Preparation method of negative charge highly delocalized sulfimide alkali metal salt

Abstract

The invention provides a synthesis method of a negative charge highly delocalized sulfonyl imide alkali metal salt {[(R3SO2) (R2 (R1SO2N) SO) N] M), M = Li, Na, K, Rb or Cs}. The synthesis method comprises the following steps: carrying out oxidation and fluorination reaction on alkyl (S-alkyl sulfonyl imide) potassium sulfinate (or rubidium or cesium) and an N-fluorine electrophilic reagent to synthesize alkyl (S-alkyl sulfonyl imide) sulfonyl fluoride with the yield of 70-90%; the obtained alkyl (S-alkyl sulfimide) sulfonyl fluoride and sulfamide containing substituent R3 or alkali metal salt thereof are subjected to nucleophilic substitution reaction, the product is purified to obtain the high-purity negative-charge highly-delocalized sulfimide alkali metal salt, and the method has the characteristics that the operation is simple, the raw materials are low in price, the product is easy to separate and purify, the method is suitable for industrial mass production, and the like; and the prepared negative charge highly delocalized sulfimide alkali metal salt is high in chemical stability and good in solubility, and is a preferable electrolyte material for realizing high-specific-energy power and energy storage batteries.

Description

Technical Field

[0001] This invention belongs to the fields of non-aqueous electrolyte materials, power batteries and electrochemical energy storage, and relates to a method for preparing alkali metal salts of sulfonylimide with highly delocalized negative charge. Background Technology

[0002] Electrolyte conductive salts can provide charge carriers for the electrolyte bulk and participate in the formation and stabilization process of the electrode-electrolyte interface phase. Therefore, the basic physical, chemical and electrochemical properties of conductive salts (such as chemical and electrochemical stability, electrode interface compatibility, etc.) are closely related to the electrochemical performance of secondary batteries and are one of the key materials for constructing high-energy-density secondary battery systems. Existing commercial lithium-ion batteries (LIBs) generally use non-aqueous liquid electrolytes based on lithium hexafluorophosphate (LiPF6) as the main conductive salt as ion conductors, mainly due to the unique advantages of this type of electrolyte: (1) high ionic conductivity (approximately 10 Ω·cm at room temperature). -2 S cm -1 (2) Good resistance to aluminum foil corrosion, and (3) Wide electrochemical window (>4.5V vs. Li / Li). + [See: K. Xu, Chemical Reviews, 2014, 114, 11503]. However, LiPF6 has poor chemical stability. Its electrolyte is easily decomposed by protonated impurities (such as water and hydrogen fluoride) to produce harmful substances such as phosphorus pentafluoride (PF5), phosphorus trifluoride (POF3), and hydrogen fluoride (HF), which greatly reduces the coulombic efficiency and cycle stability of the battery [See: L. Zheng, Electrochimica Acta, 2016, 196, 169–188].

[0003] To address these challenges, researchers in academia and industry have been continuously exploring the molecular structure design of conductive salt anions to overcome the shortcomings of existing hexafluorophosphate systems and meet the application requirements of next-generation high-energy-density batteries. Among these, the sulfonamide anion [–SO2–N…]… (-)[-SO2-] possesses characteristics such as high delocalization of the negative charge of the anion, high conformational freedom, and strong structural designability. Previous studies have shown that non-aqueous electrolytes based on sulfonylimide anions of alkali metal salts exhibit excellent chemical stability (e.g., low susceptibility to hydrolysis, good tolerance to protonated impurities), high thermal decomposition temperature (>300℃), high ionic conductivity, and a wide electrochemical window, making them a promising class of alkali metal salts [see: Q.Ma, ChemElectroChem, 2021, 8(10): 1807–1816]. For example, non-aqueous liquid electrolytes using lithium asymmetric (perfluoroalkylsulfonyl)(polyfluoroalkoxysulfonyl)imide as the conductive salt exhibit excellent properties such as high thermal stability, strong resistance to oxidation-reduction, and no aluminum foil corrosion. In particular, compared with battery devices containing LiPF6 conductive salts, batteries based on asymmetric (perfluoroalkyl sulfonyl) (polyfluoroalkoxy sulfonyl) imine lithium exhibit superior high-temperature cycling stability and shelf storage performance [see: Chinese Patent CN103515650A].

[0004] Using perfluoroalkyl sulfonamide (R) 1 Replacing the oxygen atom (O=) on the sulfonyl group with SO2N= can construct a novel alkali metal salt of sulfonylimide with a high degree of negative charge delocalization, thereby obtaining a non-aqueous electrolyte material system with better performance and thus improving the performance of secondary batteries. For example, replacing one oxygen atom (O=) in the bis(trifluoromethylsulfonyl)imide anion structure with trifluoromethylsulfonylimide (CF3SO2N=) can effectively increase the degree of delocalization of the negative charge of the anion, thereby improving the ionic conductivity of non-aqueous electrolytes based on sulfonylimide anions [see: H. Zhang, ChemElectroChem, 2021, 8: 1322–1328]. Furthermore, based on the highly delocalized sulfonylimide structure, introducing substituents containing unsaturated double bonds can prepare a special type of anion-immobilized "polyanion" conductive salt. Its main characteristics are: (1) large molecular weight and large volume of anions, making migration difficult; (2) high cation transference number, close to 1. The prepared electrolyte material possesses advantages such as high room-temperature ionic conductivity, high cation transference number, good mechanical properties, and a wide electrochemical window, effectively improving the interfacial stability of the electrode-electrolyte phase and enhancing the cycle performance and high- and low-temperature performance of the battery [see: Q. Ma, Angewandte Chemie-International Edition, 2016, 55: 2521–2525]. Therefore, highly delocalized negatively charged sulfonyl imide alkali metal salts are an important class of electrolyte conductive salt materials; however, existing methods for preparing highly delocalized negatively charged sulfonyl imide alkali metal salts suffer from problems such as harsh synthesis conditions, high latent heat of reaction, high cost, and low yield, making it difficult to achieve industrial application.

[0005] Currently, the synthesis of highly delocalized negatively charged sulfonyl imide alkali metal salts mainly employs alkyl (S-alkylsulfonyl imide) sulfonyl fluoride [R 1 SO2NS(O)(R 2 [F] is obtained by nucleophilic substitution reaction with the corresponding sulfonamide salt. For the synthesis of the key intermediate trifluoromethyl (S-trifluoromethylsulfonylimide)sulfonyl fluoride [CF3SO2NS(O)(CF3)F], Professor Yagupolskii's team at the Institute of Organic Chemistry, National Academy of Sciences of Ukraine, proposed a two-step synthetic route, which includes: (1) using potassium trifluoromethyl (S-trifluoromethylsulfonylimide)sulfinate {K[CF3SO2NS(O)CF3]} as a substrate, reacting it with chlorine gas in an oxidative chlorination reaction to generate trifluoromethyl (S-trifluoromethylsulfonylimide)sulfonyl chloride [CF3SO2NS(O)(CF3)Cl]; (2) using the above CF3SO2NS(O)(CF3)Cl and cesium fluoride in a nucleophilic substitution reaction to prepare CF3SO2NS(O)(CF3)F [see: LMYagupolskii, Journal of the Chemical Society Perkin Transactions 1, 2002, 2(16): 1887–1889]. This preparation method uses hazardous gases, and the synthesis conditions are harsh with a large latent heat of reaction. It also suffers from high cost, complex operation, and low yield. The main difficulties are: (1) harsh reaction conditions and a synthesis cycle requiring 48 hours; (2) CF3SO2NS(O)(CF3)F is sensitive to water and easily hydrolyzed; (3) CF3SO2NS(O)(CF3)F is volatile and difficult to collect and transfer. In summary, establishing an efficient synthetic methodology for the key intermediate alkyl (S-alkylsulfonylimide)sulfonyl fluoride is crucial for preparing highly delocalized negatively charged sulfonylimide alkali metal salts and is also a key technological bottleneck for realizing the application of this type of novel conductive salt in high-energy-density secondary batteries. Summary of the Invention

[0006] Based on the current research status of sulfonylimide alkali metal salts, the objective of this invention is to provide a method for preparing a highly delocalized negatively charged sulfonylimide alkali metal salt, overcoming the difficulties of existing methods involving hazardous gases (chlorine), complicated steps, and low yields. This method offers advantages such as mild reaction conditions, low cost, and high efficiency, thereby addressing the shortcomings of existing preparation methods and enabling the industrial application of novel highly delocalized negatively charged imine alkali metal salts.

[0007] The negatively charged, highly delocalized sulfonylimide alkali metal salt has the structure shown in formula (I).

[0008]

[0009] In formula (I):

[0010] M = Li, Na, K, Rb, or Cs

[0011] Substituent R 1 R 2 R 3 Each of them independently has the meaning described in any one of ① to ⑧ below, and R 1 R 2 and R 3 They can be the same or different:

[0012] ① is a perfluoroalkyl C m F 2m+1 , where m is 0 or a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0013] ② is a perfluoroalkoxy C m F 2m+1 O, where m is a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0014] ③ is a fluoroalkyl group H (CF2CF2O) containing fluorinated ethylene oxide. m CF2CF2 or F(CF2CF2O) m CF2CF2, where m is a positive integer from 1 to 8;

[0015] ④ is a hydrocarbon alkyl group (C). m H 2m+1 , where m is a positive integer from 1 to 10; preferably m is a positive integer from 1 to 4;

[0016] ⑤ is a hydrocarbon alkoxy group (C). m H 2m+1 O; where m is a positive integer from 1 to 10;

[0017] ⑥ is a partially haloalkyl group, i.e., C m X n H 2m+1-n Where X = F, Cl, Br or I, n≤2m+1, and m is a positive integer from 1 to 10; preferably CF2H, CH2F, CF3CH2, (CF3)2CH, CCl2H, CH2Cl or CCl3CH2;

[0018] ⑦ is a partially haloalkoxy group, i.e., C m X n H 2m+1-n O, where X = F, Cl, Br or I, n≤2m+1, m is a positive integer from 1 to 10; preferably CF3CH2O, (CF3)2CHO, ClCH2O, Cl2CHO or CCl3CH2O;

[0019] ⑧ is a group containing an unsaturated double bond, wherein the unsaturated double bond group can be CH2=CH–C6H4, CH2=CH–

[0020] C6H3CH3, CH2=CH–C6H3Cl, CH2=CH–C6H3F, CH2=CH–COOCH2, CH2=C(CH3)–

[0021] COOCH2, CH2=CH–COOCH2CH2, CH2=C(CH3)–COOCH2CH2, CH2=CH–

[0022] COOCH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=CH–COOCH2CH2CH2CH2 or

[0023] CH2=C(CH3)–COOCH2CH2CH2CH2; preferably CH2=CH–C6H4 or CH2=C(CH3)–COOCH2CH2

[0024] Or CH2=C(CH3)–COOCH2CH2CH2.

[0025] The technical solution of this invention is: the preparation method of negatively charged highly delocalized sulfonylimide alkali metal salt provided by this invention includes the following steps:

[0026] Step 1: In a non-aqueous solvent, the alkali metal salt of alkyl (S-alkylsulfonylimide) sulfinic acid is subjected to an oxidative fluorination reaction with an N-fluorine electrophilic reagent to generate alkyl (S-alkylsulfonylimide) sulfonyl fluoride as shown in formula (II).

[0027]

[0028] In formula (II):

[0029] R 1 R 2 Each of them independently has the meaning described in any one of ① to ⑧ below, and R 1 R 2 They can be the same or different:

[0030] ① is a perfluoroalkyl C m F 2m+1 , where m is a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0031] ② is a perfluoroalkoxy C m F 2m+1 O, where m is a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0032] ③ is a fluoroalkyl group H (CF2CF2O) containing fluorinated ethylene oxide. m CF2CF2 or F(CF2CF2O) m CF2CF2, where m is a positive integer from 1 to 6;

[0033] ④ is a hydrocarbon alkyl group (C). m H 2m+1 , where m is a positive integer from 1 to 10, preferably a positive integer from 1 to 4;

[0034] ⑤ is a hydrocarbon alkoxy group (C). m H 2m+1 O, where m is a positive integer from 1 to 10;

[0035] ⑥ is a partially haloalkyl group, i.e., C m X n H 2m+1-n Where X = F, Cl, Br or I, n≤2m+1, and m is a positive integer from 1 to 10; preferably CF2H, CH2F, CF3CH2, (CF3)2CH, CCl2H, CH2Cl or CCl3CH2;

[0036] ⑦ is a partially haloalkoxy group, i.e., C m X n H 2m+1-n O, where X = F, Cl, Br or I, n≤2m+1, m is a positive integer from 1 to 10; preferably CF3CH2O, (CF3)2CHO, ClCH2O, Cl2CHO or CCl3CH2O;

[0037] ⑧ is a group containing an unsaturated double bond. The unsaturated double bond group can be CH2=CH–C6H4, CH2=CH–C6H3CH3, CH2=CH–C6H3Cl, CH2=CH–C6H3F, CH2=CH–COOCH2, CH2=C(CH3)–COOCH2, CH2=CH–COOCH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=CH–COOCH2CH2CH2 or CH2=C(CH3)–COOCH2CH2CH2CH2; preferably CH2=CH–C6H4, CH2=C(CH3)–COOCH2CH2 or CH2=C(CH3)–COOCH2CH2CH2.

[0038] Step 2: Using an inorganic or organic base as an acid-binding agent, react the alkyl (S-alkylsulfonylimide) sulfonyl fluoride obtained in Step 1 with a substituent R. 3 sulfonamide (R) 3SO2NH2) or its alkali metal salt (R) 3 SO2NHM) undergoes a nucleophilic substitution reaction, and the reaction product is purified to obtain a highly delocalized sulfonylimide salt with a negative charge containing hydrogen protons;

[0039] The structure of the highly delocalized sulfonylimide salt containing hydrogen protons is shown in formula (Ⅲ):

[0040]

[0041] In formula (Ⅲ), C ⊕ It is a cation containing a hydrogen proton.

[0042] The substituent R 3 sulfonamide (R) 3 The structure of SO2NH2 is shown in formula (Ⅳ):

[0043]

[0044] In formula (Ⅳ):

[0045] R 3 It has any of the meanings described in ① to ⑧ below:

[0046] ① is a perfluoroalkyl C m F 2m+1 , where m is 0 or a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0047] ② is a perfluoroalkoxy C m F 2m+1 O, where m is a positive integer from 1 to 8, preferably a positive integer from 1 to 4;

[0048] ③ is a fluoroalkyl group H (CF2CF2O) containing fluorinated ethylene oxide. m CF2CF2 or F(CF2CF2O) m CF2CF2, where m is a positive integer from 1 to 6;

[0049] ④ is a hydrocarbon alkyl group (C). m H 2m+1 , where m is a positive integer from 1 to 10, preferably a positive integer from 1 to 4;

[0050] ⑤ is a hydrocarbon alkoxy group (C). m H 2m+1 O, where m is a positive integer from 1 to 10;

[0051] ⑥ is a partially haloalkyl group, i.e., C m X n H 2m+1-nWhere X = F, Cl, Br or I, n≤2m+1, and m is a positive integer from 1 to 10; preferably CF2H, CH2F, CF3CH2, (CF3)2CH, CCl2H, CH2Cl or CCl3CH2;

[0052] ⑦ is a partially haloalkoxy group, i.e., C m X n H 2m+1-n O, where X = F, Cl, Br or I, n≤2m+1, m is a positive integer from 1 to 10; preferably CF3CH2O, (CF3)2CHO, ClCH2O, Cl2CHO or CCl3CH2O;

[0053] ⑧ is a group containing an unsaturated double bond. The unsaturated double bond group can be CH2=CH–C6H4, CH2=CH–C6H3CH3, CH2=CH–C6H3Cl, CH2=CH–C6H3F, CH2=CH–COOCH2, CH2=C(CH3)–COOCH2, CH2=CH–COOCH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=CH–COOCH2CH2CH2 or CH2=C(CH3)–COOCH2CH2CH2CH2; preferably CH2=CH–C6H4, CH2=C(CH3)–COOCH2CH2 or CH2=C(CH3)–COOCH2CH2CH2.

[0054] The substituent R 3 sulfonamide (R) 3 Alkali metal salts of SO2NH2 (R) 3 The structure of SO2NHM is shown in equation (V):

[0055]

[0056] R in equation (V) 3 With R in equation (Ⅳ) 3 The meanings are the same; M in formula (V) is Li, Na, K, Rb or Cs.

[0057] Step 3: The hydrogen-containing proton-containing, highly delocalized sulfonylimide salt [Formula (III)] obtained in Step 2 is subjected to a metathesis reaction with an alkali metal oxygen-containing compound or an oxoacid salt. The reaction product is purified to obtain a negatively charged, highly delocalized sulfonylimide alkali metal salt [Formula (I)].

[0058] The N-fluorine electrophilic reagent mentioned in step one can be one, or a mixture of two or more of the following: N-fluorosuccinimide (NFS), N-fluorophthalimide (NFOBS), N-fluoropyridinium salt (NFPY), 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt (F-TEDA), N-fluorobisbenzenesulfonamide (NFSI), and N-fluorobistrifluoromethylsulfonamide (F-TFSI).

[0059] In step one, the ratio of the alkyl (S-alkylsulfonylimide) sulfinic acid alkali metal salt to the N-fluorine electrophilic reagent, calculated by molar amount, is 100:20 to 100:500, preferably 100:50 to 100:300.

[0060] The non-aqueous solvent mentioned in step one can be one or a mixture of two or more of the following: butyl acetate, N,N-dimethylaniline, dimethylamine, ethylene glycol dimethyl ether, diethyl ether, methyl tert-butyl ether, ethyl acetate, tetrahydrofuran, 1,2-dichloroethane, acetone, butanone, 4-methyl-2-pentanone, ethanol, ethylene glycol, isopropanol, 1,2-propanediol, nitromethane, nitrobenzene, hexamethylphosphonic triamide, acetonitrile, propionitrile, succinic anion, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, sulfolane, 1,3-dimethylpropylene urea (DMPU), and 1,3-dimethyl-2-imidazolinone (DMEU); preferably, one or a mixture of two or more of the following: acetonitrile, dichloromethane, diethyl ether, tetrahydrofuran, acetonitrile, and dichloromethane.

[0061] The reaction temperature range for the reaction described in step one is -20°C to 80°C; preferably, the reaction temperature range is 10°C to 60°C.

[0062] The reaction time for the reaction described in step one is from 0.5 hours to 48 hours; preferably, the reaction time is from 0.5 hours to 10 hours.

[0063] The organic base used as an acid-binding agent in step two can be one or a mixture of two or more of the following: imidazole, 1-methylimidazolium, triazole, pyridine, 2,6-dimethylpyridine, triethylamine, diisopropylethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), potassium hexamethyldisilamide, sodium hexamethyldisilamide, lithium hexamethyldisilamide, sodium tetramethylpiperidine, and lithium tetramethylpiperidine; preferably, one or a mixture of two or more of the following: triethylamine, imidazole, 1-methylimidazolium, pyridine, 2,6-dimethylpyridine, sodium hexamethyldisilamide, pyridine, and 1-methylimidazolium.

[0064] The inorganic base used as an acid-binding agent in step two can be one, or a mixture of two or more of the following: potassium phosphate (K3PO4), sodium phosphate (Na3PO4), lithium phosphate (Li3PO4), dipotassium hydrogen phosphate (K2HPO4), disodium hydrogen phosphate (Na2HPO4), dilithium hydrogen phosphate (Li2HPO4), potassium dihydrogen phosphate (KH2PO4), sodium dihydrogen phosphate (NaH2PO4), lithium dihydrogen phosphate (LiH2PO4), sodium thiosulfate (Na2S2O3), and potassium dithiosulfate (K2S2O3); preferably, one, or a mixture of two or more of the following: potassium phosphate, lithium phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, tripotassium phosphate, and sodium dihydrogen phosphate.

[0065] In step two, the amount of substituent R calculated by molar amount 3 The feed ratio of sulfonamide or its alkali metal salt to alkyl (S-alkylsulfonylimide) sulfonyl fluoride is 100:50 to 100:500, preferably 100:100 to 100:300.

[0066] The reaction solvent mentioned in step two can be one or a mixture of two or more of the following: tetrahydrofuran, methyl tert-butyl ether, diethyl ether, ethylene glycol dimethyl ether, 1,3-dioxane, 1,4-dioxane, acetonitrile, dichloroacetonitrile, methyl acetate, ethyl acetate, butyl acetate, dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, γ-butyrolactone, acetone, n-butanone, 2-butanone, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 1,3-dimethylpropylene urea (DMPU), and 1,3-dimethyl-2-imidazolinone (DMEU); preferably, one or a mixture of two or more of the following: acetonitrile, dichloromethane, diethyl ether, and methyl tert-butyl ether.

[0067] The reaction temperature range for step two is -20°C to 150°C; preferably, the reaction temperature range is 0°C to 100°C.

[0068] The reaction time for step two is 4 to 24 hours; preferably, it is 6 to 12 hours.

[0069] The alkali metal oxygen-containing compound mentioned in step three can be one, or a mixture of two or more of the following: lithium oxide (Li2O), sodium oxide (Na2O), potassium oxide (K2O), lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), and cesium hydroxide (CsOH).

[0070] The alkali metal oxoacid salt mentioned in step three can be one, or a mixture of two or more of the following: lithium bicarbonate (LiHCO3), sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), rubidium bicarbonate (RbHCO3), cesium bicarbonate (CsHCO3), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), rubidium carbonate (Rb2CO3), cesium carbonate (Li2CO3), lithium hydrogen phosphate (LiH2PO4), sodium hydrogen phosphate (NaH2PO4), potassium hydrogen phosphate (KH2PO4), lithium phosphate (Li3PO4), sodium phosphate (Na3PO4), and potassium phosphate (K3PO4).

[0071] This invention provides a negatively charged, highly delocalized sulfonylimide alkali metal salt {[(R 3 SO2)(R 2 (R 1 The method for synthesizing SO2N)SO)N]M), M=Li,Na,K,Rb or Cs}, the present invention utilizes the oxidative fluorination reaction of alkyl (S-alkylsulfonylimide) potassium sulfinate (or rubidium, cesium) with N-fluorine electrophilic reagent to synthesize alkyl (S-alkylsulfonylimide) sulfonyl fluoride, with a yield of 70-90%; the obtained alkyl (S-alkylsulfonylimide) sulfonyl fluoride is then reacted with a substituent R 3 The sulfonamide or its alkali metal salt is subjected to a nucleophilic substitution reaction, and the resulting product is purified to obtain a high-purity negatively charged highly delocalized sulfonamide alkali metal salt. This method has the advantages of simple operation, low raw material price, easy separation and purification of product, and suitability for industrial mass production. The obtained negatively charged highly delocalized sulfonamide alkali metal salt has high chemical stability and good solubility, and is a preferred electrolyte material for achieving high specific energy power and energy storage batteries.

[0072] Compared with existing technologies, the synthesis method provided by this invention has advantages such as high safety, low cost, high conversion rate, and the ability to achieve large-scale industrial application. Existing preparation methods use highly hazardous chlorine gas as the oxidizing chlorination reagent, which suffers from harsh synthesis conditions and high latent heat of reaction. Furthermore, existing preparation methods utilize expensive metal fluorides such as cesium fluoride as fluorinating reagents, reacting the intermediate alkyl (S-alkylsulfonylimide)sulfonyl chloride [R...] 1 SO2NS(O)(R 2 [Cl] is converted to alkyl (S-alkylsulfonylimide)sulfonyl fluoride [R] 1 SO2NS(O)(R 2The high cost of the reaction is due to the high risk of chlorine gas and the high cost of cesium fluoride. The synthesis method provided by this invention uses an N-fluorine electrophilic reagent to replace the highly hazardous gas (chlorine) and the expensive cesium fluoride, and reacts it with an alkali metal salt of alkyl (S-alkylsulfonylimide) sulfinic acid through an oxidative fluorination reaction, directly converting it into the target product alkyl (S-alkylsulfonylimide) sulfonyl fluoride [R] in a one-pot process. 1 SO2NS(O)(R 2 [F] This reaction has the advantages of high safety, low cost and high conversion rate. It shortens the reaction time from the original 48 hours to 4 hours and increases the yield from 51% to 85%. At the same time, it eliminates the use of highly dangerous gases and meets the requirements for large-scale industrial application, thus enabling the large-scale industrial application of alkali metal salts with highly delocalized negative charge sulfonylimide. Attached Figure Description

[0073] Figure 1 The NMR fluoride spectrum of the synthesized trifluoromethyl (S-trifluoromethylsulfonylimide) sulfonyl fluoride was determined using potassium trifluoromethyl (S-trifluoromethylsulfonylimide) sulfinate as the substrate and 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt (F-TEDA) as the oxidative fluorination reagent. Acetonitrile was used as the reaction solvent, the reaction time was 4 hours, and the reaction temperature was 60℃. Deuterated acetone was used as the deuteration reagent.

[0074] Figure 2 The NMR fluorine spectra of the hydrogen-containing proton-containing (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imide pyridine salt {[PyH][(CF3SO2)(CF3(CF3SO2N)SO)N],[PyH][sTFSI]} were analyzed using trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl(S-trifluoromethylsulfonyl)imide pyridine salt as the substrate, potassium trifluoromethylsulfonamide as the nucleophile, and pyridine as the acid-binding agent. Acetonitrile was used as the reaction solvent, the reaction time was 12 hours, and the reaction temperature was 25 °C. Deuterated acetone was used as the deuteration reagent.

[0075] Figure 3 The NMR fluorine spectra of potassium (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imide pyridine salt containing hydrogen protons were prepared by neutralization with potassium carbonate, and the resulting potassium (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imide {K[(CF3SO2)(CF3(CF3SO2N)SO)N],K[sTFSI]} was analyzed. The reaction solvents were acetonitrile and water, the reaction time was 2 hours, and the reaction temperature was 25℃. The deuteration reagent was deuterated acetone.

[0076] Figure 4The nuclear magnetic resonance (NMR) fluorine spectra of potassium (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(p-styrenesulfonamide)imine {K[(CH2=CH–C6H4)(CF3(CF3SO2N)SO)N],K[SsTFSI]} were obtained by reacting p-styrenesulfonamide as a nucleophile and dipotassium hydrogen phosphate as an acid-binding agent with trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl fluoride. Acetonitrile was used as the reaction solvent, the reaction time was 24 hours, and the reaction temperature was 25 °C. Heavy water was used as the deuteration reagent. Detailed Implementation

[0077] The following lists some of the compounds involved in this invention for further detailed explanation, but the preparation methods of the embodiments are not limited to the preparation of the listed compounds.

[0078] The main instruments and equipment used in the embodiments are as follows: nuclear magnetic resonance spectrometer (AV 400M, Bruker, Switzerland) and thermostatic magnetic stirrer (DF-101S, Gongyi Yuhua Instrument Co., Ltd.).

[0079] The main reagents used in the examples were sourced from: 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt (F-TEDA, analytical grade, Aladdin Reagent Co., Ltd.); acetonitrile (CH3CN, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); ethanol (C2H5OH, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); dichloromethane (CH2Cl2, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); dimethyl sulfoxide (DMSO, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); N,N-dimethylformamide. Amide (DMF, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); Trifluoromethanesulfonamide (CF3SO2NH2, analytical grade, Solvay Group); Imidazole (C3H4N2, analytical grade, Aladdin Reagent Co., Ltd.); Triethylamine (Et3N, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); Pyridine (C5H5N, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); Dipotassium hydrogen phosphate (K2HPO4, analytical grade, Sinopharm Chemical Reagent Co., Ltd.); Anhydrous potassium carbonate (K2CO3, analytical grade, Sinopharm Chemical Reagent Co., Ltd.). The following drugs were prepared according to the methods described in the literature [see: Han Hongbo, Wuhan: Huazhong University of Science and Technology, 2012; Liu Chengyong, Wuhan: Huazhong University of Science and Technology, 2014; Ma Qiang, Wuhan: Huazhong University of Science and Technology, 2017]: potassium trifluoromethyl (S-trifluoromethylsulfonylimide)sulfinate {K[CF3SO2NS(O)CF3]}, potassium trifluoromethylsulfonamide (CF3SO2NHK), potassium fluorosulfonamide (FSO2NHK), potassium pentafluoroethylsulfonamide (C2F5SO2NHK), potassium difluoromethylsulfonamide (CHF2SO2NHK), potassium perfluoro-n-butylsulfonamide (C4F9SO2NHK), potassium trifluoroethoxysulfonamide (CF3CH2SO2NHK), potassium hexafluoroisopropoxysulfonamide [(CF3)2CHSO2NHK], and p-styrenesulfonamide (CH2=CH–C6H4SO2NH2).

[0080] I. Synthesis of Alkyl (S-alkylsulfonylimide)sulfonyl fluoride

[0081] Example 1:

[0082] Under nitrogen protection, 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt (F-TEDA, 42.51 g, 0.12 mol) and acetonitrile (CH3CN, 50 mL) were added to a 250 mL flask. After stirring for 20 minutes in an ice bath, a 100 mL solution of potassium trifluoromethyl(S-trifluoromethylsulfonylimide)sulfinate {K[CF3SO2NS(O)CF3], 30.32 g, 0.10 mol} in acetonitrile was slowly added. Stirring was continued for another 20 minutes in an ice bath, then the ice bath was removed, and the reaction was carried out at 60 °C for 4 hours. After the reaction was complete, the mixture was distilled at atmospheric pressure, and a colorless liquid was collected at 100 °C. After distillation, 24.06 g of a colorless liquid was obtained, with a yield of 85%. The structure was characterized by nuclear magnetic resonance fluorine spectroscopy, confirming that the product is trifluoromethyl (S-trifluoromethylsulfonylimide)sulfonyl fluoride [(CF3SO2NS(O)(CF3)F)].

[0083] The nuclear magnetic resonance fluorine spectrum of the obtained CF3SO2NS(O)(CF3)F ( 19 F NMR, Figure 1 )data: 19 F NMR (Acetone-d6, 376MHz, CCl3F, ppm) δ = 46.26 [q, 1F, J FF =18.8Hz, CF3SO2NS(O)(CF3) F ],-71.36[d,3F,J FF =18.8Hz,CF3SO2NS(O)(C F 3)F],-79.04[s,3F,C F The above data are consistent with the nuclear magnetic resonance fluorine spectrum results of CF3SO2NS(O)(CF3)F in published literature [see: LMYagupolskii, Journal of the Chemical Society Perkin Transactions 1, 2002, 2(16): 1887–1889].

[0084] The chemical structural formula (VI) of CF3SO2NS(O)(CF3)F is as follows:

[0085]

[0086] Example 2:

[0087] Example 2 uses other reaction times instead of the 4 hours in Example 1. These other reaction times are 2 hours, 6 hours, and 8 hours, respectively, as in Examples 2a, 2b, and 2c. Following the steps in Example 1, CF3SO2NS(O)(CF3)F was synthesized. The other reaction times and corresponding experimental results are listed in Table 1. Table 1 shows that using 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt as the oxidative fluorinating agent, and reacting with potassium trifluoromethyl(S-trifluoromethylsulfonylimide)sulfinate {K[CF3SO2NS(O)CF3]} for oxidative fluorination reactions with reaction times ranging from 2 hours to 8 hours, high yields can be obtained.

[0088] Table 1. Synthesis of trifluoromethyl (S-trifluoromethylsulfonylimide) sulfonyl fluoride using 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroboronic acid) salt at different reaction times

[0089]

[0090] II. Synthesis of Sulfonamide Salts with Highly Delocalized Negative Charges Containing Hydrogen Protons

[0091] Example 3:

[0092] In a 100 mL flask, potassium trifluoromethanesulfonamide (CF3SO2NHK, 2.57 g, 13.70 mmol), acetonitrile (CH3CN, 20 mL), and pyridine (C5H5N, 1.30 g, 16.5 mmol) were added sequentially. After stirring and dissolving, a nucleophilic substitution reaction was initiated by slowly adding a 30 mL solution of acetonitrile containing CF3SO2NS(O)(CF3)F (4.67 g, 16.50 mmol) under nitrogen protection in an ice bath. After the addition was complete, the mixture was stirred at room temperature for 48 h. After the reaction was complete, insoluble substances were removed by filtration under reduced pressure, and the filtrate was concentrated to give a pale yellow liquid (6.33 g), with a yield of 94%. Structural characterization by proton NMR and fluorine NMR confirmed that the product is (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imidepyridine salt {[PyH][(CF3SO2)(CF3(CF3SO2N)SO)N]}.

[0093] The proton NMR spectrum of [PyH][(CF3SO2)(CF3(CF3SO2N)SO)N] 1 ¹H NMR and fluorine spectrum ( 19 F NMR, Figure 2 )data: 1H NMR (Acetone-d6, TMS, 400MHz, ppm) δ = 8.38 (d, J = 4.8Hz, o-2H), 7.84 (t, J = 7.8Hz, p-1H), 7.42–7.34 (m, m-2H); 19 F NMR(Acetone-d6,376MHz,CCl3F,ppm)δ=-80.03[s,6F,(C F 3SO2)(CF3(C F 3SO2N)SO)N],-80.46[s,3F,(CF3SO2)(C F 3(CF3SO2N)SO)N]. The above data are consistent with the 1H and fluorine NMR spectra of [PyH][(CF3SO2)(CF3(CF3SO2N)SO)N] in published literature [see: Cheng Xiaorong, Wuhan: Huazhong University of Science and Technology, 2012].

[0094] The chemical structural formula (VII) of [PyH][(CF3SO2)(CF3(CF3SO2N)SO)N] is as follows:

[0095]

[0096] III. Synthesis of Alkali Metal Salts with Highly Delocalized Negative Charge Sulfonamides

[0097] Example 4:

[0098] To a 250 mL flask, add hydrogen-proton-containing (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imide pyridine salt {[PyH][(CF3SO2)(CF3(CF3SO2N)SO)N], 6.33 g, 12.9 mmol}, anhydrous potassium carbonate (K2CO3, 0.89 g, 6.45 mmol), deionized water (10 mL), and acetonitrile (10 mL), and stir for 1 h to carry out a metathesis reaction. After the reaction is complete, remove insoluble substances by vacuum filtration, and concentrate the filtrate to obtain a light yellow solid (5.52 g), with a yield of 95%. Structural characterization by nuclear magnetic resonance fluorine spectroscopy confirmed that the product is (trifluoromethyl(S-trifluoromethylsulfonylimide)sulfonyl)(trifluoromethylsulfonyl)imide potassium {K[(CF3SO2)(CF3(CF3SO2N)SO)N], K[sTFSI]}.

[0099] The nuclear magnetic resonance fluorine spectrum of the obtained K[sTFSI] product ( 19 F NMR, Figure 3 )data: 19 F NMR (Acetone-d6, CCl3F, 376.5MHz, ppm) δ = -79.74 [s, 6F, (CF 3SO2)(CF3(C F 3SO2N)SO)N],-80.13[s,3F,(CF3SO2)(C F 3(CF3SO2N)SO)N]. The above data are consistent with those in published literature [sTFSI]. - The results of the NMR fluorine spectrum of the anion were consistent [see: H. Zhang, Journal of Power Sources, 2015, 296: 142–149].

[0100] The chemical structural formula (VIII) of K[sTFSI] is as follows:

[0101]

[0102] Example 5:

[0103] To a 250 mL p-bell-shaped flask, 15.73 g (86 mmol) of p-styrene sulfonamide (CH2=CHC6H4SO2NH2), 32.88 g (189 mol) of dipotassium hydrogen phosphate (K2HPO4), 0.21 g (1.7 mmol) of dimethylaminopyridine (DMAP), 0.14 g (0.86 mmol) of 4-tert-butylcatechol (TBC), and 80 mL of acetonitrile were added sequentially. After stirring to dissolve, an electrophilic substitution reaction was initiated by slowly adding a solution of 60 mL of acetonitrile containing CF3SO2NS(O)(CF3)F (29.21 g, 103.20 mmol) under nitrogen protection in an ice bath. After the addition was complete, the mixture was stirred at room temperature for 48 h. After the reaction was complete, insoluble substances were removed by filtration under reduced pressure, and the filtrate was concentrated to give a pale yellow solid (30.53 g), with a yield of 55%. Structural characterization by proton NMR and fluorine NMR confirmed that the product is (trifluoromethyl(S-trifluoromethylsulfonylimino)sulfonyl)(p-styrenesulfonamide)imino potassium {K[(CH2=CH–C6H4)(CF3(CF3SO2N)SO)N],K[SsTFSI]}.

[0104] The proton NMR spectrum of the obtained K[SsTFSI] product ( 1 ¹H NMR and fluorine spectrum ( 19 F NMR, Figure 4 )data: 1 H NMR(D2O,TMS,400MHz,ppm)δ=7.76[d,J HH =8.20Hz, 2H, -(NH2SO2)C=C H -],7.53[d,J HH =8.2Hz, 2H, -(CH2=CH)C=C H-],6.70[dd,J HH =17.6, 11.0 Hz, 1H, CH2=C H -],5.86(d,J HH =17.6Hz,1H,H( H )C=CH-],5.35[d,J HH =11.0Hz, 1H, H [(H)C=CH-]; 19 F NMR(D2O,CCl3F,376.5MHz,ppm)δ=-78.78[s,3F,(CF3(C F 3SO2N)SO)N-],-79.04[s,3F,(C F 3(CF3SO2N)SO)N-]. The above data are consistent with the nuclear magnetic resonance fluorine spectrum results of K[SsTFSI] in published literature [see: Q.Ma, Angewandte Chemie-International Edition, 2016, 55(7):2521–2525].

[0105] The chemical structural formula (IX) of K[SsTFSI] is as follows:

[0106]

Claims

1. A negatively charged, highly delocalized sulfonylimide alkali metal salt having the structure of formula (Ⅰ), In formula (I): M = Li, Na, K, Rb or Cs; Substituent R 1 R 2 R 3 Each of them independently has the meaning described in any one of ① to ⑧ below, and R 1 R 2 and R 3 They can be the same or different: ① is a perfluoroalkyl C m F 2m+1 , where m is 0 or a positive integer from 1 to 8; preferably m is a positive integer from 1 to 4; ② is a perfluoroalkoxy C m F 2m+1 O, where m is a positive integer from 1 to 8; preferably m is a positive integer from 1 to 4; ③ is a fluoroalkyl group H (CF2CF2O) containing fluorinated ethylene oxide. m CF2CF2 or F(CF2CF2O) m CF2CF2, where m is 0 or a positive integer from 1 to 6; ④ is a hydrocarbon alkyl group (C). m H 2m+1 , where m is a positive integer from 1 to 10; preferably m is a positive integer from 1 to 4; ⑤ is a hydrocarbon alkoxy group (C). m H 2m+1 O, where m is a positive integer from 1 to 10; ⑥ is a partially haloalkyl group, i.e., C m X n H 2m+1-n Where X = F, Cl, Br or I; n ≤ 2m + 1, where m is a positive integer from 1 to 10; preferably CF2H, CH2F, CF3CH2, (CF3)2CH, CCl2H, CH2Cl or CCl3CH2; ⑦ is a partially haloalkoxy group, i.e., C m X n H 2m+1-n O, where X = F, Cl, Br or I; n≤2m+1, m is a positive integer from 1 to 10; preferably CF3CH2O, (CF3)2CHO, ClCH2O, Cl2CHO or CCl3CH2O; ⑧ is a group containing an unsaturated double bond, which includes, but is not limited to, the following groups containing unsaturated double bonds: CH2=CH–C6H4, CH2=CH–C6H3(CH3), CH2=CH–C6H3Cl, CH2=CH–C6H3F, CH2=CH–COOCH2, CH2=C(CH3)–COOCH2, CH2=CH–COOCH2CH2, CH2=C(CH3)– COOCH2CH2, CH2=CH–COOCH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=CH– COOCH2CH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2CH2; preferably CH2=CH–C6H4. CH2=C(CH3)–COOCH2CH2 or CH2=C(CH3)–COOCH2CH2CH2.

2. The method for synthesizing the negatively charged, highly delocalized sulfonylimide alkali metal salt according to claim 1, comprising the following steps: Step 1: In a non-aqueous solvent, the alkali metal salt of alkyl (S-alkylsulfonylimide) sulfinic acid is subjected to an oxidative fluorination reaction with an N-fluorine electrophilic reagent to generate alkyl (S-alkylsulfonylimide) sulfonyl fluoride, the structure of which is shown in formula (II): In formula (II): R 1 R 2 Each of them independently has the meaning described in any one of ① to ⑧ below, and R 1 R 2 They can be the same or different: ① is a perfluoroalkyl C m F 2m+1 , where m is 0 or a positive integer from 1 to 8; preferably m is a positive integer from 1 to 4; ② is a perfluoroalkoxy C m F 2m+1 O, where m is a positive integer from 1 to 8; preferably m is a positive integer from 1 to 4; ③ is a fluoroalkyl group H (CF2CF2O) containing fluorinated ethylene oxide. m CF2CF2 or F(CF2CF2O) m CF2CF2, where m is 0 or a positive integer from 1 to 6; ④ is a hydrocarbon alkyl group (C). m H 2m+1 , where m is a positive integer from 1 to 10; preferably m is a positive integer from 1 to 4; ⑤ is a hydrocarbon alkoxy group (C). m H 2m+1 O, where m is a positive integer from 1 to 10; ⑥ is a partially haloalkyl group, i.e., C m X n H 2m+1-n Where X = F, Cl, Br or I, n≤2m+1, and m is a positive integer from 1 to 10; preferably CF2H, CH2F, CF3CH2, (CF3)2CH, CCl2H, CH2Cl or CCl3CH2; ⑦ is a partially haloalkoxy group, i.e., C m X n H 2m+1-n O, where X = F, Cl, Br or I, n≤2m+1, m is a positive integer from 1 to 10; preferably CF3CH2O, (CF3)2CHO, ClCH2O, Cl2CHO or CCl3CH2O; ⑧ is a group containing an unsaturated double bond, which includes, but is not limited to, the following groups containing unsaturated double bonds: CH2=CH–C6H4, CH2=CH–C6H3(CH3), CH2=CH–C6H3Cl, CH2=CH– C6H3F, CH2=CH–COOCH2, CH2=C(CH3)–COOCH2, CH2=CH–COOCH2CH2, CH2=C(CH3)–COOCH2CH2, CH2=CH–COOCH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2, CH2=CH– COOCH2CH2CH2CH2, CH2=C(CH3)–COOCH2CH2CH2CH2; preferably CH2=CH–C6H4. CH2=C(CH3)–COOCH2CH2 or CH2=C(CH3)–COOCH2CH2CH2. Step 2: Using an inorganic or organic base as an acid-binding agent, react the alkyl (S-alkylsulfonylimide) sulfonyl fluoride obtained in Step 1 with the structural formula R. 3 sulfonamides of SO2NH2 or their alkali metal salts (R) 3 SO2NHM) undergoes a nucleophilic substitution reaction, and the reaction product is purified to obtain a hydrogen-containing, highly delocalized sulfonylimide salt with the structure shown in formula (III). 3 SO2NH2 and R 3 R in SO2NHM 3 R in formula (I) of claim 1 3 The meaning is the same, the R 3 In SO2NHM, M is Li, Na, K, Rb, or Cs; In formula (Ⅲ): C⊕ is a cation containing a hydrogen proton; R 1 R 2 R 3 The meaning of R as described in claim 1 1 R 2 R 3 The meanings are the same. Step 3: The negatively charged highly delocalized sulfonylimide salt containing hydrogen protons obtained in Step 2 [Formula (III)] is subjected to a metathesis reaction with an alkali metal oxygen-containing compound or an oxoacid salt. The reaction product is purified to obtain a negatively charged highly delocalized sulfonylimide alkali metal salt with the structure shown in Formula (I) of claim 1.

3. The synthesis method according to claim 2, characterized in that, The N-fluorine electrophilic reagent mentioned in step one is one, two, or a mixture of two or more of the following: N-fluorosuccinimide (NFS), N-fluorophthalimide (NFOBS), N-fluoropyridinium salt (NFPY), 1-chloromethyl-4-fluoro-1,4-diazabicyclo[2.2.2]octane di(tetrafluoroborate) salt (F-TEDA), N-fluorobisbenzenesulfonamide (NFSI), and N-fluorobistrifluoromethylsulfonamide (F-TFSI).

4. The synthesis method according to claim 2, characterized in that, In step one, the ratio of the alkyl (S-alkylsulfonylimide) sulfinic acid alkali metal salt to the N-fluorine electrophilic reagent, calculated by molar amount, is 100:20 to 100:500, preferably 100:50 to 100:

300.

5. The synthesis method according to claim 2, characterized in that, The non-aqueous solvent mentioned in step one is one, two, or a mixture of two or more of the following: butyl acetate, N,N-dimethylaniline, dimethylamine, ethylene glycol dimethyl ether, diethyl ether, methyl tert-butyl ether, ethyl acetate, tetrahydrofuran, 1,2-dichloroethane, acetone, butanone, 4-methyl-2-pentanone, ethanol, ethylene glycol, isopropanol, 1,2-propanediol, nitromethane, nitrobenzene, hexamethylphosphonic triamide, acetonitrile, propionitrile, succinic anion, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylformamide, sulfolane, 1,3-dimethylpropylene urea (DMPU), and 1,3-dimethyl-2-imidazolinone (DMEU); preferably, acetonitrile, dichloromethane, diethyl ether, and tetrahydrofuran are one, two, or a mixture of two or more of these.

6. The synthesis method according to claim 2, characterized in that, The reaction temperature in step one is a constant temperature between -20°C and 80°C, preferably between 10°C and 60°C; the reaction time in step one is between 0.5 hours and 48 hours, preferably between 0.5 hours and 10 hours.

7. The synthesis method according to claim 2, characterized in that, The organic base used as an acid-binding agent in step two is one, two, or a mixture of two or more of the following: imidazole, 1-methylimidazole, triazole, pyridine, 2,6-dimethylpyridine, triethylamine, diisopropylethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), potassium hexamethyldisilamide, sodium hexamethyldisilamide, lithium hexamethyldisilamide, sodium tetramethylpiperidine, and lithium tetramethylpiperidine; preferably, one, two, or a mixture of two or more of the following: triethylamine, imidazole, 1-methylimidazole, pyridine, 2,6-dimethylpyridine, and sodium hexamethyldisilamide.

8. The synthesis method according to claim 2, characterized in that, The inorganic base used as an acid-binding agent in step two is one, two, or a mixture of two or more of the following: potassium phosphate (K3PO4), sodium phosphate (Na3PO4), lithium phosphate (Li3PO4), dipotassium hydrogen phosphate (K2HPO4), disodium hydrogen phosphate (Na2HPO4), dilithium hydrogen phosphate (Li2HPO4), potassium dihydrogen phosphate (KH2PO4), sodium dihydrogen phosphate (NaH2PO4), lithium dihydrogen phosphate (LiH2PO4), sodium thiosulfate (Na2S2O3), and potassium thiosulfate (K2S2O3); preferably, one, two, or a mixture of two or more of the following: potassium phosphate, lithium phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and tripotassium phosphate.

9. The synthesis method according to claim 2, characterized in that, The reaction temperature in step two is a constant temperature between -20°C and 150°C, preferably between 0°C and 100°C; the reaction time in step two is 4 hours to 24 hours, preferably between 6 hours and 12 hours.

10. The synthesis method according to claim 2, characterized in that, The alkali metal oxygen-containing compound mentioned in step three is one, two, or a mixture of two or more of lithium oxide (Li₂O), sodium oxide (Na₂O), potassium oxide (K₂O), lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), and cesium hydroxide (CsOH); the alkali metal oxyacid salt mentioned in step three is lithium bicarbonate (LiHCO₃), sodium bicarbonate (NaHCO₃), potassium bicarbonate (KHCO₃), and rubidium bicarbonate. A mixture of one, two, or more of the following: (RbHCO3), cesium bicarbonate (CsHCO3), lithium carbonate (Li2CO3), sodium carbonate (Na2CO3), potassium carbonate (K2CO3), rubidium carbonate (Rb2CO3), cesium carbonate (Li2CO3), lithium hydrogen phosphate (LiH2PO4), sodium hydrogen phosphate (NaH2PO4), potassium hydrogen phosphate (KH2PO4), lithium phosphate (Li3PO4), sodium phosphate (Na3PO4), and potassium phosphate (K3PO4).

11. The synthesis method according to claim 2, characterized in that, The specific purification method described in step two and / or step three is as follows: filter the obtained reaction product through a vacuum funnel, wash it multiple times with the reaction solvent, collect the filtrate, concentrate the filtrate under reduced pressure and dry it under vacuum to finally obtain the target product.

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