A synthesis method of alkali-promoted monoaryl-substituted stibane derivatives

Abstract

The application relates to the technical field of organic synthesis, and particularly discloses a synthesis method of monoaryl-substituted stibane derivatives based on alkali promotion, which does not use any transition metal catalyst, and only uses a cheap inorganic alkali (Na2CO3) as a promoter, so that metal toxicity, catalyst cost and product metal residual pollution and the like are eliminated from the source; the reaction temperature of the application is only 100-120 DEG C, which is much lower than the high temperature (more than 200 DEG C) required by a traditional reduction coupling method, and is also lower than the temperature (usually 120-150 DEG C) of most transition metal catalytic coupling reactions. The mild reaction condition not only reduces energy consumption and equipment requirement, but also improves the safety and operability of the reaction. In addition, the reaction is carried out in a conventional organic solvent (acetonitrile or ethyl acetate), and strict anhydrous conditions are not required, so that the operation is extremely simple.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for synthesizing monoaryl-substituted antimonyane derivatives based on base promotion. Background Technology

[0002] In recent years, transition metal-catalyzed cross-coupling reactions have become an important tool for constructing carbon-heteroatom bonds. In the field of C-Sb bond formation, researchers have developed various transition metal-catalyzed coupling methods: (I) Nickel-catalyzed coupling. Nickel catalysts have been extensively studied in C-Sb bond formation reactions due to their relatively low cost and unique catalytic activity. Reported nickel-catalyzed systems include: nickel-catalyzed coupling reactions of antimonyanes with arylboronic acids, nickel-catalyzed coupling reactions of antimonyanes with aryl halides, and nickel-catalyzed coupling reactions of antimonyanes with aryl trifluoromethanesulfonates. Although nickel catalysis has a certain cost advantage compared to noble metal catalysis such as palladium and platinum, nickel catalysts still have the following problems: nickel salts are sensitive to moisture and air, and the catalytic system usually requires complex ligand design; the reaction temperature is relatively high, usually in the range of 120-150℃; some nickel complexes have skin sensitization and potential carcinogenicity, posing occupational health risks.

[0003] (II) Palladium-catalyzed coupling. Palladium catalysts are among the most widely used catalysts in cross-coupling reactions, and have also been reported in C-Sb bond formation. Palladium catalytic systems typically exhibit high catalytic activity; however, palladium is a rare and precious metal, making it expensive and significantly increasing synthesis costs. More importantly, palladium residue severely limits the application of the products in functional materials (especially optoelectronic and catalytic materials), as even trace amounts of palladium can significantly affect the electronic properties and catalytic selectivity of the materials.

[0004] (III) Other transition metal catalysis. In addition to nickel and palladium, transition metals such as copper and cobalt have also been attempted for C-Sb bond formation reactions. However, these catalytic systems generally suffer from problems such as low catalytic efficiency, narrow substrate applicability, and harsh reaction conditions, and no synthetic method with practical application value has yet been formed.

[0005] Although transition metal-catalyzed C-Sb bond formation methods have improved reaction efficiency and selectivity to some extent, their inherent defects are also very prominent: (1) Metal toxicity and environmental pollution: Transition metal catalysts (especially palladium and nickel) are highly toxic, and their use and emission cause environmental pollution; (2) High cost: Transition metals and their ligands are expensive, which significantly increases the cost of synthesis; (3) Metal residue problem: Trace metal residues in the product that are difficult to completely remove seriously limit their application in functional materials, biomedicine and other fields; (4) Limited functional group tolerance: Some catalytic systems have poor tolerance to substrates containing heteroatom functional groups; (5) Substrate limitations: Some methods are only applicable to specific types of antimony sources or coupling partners, and the universality of substrates needs to be improved.

[0006] Therefore, there is an urgent need in the field for a new method for C(sp²)-Sb bond formation that does not require a transition metal catalyst, has mild reaction conditions, a wide range of applicable substrates, high product purity, and can be extended to the synthesis of antimony-containing functional materials. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a base-promoted method for the synthesis of monoaryl-substituted antimony alkyl derivatives. The method provided by the present invention does not require the participation of transition metal catalysts, is simple to operate, has mild reaction conditions, and has a wide range of applicable substrates, fundamentally eliminating the problems of toxicity, cost, and residual pollution caused by metal catalysts.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A method for synthesizing monoaryl-substituted antimonyane derivatives based on base promotion includes the following steps: Under an inert atmosphere, compounds 1 and 2 were used as reactants, and an inorganic base was used as a promoter. The reaction was carried out in an organic solvent under heating. After the reaction was completed, the product was separated and purified to obtain monoaryl-substituted antimony alkyl derivative 3.

[0009] In the technical solution disclosed in this invention, R1 in compound 1 represents unsubstituted or substituted by one or more substituents.

[0010] The substituents are selected from halogens, C1-C6 alkyl groups, C1-C6 alkoxy groups, C1-C6 haloalkyl groups, hydroxyl groups, amino groups, nitro groups, cyano groups, or ester groups.

[0011] For example, compound 1 can be selected from 5-chloro-5H-dibenzo[b,d]antimonycyclopentane and its derivatives.

[0012] In the technical solution disclosed in this invention, R2 in compound 2 represents unsubstituted or substituted by one or more substituents.

[0013] The substituents are selected from one or more of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, halogen, amino, nitro, cyano, hydroxy, aldehyde, ester, amide, alkynyl, vinyl, trifluoromethyl, and acetyl.

[0014] In the technical solution disclosed in this invention, the inorganic base is selected from at least one of sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, potassium phosphate, sodium acetate, sodium hydroxide, and potassium hydroxide.

[0015] In the technical solution disclosed in this invention, the molar ratio of compound 1 to compound 2 is 1.0-1.5:1, for example, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1 can be selected, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] In the technical solution disclosed in this invention, the molar ratio of compound 1 to inorganic base is 1:1.0-2.0, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2 can be selected, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] In the technical solution disclosed in this invention, the organic solvent is selected from acetonitrile or ethyl acetate.

[0018] In the technical solution disclosed in this invention, the heating reaction temperature is 80-120℃, for example, 80℃, 90℃, 100℃, 110℃, or 120℃ can be selected; the heating reaction time is 8-24h, for example, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, or 24h can be selected, but it is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The synthesis method provided by the present invention does not use any transition metal catalysts at all, but only uses inexpensive inorganic base (Na2CO3) as a promoter, thus eliminating problems such as metal toxicity, catalyst cost and metal residue pollution in the product from the source.

[0020] (2) The reaction temperature of this invention is only 100-120℃, which is much lower than the high temperature of over 200℃ required by traditional reductive coupling methods, and also lower than the temperature of most transition metal catalytic coupling reactions (usually 120-150℃). The mild reaction conditions not only reduce energy consumption and equipment requirements, but also improve the safety and operability of the reaction. In addition, the reaction is carried out in a conventional organic solvent (acetonitrile or ethyl acetate), without the need for strict anhydrous conditions, making the operation extremely simple.

[0021] (3) The synthesis method provided by the present invention exhibits excellent tolerance to a variety of functional groups. The starting compound 2 can carry a variety of substituents such as methyl, ethyl, isopropyl, methoxy, fluorine, chlorine, bromine, iodine, trifluoromethyl, aldehyde, ester, amide, amino, nitro, cyano, hydroxyl, alkynyl, vinyl, and trimethylsilyl. The substrate scope covers electron donor substituents and electron acceptor substituents, as well as functional groups that can be further transformed.

[0022] (4) The synthesis method provided by the present invention can achieve a yield of 98% for monoaryl-substituted antimonanes under optimized reaction conditions, which shows a reaction efficiency comparable to or even better than that of transition metal catalytic methods. Detailed Implementation

[0023] The present invention will be further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0024] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0025] The synthesis steps of the chloroantimonane substrate (5-chloro-5H-dibenzo[b,d]antimonycyclopentane) used in the embodiments of the present invention are as follows: In a dry 250 mL three-necked round-bottom flask, 3.12 g (10.0 mmol) of 2,2'-dibromobiphenyl and 60 mL of dry THF were added and dissolved completely with magnetic stirring. The reaction system was cooled to -78 °C (dry ice / acetone bath), and n-butyllithium (nBuLi, 2.5 M in hexane, 8.8 mL, 22.0 mmol, 2.2 equiv) was slowly added dropwise at a rate of approximately 1 mL / min to keep the reaction temperature below -70 °C. After the addition was complete, the mixture was stirred at -78 °C for 1 hour, at which point the solution changed from colorless to pale yellow.

[0026] Antimony trichloride (SbCl3, 2.74 g, 12.0 mmol, 1.2 equiv) was dissolved in dry THF (20 mL) and slowly added to the above reaction system using a syringe. The reaction temperature was maintained at -78°C during the addition process. After the addition was completed, the reaction mixture was slowly raised to room temperature (2 hours) and stirred overnight at room temperature (16 hours).

[0027] After the reaction was complete, the mixture was quenched in ice water (100 mL) and extracted with dichloromethane (3 × 50 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (eluent: petroleum ether / dichloromethane = 5:1, v / v) to give solid product 1a (2.96 g, 96% yield).

[0028] Characterization data: 1 H NMR (400 MHz, DMSO- d 6) δ = 7.99 (d, J = 7.8 Hz, 2H), 7.90 (d, J = 7.1Hz, 2H), 7.46 (t, J = 7.5 Hz, 2H), 7.36 (t, J = 7.2 Hz, 2H) ppm. 13 C NMR (101 MHz, DMSO- d 6) δ = 152.5, 150.1, 133.6, 129.5, 128.1,123.3 ppm. HRMS-ESI (m / z) [M+H] + calculated for [C 12 H9ClSb] + , 308.9425, found, 308.9416. Example 1 Synthesis of 5-(p-Tolyl)-5H-Dibenzo[b,d]antimonycyclopentane In a 10 mL dry Schlenk tube, a magnetic stir bar, 5-chloro-5H-dibenzo[b,d]antimonycyclopentane (37.1 mg, 0.12 mmol), p-tolylboronic acid (13.6 mg, 0.10 mmol), and anhydrous sodium carbonate (Na₂CO₃, 12.7 mg, 0.12 mmol) were added. The Schlenk tube was connected to a double-row tube, and the tube was evacuated and purged with nitrogen three times to ensure thorough deoxygenation and dehydration. Dry acetonitrile (CH₃CN, 2 mL) was added to the tube using a syringe. After sealing, the Schlenk tube was immersed in an oil bath preheated to 100°C, and the reaction was carried out for 12 hours with magnetic stirring.

[0029] After the reaction was completed, the reaction mixture was cooled to room temperature, and 20 μL of n-tetane was added as an internal standard. A sample was taken for GC analysis to determine the yield. The solvent was removed by vacuum distillation, and the residue was purified by neutral alumina column chromatography to give 37.1 mg of the white solid product 5-(p-tolyl)-5H-dibenzo[b,d]antimonycyclopentane, with a yield of 98%.

[0030] Characterization data: 1 H NMR (400 MHz, CDCl3) δ = 7.95 (d, J = 7.9 Hz, 2H), 7.73 (d, J = 7.2Hz, 2H), 7.46 (t, J = 7.6 Hz, 2H), 7.30 (t, J = 7.3 Hz, 2H), 7.24 (d, J = 7.5Hz, 2H), 7.00 (d, J = 7.5 Hz, 2H), 2.25 (s, 3H) ppm. 13 C NMR (101 MHz, CDCl3) δ = 150.3, 145.3, 138.6, 135.4, 134.4, 129.7,128.9, 128.0, 123.5, 21.4 ppm. HRMS (m / z) [M+K] + calculated for [C 19 H 15 KSb] + , 402.9844, found 402.9844. Example 2 Synthesis of (5-(4-fluorophenyl)-5H-dibenzo[b,d]antimonycyclopentane) In a 10 mL dry Schlenk tube, a magnetic stir bar, 5-chloro-5H-dibenzo[b,d]antimonycyclopentane (37.1 mg, 0.12 mmol), 4-fluorophenylboronic acid (14.0 mg, 0.10 mmol), and anhydrous sodium carbonate (Na₂CO₃, 12.7 mg, 0.12 mmol) were added. The Schlenk tube was connected to a double-row tube, and the tube was evacuated and purged with nitrogen three times to ensure thorough deoxygenation and dehydration. Dry acetonitrile (CH₃CN, 2 mL) was added to the tube using a syringe, and the tube was sealed. The Schlenk tube was then immersed in an oil bath preheated to 100°C, and the reaction was carried out under magnetic stirring for 12 hours.

[0031] After the reaction was complete, the reaction mixture was cooled to room temperature. The solvent was removed by vacuum distillation, and the residue was purified by neutral alumina column chromatography to give 33.5 mg of a white solid product (5-(4-fluorophenyl)-5H-dibenzo[b,d]antimonycyclopentane), in 97% yield.

[0032] Characterization data: 1 H NMR (400 MHz, CDCl3) δ = 7.95 (d, J = 7.9 Hz, 2H), 7.72 (d, J = 7.2Hz, 2H), 7.47 (t, J = 7.6 Hz, 2H), 7.30 (q, J = 7.7 Hz, 4H), 6.87 (t, J = 8.4Hz, 2H) ppm. 13 C NMR (101 MHz, CDCl3) δ = 163.3 (d, J = 247.6 Hz), 150.1, 145.0,137.0 (d, J = 7.3 Hz), 135.2, 132.7 (d, J = 3.7 Hz), 129.0, 127.9, 123.5,115.9 (d, J = 19.8 Hz) ppm. 19 F NMR (376 MHz, CDCl3) δ = -113.0 ppm. Example 3 Synthesis of 5-phenyl-5H-dibenzo[b,d]antimonycyclopentane In a 10 mL dry Schlenk tube, a magnetic stir bar, 5-chloro-5H-dibenzo[b,d]antimonycyclopentane (37.1 mg, 0.12 mmol), phenylboronic acid (12.2 mg, 0.10 mmol), and anhydrous sodium carbonate (Na₂CO₃, 12.7 mg, 0.12 mmol) were added. The Schlenk tube was connected to a double-row tube, and the tube was evacuated and purged with nitrogen three times to ensure thorough deoxygenation and dehydration. Dry acetonitrile (CH₃CN, 2 mL) was added to the tube using a syringe. After sealing, the Schlenk tube was immersed in an oil bath preheated to 100°C, and the reaction was carried out for 12 hours with magnetic stirring.

[0033] After the reaction was complete, the reaction mixture was cooled to room temperature. The solvent was removed by vacuum distillation, and the residue was purified by neutral alumina column chromatography to give 26.6 mg of the white solid product 5-phenyl-5H-dibenzo[b,d]antimonycyclopentane, in 76% yield.

[0034] Characterization data: 1 H NMR (400 MHz, CDCl3) δ = 7.95 (d, J = 7.9 Hz, 2H), 7.74 (d, J = 7.2Hz, 2H), 7.46 (t, J = 7.5 Hz, 2H), 7.38-7.27 (m, 4H), 7.25-7.12 (m, 3H) ppm. 13 C NMR (101 MHz, CDCl3) δ = 150.3, 145.2, 138.2, 135.4, 129.0, 128.9,128.6, 128.0, 123.6 ppm. HRMS (m / z) [M+K] + calculated for [C 18 H 13 KSb] + , 388.9687, found 388.9687. Comparative Example 1 Compared with Comparative Example 1 and Example 3, the reaction was carried out under alkaline-free conditions.

[0035] In a 10 mL dry Schlenk tube, a magnetic stir bar, 5-chloro-5H-dibenzo[b,d]antimonycyclopentane (37.1 mg, 0.12 mmol), and phenylboronic acid (12.2 mg, 0.10 mmol) were added. The Schlenk tube was connected to a double-row tube, and the tube was evacuated and purged with nitrogen three times to ensure thorough deoxygenation and dehydration. Dry acetonitrile (CH3CN, 2 mL) was added to the tube using a syringe. After sealing, the Schlenk tube was immersed in an oil bath preheated to 100°C, and the reaction was carried out for 12 hours with magnetic stirring.

[0036] After the reaction was complete, the reaction mixture was cooled to room temperature. The solvent was removed under reduced pressure, and the residue was purified by neutral alumina column chromatography. GC analysis showed almost no product formation (yield <5%), demonstrating that the base is crucial for the transmetallization process.

[0037] Comparative Example 2 Compared to Comparative Example 2 and Example 3, the reaction was carried out in an air atmosphere.

[0038] In a 10 mL dry Schlenk tube, a magnetic stir bar, 5-chloro-5H-dibenzo[b,d]antimonycyclopentane (37.1 mg, 0.12 mmol), phenylboronic acid (12.2 mg, 0.10 mmol), and anhydrous sodium carbonate (Na₂CO₃, 12.7 mg, 0.12 mmol) were added. Dry acetonitrile (CH₃CN, 2 mL) was added to the tube via a syringe. After sealing, the Schlenk tube was immersed in an oil bath preheated to 100°C, and the reaction was carried out for 12 hours with magnetic stirring.

[0039] After the reaction was complete, the reaction mixture was cooled to room temperature. The solvent was removed under reduced pressure, and the residue was purified by neutral alumina column chromatography. GC analysis showed that the yield decreased significantly to about 30%, indicating that oxygen inhibited the reaction, possibly because oxygen oxidized the antimony(III) intermediate.

[0040] Alkali type screening: To systematically investigate the effect of base type on the target product, under the conditions of a fixed reaction temperature of 100℃ and acetonitrile as solvent, this invention selected dibenzo-antimonazole chlorinated derivative 1a and arylboronic acid 2b as template substrates, and used 24 different types of bases (covering inorganic strong bases, inorganic weak bases, organic strong bases, organic weak bases, and other types of bases) to systematically investigate the effect of base type on the yield of target product 3b. The specific synthetic route is shown below: The experimental results are shown in Table 1.

[0041] Table 1 Screening of Alkali Types a Reaction conditions: 1a (0.10 mmol, 1.0 eq.), 2b (0.15 mmol, 1.5 eq.), Base (0.20 mmol, 2.0 eq.), acetonitrile (2 mL), 100 °C, N2 atmosphere, reaction for 12 h. b GC yield (with 20 μL n-tetrazane as internal standard, correction factor f = 0.9). DMAP = 4-dimethylaminopyridine, DIPEA = diisopropylethylamine, DABCO = 1,4-diazabicyclo[2.2.2]octane, DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene.

[0042] Table 1 shows that different types and strengths of bases have a significant impact on the yield of this coupling reaction, and their reactivity varies significantly. Organic bases such as Et3N and DIPEA perform poorly, possibly because the nitrogen atom coordinates with the antimony center, thus inhibiting the reactivity. Strong bases such as NaO... t Bu, KO t Bu and Cs₂CO₃ attack the antimony center, causing 1a to decompose and generate biphenyl (m / z = 154). Simultaneously, the formation of the byproduct tri-p-tolylantimony (m / z = 394) increases, leading to a decrease in yield. In contrast, Na₂CO₃, with its moderate alkalinity, effectively activates boric acid without destroying the structure of the antimony chloride, achieving a 67% yield. Furthermore, the yield ranges from 58% to 65% upon the addition of a fluoride salt, presumably because the antimony chloride is converted in situ to the antimony fluoride (m / z = 293), thus accelerating the reaction rate.

[0043] Comparative experiment of arylboronic acid compounds: Take a 10 mL dry reaction tube, place a magnetic stir bar inside, and add 5-chloro-5- H -dibenzo[ b , d Antimonazole (1a, 37.1 mg, 0.12 mmol), arylboronic acid compound 2 (0.10 mmol), and sodium carbonate (Na2CO3, 12.7 mg, 0.12 mmol) were used. The reaction system was evacuated, then purged with nitrogen. This displacement procedure was repeated three times. After completion, acetonitrile (2 mL) was added. The reaction tube was then sealed and immersed in an oil bath preheated to 100 °C for 12 h. After the reaction, 20 μL of n-tetane was added as an internal standard, and the GC yield of product 3 was determined by gas chromatography. The specific synthetic route is as follows: The experimental results are shown in Table 2.

[0044] Table 2 Substrate Expansion for Arylboronic Acids Comparative experiment of dibenzo-antimonazole chlorinated compounds: To further improve the applicability of the coupling method provided by this invention, the reactivity of dibenzo-antimonazole chlorinated substrates was systematically investigated. The specific synthetic route is as follows: The experimental results are shown in Table 3.

[0045] Table 3 Substrate Expansion for Dibenzo-antimonazole Chlorinated Compounds a Reaction conditions: 1 (0.12 mmol, 1.2 eq.), 2e (0.10 mmol, 1.0 eq.), Na2CO3 (0.12 mmol, 1.2 eq.), 100 °C, acetonitrile (2 mL), reaction under N2 atmosphere for 12 h. b Separation yield. c The boric acid substrate is 4-methylboric acid.

[0046] As shown in Table 3, substrates with different electronic effects and steric hindrances can all react efficiently under optimal reaction conditions to generate the target coupling product (4a–4h) in high yields. Among them, the reaction yields of halogenated and electronically neutral substrates are slightly lower than those of electron-rich substituted substrates.

[0047] Meanwhile, substrate 4h (containing a tert-butyl substituent), which has significant steric hindrance, still maintained a certain level of reactivity in the reaction system and successfully generated the target product, fully demonstrating the strong stability and practicality of this coupling method, and its ability to withstand significant steric hindrance. Furthermore, for substrates containing an N→Sb coordination framework structure, no target product was observed in the reaction system, suggesting that this coordination structure may have a significant inhibitory effect on reactivity, preventing the reaction from proceeding smoothly.

[0048] Finally, it should be noted that the above embodiments do not limit the present invention in any way. Those skilled in the art can make modifications and improvements based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A method for synthesizing monoaryl-substituted antimonyane derivatives based on base promotion, characterized in that, Includes the following steps: Under an inert atmosphere, compounds 1 and 2 were used as reactants, and an inorganic base was used as a promoter. The reaction was carried out in an organic solvent under heating. After the reaction was completed, the product was separated and purified to obtain monoaryl-substituted antimony alkyl derivative 3.

2. The synthesis method according to claim 1, characterized in that, In compound 1, R1 represents unsubstituted or substituted with one or more substituents, wherein the substituents are selected from halogens, C1-C6 alkyl groups, C1-C6 alkoxy groups, C1-C6 haloalkyl groups, hydroxyl groups, amino groups, nitro groups, cyano groups, or ester groups.

3. The synthesis method according to claim 1, characterized in that, In compound 2, R2 represents unsubstituted or substituted with one or more substituents, wherein the substituents are selected from one or more of hydrogen, C1-C6 alkyl, C1-C6 alkoxy, halogen, amino, nitro, cyano, hydroxy, aldehyde, ester, amide, alkynyl, vinyl, trifluoromethyl, and acetyl.

4. The synthesis method according to claim 1, characterized in that, The inorganic base is selected from at least one of sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, potassium phosphate, sodium acetate, sodium hydroxide, and potassium hydroxide.

5. The synthesis method according to claim 1, characterized in that, The molar ratio of compound 1 to compound 2 is 1.0-1.5:

1.

6. The synthesis method according to claim 1, characterized in that, The molar ratio of compound 1 to the inorganic base is 1:1.0-2.

0.

7. The synthesis method according to claim 1, characterized in that, The organic solvent is selected from acetonitrile or ethyl acetate.

8. The synthesis method according to claim 1, characterized in that, The heating reaction temperature is 80-120℃, and the heating reaction time is 8-24h.

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