阅读说明：本技术 一种环状硫酸酯的制备方法 (Preparation method of cyclic sulfate ) 是由 邹凯 卢建龙 蒋达伟 顾新红 施苏萍 任齐都 于 2019-09-30 设计创作，主要内容包括：本发明提供了一种环状硫酸酯的制备方法,在有机体系中,将双(三甲基硅)硫酸酯和烷基二醇进行酯交换环化反应制得所述的环状硫酸酯,其中,所述的环状硫酸酯的结构式为：<Image he="252" wi="365" file="DDA0002222141010000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>n为1～4之间的数。本发明采用双(三甲基硅)硫酸酯作为原料,替代剧毒和高毒的硫酸二甲酯和硫酸二乙酯,从而降低了原料的毒性,另外,本发明的反应具有高度的选择性和收率,适合工业化和绿色环保的化工要求。(The invention provides a preparation method of cyclic sulfate, which is characterized in that bis (trimethylsilyl) sulfate and alkyl diol are subjected to ester exchange cyclization reaction in an organic system to prepare the cyclic sulfate, wherein the structural formula of the cyclic sulfate is as follows: n is a number between 1 and 4. The invention adopts bis (trimethyl silicon) sulfate as raw material to replace highly toxic and highly toxic dimethyl sulfate and diethyl sulfate, thereby reducing the toxicity of the raw material.)

1. A preparation method of cyclic sulfate is characterized in that: in an organic system, bis (trimethylsilyl) sulfate and alkyl diol are subjected to ester exchange cyclization reaction to prepare the cyclic sulfate, wherein the cyclic sulfate is prepared by the reaction of the bis (trimethylsilyl) sulfate and the alkyl diolThe structural formula of the sulfate is:n is a number between 1 and 4.

2. The process for producing a cyclic sulfate according to claim 1, characterized in that: the structural formula of the alkyl diol is shown in the specificationWherein s is a number between 1 and 4.

3. The process for producing a cyclic sulfate according to claim 1, characterized in that: the reaction is carried out at a temperature of 80-120 ℃.

4. The process for producing a cyclic sulfate according to claim 3, characterized in that: the temperature for carrying out the reaction is 105-108 ℃.

5. The process for producing a cyclic sulfate according to claim 1, characterized in that: the feeding molar ratio of the bis (trimethylsilyl) sulfate to the alkyl diol is 1: 1-5.

6. The process for producing a cyclic sulfate according to claim 1, characterized in that: the organic solvent of the organic system is one or more of toluene, ethylene glycol dimethyl ether, acetonitrile and acetone.

7. The process for producing a cyclic sulfate according to claim 1, characterized in that: during the reaction, trimethylsilanol was continuously distilled off.

8. The process for producing a cyclic sulfate according to claim 1, characterized in that: the preparation method also comprises the following steps of carrying out post-treatment after the reaction is finished: the post-processing method comprises the following steps: filtering, recrystallizing and vacuum drying the reaction liquid to obtain the cyclic sulfate.

9. The process for producing a cyclic sulfate according to claim 8, wherein: the solvent for recrystallization is one or more of dimethyl carbonate, diethyl carbonate, acetonitrile and toluene.

10. The method for producing a cyclic sulfate according to any one of claims 1 to 9, characterized in that: the preparation method comprises the following specific steps: adding an organic solvent, the bis (trimethylsilyl) sulfate and the alkyl diol into a reaction device under a stirring state to perform ester exchange cyclization reaction, evaporating the trimethylsilanol in the reaction process, stopping the reaction after the reaction is finished, protecting the reaction liquid with nitrogen, cooling the reaction liquid to-5 to-15 ℃, precipitating crystals, filtering under reduced pressure to obtain primary crystals, recrystallizing the primary crystals at 0 to-10 ℃ to obtain secondary crystals, and drying the secondary crystals at 40 to 90 ℃ in vacuum to obtain the cyclic sulfate.

Technical Field

The invention relates to a preparation method of cyclic sulfate.

Background

In recent years, organic sulfonate has been widely studied and applied as an additive for lithium ion battery electrolyte. After the organic sulfonate is added into the electrolyte of the high-voltage lithium ion battery, the occurrence of side reactions on the surface of an electrode and the dissolution of metal ions are effectively inhibited, the organic sulfonate has a good modification effect on an SEI film of the positive electrode, the interfacial impedance of the electrode/electrode liquid can be obviously reduced even under high voltage, and the cycling stability of the positive electrode material is improved. Such organic sulfonates include: vinyl sulfate (DTD), vinylene sulfate (ES), 1, 3-Propane Sultone (PS), and the like, wherein the electrochemical performance of the vinyl sulfate (DTD) is more excellent. The synthesis and preparation methods of the vinyl sulfate ester disclosed at present mainly comprise three methods:

the method comprises the following steps: the method for preparing the vinyl sulfate ester by directly esterifying the sulfone chloride (or the sulfoxide chloride) and the ethylene glycol, such as CN106187989A, CN109232518A, CN108822075A and CN109369609A, has the defects that the sulfoxide chloride and other raw materials are used, a large amount of hydrochloric acid and other byproducts are generated, side reactions are more, impurities are more, the purification is difficult, and a green and environment-friendly synthetic technical route which is far from advocation is provided.

The second method comprises the following steps: the sulfur dioxide (or sulfur trioxide) and ethylene oxide are used as raw materials for preparation, such as CN108658928A, the method uses highly explosive ethylene oxide as a raw material, green and economic synthesis is carried out under certain catalysis conditions, the atom utilization rate is extremely high, but the reaction conditions are harsh, and the difficulty of process equipment is extremely high.

The third method comprises the following steps: the preparation method is an industrial method which is relatively easy to realize and has mild reaction conditions, but the strong toxicity of dimethyl sulfate and diethyl sulfate (the former is a high-toxicity product, and the latter is a high-toxicity product) limits the industrial application of the dimethyl sulfate and the diethyl sulfate.

Disclosure of Invention

The invention aims to provide a preparation method of cyclic sulfate with low toxicity of reaction raw materials and mild reaction conditions.

In order to solve the technical problems, the invention adopts the following technical scheme:

a method for preparing cyclic sulfate, in an organic system, bis (trimethylsilyl) sulfate and alkyl diol are subjected to ester exchange cyclization reaction to prepare the cyclic sulfate, wherein the structural formula of the cyclic sulfate is as follows:n is a number between 1 and 4.

In the invention, the structural formula of the alkyl diol is shown in the specificationWherein s is a number between 1 and 4. Specifically, the alkyl diol is ethylene glycol, 1, 3-propylene glycol, 1, 4-butanediol or 1, 5-pentanediol. Correspondingly, the synthesized cyclic sulfate is vinyl sulfate, allyl sulfate, butenyl sulfate or pentenyl sulfate.

In the invention, the reaction temperature is 80-120 ℃, and when the reaction temperature is lower than 100 ℃, trimethylsilanol can be distilled out in a decompression mode, so that the forward reaction is promoted.

Preferably, the temperature for carrying out the reaction is 105-108 ℃, so that the reaction is ensured to be carried out while the energy consumption is low.

Preferably, the feeding molar ratio of the bis (trimethylsilyl) sulfate to the alkyl diol is 1: 1-5, and more preferably 1: 2-3.

In the invention, the excessive addition of the alkyl diol is preferred, on one hand, the complete reaction of the bis (trimethylsilyl) sulfate can be promoted, and the cost is reduced; on the other hand, trimethylsilanol can be stabilized to prevent side reactions.

Preferably, the organic solvent of the organic system is one or more of toluene, ethylene glycol dimethyl ether, acetonitrile and acetone, and more preferably toluene. In the invention, the organic solvent is an inert solvent, so that the organic solvent can be prevented from participating in the reaction.

Preferably, during the reaction, the trimethylsilanol is continuously distilled off to promote the forward direction of the reaction, thereby improving the conversion rate and yield of the raw materials.

In the invention, the reaction time is controlled to be finished when no trimethylsilanol is distilled out in the reaction system, and the reaction time is about 8-16 hours by research.

In the invention, the preparation method further comprises the following steps of carrying out post-treatment after the reaction is finished: the post-processing method comprises the following steps: filtering, recrystallizing and vacuum drying the reaction liquid to obtain the cyclic sulfate. The post-treatment can improve the purity of the product, so that the product meets the use standard of the electrolyte of the secondary battery.

Preferably, the solvent for carrying out the recrystallization is one or more of dimethyl carbonate, diethyl carbonate, acetonitrile and toluene, and more preferably dimethyl carbonate or diethyl carbonate. The selection of the recrystallization solvent improves the purity of the product and simultaneously causes less product loss.

According to a specific and preferred mode, the preparation method comprises the following specific steps: adding an organic solvent, the bis (trimethylsilyl) sulfate and the alkyl diol into a reaction device under a stirring state to perform ester exchange cyclization reaction, evaporating the trimethylsilanol in the reaction process, stopping the reaction after the reaction is finished, protecting the reaction liquid with nitrogen, cooling the reaction liquid to-5 to-15 ℃, precipitating crystals, filtering under reduced pressure to obtain primary crystals, recrystallizing the primary crystals at 0 to-10 ℃ to obtain secondary crystals, and drying the secondary crystals at 40 to 90 ℃ in vacuum to obtain the cyclic sulfate.

The specific method has the advantages of simple and convenient operation, good selectivity, high product yield, high purity, no halogen residue, suitability for large-scale production, accordance with the industrial and green and environment-friendly chemical requirements, and capability of meeting the requirements of the lithium ion battery electrolyte.

The reaction equation of the present invention is as follows:

due to the implementation of the technical scheme, compared with the prior art, the invention has the following advantages:

the invention adopts bis (trimethyl silicon) sulfate as raw material to replace highly toxic and highly toxic dimethyl sulfate and diethyl sulfate, thereby reducing the toxicity of the raw material.

Drawings

FIG. 1 is a carbon NMR spectrum of the product obtained in example 1;

FIG. 2 is an MS spectrum of the product obtained in example 1;

FIG. 3 is a NMR carbon spectrum of the product obtained in example 3;

FIG. 4 is an MS spectrum of the product obtained in example 3.

Detailed Description

The following examples are intended to illustrate several embodiments of the present invention, but are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.