Preparation method of high-boiling-point solvent of 2-thiophenesulfonyl fluoride

Abstract

The invention discloses a preparation method of a high-boiling-point solvent of 2-thiophenesulfonyl fluoride, which comprises the following steps: carrying out nucleophilic fluorination reaction on 2-thiophenesulfonyl chloride in the high-boiling-point solvent under the action of a fluorination reagent at 0-70 DEG C to generate a 2-thiophenesulfonyl fluoride crude product, carrying out suction filtration to remove inorganic fluoride salt filter residues, and distilling the filtrate under vacuum conditions to obtain the high-boiling-point solvent of 2-thiophenesulfonyl fluoride. And separating the product at the temperature of 30-100 DEG C to obtain the colorless and transparent high-purity 2-thiophenesulfonyl fluoride. The preparation method provided by the invention has the advantages of easily available raw materials, low cost, simple synthesis process, high product purity, high yield, reusable solvent and no generation of toxic and harmful substances, and is suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery materials, and in particular to a method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride. Background Art

[0002] With the rapid development of electric vehicles, electronic equipment and other fields, the demand for lithium-ion batteries has greatly increased. Driven by the market of new energy vehicles and energy storage, the performance of batteries has become more and more demanding, and research has begun on lithium-ion batteries and sodium-ion batteries with high energy density and high cycle yield.

[0003] Thiophenesulfonic acid metal salts have good high-temperature cycle benefits. Thiophene groups can form self-polymerized films at 60°C, which can effectively improve inorganic film-forming properties and inhibit organic film-forming properties. Fluorinated compounds usually have the advantages of improving bioavailability and enhancing their metabolic stability.

[0004] At present, the preparation method of traditional sulfonyl fluoride products is mostly prepared by nucleophilic fluorination reaction in low boiling point solvents (dichloromethane, acetonitrile, etc.). The solvent in the obtained crude sulfonyl fluoride is first distilled to remove the low boiling point solvent after filtration, and then the high-purity sulfonyl fluoride product is obtained by distillation. However, this method of first removing the low boiling point solvent by distillation greatly increases the workload, prolongs the reaction time, reduces the purification efficiency and purity, increases energy consumption, and increases the burden of tail gas treatment, which is unfriendly to the environment. For 2-thiophenesulfonyl fluoride, its preparation method is rarely reported; 2-thiophenesulfonyl fluoride is an additive for lithium ion battery electrolyte, and its purity and other requirements are relatively high. The existing preparation method in a low boiling point solvent is not applicable to the preparation of 2-thiophenesulfonyl fluoride. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride; the reaction process in the preparation method of the present invention is carried out in a high boiling point solvent, which can simplify the process flow, improve product purity and yield, reduce energy consumption, and alleviate environmental burden.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride comprises the following steps: at 0-70°C, 2-thiophenesulfonyl chloride undergoes a nucleophilic fluorination reaction in a high boiling point solvent under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride product; the inorganic fluoride salt filter residue is removed by suction filtration; the filtrate is distilled under vacuum conditions; the product is separated at 30-100°C to obtain colorless and transparent high-purity 2-thiophenesulfonyl fluoride.

[0008] Preferably, the fluorination agent is at least one of an inorganic fluoride salt, a BAST organic fluorination agent, triethylamine hydrofluoride, and tetrabutylammonium fluoride.

[0009] Preferably, the inorganic fluoride salt is at least one of KF, AgF, CsF, NaF and CaF.

[0010] Furthermore, the molar ratio of the fluorination agent to 2-thiophenesulfonyl chloride is (1-5):1.

[0011] Preferably, the high boiling point solvent is at least one of dimethyl glutarate, diethyl glutarate, dimethyl adipate, diethyl adipate, caprylic acid glyceride, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether, ethylene glycol dibutyl ether, diphenyl ether, dibenzene ether, n-hexyl ether, dioctyl ether, n-butyl phenyl ether, ethylene glycol phenyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dodecane, n-tetradecane, n-hexadecane, n-octadecane, chlorododecane, chlorotetradecane, and chlorohexadecane.

[0012] Furthermore, the molar ratio of 2-thiophenesulfonyl chloride to the high boiling point solvent is 1:(3-10).

[0013] Furthermore, the reaction temperature of the nucleophilic fluorination reaction is 0-70°C.

[0014] Furthermore, the nucleophilic fluorination reaction time is 0.5-5 hours.

[0015] Furthermore, the vacuum distillation temperature is 30-100° C., and the distillation pressure is 0.1 kPa-50 kPa.

[0016] The beneficial effects of the present invention are:

[0017] Compared with the prior art, the preparation method of the present invention adopts reverse thinking and uses a solvent with a boiling point higher than that of 2-thiophenesulfonyl fluoride, so that in the purification process of the reaction, only the earliest distilled component needs to be taken to collect high-purity 2-thiophenesulfonyl fluoride, and the remaining undistilled reaction liquid is cooled by the specific gravity difference, and can be reused as the solvent of the next wave of products. The preparation method of the present invention simplifies the process flow, reduces production costs, saves reaction time, improves product purity and yield, and can reduce energy consumption and reduce environmental burden.

[0018] The preparation method of the invention can prepare 2-thiophenesulfonyl fluoride with high purity and high yield through nucleophilic fluorination reaction in a high boiling point solvent and specific post-treatment. The raw materials of the invention are easily available, the cost is low, the synthesis process is simple, the product purity is high, the yield is high, the solvent can be reused, no toxic and harmful substances are generated, and it is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The gas phase content spectrum for purity identification of 2-thiophenesulfonyl fluoride in Example 1 of the present invention;

[0020] Figure 2 The nuclear magnetic resonance spectrum for structural identification of 2-thiophenesulfonyl fluoride in Example 1 of the present invention;

[0021] Figure 3 This is the gas phase-mass spectrum of 2-thiophenesulfonyl fluoride in Example 1 of the present invention. DETAILED DESCRIPTION

[0022] The technical solutions in the present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The invention provides a method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride. At 0-70 DEG C, 2-thiophenesulfonyl chloride undergoes a nucleophilic fluorination reaction in a high boiling point solvent under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride product, and the inorganic fluoride salt filter residue is removed by suction filtration, and the filtrate is distilled under vacuum conditions. The product is separated at 30-100 DEG C to obtain colorless and transparent high-purity 2-thiophenesulfonyl fluoride.

[0024]

[0025] The fluorination agent is at least one of an inorganic fluoride salt, a BAST organic fluorination agent, triethylamine hydrofluoride, and tetrabutylammonium fluoride. The inorganic fluoride salt is at least one of KF, AgF, CsF, NaF, and CaF.

[0026] In the preparation method, the molar ratio of the fluorination agent to 2-thiophenesulfonyl chloride is (1-5):1.

[0027] Wherein, the high boiling point solvent is at least one of dimethyl glutarate, diethyl glutarate, dimethyl adipate, diethyl adipate, caprylic acid glyceride, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether, ethylene glycol dibutyl ether, diphenyl ether, dibenzene ether, n-hexyl ether, dioctyl ether, n-butyl phenyl ether, ethylene glycol phenyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dodecane, n-tetradecane, n-hexadecane, n-octadecane, chlorododecane, chlorotetradecane, and chlorohexadecane.

[0028] The molar ratio of 2-thiophenesulfonyl chloride to the high boiling point solvent is 1:(3-10).

[0029] In the preparation method, the reaction temperature of the nucleophilic fluorination reaction is 0-70° C., and the reaction time of the nucleophilic fluorination reaction is 0.5-5 hours.

[0030] In the preparation method, the vacuum distillation temperature is 30-100° C., and the distillation pressure is 0.1 kPa-50 kPa.

[0031] The present invention is further described in detail below through specific examples.

[0032] The following examples are 1 H-NMR and GC-MS spectra characterize and confirm that the obtained product has a 2-thiophenesulfonyl fluoride structure. The instruments used for detection are: Bruker ARX 400 nuclear magnetic resonance instrument (using deuterated DMSO as solvent), Agilent GC-MSD5977C; the purity of the product is tested by gas chromatography, and the instrument used for detection is: Agilent 8860 gas chromatograph.

[0033] In the following examples, purity and yield were calculated as follows:

[0034] Purity: The purity of 2-thiophenesulfonyl chloride is expressed by gas chromatography content using a hydrogen flame ionization detector. The purity is calculated by area normalization method.

[0035] Yield: Yield (%) = actual 2-thiophenesulfonyl fluoride (g) / theoretically calculated 2-thiophenesulfonyl fluoride (g) * 100%.

[0036] Example 1

[0037] Dissolve triethylamine hydrofluoride (66 g, 0.41 mol) in dry dimethyl glutarate (200 mL), add 2-thiophenesulfonyl chloride (25 g, 0.136 mol) and react at 50°C for 5 hours. Monitor the gas phase and stop the reaction. Take the filtrate after suction filtration and distill under reduced pressure at 60°C to remove the product. The fraction is 20.5 g of colorless transparent liquid with a yield of 93%. Figure 1 As shown, the purity of the product reached 99.5% after gas phase detection, and the gas chromatography data are shown in Table 1.

[0038] Table 1

[0039] Retention time (min) type Peak width (min) Peak area Peak height Peak area% 6.145 BB 0.68 8456.20 1309.83 0.49 7.042 BB 0.62 1717723.21 176366.77 99.49 12.977 VV 0.17 305.75 29.30 0.02

[0040] like Figure 2 and Figure 3 As shown, it can be confirmed that the product is 2-thiophenesulfonyl fluoride, and the H NMR spectrum data are as follows:

[0041] 1 H NMR (400MHz, DMSO-d6): δ 8.39 (dd, J = 5.0, 1.5 Hz, 1H), 8.18 (dt, J = 4.0, 1.4 Hz, 1H), 7.39 (ddd, J = 4.9, 3.9, 0.9 Hz, 1H).

[0042] Example 2

[0043] Tetrabutylammonium fluoride (177 g, 0.68 mol) was dissolved in dry n-hexyl ether (300 mL), and 2-thiophenesulfonyl chloride (25 g, 0.136 mol) was added to react at 20°C for 5 hours. The reaction was stopped by gas phase monitoring. The filtrate was filtered and distilled under reduced pressure at 60°C to obtain 19 g of colorless transparent liquid with a yield of 86% and a purity of 99.0%.

[0044] Example 3

[0045] AgF (34.4 g, 0.273 mol) was dissolved in dry diphenyl ether (100 mL), and 2-thiophenesulfonyl chloride (50 g, 0.272 mol) was added to react at 70°C for 3 hours. The reaction was stopped after gas phase monitoring. The filtrate was filtered and distilled under reduced pressure at 50°C to obtain 36 g of 2-thiophenesulfonyl fluoride, with a yield of 82% and a purity of 99.5%.

[0046] Example 4

[0047] KF (47.4 g, 0.816 mol) was dissolved in dry diethylene glycol dibutyl ether (100 mL), and 2-thiophenesulfonyl chloride (50 g, 0.272 mol) was added to react at 50°C for 0.5 hour, and the reaction was stopped after gas phase monitoring. The filtrate was filtered and distilled under reduced pressure at 55°C to obtain 40 g of 2-thiophenesulfonyl fluoride, with a yield of 91% and a purity of 99.5%.

[0048] Example 5

[0049] CsF (41.2 g, 0.273 mol) was dissolved in dry n-hexadecane (200 mL), and 2-thiophenesulfonyl chloride (50 g, 0.272 mol) was added to react at 20°C for 4 hours, and the reaction was stopped after gas phase monitoring. The filtrate was filtered and vacuum distilled at 70°C to evaporate the product, and the reaction was stopped to obtain 35 g of the product 2-thiophenesulfonyl fluoride, with a yield of 80% and a product purity of 99%.

[0050] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0051] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride, characterized in that: At 0-70°C, 2-thiophenesulfonyl chloride undergoes nucleophilic fluorination reaction in a high boiling point solvent under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride. The inorganic fluoride salt residue is removed by suction filtration, and the filtrate is distilled under vacuum conditions. The product is separated at 30-100°C to obtain colorless, transparent, high-purity 2-thiophenesulfonyl fluoride.

2. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The fluorination agent is at least one of an inorganic fluoride salt, a BAST organic fluorination agent, triethylamine hydrofluoride, and tetrabutylammonium fluoride.

3. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 2, characterized in that: The inorganic fluoride salt is at least one of KF, AgF, CsF, NaF, and CaF.

4. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The molar ratio of the fluorination agent to 2-thiophenesulfonyl chloride is (1-5):

1.

5. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The high boiling point solvent is at least one of dimethyl glutarate, diethyl glutarate, dimethyl adipate, diethyl adipate, caprylic acid glyceride, diethylene glycol dibutyl ether, diethylene glycol monobutyl ether, ethylene glycol dibutyl ether, diphenyl ether, dibenzene ether, n-hexyl ether, dioctyl ether, n-butyl phenyl ether, ethylene glycol phenyl ether, triethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dodecane, n-tetradecane, n-hexadecane, n-octadecane, chlorododecane, chlorotetradecane, and chlorohexadecane.

6. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The molar ratio of 2-thiophenesulfonyl chloride to the high boiling point solvent is 1:(3-10).

7. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The reaction temperature of the nucleophilic fluorination reaction is 0-70°C.

8. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The nucleophilic fluorination reaction time is 0.5-5 hours.

9. The method for preparing a high boiling point solvent of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The vacuum distillation temperature is 30-100°C, and the distillation pressure is 0.1kPa-50kPa.

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