Phosphino multi-element cyclic ester and preparation method thereof

Abstract

The invention belongs to the field of organic synthesis, and provides a phosphino multi-element cyclic ester and a preparation method thereof, the structural general formula of the phosphino multi-element cyclic ester is # imgabs0 #, and the preparation method comprises the following steps: S1a: esterifying a compound A to obtain a compound B; s1b, the compound B is oxidized to obtain a compound C, and the step is carried out after the step S1a, and can be carried out or not; # imgabs1 # S2a: esterifying the compound B and / or the compound C to obtain a compound D, namely phosphino multi-element cyclic ester; s2b, the compound D continues to be oxidized to obtain phosphine-based multi-element cyclic ester in an oxidation state, and the step is carried out after the step S2a and can be selectively carried out or not carried out; the esterification in the steps S1a and S2a in the # imgabs2 is an ester exchange reaction or a dehalogenation reaction; a, A1, A2 and A3 are independently selected from C or S elements; p, n and m are independently selected from 0 or 1; a, b, c, d and e are independently selected from 1 or 2. The method is simple in step, the process is easy to control, industrial production is easy, and the prepared product can be directly used as an electrolyte additive.

Description

Technical Field

[0001] The present invention belongs to the field of organic synthesis, and particularly relates to a phosphino polycyclic ester and a preparation method thereof. Background Art

[0002] At present, carbonate is used as a solvent in the electrolyte of secondary batteries. When the charging voltage of the battery is greater than 4.2V, the carbonate solvent will be oxidized and decomposed on the surface of the positive electrode material, generating gases and other decomposition products, resulting in battery swelling and posing a safety hazard. Adding a small amount of functional additives to the electrolyte to form a stable protective film on the electrode surface is the most economical and effective strategy to improve electrode stability and achieve high-stability and high-specific-energy batteries. By using a small amount of additives, the performance of the electrolyte can be greatly improved, which is the core research direction in the field of electrolytes in recent years.

[0003] Phosphorus-containing compounds have unique flame retardant safety due to the presence of phosphorus elements in their structural formulas and play an important role in many fields. For example, in the field of electrolyte additives, phosphorus-containing additives can increase the battery voltage, improve low-temperature performance and flame retardant performance. For example, the non-aqueous electrolyte and lithium-ion battery containing a phosphorus-containing compound disclosed in Chinese Patent CN105720304B, the phosphorus-containing compound is selected from phosphate esters Chain phosphazene compounds and at least one of cyclotriphosphazene compounds improve the cycle performance and safety of lithium batteries; the non-aqueous electrolyte and lithium-ion battery of a ternary high-voltage lithium-ion battery disclosed in Chinese Patent Application CN117117310A, the additives in the non-aqueous electrolyte include a film-forming additive, an oxalate-type additive and a silane-type additive, and the film-forming additive contains a phosphorus-containing sulfate ester compound: By optimizing the formula, the electrolyte system has both high energy density and high stability, which is beneficial to meeting the requirements of the electrolyte for cycle and storage performance at high voltage and ensuring safety.

[0004] In the field of flame retardants, Chinese Patent CN105001264B discloses a flame retardant hydroxymethylphosphazacyclic methylphosphonate compound and a preparation method thereof. The structural formula of the compound is: The preparation method is as follows: under nitrogen protection, equimolar amounts of trimethylolphosphine and dimethyl methylphosphonate react at 110-160°C for 4-10h under the action of a catalyst, and after purification treatment, the product hydroxymethylphosphazacyclic methylphosphonate is obtained. The product has a high phosphorus content and excellent flame retardant performance.

[0005] It can be seen that phosphorus-containing compounds play an important role in improving flame retardancy and safety. Widening the scope of the structural formula of phosphorus-containing compounds and developing new phosphorus-containing compounds containing multiple groups will have important practical significance. Summary of the Invention

[0006] The object of the present invention is to provide a phosphono polycyclic ester and a preparation method thereof, which have simple preparation steps, easy control and realization of the reaction process, are easy to be industrially produced, and the obtained phosphono polycyclic ester product can be directly used as an electrolyte additive to improve the battery performance.

[0007] To achieve the above technical object, the technical solution adopted by the present invention is: to provide a phosphono polycyclic ester, and the phosphono polycyclic ester has the following general structural formula: Wherein, A1, A2, and A3 independently select from the elements C or S; n and m independently select from 0 or 1; c, d, and e independently select from 1 or 2.

[0008] Further, the phosphono polycyclic ester selects at least one of the following structural formulas:

[0009]

[0010]

[0011] The present invention also provides a preparation method of a phosphono polycyclic ester, comprising the following steps:

[0012] S1a: Compound A is esterified to obtain compound B;

[0013] S1b: Compound B is oxidized to obtain compound C, and this step can be selected or not after S1a;

[0014]

[0015] S2a: Compound B and / or compound C are esterified to obtain compound D, that is, the phosphono polycyclic ester;

[0016] S2b: Compound D is further oxidized to obtain an oxidized phosphono polycyclic ester, and this step can be selected or not after S2a;

[0017]

[0018] The esterification in steps S1a and S2a is transesterification or dehalogenation reaction; A, A1, A2, and A3 independently select from the elements C or S; p, n, and m independently select from 0 or 1; a, b, c, d, and e independently select from 1 or 2.

[0019] Further, compound B selects at least one of the following structural formulas:

[0020]

[0021] Further, the compound C is selected from at least one of the following structural formulas:

[0022]

[0023] Further, the specific preparation routes of steps S1a and S1b are as follows:

[0024]

[0025]

[0026] Further, when the esterification in steps S1a and S2a is a dehalogenation reaction, the esterification reagent used is selected from at least one of carbonyl halides, thionyl halides or sulfuryl halides; a tertiary amine compound is used as an acid-binding agent during the reaction to promote the reaction.

[0027] Further, when the esterification in steps S1a and S2a is a dehalogenation reaction, the esterification reagent used is selected from at least one of phosgene, diphosgene, triphosgene, carbonyl fluoride, carbonyl bromide, thionyl fluoride, thionyl chloride, thionyl bromide, sulfuryl chloride or sulfuryl fluoride; the tertiary amine compound is selected from at least one of trimethylamine, triethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N,N-dimethylaniline, pyridine, 4-dimethylaminopyridine or 2,6-di-tert-butylpyridine.

[0028] Further, the molar ratio of the acid-binding agent to compound A in step S1a is 0.8 to 3.0:1, and the molar ratio of the acid-binding agent to the total hydroxyl groups in compound B and compound C in step S2a is 0.5 to 2.5:1.

[0029] Further, the molar ratio of the acid-binding agent to compound A in step S1a is 1.0 to 2.5:1, and the molar ratio of the acid-binding agent to the total hydroxyl groups in compound B and compound C in step S2a is 0.5 to 2.1:1.

[0030] Further, when the esterification in steps S1a and S2a is transesterification, the esterification reagent used is selected from at least one of carbonates, sulfites or sulfates.

[0031] Further, when the esterification in steps S1a and S2a is transesterification, the esterification reagent used is selected from at least one of dimethyl carbonate, diethyl carbonate, bis(trifluoromethyl) carbonate, bis(2,2,2-trifluoroethyl) carbonate, diphenyl carbonate, dimethyl sulfite, diethyl sulfite, dimethyl sulfate or diethyl sulfate.

[0032] Further, a catalyst is used to promote the reaction during the reaction processes of steps S1a and S2a, and the catalyst is selected from at least one of metal oxides, metal hydroxides, metal salts, metal organic compounds, transition metal complexes, solid acids or molecular sieve catalysts.

[0033] Further, the catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate, sodium acetate, triethylamine, pyridine, 4-dimethylaminopyridine, aluminum trichloride, titanium tetrachloride, sodium methoxide, sodium ethoxide, sodium tert-butoxide, potassium tert-butoxide, p-toluenesulfonic acid, acid clay, tetraisopropyl titanate, n-butyl titanate, metal-loaded modified molecular sieve, acidic ion exchange resin, basic ion exchange resin, cobalt carbonyl or samarium trifluoromethanesulfonate.

[0034] Further, in step S1a, the reaction temperature for esterification is -30 to 110 °C, and the molar ratio of the esterification reagent to compound A is 0.5 to 2:1.

[0035] Further, in step S1a, the reaction temperature for esterification is -20 to 105 °C, and the molar ratio of the esterification reagent to compound A is 1.0 to 1.5:1.

[0036] Further, in step S2a, the reaction temperature for esterification is -30 to 110 °C, and the molar ratio of the esterification reagent to the total hydroxyl groups in compound B and compound C is 0.4 to 3.0:1.

[0037] Further, in step S2a, the reaction temperature for esterification is -20 to 105 °C, and the molar ratio of the esterification reagent to the total hydroxyl groups in compound B and compound C is 0.5 to 2.5:1.

[0038] Further, in steps S1b and S2b, the oxidant used for oxidation is selected from at least one of hypochlorous acid, hypochlorites, peroxides, ozone, oxygen, air or metal oxides.

[0039] Further, the oxidant is selected from at least one of aqueous hypochlorous acid, sodium hypochlorite, calcium hypochlorite, hydrogen peroxide, peracetic acid, persulfuric acid, sodium peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, potassium hydrogen persulfate, sodium percarbonate, ozone, oxygen, air, potassium permanganate or sodium dichromate.

[0040] Further, in steps S1b and S2b, the reaction temperature for oxidation is -20 to 60 °C.

[0041] Further, the obtained phosphono polycyclic ester is purified to obtain a high-purity product with a purity ≥ 99%.

[0042] Further, the purification treatment method adopts at least one of crystallization or column chromatography.

[0043] The beneficial effects of the present invention are as follows:

[0044] The preparation method of the phosphono polycyclic ester provided by the present invention has simple steps, the reaction process is easy to control and implement, is easy to industrialize, and the purity of the obtained phosphono polycyclic ester product is above 99%. It can be directly used as an electrolyte additive. The product structural formula contains both phosphorus element and various ester group structures, which can improve the safety performance of the battery and has good technical effects. Specific Embodiments

[0045] The technical solutions of the present invention will be further explained and illustrated below in conjunction with specific embodiments. However, the following embodiments are only examples for explaining the present application and do not limit the content of the present application. Those skilled in the art can make improvements or modifications without creative contributions to the content of the present invention according to the inspiration of this specification, and all fall within the protection scope of the present invention.

[0046] The reaction temperature, unless otherwise specified, generally refers to the internal temperature of the reaction materials.

[0047] The reaction pressure, unless otherwise specified, generally refers to the gauge pressure; the definition of gauge pressure is the difference between the absolute pressure and the atmospheric pressure.

[0048] The present application will be further described in detail below in conjunction with embodiments.

[0049]

Example 1

[0050] A preparation method of a phosphono polycyclic ester includes the following steps:

[0051]

[0052] S1: Add 54.0 g of dimethyl carbonate and 5.0 g of acidic clay catalyst into a 250 mL reaction flask equipped with nitrogen protection, magnetic stirring, thermometer, water separator, and reflux condenser. Stir and heat up to 70 °C, and heat-melt 55.8 g of trimethylolphosphine in a dropping funnel. Keep the temperature at 60 °C constant and gradually add drops. As the drops are added, the reaction proceeds, and the by-product methanol is separated out through the condensation water separator; the reaction temperature gradually drops to 66 °C. After the dropping is completed, heat up to 77 - 80 °C and keep warm for 30 minutes. After the reaction is completed, cool down, filter to remove the catalyst, and distill under reduced pressure to remove the low-boiling substances to obtain a crude product. The crude product is purified by column chromatography to obtain 45.9 g of compound B-1 with a purity of 98.0%.

[0053] S2: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 45.9 g of compound B-1 and 300 mL of tetrahydrofuran. After stirring and dissolving thoroughly, add 36.4 g of triethylamine. Stir and cool down to -20 °C, then slowly add dropwise 18.5 g of thionyl chloride, maintaining the temperature at -15 to -10 °C during the process. After dropping, keep the temperature and continue to react for 6 h. Filter to remove the solid salt. After the mother liquor is distilled under reduced pressure to recover the solvent, the crude product is purified by column chromatography to obtain 26.1 g of the intermediate product. Add it to 300 mL of dichloromethane, add 1.8 g of titanium silicalite molecular sieve catalyst, stir and cool down to -20 °C, slowly add dropwise 36.3 g of 27% hydrogen peroxide, maintaining the temperature at -15 to -10 °C during this period. After the addition, slowly warm up to room temperature and continue to stir for 2 h. Let it stand for liquid separation. Add sodium bisulfite to the aqueous phase to remove the excess hydrogen peroxide, extract the aqueous phase with dichloromethane, combine the organic phases, dehydrate the organic phase with molecular sieve, then distill under reduced pressure to remove the solvent to obtain the crude product, and purify it by column chromatography to obtain 19.9 g of compound D-1 with a purity of 99.0%.

[0054]

Example 2

[0055] A preparation method of a phosphino polycyclic ester, comprising the following steps:

[0056]

[0057] S1: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 46.5 g of trimethylolphosphine, 75.9 g of triethylamine, and 200 mL of tetrahydrofuran. Stir and cool down to -10 °C, then add dropwise 47.6 g of thionyl chloride, maintaining the temperature at -5 to 0 °C during the addition process. After dropping, keep the temperature at -5 to 0 °C and continue to react for 4 h. Filter to remove the solid salt. The mother liquor is distilled under reduced pressure with a water pump to recover the solvent to obtain the crude product, and the crude product is purified by column chromatography to obtain 48.4 g of compound B-2 with a purity of 98.2%.

[0058] S2: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 48.4 g of compound B-2 and 250 mL of dichloromethane. Stir and cool to 0 °C, then slowly add 44.6 g of triphosgene, and gradually dropwise add 49.1 g of N,N-diisopropylethylamine while maintaining the temperature at 0 - 5 °C. After the addition of triphosgene and N,N-diisopropylethylamine is complete, continue the reaction for 3 h. Slowly raise the temperature to room temperature, filter to remove the solid salt, and recover the solvent by vacuum distillation with a water pump from the mother liquor to obtain the crude product. After recrystallization and purification of the crude product, 38.9 g of the intermediate product is obtained. Add it to 150 mL of dichloromethane, stir and cool to -20 °C, and dropwise add 74.8 g of 30% hydrogen peroxide solution while maintaining the temperature at -15 - -10 °C. After the addition is complete, keep the temperature at 0 - 5 °C and continue the reaction for 4 h. Separate the layers, add sodium bisulfite to the aqueous phase to remove the excess hydrogen peroxide, extract the aqueous phase with dichloromethane, combine the organic phases, dry over molecular sieves, and then distill off the low-boiling substances under reduced pressure. After recrystallization and purification of the crude product, 30.4 g of compound D-2 is obtained with a purity of 99.2%.

[0059]

Example 3

[0060] A method for preparing a phosphino polycyclic ester, comprising the following steps:

[0061]

[0062] S1: In a 1 L reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 67.0 g of trimethylolphosphine and 500 mL of dichloromethane. Slowly add 166.2 g of triphosgene in batches, stir and cool to -20 °C, then dropwise add 88.6 g of pyridine while maintaining the temperature at -15 - -10 °C. After the addition is complete, keep the temperature at -15 - -10 °C and continue the reaction for 2 h. Slowly raise the temperature to room temperature, filter to remove the solid salt, and recover the solvent by vacuum distillation with a water pump from the mother liquor to obtain the crude product. Purify the crude product by column chromatography to obtain 53.8 g of compound B-1 with a purity of 98.0%.

[0063] S2: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 45.9 g of compound B-1 and 250 mL of dichloromethane. Stir and cool to 0 °C, slowly add 45.4 g of triphosgene, and at the same time gradually dropwise add 38.8 g of N,N-diisopropylethylamine while maintaining the temperature at 0 - 5 °C. After the addition of triphosgene and N,N-diisopropylethylamine is complete, continue the reaction for 3 h. Slowly raise the temperature to room temperature, filter to remove the solid salt, and recover the solvent by vacuum distillation with a water pump from the mother liquor to obtain the crude product. Purify the crude product by column chromatography to obtain 36.2 g of compound D-3 with a purity of 99.5%.

[0064]

Example 4

[0065] A method for preparing a phosphino polycyclic ester, comprising the following steps:

[0066]

[0067] S1: In a 500 mL reaction flask equipped with magnetic stirring, a thermometer, a reflux condenser, and a water separator, add 63.0 g of trimethylolphosphine oxide, then add 59.0 g of diethyl carbonate, 3.15 g of potassium carbonate, and 200 mL of toluene. Heat up to 100 - 105 °C and reflux for 2 h. The reaction by-product ethanol is removed through the water separator. After the reaction is completed, cool to room temperature, distill off the low-boiling substances under reduced pressure, and use recrystallization for purification to obtain 53.1 g of compound B-3 with a purity of 97.0%.

[0068] S2: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, a reflux condenser, and a water separator, add 53.1 g of B-3, 300.0 mL of toluene, 2.0 g of p-toluenesulfonic acid, and 27.6 g of dimethyl sulfite. Stir and heat up to 95 - 98 °C and react for 5 h. The by-product methanol is separated from the water separator. After the reaction is completed, distill off the solvent and low-boiling substances under reduced pressure. The crude product is purified by recrystallization to obtain 26.7 g of compound D-4 with a purity of 99.3%.

[0069]

Example 5

[0070] A method for preparing a phosphino polycyclic ester, comprising the following steps:

[0071]

[0072] S1: In a 500 mL reaction flask equipped with nitrogen protection, magnetic stirring, a thermometer, and a reflux condenser, add 42.0 g of trimethylolphosphine oxide, 63.7 g of triethylamine, and 200 mL of tetrahydrofuran. Stir and cool down to -18 °C, then dropwise add 37.1 g of thionyl chloride. During the dropping process, maintain the temperature at -10 to -5 °C. After dropping, continue to react at -10 to -5 °C for 6 h. Filter to remove the solid salt, and recover the solvent from the mother liquor by water pump vacuum distillation to obtain the crude product. The crude product is purified by column chromatography to obtain 39.1 g of compound B-4.

[0073] S2: Dissolve 39.1 g of compound B-4 in 250 mL of toluene. After stirring until completely dissolved, add 19.0 g of pyridine. Stir and cool down to -20°C, then slowly add dropwise 14.3 g of thionyl chloride while maintaining the temperature at -15 to 10°C. After the addition, raise the temperature to 105°C and maintain reflux reaction for 2 h. After the reaction is completed, filter to remove the solid salt. The mother liquor is distilled under reduced pressure to remove the solvent and excessive thionyl chloride. The crude product is purified by recrystallization to obtain 33.4 g of the intermediate product. Then, add 33.4 g of the intermediate product to 200 mL of dichloromethane. Stir and cool down to -15°C, then add dropwise 59.5 g of 30% hydrogen peroxide solution while maintaining the temperature at -15 to -5°C. After the addition, keep the temperature and continue the reaction for 6 h. Separate the layers. Add sodium bisulfite to the aqueous phase to remove the excessive hydrogen peroxide. Extract the aqueous phase with dichloromethane. Combine the organic phases, dry over molecular sieve, and then distill under reduced pressure to remove the low-boiling components. Concentrate by distillation under reduced pressure with a water pump to obtain the crude product. The crude product is purified by recrystallization to obtain 32.9 g of compound D-5 with a purity of 99.1%.

[0074] In summary, the preparation method of the phosphino polycyclic ester provided by the present invention has simple steps, the reaction process is easy to control and implement, is easy to industrialize, and the obtained phosphino polycyclic ester product has high purity and can be directly used as an electrolyte additive. The product structural formula contains both phosphorus element and multiple ester group structures, which can improve the safety performance of the battery and has good technical effects.

Claims

1. A phosphono polycyclic ester, characterized in that, The phosphino polycyclic ester described has the following general structural formula: Wherein, A1, A2, and A3 are independently selected from the elements C or S; n and m are independently selected from 0 or 1; c, d, and e are independently selected from 1 or 2.

2. The phosphono polycyclic ester according to claim 1, characterized in that, The phosphono polycyclic ester described above is selected from at least one of the following structural formulas:

3. The preparation method of the phosphono polycyclic ester according to claim 1, comprising the following steps: S1a: Compound A is esterified to obtain compound B; S1b: Compound B is oxidized to obtain compound C. This step can be optionally carried out or not carried out after S1a; S2a: Compound B and / or compound C are esterified to obtain compound D, namely the phosphono polycyclic ester; S2b: Compound D is further oxidized to obtain an oxidized phosphono polycyclic ester. This step can be optionally carried out or not carried out after S2a; The esterification described in steps S1a and S2a is transesterification or dehalogenation reaction; A, A1, A2, A3 are independently selected from C or S elements; p, n, m are independently selected from 0 or 1; a, b, c, d, e are independently selected from 1 or 2.

4. The preparation method of the phosphono polycyclic ester according to claim 3, characterized in that, The specific preparation routes of steps S1a and S1b are as follows: The obtained compound B is selected from at least one of the following structural formulas: The obtained compound C is selected from at least one of 5. The preparation method of the phosphono polycyclic ester according to claim 3, characterized in that, When the esterification described in steps S1a and S2a is a dehalogenation reaction, the esterification reagent used is selected from at least one of carbonyl halides, thionyl halides or sulfuryl halides; a tertiary amine compound is used as an acid-binding agent during the reaction to promote the reaction; the molar ratio of the acid-binding agent to compound A in step S1a is 0.8 - 3.0:1; the molar ratio of the acid-binding agent to the total hydroxyl groups in compound B and compound C in step S2a is 0.5 - 2.5:

1.

6. The preparation method of the phosphono polycyclic ester according to claim 5, characterized in that, The esterification reagent is selected from at least one of phosgene, diphosgene, triphosgene, carbonyl fluoride, carbonyl bromide, thionyl fluoride, thionyl chloride, thionyl bromide, sulfuryl chloride or sulfuryl fluoride; the tertiary amine compound is selected from at least one of trimethylamine, triethylamine, N,N - diisopropylethylamine, N,N - dimethylcyclohexylamine, N,N - dimethylaniline, pyridine, 4 - dimethylaminopyridine or 2,6 - di - tert - butylpyridine.

7. The preparation method of the phosphono polycyclic ester according to claim 3, characterized in that, When the esterification described in steps S1a and S2a is transesterification, the esterification reagent used is selected from at least one of carbonates, sulfites or sulfates; a catalyst is used to promote the reaction during the reaction, and the catalyst is selected from at least one of metal oxides, metal hydroxides, metal salts, metal organic compounds, transition metal complexes, solid acids or molecular sieve catalysts.

8. The method for preparing the phosphono polycyclic ester according to claim 7, characterized in that, The esterification reagent is selected from at least one of dimethyl carbonate, diethyl carbonate, bis(trifluoromethyl) carbonate, bis(2,2,2 - trifluoroethyl) carbonate, diphenyl carbonate, dimethyl sulfite, diethyl sulfite, dimethyl sulfate or diethyl sulfate; the catalyst is selected from at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium bicarbonate, sodium acetate, triethylamine, pyridine, 4 - dimethylaminopyridine, aluminum trichloride, titanium tetrachloride, sodium methoxide, sodium ethoxide, sodium tert - butoxide, potassium tert - butoxide, p - toluenesulfonic acid, acidic clay, titanium tetraisopropoxide, titanium n - butoxide, metal - loaded modified molecular sieve, acidic ion exchange resin, basic ion exchange resin, cobalt carbonyl or samarium trifluoromethanesulfonate.

9. The preparation method of the phosphono polycyclic ester according to claim 3, characterized in that, In the described step S1a, the reaction temperature for esterification is -30 to 110 °C, and the molar ratio of the esterification reagent to compound A is 0.5 to 2:1; in step S2a, the reaction temperature for esterification is -30 to 110 °C, and the molar ratio of the esterification reagent to the total hydroxyl groups in compound B and compound C is 0.4 to 3.0:1; in steps S1b and S2b, the oxidizing agent used is selected from at least one of hypochlorous acid, hypochlorite, peroxide, ozone, oxygen, air or metal oxide, and the temperature of the oxidation reaction is -20 to 60 °C.

10. The method for preparing the phosphono polycyclic ester according to claim 9, characterized in that, The oxidizing agent used in steps S1b and S2b is selected from at least one of aqueous hypochlorous acid, sodium hypochlorite, calcium hypochlorite, hydrogen peroxide, peracetic acid, persulfuric acid, sodium peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, potassium bisulfate, sodium percarbonate, oxygen, potassium permanganate or sodium dichromate.

11. The method for preparing the phosphono polycyclic ester according to claim 3, characterized in that, The obtained phosphono polycyclic ester is subjected to purification treatment to obtain a high-purity product with a purity ≥ 99%.

12. The preparation method of the phosphino polycyclic ester according to claim 11, characterized in that, The described purification treatment method adopts at least one of crystallization or column chromatography.

Images