Solvent-free preparation method of 2-thiophenesulfonyl fluoride

Abstract

The invention discloses a solvent-free preparation method of 2-thiophenesulfonyl fluoride, which comprises the following steps: carrying out nucleophilic fluorination reaction on 2-thiophenesulfonyl chloride under the action of a fluorination reagent at 0-70 DEG C to generate a 2-thiophenesulfonyl fluoride crude product, distilling under a vacuum condition, and separating the product at 30-100 DEG C to obtain colorless and transparent high-purity 2-thiophenesulfonyl fluoride. The method provided by the invention has the advantages of easily available raw materials, simple synthesis process, high product purity, high yield, large material contact area by adopting a solvent-free method, and reaction time saving; the method does not need solvent recycling and post-treatment links, is energy-saving and environment-friendly, saves the production cost, achieves the purpose of clean production, and has a wide application prospect.

Description

Technical Field

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

[0002] As the demand for lithium-ion batteries increases, research has begun on lithium-ion batteries with high energy density, high capacity, high output, and high cycle characteristics. This requires adding appropriate additives to the electrolyte of lithium-ion batteries to improve their performance, among which 2-thiophenesulfonyl fluoride has gradually come into the public's view.

[0003] At present, the preparation method of traditional sulfonyl fluoride products is mostly prepared by nucleophilic fluorination reaction in solvent (dichloromethane, acetonitrile, etc.). The solvent in the obtained crude sulfonyl fluoride product 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 prolongs the reaction time, reduces the purification efficiency and purity, increases energy consumption, and the excessive solvent concentration may have the risk of material impact. In addition, inorganic fluoride salts are slightly soluble in solvents, and pigments are taken out during the distillation process, causing the product color purity to be substandard, and there are a large number of impurities after the solvent is reused many times, and wastewater needs to be treated, which greatly increases the workload and production cost, and violates the concept of green chemistry. 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 solvent cannot be applied to the preparation of 2-thiophenesulfonyl fluoride. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a solvent-free preparation method of 2-thiophenesulfonyl fluoride; the preparation method of the present invention is a solvent-free preparation method, which can simplify the process flow, improve product purity and yield, reduce energy consumption, and reduce environmental burden.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] The invention provides a solvent-free preparation method of 2-thiophenesulfonyl fluoride, which specifically comprises the following steps: at 0-70°C, 2-thiophenesulfonyl chloride undergoes a nucleophilic fluorination reaction under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride product, and then distills the product under vacuum conditions, and the product is separated at 30-100°C to obtain colorless and transparent high-purity 2-thiophenesulfonyl fluoride.

[0007] Preferably, 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 preferably at least one of KF, AgF, CsF, NaF, and CaF.

[0008] Furthermore, the molar ratio of the fluorination agent to 2-thiophenesulfonyl chloride is (1-5):1.

[0009] Furthermore, the fluorination agent is added to 2-thiophenesulfonyl chloride by dropwise addition, and the dropwise addition time of the fluorination agent is 0-2 hours.

[0010] Furthermore, the reaction temperature of the nucleophilic fluorination reaction is 0-70°C.

[0011] Furthermore, the nucleophilic fluorination reaction time is 0.5-5 hours.

[0012] Furthermore, the vacuum distillation temperature is 30-100° C., and the distillation pressure is 0.1 kPa-50 kPa.

[0013] The beneficial effects of the present invention are:

[0014] The preparation method of the present invention abandons the traditional preparation process in a solvent, not only reduces the amount of fluorination reagent, accelerates the reaction rate, improves the yield and product purity, but also avoids the recycling and post-processing of the solvent, reduces the production cost, saves the reaction time, simplifies the process flow, meets the production concept of green chemistry, and achieves the effect of clean production. The preparation method of the present invention can obtain high-purity and high-yield 2-thiophenesulfonyl fluoride through solvent-free nucleophilic fluorination reaction and specific post-processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The gas phase content spectrum for purity identification of 2-thiophenesulfonyl fluoride in Example 1 of the present invention;

[0016] Figure 2 The nuclear magnetic resonance spectrum for structural identification of 2-thiophenesulfonyl fluoride in Example 1 of the present invention;

[0017] Figure 3 This is the gas phase-mass spectrum of 2-thiophenesulfonyl fluoride of Example 1 of the present invention. DETAILED DESCRIPTION

[0018] 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.

[0019] The invention provides a solvent-free preparation method of 2-thiophenesulfonyl fluoride, which specifically comprises the following steps: at 0-70°C, 2-thiophenesulfonyl chloride undergoes a nucleophilic fluorination reaction under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride product, and then distills the product under vacuum conditions, and the product is separated at 30-100°C to obtain colorless and transparent high-purity 2-thiophenesulfonyl fluoride.

[0020]

[0021] The fluorination agent is preferably at least one of an inorganic fluoride salt, a BAST organic fluorination agent, triethylamine hydrofluoride, and tetrabutylammonium fluoride. The inorganic fluoride salt is preferably at least one of KF, AgF, CsF, NaF, and CaF, and the inorganic fluoride salt needs to be activated in advance.

[0022] In the preparation method of the present invention, the molar ratio of the fluorination agent to 2-thiophenesulfonyl chloride is (1-5):1.

[0023] The fluorination agent is added to 2-thiophenesulfonyl chloride by dropwise addition, and the dropwise addition time of the fluorination agent is 0-2 hours.

[0024] 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.

[0025] After the reaction is completed, the vacuum distillation temperature is 30-100°C and the distillation pressure is 0.1 kPa-50 kPa.

[0026] The present invention is further described in detail below through specific examples.

[0027] 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.

[0028] In the following examples, purity and yield were calculated as follows:

[0029] 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.

[0030] Yield: Yield (%) = actual 2-thiophenesulfonyl fluoride (g) / theoretically calculated 2-thiophenesulfonyl fluoride (g) * 100%.

[0031] Example 1

[0032] 2-Thiophenesulfonyl chloride (25 g, 0.136 mol) was added dropwise into triethylamine hydrofluoride (66 g, 0.41 mol) within 0.5 hours, and the mixture was reacted at 50°C for 5 hours. The reaction was stopped by gas phase monitoring, and the product was distilled under reduced pressure at 60°C. The fraction was 21 g of colorless transparent liquid, and the yield was 95%. 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.

[0033] Table 1

[0034] Retention time (min) type Peak width (min) Peak area Peak height Peak area% 6.163 BM 0.66 8941.18 1364.66 0.49 7.070 MM 0.72 1813697.78 182562.64 99.51

[0035] 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:

[0036] 1 H NMR (400MHz, DMSO-d6): δ8.39 (dd, J=5.0, 1.5Hz, 1H), 8.18 (dt, J=4.0, 1.4Hz, 1H), 7.39 (ddd, J=4.9, 3.9, 0.9Hz, 1H).

[0037] Example 2

[0038] 2-Thiophenesulfonyl chloride (25 g, 0.136 mol) was added dropwise to tetrabutylammonium fluoride (177 g, 0.68 mol) within 1 hour, and the mixture was reacted at 20°C for 5 hours. The reaction was stopped by gas phase monitoring and vacuum distillation was performed. The product was evaporated at 60°C to obtain 20.5 g of a colorless transparent liquid with a yield of 93% and a purity of 99.8%.

[0039] Example 3

[0040] 2-Thiophenesulfonyl chloride (50 g, 0.272 mol) was added dropwise to AgF (34.4 g, 0.273 mol) within 1 hour, and the mixture was reacted at 70°C for 3 hours. The reaction was stopped and the product was distilled under reduced pressure at 50°C to obtain 41 g of 2-thiophenesulfonyl fluoride with a yield of 93% and a purity of 99.5%.

[0041] Example 4

[0042] 2-Thiophenesulfonyl chloride (50 g, 0.272 mol) was added dropwise into KF (47.4 g, 0.816 mol) within 1 hour, and the reaction was carried out at 50°C for 0.5 hour. The reaction was stopped and the product was 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%.

[0043] Example 5

[0044] 2-Thiophenesulfonyl chloride (50 g, 0.272 mol) was added dropwise into CsF (41.2 g, 0.273 mol) within 0.5 hours, and the mixture was reacted at 20°C for 4 hours. The reaction was stopped after gas phase monitoring. The product was evaporated at 70°C and the reaction was stopped to obtain 43 g of 2-thiophenesulfonyl fluoride with a yield of 98% and a purity of 99%.

[0045] 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.

[0046] 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 solvent-free preparation method of 2-thiophenesulfonyl fluoride, characterized in that: At 0-70°C, 2-thiophenesulfonyl chloride undergoes a nucleophilic fluorination reaction under the action of a fluorinating agent to generate a crude 2-thiophenesulfonyl fluoride, which is then distilled under vacuum conditions. At 30-100°C, the product is separated to obtain colorless, transparent, high-purity 2-thiophenesulfonyl fluoride.

2. A solvent-free preparation method 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. A solvent-free preparation method 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 solvent-free preparation method 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 solvent-free preparation method of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The fluorination agent is added to 2-thiophenesulfonyl chloride by dropwise addition, and the dropwise addition time of the fluorination agent is 0-2 hours.

6. The solvent-free preparation method of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The reaction temperature of the nucleophilic fluorination reaction is 0-70°C.

7. The solvent-free preparation method of 2-thiophenesulfonyl fluoride according to claim 1, characterized in that: The nucleophilic fluorination reaction time is 0.5-5 hours.

8. The solvent-free preparation method 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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