethane, ethylene, propane or argon as the solvent, wherein the solvent is in a liquid or supercritical fluid form;

wherein, X, R¹And R²The definitions of (A) and (B) are as described above.

The invention also provides a preparation method of the bis-sulfonyl imide compound metal salt shown in the formula II, which comprises the following steps:

the method comprises the following steps: the preparation method of the bissulfimide compound shown as the formula I comprises the following steps: reacting the bissulfonyl imide salt shown as the formula A with sulfuric acid in a solvent to obtain a bissulfonyl imide compound shown as the formula I;

step two: reacting the bissulfoimide compound shown in the formula I prepared in the step one with a metal ion source in an organic solvent to obtain a bissulfoimide compound metal salt shown in a formula II, wherein the metal ion source is metal carbonate, metal bicarbonate, metal hydroxide or metal oxide;

the reaction conditions and operation in the step one are the same as those described above;

in formula II, y is 1, 2 or 3; m is a metal in the metal ion source.

In the formula II, y is 1 or 2.

In formula II, M may be lithium, sodium, potassium, , cesium, magnesium, calcium, strontium, barium, copper, zinc, palladium, nickel, rhodium, ruthenium, platinum, silver, gold, cobalt, manganese, iron, or iridium, and may be lithium, sodium, potassium, magnesium, silver, nickel, copper, or cobalt.

In the second step, the molar ratio of the metal ion source to the bissuccinimide compound may be a molar ratio which is conventional in the art, and is preferably 0.3 to 1.4, and may be preferably 0.3 to 1.2.

In the second step, the molar ratio of the metal ions in the metal ion source to the bis-sulfonyl imide compound is preferably 1.0 to 1.7, and may be preferably 1.0 to 1.4, for example, 1.1.

In the second step, the organic solvent may be an organic solvent conventional in the art for such reactions, preferably an ether solvent and/or a halogenated hydrocarbon solvent. The ether solvent may be one or more of diethyl ether, methyl tert-butyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether, and may also be diethyl ether and/or methyl tert-butyl ether. The halogenated hydrocarbon solvent can be one or more of dichloromethane, chloroform and 1, 2-dichloroethane, and can also be dichloromethane.

In the second step, the metal carbonate may be a metal carbonate conventional in the art, preferably one or more of an alkali metal carbonate, an alkaline earth metal carbonate and a transition metal carbonate. The alkali metal carbonate can be one or more of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate and cesium carbonate, and can also be lithium carbonate. The earth metal carbonate may be one or more of magnesium carbonate, calcium carbonate, strontium carbonate and barium carbonate. The transition metal carbonate may be one or more of copper carbonate, zinc carbonate, basic copper carbonate, palladium carbonate, nickel carbonate, rhodium carbonate, ruthenium carbonate, platinum carbonate, silver carbonate, gold carbonate, cobalt carbonate, manganese carbonate, iron carbonate, and iridium carbonate, and may also be silver carbonate.

In the second step, the alkali metal carbonate may also be lithium carbonate, potassium carbonate, sodium carbonate or lithium hydroxide, and may also be lithium hydroxide.

In step two, the metal bicarbonate can be a metal bicarbonate conventional in the art, preferably one or more of an alkali metal bicarbonate, an alkaline earth metal bicarbonate, and a transition metal bicarbonate. The alkali metal bicarbonate can be one or more of lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, rubidium bicarbonate, and cesium bicarbonate. The alkaline earth metal bicarbonate may be one or more of magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate and barium bicarbonate. The transition metal bicarbonate can be one or more of copper bicarbonate, zinc bicarbonate, palladium bicarbonate, nickel bicarbonate, rhodium bicarbonate, ruthenium bicarbonate, platinum bicarbonate, silver bicarbonate, gold bicarbonate, cobalt bicarbonate, manganese bicarbonate, iron bicarbonate, and iridium bicarbonate.

In the second step, the metal hydroxide may be a metal hydroxide conventional in the art, preferably one or more of an alkali metal hydroxide, an alkaline earth metal hydroxide and a transition metal hydroxide. The alkali metal hydroxide may be one or more of lithium hydroxide, sodium hydroxide and potassium hydroxide, and may also be lithium hydroxide. The alkaline earth metal hydroxide may be one or more of magnesium hydroxide, calcium hydroxide, strontium hydroxide and barium hydroxide, and may also be magnesium hydroxide. The transition metal hydroxide may be one or more of copper hydroxide, mercury hydroxide, palladium hydroxide, nickel hydroxide, rhodium hydroxide, ruthenium hydroxide, platinum hydroxide, gold hydroxide, manganese hydroxide, and iron hydroxide, and may also be nickel hydroxide.

In the second step, when the metal hydroxide is a transition metal hydroxide, the metal hydroxide may be cobalt hydroxide or basic copper carbonate.

In the second step, the metal oxide may be a metal oxide conventional in the art, preferably one or more of an alkali metal oxide, an alkaline earth metal oxide and a transition metal oxide. The alkali metal oxide may be one or more of lithium oxide, sodium oxide, and potassium oxide, and may also be lithium oxide. The alkaline earth metal oxide may be one or more of magnesium oxide, calcium oxide, strontium oxide and barium oxide. The transition metal oxide may be one or more of copper oxide, palladium oxide, nickel oxide, rhodium oxide, ruthenium oxide, platinum oxide, silver oxide, gold oxide, cobalt oxide, iron oxide, and iridium oxide. The reaction temperature can be conventional in the field, can be-20-40 ℃, and can also be 0-30 ℃.

The progress of the reaction can be monitored by detection methods conventional in the art (pH monitoring or nuclear magnetic monitoring). The reaction time can be 0.5-10 hours, such as 4 hours.

After the reaction is finished, the method can further comprise the following post-treatment steps: and (3) concentrating, washing, dissolving, filtering, concentrating the filtrate and drying the reaction solution after the reaction is finished. The washed organic solvent may be one or more of an ether solvent (e.g., one or more of diethyl ether, tetrahydrofuran, and tert-butyl methyl ether, and also, for example, tert-butyl methyl ether), an ester solvent (e.g., ethyl acetate and/or butyl acetate), and a nitrile solvent (e.g., acetonitrile and/or propionitrile), and a ketone solvent (e.g., acetone), such as tert-butyl methyl ether.

The invention also provides an application of sulfur dioxide in preparing the bissulfimide compound shown in the formula I.

In the application, the sulfur dioxide can be used as a solvent.

The application can also further comprise a preparation method of the bissuccinimide compound shown in the formula I. The operation and conditions of the preparation method of the bissuccinimide compound shown in the formula I are described.

In the present invention, "metal ion source" means a substance capable of providing metal ions, such as metal oxide, metal hydroxide, metal salt; specific compounds are, for example, lithium hydroxide, lithium oxide, potassium carbonate, nickel carbonate.

In the present invention, the "metal" in the "metal ion source", "metal carbonate", "metal bicarbonate", "metal hydroxide" and "metal oxide" includes metals in the main group and the sub-group of the periodic table, such as lithium, magnesium, silver, copper.

In the invention, the "metal salt of the bis-sulfonyl imide compound shown in the formula II" refers to a salt formed by combining metal ions and free bis-sulfonyl imide compounds shown in the formula II ".

In the invention, "room temperature" means 10-30 ℃, and "overnight" means 8-16 hours.

The above preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention without departing from the common general knowledge in the art.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: (1) the preparation method of the invention adopts gas as solvent, reduces the occurrence of side reaction, has the yield of over 91 percent, lower ion content, easy separation, simple post-treatment, and can be recycled after the reaction is finished, thereby being green and environment-friendly.

(3) The invention adopts the organic solvent to dissolve the bissulfonyl imide out for direct reaction, avoids the decomposition of the bissulfonyl imide caused by distillation, and avoids the use of expensive strong acid resistant devices. In particular to the bis-fluorosulfonyl imide, the bis-fluorosulfonyl imide and unreacted concentrated sulfuric acid can react to generate fluorosulfonic acid which is not easy to remove.

(4) The bissulfonylimide and the metal salt thereof can be prepared at room temperature or low temperature (-20-40 ℃) and under normal pressure or lower pressure (0.01 MPa-4 MPa), and the operation is simple and easy.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Lithium carbonate, lithium hydroxide, lithium oxide, silver carbonate, potassium carbonate, sodium carbonate, magnesium hydroxide, and nickel hydroxide used in the following examples are all electronic grade.

Lithium carbonate: the purity is 99.998 percent, and the total content of impurities is less than 20 ppm; lithium hydroxide: the purity is 99.999 percent, and the total content of impurities is less than 10 ppm; lithium oxide: the purity is 99.99 percent, and the total content of impurities is less than 100 ppm; potassium carbonate: the purity is 99.995 percent, and the total content of impurities is less than 50 ppm; sodium carbonate: the purity is 99.999 percent, and the total content of impurities is less than 10 ppm; silver carbonate: the purity is 99.9 percent, and the total content of impurities is less than 1000 ppm; magnesium hydroxide: the purity is 99.9 percent, and the total content of impurities is less than 1000 ppm; nickel hydroxide: 61% of nickel.

Due to the fact that the acidity of the bis-fluorosulfonyl imide is extremely strong, on one hand, the bis-fluorosulfonyl imide corrodes equipment and devices for testing, on the other hand, due to the fact that the bis-fluorosulfonyl imide is too high in acidity, peaks of other ions can be covered, the detection limit is extremely high, and the ion content cannot be accurately measured. In order to avoid the above problems, the present application does not directly measure the ion content of the bis (fluorosulfonyl) imide, but rather, the ion content of the bis (fluorosulfonyl) imide is estimated by detecting the ion content of the bis (fluorosulfonyl) imide salt by reacting the electronic grade salt with the bis (fluorosulfonyl) imide salt (pages 8-9 of patent CN103664712A, examples 1-4, wherein lithium carbonate (99.999%) is used and bis (fluorosulfonyl) imide acid (99.95%) to obtain a product having an impurity ion content almost the same as the ion content of bis (fluorosulfonyl) imide acid.

The detection method of the ion content comprises the following steps:

a detection instrument: an american semer flight ICS-5000+ ion chromatograph;

the detection mode is as follows: detecting by a conductance method;

separating the column: IonPac AS19-AG 19;

flow rate: 1.0 mL/min; leacheate: 0-15min 10mM KOH, 15-30min 100mM KOH, 30-45min10mM KOH.

Preparation of potassium bis (fluorosulfonyl) imide

100mL of acetonitrile, 2.55g of potassium fluoride (KF, 44mmol, 0.2eq) and 63g of triethylamine (Et)₃N, (624mmol, 2.8eq) was added to a 2L round bottom flask and the reaction was evacuated to 0.09MPa in an ice-water bath. Sulfuryl fluoride (SO)₂F₂And 2L) introducing gas into the three-neck flask until the pressure in the flask is recovered to normal pressure. Slowly injecting 5-10 ℃ acetonitrile ammonia solution (223mmol) (111mL, 2mmol/mL) (liquid dropwise adding too fast can generate a large amount of ammonium fluoride and byproducts which are difficult to dissolve in acetonitrile), and replenishing residual SO while adding the acetonitrile ammonia solution₂F₂(reacting SO)₂F₂With Et₃The molar ratio of N is 2.2:3), introducing one equivalent of nitrogen into the system after the raw materials are added, stirring for one hour at room temperature to complete the reaction to obtain a light yellow solution, removing acetonitrile and part of triethylamine hydrogen fluoride under reduced pressure to obtain a light yellow viscous liquid, adding water to wash the reaction (which can remove more residual triethylamine hydrogen fluoride and fluorine salt), then concentrating the organic solvent under reduced pressure to obtain 57g of bis (fluorosulfonyl) imide triethylamine salt (205mmol), adding 1.2 equivalent of potassium hydroxide 40% aqueous solution of 14g of potassium hydroxide, removing generated triethylamine and water under reduced pressure in the reaction process, and recrystallizing to obtain 40g of bis (fluorosulfonyl) imide potassium.¹⁹F NMR (acetonitrile as solvent, monochlorotrifluoromethane as internal standard): +52.41, melting point: 101.2-102.5 ℃.

Preparation of sodium bis (fluorosulfonyl) imide

100mL of acetonitrile, 2.55g of potassium fluoride (KF, 44mmol, 0.2eq) and 63g of triethylamine (Et)₃N, 624mmol, 2.8eq) was added to a 2L round bottom flask and the reaction was evacuated to 0.09MPa under an ice water bath. Adding SO₂F₂(2L) gas was introduced into the three-necked flask until the pressure in the flask was returned to normal. Slowly injecting 5-10 ℃ acetonitrile ammonia gas solution (223mmol) (111mL, 2mmol/mL) (liquid dropwise adding too fast can generate a large amount of ammonium fluoride and byproducts which are difficult to dissolve in acetonitrile), and replenishing residual sulfuryl fluoride (SO that SO is added into the reaction system) while adding the acetonitrile ammonia gas solution₂F₂With Et₃The molar ratio of N is 2.2:3), introducing one equivalent of nitrogen into the system after the raw materials are added, stirring for one hour at room temperature to complete the reaction to obtain a light yellow solution, removing acetonitrile and part of triethylamine hydrogen fluoride under reduced pressure to obtain a light yellow viscous liquid, adding water to wash the reaction (which can remove more residual triethylamine hydrogen fluoride and fluorine salt), then concentrating the organic solvent under reduced pressure to obtain 57g of bis (fluorosulfonyl) imide triethylamine salt (205mmol), adding 1.2 equivalent of 40% potassium hydroxide aqueous solution of 9.8g of sodium hydroxide, removing generated triethylamine and water under reduced pressure in the reaction process, and recrystallizing to obtain 37g of bis (fluorosulfonyl) imide sodium.¹⁹F NMR (acetonitrile as solvent, monochlorotrifluoromethane as internal standard): +52.45.