CN108586303B

CN108586303B - Synthesis method of trimethyl sulfonium bicarbonate

Info

Publication number: CN108586303B
Application number: CN201810593148.9A
Authority: CN
Inventors: 李焰; 李超; 罗文萍; 武忠忠; 任君; 陈祖兴
Original assignee: Hubei University
Current assignee: Hubei University
Priority date: 2018-06-11
Filing date: 2018-06-11
Publication date: 2020-07-31
Anticipated expiration: 2038-06-11
Also published as: CN108586303A

Abstract

The invention provides a preparation method of trimethylsulfonium bicarbonate solid, which comprises the steps of mixing and reacting a trimethylsulfonium chloride salt alcoholic solution with a sodium hydroxide alcoholic solution with an equal molar ratio at a temperature of-5-40 ℃, filtering to obtain a trimethylsulfonium hydroxide alkaline alcoholic solution, introducing a little excessive carbon dioxide gas until the pH value of the reaction solution is 7.5-8.5, and removing an alcohol solvent under reduced pressure to obtain the trimethylsulfonium bicarbonate solid product, wherein the yield can reach more than 96%. The synthesis method has the advantages of simple operation, little environmental pollution, high yield, suitability for industrial production and the like.

Description

Synthesis method of trimethyl sulfonium bicarbonate

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a synthetic method for industrially producing trimethyl sulfonium bicarbonate solid salt.

Background

The trimethylsulfonium bicarbonate belongs to trimethylsulfonium salt, can be used as a methylating reagent for methylation reaction of carboxylic acid, amine and other compounds, can also be used for preparing corresponding epoxy compounds from aldehyde ketone compounds, and particularly can be used for producing herbicide phoxim as a pesticide intermediate. Currently, the synthesis method of trimethylsulfonium bicarbonate reported in document WO 9722612 a (1997) is to use an aqueous solution of trimethylsulfonium hydroxide to react with carbon dioxide to obtain an aqueous solution of trimethylsulfonium bicarbonate, the stability of the aqueous solution of the sulfonium bicarbonate is better than that of the trimethylsulfonium hydroxide solution, but the transportation and storage are still inconvenient, the trimethylsulfonium bicarbonate itself is easily decomposed by heat, and the preparation of a solid product by removing solvent water from the aqueous solution may cause problems of low yield and high energy consumption. In addition, trimethylsulfonium hydroxide is a key raw material for synthesizing trimethylsulfonium bicarbonate, and the synthesis method mainly comprises the following steps:

preparing alcoholic solution from trimethylsulfonium halide, such as trimethylsulfonium iodide reacting with silver oxide to produce silver halide precipitate, filtering to obtain trimethylsulfonium hydroxide solution, and precipitating potassium bromide by reacting trimethylsulfonium bromide with potassium hydroxide to obtain trimethylsulfonium hydroxide alcoholic solutionThe main representative documents areJ. Org. Chem. 1997, 44(4): 638~639;Analytical Letters1982, 15(A10): 841~850; PL417964A1（2018）；

2, trimethyl sulfonium iodide is taken as a raw material and directly passes through basic ion exchange resin to directly prepare trimethyl sulfonium hydroxide aqueous solution or tetrabutyl ammonium hydroxide is used for ion exchange and then is used for extracting tetrabutyl ammonium iodide by using an organic solvent to prepare trimethyl sulfonium hydroxide aqueous solution, and the main representative documents are EP 1216989A1 (2002);Tetrahedron Letters1991,32(31):3621~3622。

trimethyl sulfonium hydroxide solution is obtained by an electrolytic method by taking trimethyl sulfonium halide as a raw material, and the main representative document of the trimethyl sulfonium hydroxide solution is US 3320141 (1967).

And 4, taking trimethyl sulfonium iodide as a raw material, and extracting and removing iodine elementary substance generated by oxidizing hydrogen peroxide by using an organic solvent to prepare a trimethyl sulfonium hydroxide aqueous solution, wherein the main representative document of the trimethyl sulfonium hydroxide aqueous solution is WO 9722612A (1997).

And 5, taking trimethyl sulfonium bisulfate as a raw material, reacting with barium hydroxide or sodium hydroxide to generate corresponding barium sulfate or sodium bisulfate precipitate, and filtering to obtain a trimethyl sulfonium hydroxide aqueous solution, wherein the main representative document of the trimethyl sulfonium hydroxide aqueous solution is WO 9722612A (1997).

The synthesis methods have characteristics, but have obvious defects, such as expensive raw material cost, high equipment requirement, high toxicity of byproducts and high environment-friendly treatment pressure, and particularly, most of the synthesis methods obtain trimethylsulfonium hydroxide aqueous solution which is not suitable for synthesizing solid trimethylsulfonium bicarbonate, so that the development of a novel method for preparing the trimethylsulfonium hydroxide solution, which is simple and efficient to operate, economic and environment-friendly, and the synthesis of the solid trimethylsulfonium bicarbonate convenient to transport and store is significant.

Disclosure of Invention

The invention aims to provide a synthesis method of solid trimethylsulfonium bicarbonate, which has the advantages of cheap raw materials, high synthesis yield, low production cost, easiness in storage and transportation of products and suitability for industrial production.

In order to solve the problems, the technical scheme provided by the invention is as follows: a method for synthesizing trimethylsulfonium bicarbonate comprises the following steps: dropwise adding sodium hydroxide alcoholic solution with equal molar ratio into trimethyl sulfonium chloride alcoholic solution at-5-40 ℃ by taking anhydrous alcohol as a solvent, stirring and reacting for 0.5-2.0 h, filtering to remove sodium chloride precipitate to obtain trimethyl sulfonium hydroxide alkaline alcoholic solution, then introducing slightly excessive carbon dioxide gas into the alkaline alcoholic solution until the pH value of reaction liquid is 7.5-8.5, and decompressing and removing the alcoholic solution after complete reaction to obtain trimethyl sulfonium bicarbonate solid salt. The reaction equation of the invention is as follows:

according to the method, dry anhydrous alcohol is used as a reaction solvent, the thermal stability of a target product trimethylsulfonium bicarbonate is poor, the reaction solvent is preferably selected from various alcohols of C1-C4, meanwhile, the solubility difference of sodium chloride and sodium hydroxide in the alcohol is considered, mixed alcohol combining two kinds of C1-C4 alcohol can be used, the use mode of the mixed solvent can be two modes, one mode is that methanol or ethanol is used for dissolving sodium hydroxide, propanol or butanol is used for dissolving trimethylsulfonium chloride salt, and then mixing reaction is carried out; another way is to directly use a reactant of a mixed solvent with a volume ratio of two alcohols of about 1:1, the mixed solvent is used for increasing the solubility of sodium hydroxide by using methanol or ethanol, reducing the dosage of the solvent, and simultaneously using propanol or butanol to further reduce the solubility of byproduct sodium chloride and improve the purity of the product, wherein the preferred solvents are methanol, ethanol, propanol, isopropanol, methanol (ethanol) -isopropanol mixed solution and methanol (ethanol) -butanol mixed solution.

The reaction for synthesizing trimethylsulfonium hydroxide has no special requirements on reactant concentration and reaction time, and only needs to ensure that the initial raw materials of sodium hydroxide and trimethylsulfonium chloride are completely dissolved at corresponding reaction temperature in the aspect of reactant concentration; in the aspect of reaction time, when the dropwise addition of the sodium hydroxide alcohol solution is finished, the reaction is almost complete, and the reaction time can be properly prolonged for ensuring that the product sodium chloride is fully crystallized and separated out, and is preferably 0.5-2.0 h.

The trimethyl sulfonium hydroxide intermediate used in the invention is easy to decompose after being heated and placed for a long time, so the reaction temperature of each step is controlled within the range of-5 to 40 ℃, wherein the preferable temperature range is 0 to 30 ℃.

The theoretical reaction molar ratio of the trimethylsulfonium hydroxide and the carbon dioxide is 1:1, the carbon dioxide introduced is excessive in practice, and the preferred molar ratio is 1: 1.1-1.5.

The method can judge the end point of the reaction for synthesizing the trimethylsulfonium bicarbonate according to the change of the pH value in the reaction process, the pH value of the initial trimethylsulfonium hydroxide alkaline alcoholic solution is about 13, and the reaction can be judged to be complete when the pH value of the reaction solution is reduced to 7.5-8.5 after carbon dioxide is introduced.

After the reaction is finished, the reaction liquid can be subjected to reduced pressure distillation to remove the solvent to obtain a pure product of the solid trimethylsulfonium bicarbonate, the trimethylsulfonium bicarbonate product is obviously decomposed by heating at the temperature of more than 60 ℃, the temperature for removing the solvent by reduced pressure distillation is preferably controlled to be below 60 ℃, and in addition, the distilled alcohol solvent can be recycled to achieve the purpose of reducing the cost.

The invention is characterized in that: compared with the literature report method, the preparation method of the trimethyl sulfonium hydroxide alkaline alcoholic solution has the advantages of high reaction conversion rate, easily obtained raw materials, short reaction time, simple process, small environmental protection risk and the like, and is suitable for large-scale industrial production; secondly, the trimethylsulfonium hydroxide alkaline alcoholic solution is used for replacing the corresponding alkaline aqueous solution to synthesize the solid trimethylsulfonium bicarbonate, so that the risk of thermal decomposition of the trimethylsulfonium bicarbonate can be greatly reduced, the synthesis yield is improved, and the production energy consumption is reduced; finally, the solid trimethylsulfonium bicarbonate product is convenient to transport and store, and has good stability, and the solid product is sealed and placed at room temperature for more than 1 year without obvious deterioration.

Drawings

FIG. 1 shows the preparation of trimethylsulfonium bicarbonate salt according to the invention¹H NMR(600 MHz，D₂O) diagram.

Detailed Description

The technical scheme of the present invention will be further specifically described below by way of specific examples, but the present invention is not limited to these examples, and the preparation process under other conditions can be realized by referring to the methods of the following examples.

Example one, 2.05 g trimethylsulfonium chloride salt is dissolved in 15m L absolute ethyl alcohol, the solution is cooled and stirred in ice water bath, 10m L ethanol solution containing 0.80 g sodium hydroxide is slowly dripped, after the dripping is finished, the solution is continuously stirred and reacted for 0.5h at 10-15 ℃, the solution is kept stand for 1.0 h and then filtered to remove the sodium chloride, 0.98 g carbon dioxide gas is slowly introduced into the filtrate until the pH value of the reaction solution is about 8.2, and then the ethanol is recovered by reduced pressure rotary evaporation at 45 ℃ to obtain 2.37 g target product trimethylsulfonium bicarbonate salt, the yield is 94.2%,¹HNMR(D₂o, 600M): 2.98 (s.9H), and a typical hydrogen nuclear magnetic resonance spectrum diagram of the product is shown in an attached figure 1, and the product can be directly applied to the subsequent application.

Example II A, 11.26g of trimethylsulfonium chloride salt is dissolved in 50m L anhydrous methanol, the solution is cooled and stirred in an ice salt bath at the temperature of minus 5 ℃, a 30m L methanol solution containing 4.02 g of sodium hydroxide is slowly dripped, after the dripping is finished, the temperature is continuously maintained at 0-5 ℃ for stirring and reacting for 2.0 hours, the sodium chloride is removed by filtration, 6.6 g of carbon dioxide gas is slowly introduced into the filtrate, the pH value of the reaction solution is about 7.5, and then the methanol is recovered by rotary evaporation at the temperature of 40 ℃, so that 13.28 g of target product trimethylsulfonium bicarbonate salt is obtained, the yield is 96.1%, the product can be directly applied subsequently, and the crude product can be reprocessed by using anhydrous isopropanol to obtain the trimethylsulfonium salt with higher purity.

Example III A trimethylsulfonium chloride salt 11.25g is dissolved in anhydrous isopropanol 75m L, the solution is stirred in a water bath at room temperature, a 30m L methanol solution containing 4.02 g of sodium hydroxide is slowly dripped, after the dripping is finished, the stirring reaction is continued for 1.0 h, the sodium chloride is removed by filtration, 6.0 g of carbon dioxide gas is slowly introduced into the filtrate until the pH value of the reaction solution is about 8.0, and then the alcohol solvent is recovered by reduced pressure rotary evaporation at 45 ℃ to obtain a target product trimethylsulfonium bicarbonate salt 12.82 g, wherein the yield is 92.8 percent, and the product can be directly applied subsequently.

Example four, 5.63g trimethylsulfonium chloride salt is dissolved in 30m L anhydrous n-butanol, stirred in water bath at room temperature, 15m L ethanol solution containing 2.01 g sodium hydroxide is slowly dropped, after dropping, the reaction is continuously stirred at room temperature for 1.0 h, sodium chloride is removed by filtration, 3.3 g carbon dioxide gas is slowly introduced into the filtrate until the pH value of the reaction solution is about 8.2, then alcohol solvent is recovered by reduced pressure rotary evaporation at 50 ℃, the crude product is further dried at 60 ℃ for 0.5h under reduced pressure, and 5.83 g target product trimethylsulfonium bicarbonate salt is obtained, the yield is 84.4%, and the product can be directly used for subsequent application.

Example five, 5.63g trimethylsulfonium chloride salt is dissolved in 20m L methanol-isopropanol mixed alcohol solvent (v/v =1: 1), the mixture is cooled and stirred in an ice-water bath, 2.01 g sodium hydroxide is dissolved in 30m L methanol-isopropanol mixed alcohol solvent (v/v =1: 1), then the mixture is slowly dripped into the trimethylsulfonium chloride solution at the temperature of 5-10 ℃, the mixture is continuously stirred and reacted for 1.0 hour after the dripping is finished, sodium chloride is removed by filtration, 3.3 g carbon dioxide gas is slowly introduced into the filtrate until the pH value of the reaction solution is about 8.2, then the alcohol solvent is recovered by rotary evaporation under reduced pressure at the temperature of 45 ℃, and 6.55 g target product trimethylsulfonium bicarbonate salt is obtained, the yield is 94.8%, and the product can be directly applied subsequently.

Sixthly, 112.6g of trimethylsulfonium chloride salt is dissolved in 750m L of absolute ethyl alcohol, the mixture is cooled and stirred in an ice water bath, 400m L of ethanol solution containing 40.1 g of sodium hydroxide is slowly dripped, the reaction temperature is maintained at 10-25 ℃, after about 1.5 h of dripping is finished, the mixture is continuously stirred and reacted for 2.0h, the mixture is kept stand for 1.0 h and filtered to remove sodium chloride, excessive carbon dioxide gas is slowly introduced into the filtrate until the pH value of the reaction solution is about 8.5, then ethanol is removed by reduced pressure rotary evaporation at 40 ℃, and 131.8 g of target product trimethylsulfonium bicarbonate salt is obtained, the yield is 95.4%, the product can be directly applied subsequently, and the recovered solvent can be recycled.

Claims

1. A method for synthesizing trimethylsulfonium bicarbonate comprises the following steps: dropwise adding sodium hydroxide alcoholic solution with equal molar ratio into trimethyl sulfonium chloride alcoholic solution at-5-40 ℃ by taking anhydrous alcohol as a solvent, stirring and reacting for 0.5-2.0 h, filtering to remove sodium chloride precipitate to obtain trimethyl sulfonium hydroxide alkaline alcoholic solution, then introducing slightly excessive carbon dioxide gas into the alkaline alcoholic solution until the pH value of reaction liquid is 7.5-8.5, and removing the alcoholic solution under reduced pressure after complete reaction to obtain a trimethyl sulfonium bicarbonate solid salt product, wherein the temperature is controlled below 60 ℃ when the solvent is removed under reduced pressure.

2. The method of synthesis according to claim 1, characterized in that: the reaction solvent is a mixed alcohol of various alcohols of C1-C4 or a combination of two alcohols of C1-C4.

3. The method of synthesis according to claim 2, characterized in that: the reaction solvent is methanol, ethanol, propanol, isopropanol, methanol-isopropanol mixed solution, ethanol-isopropanol mixed solution, methanol-butanol mixed solution or ethanol-butanol mixed solution.

4. A synthesis method according to claim 1, 2 or 3, characterized in that: the reaction temperature is controlled to be 0-30 ℃.

5. A synthesis method according to claim 1, 2 or 3, characterized in that: the molar ratio of the introduced carbon dioxide to the trimethyl sulfonium hydroxide is controlled to be 1.1: 1-1.5: 1.

6. A synthesis method according to claim 1, 2 or 3, characterized in that: the reaction solvent can be recycled.