Aryl phosphate diester compound as well as synthesis method and application thereof

Abstract

The invention provides an aryl phosphate diester compound as well as a synthesis method and application thereof. The synthesis method comprises the following steps: under an inert atmosphere condition, carrying out a first reaction on a first mixed reaction system containing a phosphodiesters compound, thionyl chloride and a catalyst to obtain a phosphoryl chloride compound; under the inert atmosphere condition, a halogenated benzene compound and organic lithium are subjected to a lithium halogen exchange reaction, a second mixed reaction system containing the phosphoryl chloride compound and a product of the lithium halogen exchange reaction is subjected to a nucleophilic reaction, and the aryl phosphate diester compound is obtained. The synthesis method is relatively mild in reaction condition, high in raw material preparation yield and rich in applicable substrate variety. The invention also provides a mixed extraction system taking the o-hydroxybenzoic acid n-octyl ester as the extraction agent and the prepared aryl phosphate diester compound as the synergistic extraction agent, the extraction system is suitable for extracting lithium from an alkaline lithium-containing solution, the configuration of the extraction agent is subjected to enol transformation during extraction, and the lithium extraction rate is relatively high.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium extraction, and specifically relates to an aromatic phosphate diester compound and a synthesis method and application thereof. Background Art

[0002] Lithium is known as "green energy metal" and "white oil". It is widely used in lithium battery energy storage, pharmaceutical chemicals, metallurgical materials, electronic industry, controlled thermonuclear fusion reactors and other fields. The lithium industry chain mainly includes upstream raw material supply, midstream lithium salt products and downstream products. Among them, the upstream raw material supply mainly comes from lithium extraction from ore (spodumene, lithium mica), lithium extraction from salt lake brine and the recovery of some waste battery lithium; the midstream lithium salt industry includes the production of high-purity lithium carbonate, lithium chloride and lithium hydroxide; the downstream products include lithium battery positive electrode materials, organic alkyl lithium, metallic lithium, etc. In recent years, with the rapid development of new energy industries such as electric vehicles, the market demand for lithium resources has increased sharply, and at the same time, the production cost of mid- and upstream lithium products has been further compressed; therefore, it is of far-reaching significance to explore and study cheaper, greener and more efficient lithium extraction methods. The existing lithium extraction methods mainly include roasting, precipitation, adsorption, membrane, electrochemical deintercalation, solvent extraction, etc. Among them, solvent extraction has high separation efficiency, large processing capacity, simple operation, easy automation and intelligence, and can better adapt to more complex natural conditions. It is used in three fields: lithium extraction from salt lakes, lithium extraction from lithium mines, and mother liquor recovery. The key to solvent extraction lies in the extractant, which mainly includes phosphorus, ketones, amides, crown ethers, etc.

[0003] Among them, phosphorus extractants are the "classic prescription" of solvent extraction. They were used as nuclear raw materials and rare earth element extractants in the early days, and later they were used for Li + Extraction, the typical representative is the TBP-FeCl3 extraction system, which uses high-concentration acid stripping and concentrated alkali saponification regeneration to form a complete process cycle, which is suitable for lithium extraction from brine with a high lithium-magnesium ratio. However, this extraction system consumes a lot of acid and alkali, corrodes equipment, and restricts the prospects for industrial application. The TBP-P507-FeCl3 extraction system can achieve stripping of Li by adjusting the chloride ion concentration of the aqueous phase. + The effect of P507 is achieved by using P507 as acid to prevent FeCl3 from hydrolyzing and increase the extraction groups, thus realizing an alkali-free process, slowing down the decomposition rate of the extractant and reducing the production cost to a certain extent. However, it still uses FeCl3 for co-extraction, which has high requirements for process flow control and separation equipment.

[0004] The prior art also reports mixed extraction systems using diketone or salicylate as extractants and phosphorus compounds such as triphenylphosphine oxide, trialkylphosphine oxide, tributyl phosphate, etc. as co-extractants. Although these mixed extraction systems can extract and separate lithium from alkaline solutions with a high sodium-to-lithium ratio, the synthesis of phosphorus extractants with new structures is difficult, and the phosphorus extractants used are all common commercial structures, lacking regularity and specificity, which seriously restricts the further optimization and application of such extraction systems.

[0005] At present, the existing synthesis methods of aromatic phosphate diester compounds are mainly the following routes 1 and 2.

[0006] Route 1:

[0007]

[0008] Route 2:

[0009]

[0010] Route 1 is to first react an aromatic compound with PCl3 under the action of a Lewis acid (ZnCl2 or AlCl3) to generate an aromatic substituted phosphorus trichloride, which is then treated with chlorine gas for chlorination, and then reacted with the corresponding alcohol to obtain the target product. The reaction steps required for this synthetic route are relatively complicated, and chlorine gas needs to be used for oxidation during the process. The source of chlorine gas and tail gas treatment increase the complexity of the reaction, resulting in a low overall reaction yield.

[0011] Route 2 is to use a trialkoxyphosphine as a substrate to directly react with a corresponding bromoaryl compound at a temperature of about 200°C to generate the corresponding target product. Compared with Route 1, although Route 2 is simple, its reaction conditions are harsh, requiring the temperature to be raised to about 200°C, and the final product type is also more complex. Summary of the invention

[0012] In order to solve all or part of the above technical problems, the present invention provides the following technical solutions:

[0013] One of the purposes of the present invention is to provide an aryl phosphate diester compound, wherein the aryl phosphate diester compound has a structure shown in Formula I:

[0014]

[0015] Wherein, R is at least selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkyne, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN; the number of substitutions of R on the benzene ring of the aromatic phosphate diester compound is 1 to 5, and the substitution position is ortho, meta or para;

[0016] R1 and R2 are at least independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl, and R1 and R2 are the same or different.

[0017] In some embodiments, R is selected from H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted C2-C8 olefin, substituted or unsubstituted C2-C8 alkynyl, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN.

[0018] In some embodiments, the substituents on R include one or more of a primary amino substituent, a secondary amino substituent, a tertiary amino substituent, or a quaternary amino substituent substituted with a heterocycle.

[0019] In some embodiments, R1 and R2 are independently selected from H, C1-C8 substituted or unsubstituted alkyl, C2-C8 substituted or unsubstituted olefin, C2-C8 substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl.

[0020] In some embodiments, the substituents on R1 and R2 include one or more heteroatoms or heterocyclic groups.

[0021] The second object of the present invention is to provide a method for synthesizing an aromatic phosphate diester compound, comprising:

[0022] Under inert atmosphere conditions, a first mixed reaction system containing a phosphoric diester compound raw material, thionyl chloride and a catalyst undergoes a first reaction to obtain a phosphoryl chloride compound; wherein the catalyst comprises N,N-dimethylformamide;

[0023] Under inert atmosphere conditions, a halogenated benzene compound and an organic lithium are subjected to a lithium-halogen exchange reaction, and a second mixed reaction system containing the phosphoryl chloride compound and a product of the lithium-halogen exchange reaction is subjected to a nucleophilic reaction to obtain an aromatic phosphate diester compound.

[0024] In some embodiments, the phosphodiester compound raw material has a structure shown in Formula II:

[0025]

[0026] Wherein, R1 and R2 are at least independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl, and R1 and R2 are the same or different.

[0027] In some embodiments, R1 and R2 are independently selected from H, C1-C8 substituted or unsubstituted alkyl, C2-C8 substituted or unsubstituted olefin, C2-C8 substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl.

[0028] In some embodiments, the substituents on R1 and R2 include one or more heteroatoms or heterocyclic groups.

[0029] In some embodiments, the halogenated benzene compound has a structure shown in Formula III:

[0030]

[0031] Wherein, X is Br; R is at least selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkyne, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -C1, -Br, -I, -CF3 or -CN; the number of substitutions of R on the benzene ring of the halogenated benzene compound is 1 to 5, and the substitution position is ortho, meta or para.

[0032] In the structure shown in Formula III, X is Br, that is, the halogenated benzene compound is a bromobenzene compound. Compared with other halogenated benzene compounds, the bromobenzene compound has a better reaction effect in the lithium-halogen exchange reaction with organic lithium in this system.

[0033] In some embodiments, R is selected from H, substituted or unsubstituted C1-C8 alkyl, substituted or unsubstituted C2-C8 olefin, substituted or unsubstituted C2-C8 alkynyl, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -C1, -Br, -I, -CF3 or -CN.

[0034] In some embodiments, the substituents on R include one or more of a primary amino substituent, a secondary amino substituent, a tertiary amino substituent, or a quaternary amino substituent substituted with a heterocycle.

[0035] In some embodiments, the first reaction time is 6 to 8 hours.

[0036] In some embodiments, the molar ratio of the phosphodiester compound to thionyl chloride is 1:1 to 2:3.

[0037] In some embodiments, the organic lithium includes n-butyl lithium.

[0038] In some embodiments, the temperature of the lithium-halogen exchange reaction is -20°C to -110°C, preferably -110°C. After the lithium-halogen exchange reaction is completed, the temperature is naturally increased to carry out the nucleophilic reaction.

[0039] In some embodiments, the lithium-halogen exchange reaction time is 5 to 120 minutes.

[0040] In some embodiments, the nucleophilic reaction time is 1-18 hours.

[0041] In some embodiments, the synthesis method specifically includes: under inert atmosphere conditions, heating a first mixed reaction system containing a phosphodiester compound raw material, thionyl chloride, a catalyst and a first solvent to the reflux temperature of the first solvent to carry out the first reaction to obtain a phosphorus oxychloride compound.

[0042] In some embodiments, the first solvent includes one or more of dichloromethane, 1,2-dichloroethane, and carbon tetrachloride, preferably dichloromethane, which has a low boiling point, mild reaction conditions, and convenient post-reaction treatment.

[0043] In some embodiments, the synthesis method further comprises: removing the first solvent and thionyl chloride in the product obtained by the first reaction by distillation, thereby separating and obtaining the phosphorus oxychloride compound. The distillation is, for example, atmospheric distillation and / or reduced pressure distillation, and the product obtained by the first reaction needs to be cryogenically cooled before distillation.

[0044] In some embodiments, the synthesis method specifically includes:

[0045] Under inert atmosphere, dispersing the halogenated benzene compound in a second solvent, controlling the temperature at -20°C to -110°C, and mixing the halogenated benzene compound with organic lithium to carry out the lithium halogen exchange reaction;

[0046] The phosphorus oxychloride compound is added in batches to the product of the lithium halogen exchange reaction to obtain the second mixed reaction system; the temperature of the second mixed reaction system is controlled at -20°C to -110°C and maintained for 10 to 80 minutes, and then the second mixed reaction system is naturally heated to carry out the nucleophilic reaction.

[0047] In some embodiments, the second solvent includes diethyl ether and / or tetrahydrofuran, preferably includes tetrahydrofuran.

[0048] The third object of the present invention is to provide an aromatic phosphate diester compound, which is prepared by any of the methods described above.

[0049] A fourth object of the present invention is to provide an application of the aromatic phosphate diester compound in extracting lithium from an alkaline lithium-containing solution.

[0050] In some embodiments, the application includes: using the aromatic phosphate diester compound as a co-extractant for extracting lithium from an alkaline lithium-containing solution.

[0051] In some embodiments, the application includes: extracting lithium from an alkaline lithium-containing solution using an extraction system containing an extractant and a co-extractant, wherein the extractant includes n-octyl o-hydroxybenzoate (OHB), and the co-extractant includes the aromatic phosphate diester compound.

[0052] A fifth object of the present invention is to provide an extraction system for extracting lithium from an alkaline lithium-containing solution, comprising an extractant and a synergist, wherein the synergist comprises the aromatic phosphate diester compound.

[0053] The extraction system has a high lithium extraction rate and extraction efficiency. Compared with the phosphorus co-extractants in the prior art, the aromatic phosphoric acid diester compounds provided by the present invention have the characteristics of adjustable structure and performance and good lithium / separation effect.

[0054] The n-octyl o-hydroxybenzoate in the extraction system changes from the keto (Keto) to the enol (Enol) configuration during the lithium extraction process. Its lithium extraction mechanism is simple and clear, and is easy to optimize and regulate.

[0055] In some embodiments, the extractant includes n-octyl o-hydroxybenzoate. The structural formula of n-octyl o-hydroxybenzoate is:

[0056]

[0057] In some embodiments, the co-extractant includes dibutyl phenyl phosphate (DPPO), di(2-ethylhexyl) phenyl phosphate (BPPO), dibutyl 4-methylphenyl phosphate (DTPO), di(2-ethylhexyl) 4-methylphenyl phosphate (BTPO), dibutyl 4-methoxyphenyl phosphate (DMPO), di(2-ethylhexyl) 4-methoxyphenyl phosphate (BMPO), dibutyl 4-dimethylaminophenyl phosphate (DAPO), di(2-ethylhexyl) 4-dimethylaminophenyl phosphate (BAPO), dibutyl 4-trifluoromethylphenyl phosphate (DTFPO), di(2-ethylhexyl) 4-trifluoromethylphenyl phosphate (BTFPO), dibutyl 4-fluorophenyl phosphate (DFPO), and di(2-ethylhexyl) 4-fluorophenyl phosphate (BFPO). One or more combinations thereof.

[0058] In some embodiments, the molar ratio of the extractant to the co-extraction agent is 1:9 to 9:1.

[0059] In some embodiments, the extraction system further comprises a diluent, and the diluent makes the total concentration of the extractant and the co-extractant in the extraction system be 0.1 to 3 mol / L.

[0060] In some embodiments, the diluent includes one or more combinations of kerosene, sulfonated kerosene, n-hexane, cyclohexane, benzene, toluene, xylene, chlorobenzene, disubstituted chlorobenzene, dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, and ethyl acetate, but is not limited thereto.

[0061] A sixth object of the present invention is to provide a method for extracting lithium from an alkaline lithium-containing solution, comprising: mixing and fully contacting the extraction system with the alkaline lithium-containing solution to extract lithium.

[0062] In some embodiments, the concentration of hydroxide ions in the alkaline lithium-containing solution is 0.01 mol / L to 4 mol / L.

[0063] In some embodiments, the extraction system is mixed with the alkaline lithium-containing solution in a ratio of 1:10 to 10:1.

[0064] In some embodiments, the method specifically includes: mixing the extraction system with the alkaline lithium-containing solution and shaking for more than 5 minutes to perform extraction, for example, 5 to 10 minutes. The extraction system has a fast extraction efficiency, and a good extraction rate can be achieved by mixing and shaking for 5 minutes.

[0065] In some embodiments, the method includes: using the extraction system to perform three or more stages of countercurrent extraction on the alkaline lithium-containing solution. The three-stage countercurrent extraction can achieve an extraction rate of more than 93%.

[0066] In some embodiments, the method further comprises: after the extraction is completed, stripping with an acid to release lithium ions. The concentration of hydrogen ions in the acid is, for example, 0.01 mol / L to 6 mol / L.

[0067] Compared with the prior art, the present invention has at least the following beneficial effects:

[0068] (1) The present invention provides a method for synthesizing an aromatic phosphodiester compound by using a halogenated aromatic compound as a substrate, reacting the halogenated aromatic compound with an organic lithium, and then reacting the halogenated aromatic compound with a corresponding phosphoryl chloride to undergo a nucleophilic reaction. The synthetic method has relatively mild reaction conditions, a high yield of raw material preparation, and a wide variety of applicable substrates.

[0069] (2) The present invention provides a mixed extraction system with n-octyl o-hydroxybenzoate as an extractant and a prepared aromatic phosphate diester compound as a co-extractant. The extraction mechanism is clear and the structural properties are controllable. The extraction system is suitable for extracting lithium from an alkaline lithium-containing solution, has good lithium / sodium selectivity, and has a high lithium extraction rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0071] Figure 1 The extraction system provided by the present invention is used for extracting lithium with n-octyl o-hydroxybenzoate. 1 H NMR spectrum changes. DETAILED DESCRIPTION

[0072] The technical solution of the present invention is described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention. The specific functional details disclosed herein should not be interpreted as limiting, but only as the basis for the claims and as a representative basis for teaching those skilled in the art to adopt the present invention in different ways in any appropriate detailed embodiment.

[0073] In addition, unless otherwise specified, the various raw materials used in the following examples can be purchased from the market and other channels, and the various production and testing equipment used are also equipment known in the art.

[0074] In some embodiments of the present invention, the synthesis route of the aryl phosphate diester compound is as follows:

[0075]

[0076] The technical solution of the present invention is fully and specifically described below in conjunction with specific implementation methods.

[0077] Example 1

[0078] Example 1 provides an aromatic phosphate diester compound and a synthesis method thereof, which specifically comprises the following steps:

[0079] Under argon protection, add 20mL of dichloromethane (DCM) and 0.1mol of dibutyl phosphate to a 250mL three-necked flask (equipped with a 100mL constant pressure funnel); then use a constant pressure funnel to add 10mL of dichloromethane and 0.25mol of SOCl2; then inject 0.5mL of N,N-dimethylformamide (DMF) into the three-necked flask as a catalyst, stir and slowly heat to reflux, connect to a tail gas treatment device (using NaOH solution to absorb tail gas), reflux for 6 hours, stop heating after observing that no gas is generated, and cool to room temperature. Keep the tail gas absorption device, evaporate DCM at normal pressure to obtain a light yellow liquid, and after cooling, distill off the excess SOCl2 under reduced pressure (take the liquid at low temperature) to obtain a light yellow oily target product, which is dibutoxyphosphoryl chloride, with a yield of 96%.

[0080] The H NMR spectrum of dibutoxyphosphoryl chloride is:

[0081] 1 H NMR (600MHz, CDCl3) δ4.29-3.96 (m, 4H), 1.63 (dt, J=15.8, 7.8Hz, 4H), 1.35 (dt, J=15.7, 7.9Hz, 4H), 0.86 (td, J=7.3, 4.0Hz, 6H); 13 C NMR (151MHz, CDCl3) δ77.39, 77.18, 76.97, 69.38, 68.71, 32.01, 31.70, 18.47, 13.35.

[0082] Under argon protection, 2.0 mmol bromobenzene and 10 mL dry tetrahydrofuran (THF) were added to a 50 mL three-necked round-bottom flask (equipped with a 10 mL constant pressure funnel); 2.0 mmol dibutoxyphosphoryl chloride prepared above and 5 mL dry THF were added to the constant pressure funnel, the system was cooled to -110°C, stirred, 2.1 mmol n-butyl lithium (n-BuLi) was slowly injected into the three-necked flask, and after stirring for 45 min, a milky turbid liquid was generated, and -110°C was maintained; dibutoxyphosphoryl chloride was slowly added dropwise to the three-necked flask through the constant pressure funnel, and after the addition was completed, the temperature was maintained at -110°C for 30 min, and then it was allowed to heat up naturally and stirred for 12 hours.

[0083] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), saturated salt water (35mL×2 times) in sequence, then add anhydrous Na2SO4 to dry, spin-dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 8 (V / V) as eluent to obtain a colorless, transparent, oily target product, i.e., dibutyl phenyl phosphate (denoted as DPPO), with a yield of 63% (n=4).

[0084] The H NMR spectrum of dibutyl phenyl phosphate (DPPO) is:

[0085] 1 H NMR (600MHz, CDCl3) δ7.80 (dddd, J=13.3, 6.9, 2.4, 1.3Hz, 2H), 7.54 (tt, J=7.3, 1.4Hz, 1H), 7.49- 7.38 (m, 2H), 4.08-3.94 (m, 4H), 1.68-1.56 (m, 4H), 1.46-1.31 (m, 4H), 0.89 (td, J=7.4, 1.2Hz, 6H); 13 C NMR (101MHz, CDCl3) δ132.31, 132.28, 131.80, 131.71, 128.49, 128.34, 77.39, 77.07, 76.75, 67.35, 65.73, 32.25, 19.23, 12.91; 31 pNMR (162MHz, CDCl3) δ18.77, -0.63; HR-MS-ESI m / z (%) 271.1461 [M+H] + Calcd.for C 14 H 24 O3P271.1458.

[0086] Example 2

[0087] Example 2 is basically the same as Example 1, except that the phosphoric acid diester compound raw material used in Example 2 is di(2-ethylhexyloxy) phosphate, and the obtained product is di(2-ethylhexyloxy) phosphoryl chloride.

[0088] The nuclear magnetic resonance hydrogen spectrum of di(2-ethylhexyloxy)phosphoryl chloride is:

[0089] 1 H NMR (600MHz, CDCl3) δ3.93 (hept, J=5.6, 5.1Hz, 4H), 1.62-1.52 (m, 2H), 1.46-1.32 (m, 6H), 1.32-1.23 (m, 10H), 0.89 (t, J=7.4Hz, 12H); 13 C NMR (151MHz, CDCl3) δ77.23, 77.02, 76.81, 69.60, 69.56, 40.03, 39.98, 29.83, 28.85, 23.18, 22.95, 14.01, 10.85.

[0090] According to the same method as in Example 1, the above-mentioned di(2-ethylhexyloxy)phosphoryl chloride was used to prepare aromatic phosphoric acid diester compounds to obtain the product di(2-ethylhexyloxy)phenyl phosphate (denoted as BPPO) with a yield of 60% (n=8).

[0091] The H NMR spectrum of bis(2-ethylhexyloxy)phenyl phosphate (BPPO) is:

[0092] 1 H NMR (600MHz, CDCl3) δ7.80 (dd, J=13.2, 7.6Hz, 2H), 7.54 (d, J=7.5Hz, 1H), 7.46 (td, J=7.6, 4.1H z, 2H), 4.07-3.81 (m, 4H), 1.61-1.48 (m, 2H), 1.47-1.13 (m, 16H), 0.87 (dq, J=19.5, 7.4Hz, 12H); 13 C NMR (101MHz, CDCl3) δ132.24, 132.21, 131.81, 131.71, 128.43, 128.28, 77.38, 77.06, 76.74, 69.61, 69.54, 67.99, 67.97, 67. 93, 67.91, 65.18, 41.98, 40.17, 40.15, 40.11, 40.08, 29.92, 28.84, 28.79, 23.30, 22.97, 22.94, 14.03, 14.01, 10.89, 10.87; 31 P NMR (162MHz, CDCl3) δ18.71, -0.52; HR-MS-ESI m / z (%) 405.2524[M+Na] + Calcd.for C 22 H39NaO3P405.2529.

[0093] Example 3

[0094] The phosphorus oxychloride used in Example 3 is the dibutoxyphosphorus oxychloride prepared in Example 1.

[0095] The method of synthesizing an aryl phosphate diester compound by using dibutoxyphosphoryl chloride specifically comprises the following steps:

[0096] Under argon protection, add 2.0mmol 4-methylbromobenzene and 10mL dry tetrahydrofuran (THF) to a 50mL three-necked round-bottom flask (equipped with a 10mL constant pressure funnel); add 2.0mmol dibutoxyphosphoryl chloride and 5mL dry THF to the constant pressure funnel, cool the system to -110°C, stir, slowly inject 2.1mmol n-butyl lithium (n-BuLi) into the three-necked flask, stir for 45min, and a milky white turbid liquid is generated. Maintain -110°C, slowly add dibutoxyphosphoryl chloride to the three-necked flask through the constant pressure funnel, maintain -110°C for 30min after the drop is complete, then allow it to warm up naturally and stir for 12 hours.

[0097] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), saturated brine (35mL×2 times), then add anhydrous Na2SO4 to dry, spin dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 8 (V / V) as eluent to obtain a colorless, transparent, oily target product, i.e., 4-methylphenyl dibutyl phosphate (DTPO), with a yield of 53% (n=4).

[0098] The H NMR spectrum of 4-methylphenyl dibutyl phosphate (DTPO) is:

[0099] 1 H NMR (600MHz, CDCl3) δ7.67 (dq, J=10.1, 6.3, 5.7Hz, 2H), 7.24 (tt, J=7.9, 3.8Hz, 2H), 3.99 (dddd, J=41.0, 13.1, 6.3, 3. 6Hz, 4H), 2.44-2.32 (m, 3H), 1.67-1.56 (m, 4H), 1.36 (dq, J=10.6, 6.3, 5.1Hz, 4H), 0.87 (ddt, J=13.9, 10.3, 5.0Hz, 6H); 13 C NMR (101MHz, CDCl3) δ142.83, 142.80, 131.86, 131.76, 129.22, 129.07, 125.93, 124.04, 77.41, 77.09 ,76.77, 67.33, 67.27, 65.65, 65.59, 32.45, 32.39, 32.31, 32.24, 21.62, 21.61, 18.71, 18.65, 13.56; 31 P NMR (162MHz, CDCl3) δ19.49, -0.64.HR-MS-ESI m / z (%) 285.1620[M+H] + Calcd.for C15 H 26 O3P 285.1614.

[0100] Example 4

[0101] The phosphorus oxychloride used in Example 4 is the di(2-ethylhexyloxy)phosphorus oxychloride prepared in Example 2. The method for synthesizing the aryl phosphate diester compound using the phosphorus oxychloride is basically the same as that in Example 3, except that the dibutoxyphosphorus oxychloride in Example 3 is replaced by di(2-ethylhexyloxy)phosphorus oxychloride. The obtained product is di(2-ethylhexyloxy)4-methylphenyl phosphate (referred to as BTPO), with a yield of 62% (n=8).

[0102] The H NMR spectrum of 4-methylphenyl di(2-ethylhexyloxy)phosphate (BTPO) is:

[0103] 1 H NMR (600MHz, CDCl3) δ7.69 (dd, J=13.0, 7.7Hz, 2H), 7.28-7.19 (m, 2H), 3.98 (tt, J=10.8, 5.6Hz, 2H ), 3.92-3.82(m, 2H), 2.41(s, 3H), 1.56(q, J=6.1Hz, 2H), 1.45-1.17(m, 16H), 0.94-0.73(m, 12H); 13 C NMR (101MHz, CDCl3) δ142.76, 142.73, 131.89, 131.79, 129.19, 129.04, 125.94, 124.05, 77.38, 77.06, 76.74, 67 .85, 67.81, 67.79, 40.17, 40.15, 40.10, 40.08, 29.92, 28.85, 28.79, 23.31, 22.96, 21.65, 14.02, 10.91, 10.89; 31 PNMR (162MHz, CDCl3) δ32.57, 19.43, -0.52; HR-MS-ESI m / z (%) 397.2879 [M+H] + Calcd.forC 23 H42O3P 397.2866.

[0104] Example 5

[0105] The phosphorus oxychloride used in Example 5 is the dibutoxyphosphorus oxychloride prepared in Example 1.

[0106] Under argon protection, 2.0 mmol 4-methoxybromobenzene and 10 mL dry tetrahydrofuran (THF) were added to a 50 mL three-necked round-bottom flask (equipped with a 10 mL constant pressure funnel); 2.0 mmol dibutoxyphosphoryl chloride and 5 mL dry THF were added to the constant pressure funnel, the system was cooled to -110°C, stirred, 2.1 mmol n-butyl lithium (n-BuLi) was slowly injected into the three-necked flask, stirred for 45 min, a milky white turbid liquid was generated, maintained at -110°C, dibutoxyphosphoryl chloride was slowly added dropwise to the three-necked flask through the constant pressure funnel, maintained at -110°C for 30 min after the dropwise addition, then allowed to heat up naturally, and stirred for 12 hours.

[0107] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), saturated brine (35mL×2 times), then add anhydrous Na2SO4 to dry, spin-dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 4 (V / V) as eluent to obtain a colorless, transparent, oily target product, i.e., 4-methoxyphenyl dibutyl phosphate (denoted as DMPO), with a yield of 69% (n=4).

[0108] The H NMR spectrum of 4-methoxyphenyl dibutyl phosphate (DMPO) is:

[0109] 1 H NMR (600MHz, CDCl3) δ7.74 (dd, J=12.6, 8.4Hz, 2H), 6.96 (dd, J=8.6, 3.3Hz, 2H), 4.01 (ddd, J=47. 1, 10.0, 6.7Hz, 4H), 3.85 (s, 3H), 1.70-1.55 (m, 4H), 1.39 (q, J=7.5Hz, 4H), 0.90 (t, J=7.4Hz, 6H); 13 C NMR (101MHz, CDCl3) δ162.79, 162.76, 133.81, 133.70, 120.48, 118.54, 114.03, 113.87, 77.38, 77.06, 76.75, 65.62, 65.57, 55.30, 32.47, 32.40, 18.74, 13.58; 31 P NMR (162MHz, CDCl3) δ32.64, 19.70, -0.64; HR-MS-ESI m / z (%) 301.1575 [M+H] + Calcd.forC 15 H 26 O4P 301.1563.

[0110] Example 6

[0111] The phosphorus oxychloride used in Example 6 is the di(2-ethylhexyloxy)phosphorus oxychloride prepared in Example 2. The method for synthesizing the aryl phosphate diester compound using the phosphorus oxychloride is basically the same as that in Example 4, except that the dibutoxyphosphorus oxychloride in Example 5 is replaced by di(2-ethylhexyloxy)phosphorus oxychloride. The obtained product is di(2-ethylhexyloxy)4-methoxyphenyl phosphate (referred to as BMPO), and the yield is 65% (n=8).

[0112] The H NMR spectrum of 4-methoxyphenyl di(2-ethylhexyloxy)phosphate (BMPO) is:

[0113] 1 H NMR (600MHz, CDCl3) δ7.73 (dd, J=12.6, 8.3Hz, 2H), 6.96 (dd, J=8.7, 3.3Hz, 2H), 3.96 (tt, J=10. 9, 5.6Hz, 2H), 3.90-3.81 (m, 5H), 1.55 (q, J=6.1Hz, 2H), 1.44-1.15 (m, 16H), 0.93-0.73 (m, 12H); 13 C NMR (101MHz, CDCl3) δ162.79, 162.76, 133.81, 133.70, 120.48, 118.54, 114.03, 113.87 ,77.38,77.06,76.75,67.37,67.31,65.62,65.57,55.30,32.47,32.40,18.74,13.58; 31 P NMR (162MHz, CDCl3) δ32.64, 19.70, -0.64; HR-MS-ESI m / z (%) 435.2651 [M+Na] + Calcd.for C 23 H 41 NaO4P 435.2635.

[0114] Example 7

[0115] The phosphorus oxychloride used in Example 7 is the dibutoxyphosphorus oxychloride prepared in Example 1.

[0116] Under argon protection, add 2.0mmol 4-dimethylaminobromobenzene and 10mL dry tetrahydrofuran (THF) to a 50mL three-necked round-bottom flask (equipped with a 10mL constant pressure funnel); add 2.0mmol dibutoxyphosphoryl chloride and 5mL dry THF to the constant pressure funnel, cool the system to -110°C, stir, slowly inject 2.1mmol n-butyl lithium (n-BuLi) into the three-necked flask, stir for 45min, and a milky white turbid liquid is generated. Maintain -110°C, slowly add dibutoxyphosphoryl chloride to the three-necked flask through the constant pressure funnel, maintain -110°C for 30min after the drop is complete, then allow it to heat up naturally and stir for 12 hours.

[0117] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), saturated salt water (35mL×2 times) in sequence, then add anhydrous Na2SO4 to dry, spin-dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 8 (V / V) as eluent to obtain the target product in a light yellow transparent oily state, i.e. 4-dimethylaminophenyl dibutyl phosphate (denoted as DAPO), with a yield of 57% (n=4).

[0118] The H NMR spectrum of 4-dimethylaminophenyl dibutyl phosphate (DAPO) is:

[0119] 1 H NMR (600MHz, CDCl3) δ7.63 (dd, J=12.4, 8.6Hz, 2H), 6.70 (dd, J=8.8, 3.4Hz, 2H), 4.02 (dd, J=10.0, 6.6Hz, 2H), 3.9 4 (dd, J=10.0, 6.8Hz, 2H), 3.02 (s, 6H), 1.64 (dd, J=8.3, 6.5Hz, 4H), 1.39 (q, J=7.5Hz, 4H), 0.90 (t, J=7.4Hz, 6H); 13 CNMR (101MHz, CDCl3) δ152.79, 152.76, 133.39, 133.28, 113.57, 111.59, 111.18 , 111.03, 77.41, 77.09, 76.77, 65.34, 65.28, 39.96, 32.51, 32.44, 18.78, 13.63; 31 P NMR (162MHz, CDCl3) δ24.11, 21.84, 19.53; HR-MS-ESI m / z (%) 336.1705 [M+Na] + Calcd.for C 16 H 28 NNaO3P.

[0120] Example 8

[0121] The phosphorus oxychloride used in Example 8 is the di(2-ethylhexyloxy)phosphorus oxychloride prepared in Example 2. The method for synthesizing the aryl phosphoric acid diester compound using the phosphorus oxychloride is basically the same as that in Example 7, except that the dibutoxyphosphorus oxychloride in Example 7 is replaced by di(2-ethylhexyloxy)phosphorus oxychloride. The obtained product is di(2-ethylhexyloxy)-4-dimethylaminophenyl phosphate (denoted as BAPO), and the yield is 67% (n=8).

[0122] The nuclear magnetic resonance hydrogen spectrum of 4-dimethylaminophenyl bis(2-ethylhexyloxy) phosphate (BAPO) is:

[0123] 1 HNMR (600MHz, CDCl3) δ7.62 (dd, J=12.4, 8.5Hz, 2H), 6.70 (dd, J=8.8, 3.4Hz, 2H), 3.93 (dq, J=10.9, 5.8, 5.3H z, 2H), 3.88-3.78 (m, 2H), 3.02 (s, 6H), 1.62-1.43 (m, 2H), 1.42-1.13 (m, 16H), 0.86 (qd, J=7.0, 4.6Hz, 12H); 13 C NMR (101MHz, CDCl3) δ152.74, 152.71, 133.38, 133.27, 113.73, 111.75, 111.14, 110.99, 77.39, 77.07, 76 .75, 67.55, 67.53, 67.49, 67.47, 60.38, 39.96, 29.96, 28.88, 23.34, 22.99, 21.04, 14.05, 10.94, 10.91; 31 P NMR (162MHz, CDCl3) δ24.12, 21.64; HR-MS-ESI m / z (%) 448.2959 [M+Na] + Calcd.for C 24 H 44 NNaO3P 448.2951.

[0124] Example 9

[0125] The phosphorus oxychloride used in Example 9 is the dibutoxyphosphorus oxychloride prepared in Example 1.

[0126] Under argon protection, 2.0 mmol 4-trifluoromethyl bromobenzene and 10 mL dry tetrahydrofuran (THF) were added to a 50 mL three-necked round-bottom flask (equipped with a 10 mL constant pressure funnel); 2.0 mmol dibutoxyphosphoryl chloride and 5 mL dry THF were added to the constant pressure funnel, the system was cooled to -110°C, stirred, 2.1 mmol n-butyl lithium (n-BuLi) was slowly injected into the three-necked flask, stirred for 45 min, a milky white turbid liquid was generated, maintained at -110°C, dibutoxyphosphoryl chloride was slowly added dropwise to the three-necked flask through the constant pressure funnel, maintained at -110°C for 30 min after the dropwise addition, then allowed to warm naturally, and stirred for 12 hours.

[0127] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), saturated salt water (35mL×2 times), then add anhydrous Na2SO4 to dry, spin-dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 4 (V / V) as eluent to obtain a colorless, transparent, oily target product, i.e., 4-trifluoromethylphenyl dibutyl phosphate (denoted as DTFPO), with a yield of 58% (n=4).

[0128] The H NMR spectrum of 4-trifluoromethylphenyl dibutyl phosphate (DTFPO) is:

[0129] 1 H NMR (600MHz, CDCl3) δ7.96-7.53 (m, 4H), 4.04 (q, J=6.8Hz, 4H), 1.66 (q, J=7.1Hz, 4H), 1.41 (dt, J=14.6, 7.4Hz, 4H), 0.93 (dt, J=15.1, 7.4Hz, 6H); 13 C NMR (101MHz, CDCl3) δ135.83, 134.81, 134.69, 134.39, 132.53, 132.43, 132.27, 132.17, 127.14, 125.93, 125.89, 125.85, 125.81, 125.77 ,125.73,125.69,125.38,125.23,125.19,124.68,121.96,77.36,77 .04, 76.73, 67.36, 67.30, 66.20, 66.14, 32.32, 32.25, 18.66, 13.56; 19 F NMR (376MHz, CDCl3) δ-62.76, -63.30, -63.34, -63.36; 31P NMR (162MHz, CDCl3) δ25.55, 16.27, -0.63; HR-MS-ESI m / z (%) 361.1154 [M+Na] + Calcd.for C 15 H 22 F3NaO3P 361.1101.

[0130] Example 10

[0131] The phosphorus oxychloride used in Example 10 is the di(2-ethylhexyloxy)phosphorus oxychloride prepared in Example 2. The method for synthesizing the aryl phosphate diester compound using the phosphorus oxychloride is basically the same as that in Example 9, except that the dibutoxyphosphorus oxychloride in Example 9 is replaced by di(2-ethylhexyloxy)phosphorus oxychloride. The obtained product is di(2-ethylhexyloxy)-4-trifluoromethylphenyl phosphate (BTFPO), with a yield of 50% (n=8).

[0132] The H NMR spectrum of 4-trifluoromethylphenyl bis(2-ethylhexyloxy)phosphate (BTFPO) is:

[0133] 1 H NMR (600MHz, CDCl3) δ7.93 (dd, J=13.0, 7.9Hz, 2H), 7.73 (dd, J=8.3, 3.5Hz, 2H), 3.98 (dtd , J=55.8, 10.3, 5.1Hz, 4H), 1.56 (q, J=6.1Hz, 2H), 1.46-1.12 (m, 16H), 1.00-0.73 (m, 12H); 13 C NMR (101MHz, CDCl3) δ133.71, 132.25, 132.16, 131.84, 125.38, 125.34, 125.30, 125.26, 1 25.23, 125.19, 125.15, 125.11, 124.92, 77.36, 77.04, 76.72, 69.60, 69.54, 68.38, 68.31 , 60.37, 40.16, 40.14, 40.12, 40.10, 40.07, 40.05, 29.88, 29.73, 28.86, 28.82, 28.77, 23.28, 23.24, 23.08, 22.96, 22.91, 18.69, 14.17, 14.01, 13.97, 13.57, 10.88, 10.85, 10.82; 19 F NMR (376MHz, CDCl3) δ-63.30; 31P NMR (162MHz, CDCl3) δ16.24, -0.47, -12.46; HR-MS-ESI m / z (%) 473.2403 [M+Na] + C 23 H 38 F3NaO3P473.2403.

[0134] Embodiment 11

[0135] The phosphorus oxychloride used in Example 11 is the dibutoxyphosphorus oxychloride prepared in Example 1.

[0136] Under argon protection, add 2.0mmol 4-fluorobromobenzene and 10mL dry tetrahydrofuran (THF) to a 50mL three-necked round-bottom flask (equipped with a 10mL constant pressure funnel); add 2.0mmol dibutoxyphosphoryl chloride and 5mL dry THF to the constant pressure funnel, cool the system to -110°C, stir, slowly inject 2.1mmol n-butyl lithium (n-BuLi) into the three-necked flask, stir for 45min, and a milky white turbid liquid is generated. Maintain -110°C, slowly add dibutoxyphosphoryl chloride to the three-necked flask through the constant pressure funnel, maintain -110°C for 30min after the drop is complete, then allow it to heat up naturally and stir for 12 hours.

[0137] Add 15mL saturated ammonium chloride solution to the three-necked flask to quench the reaction, add 30mL ethyl acetate to stir and extract, wash the organic phase with water (35mL×8 times), wash with saturated salt water (35mL×2 times), then add anhydrous Na2SO4 to dry, spin-dry the solvent, dry sample, and separate by column chromatography. Use ethyl acetate / petroleum ether=1 / 8 (V / V) as eluent to obtain a colorless, transparent, oily target product, i.e. 4-fluorophenyl dibutyl phosphate (denoted as DFPO), with a yield of 62% (n=4).

[0138] The H NMR spectrum of 4-fluorophenyl dibutyl phosphate (DFPO) is:

[0139] 1 H NMR (600MHz, CDCl3) δ7.81 (ddd, J=12.7, 8.6, 5.7Hz, 2H), 7.15 (td, J=8.7, 3.2Hz, 2H), 4 .12-3.93 (m, 4H), 1.65 (dq, J=8.9, 6.7Hz, 4H), 1.46-1.32 (m, 4H), 0.91 (t, J=7.4Hz, 6H); 13C NMR (101MHz, CDCl3) δ166.17, 166.14, 164.49, 164.46, 134.41, 134.35, 134.34, 134.28, 125.14, 123.88 , 115.91, 115.81, 115.77, 77.23, 77.02, 76.81, 67.37, 67.33, 65.91, 65.87, 32.45, 32.40, 18.73, 13.56; 19 F NMR (376MHz, CDCl3) δ-63.31; 31 P NMR (162MHz, CDCl3) δ25.51, 16.26, -0.63.

[0140] Example 12

[0141] The phosphorus oxychloride used in Example 12 is the di(2-ethylhexyloxy)phosphorus oxychloride prepared in Example 2. The method for synthesizing the aryl phosphate diester compound using the phosphorus oxychloride is basically the same as that in Example 11, except that the dibutoxyphosphorus oxychloride in Example 11 is replaced by di(2-ethylhexyloxy)phosphorus oxychloride. The obtained product is di(2-ethylhexyloxy)4-fluorophenyl phosphate (referred to as BFPO), with a yield of 53% (n=8).

[0142] The H NMR spectrum of 4-fluorophenyl bis(2-ethylhexyloxy)phosphate (BFPO) is:

[0143] 1 H NMR (600MHz, CDCl3) δ7.81 (ddd, J=13.2, 8.4, 5.7Hz, 2H), 7.16 (dt, J=8.7, 4.4Hz, 2 H), 4.02-3.87(m, 4H), 1.63-1.49(m, 2H), 1.48-1.13(m, 16H), 0.93-0.71(m, 12H); 13 C NMR (101MHz, CDCl3) δ166.55, 164.04, 134.42, 134.33, 134.30, 134.22, 115.92, 115.76, 115.71, 115.55, 77.36, 77.04, 76.72, 69.62, 69.56, 6 8.10, 68.04, 40.16, 40.13, 40.09, 40.07, 29.91, 29.89, 28.86, 28.84, 28.79, 23.30, 23.24, 22.96, 22.94, 14.02, 14.00, 10.89, 10.88, 10.86; 19F NMR (376MHz, CDCl3) δ-106.21, -115.23; 31 P NMR (162MHz, CDCl3) δ17.75, -0.48.HR-MS-ESI m / z (%) 423.2449 [M+Na] + Calcd.for C 22 H 38 FNaO3P 423.2435.

[0144] The present invention uses the above-prepared aromatic phosphate diester compounds as a co-extractant to extract lithium from a lithium-containing alkaline solution, and accordingly provides the following Examples 13-23.

[0145] Embodiment 13

[0146] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0147] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0148] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0149] Diluent: cyclohexane;

[0150] The total concentration of the extractant and the synergistic extractant is 0.18 mol / L, and the concentration ratio of OHB to BTOP is changed to prepare extraction systems with OHB and BTOP concentrations of 0.00:0.180, 0.018:0.162, 0.036:0.144, 0.054:0.126, 0.072:0.108, 0.090:0.090, 0.108:0.072, 0.126:0.054, 0.144:0.036, 0.162:0.018, and 0.180:0.00, respectively. The extraction systems are used to extract lithium from the lithium-containing alkaline solution, and the sodium hydroxide concentration C in the lithium-containing alkaline solution is 0.180:0.00. NaOH is 2mol / L, the lithium ion concentration C Li + It is 0.1mol / L.

[0151] According to the comparison V O / V A =1 / 1 Extraction systems with different OHB / BTOP concentration ratios were added to the lithium-containing alkaline solution and shaken for 10 minutes. The results showed that the extraction effect was best when the ratio of OHB to BTPO in the extraction system was 0.126:0.054, and the lithium extraction rate was 51%.

[0152] Embodiment 14

[0153] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0154] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0155] Co-extractant: di(2-ethylhexyloxy)phenyl phosphate (BPPO);

[0156] Diluent: cyclohexane;

[0157] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BPPO is 0.054 mol / L.

[0158] The extraction system is used to extract lithium from lithium-containing alkaline solution, and the lithium ion concentration C Li + 0.1mol / L, and prepare a series of hydroxide concentrations C NaOH The extraction effect under different hydroxide concentration conditions was tested in lithium alkaline solutions between 0 and 4 mol / L (0 mol / L, 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L, 3.0 mol / L, 3.5 mol / L, and 4.0 mol / L, respectively).

[0159] According to the comparison V O / V A =1 / 1 The extraction system was added to lithium alkaline solutions with different hydroxide concentrations and shaken for 10 minutes. The results showed that the sodium hydroxide concentration C in the extraction system NaOH The extraction effect was best when the concentration was 2.5 mol / L, and the lithium extraction rate was 54%.

[0160] Embodiment 15

[0161] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0162] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0163] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0164] Diluent: cyclohexane;

[0165] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BTPO is 0.054 mol / L.

[0166] The extraction system is used to extract lithium from lithium-containing alkaline solution, and the lithium ion concentration C Li +0.1mol / L, and prepare a series of hydroxide concentrations C NaOH The extraction effect under different hydroxide concentrations was tested in lithium alkaline solutions between 0 and 4 mol / L (0 mol / L, 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, 2.0 mol / L, 2.5 mol / L, 3.0 mol / L, 3.5 mol / L, 4.0 mol / L, respectively).

[0167] According to the comparison V O / V A =1 / 1 The extraction system was added to lithium-containing alkaline solutions with different hydroxide concentrations and shaken for 10 minutes. The results showed that the sodium hydroxide concentration C in the extraction system NaOH The extraction effect was best when the concentration was 3.0 mol / L, and the lithium extraction rate was 58%.

[0168] Example 16

[0169] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0170] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0171] Co-extractant: di(2-ethylhexyloxy)phenyl phosphate (BPPO);

[0172] Diluent: cyclohexane;

[0173] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BTPO is 0.054 mol / L.

[0174] The extraction system is used to extract lithium from a lithium-containing alkaline solution, wherein the lithium ion concentration C Li + is 0.1mol / L, the concentration of sodium hydroxide is C NaoH It is 2.0mol / L.

[0175] Test compared to V O / V A = Extraction effect in the range of 1 / 5 to 5 / 1, compared with V o / V A The extraction system was added to the above lithium-containing alkaline solution at 1 / 5, 1 / 4, 1 / 3, 1 / 2, 1 / 1, 2 / 1, 3 / 1, 4 / 1, and 5 / 1, respectively, and shaken for 10 minutes. The results showed that compared with V O / V A =5 / 1, the extraction effect is the best, and the lithium extraction rate is 79%.

[0176] Embodiment 17

[0177] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0178] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0179] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0180] Diluent: cyclohexane;

[0181] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BTPO is 0.054 mol / L.

[0182] The extraction system is used to extract lithium from a lithium-containing alkaline solution, wherein the lithium ion concentration C Li + is 0.1mol / L, the concentration of sodium hydroxide is C NaOH It is 2.0mol / L.

[0183] Test compared to V O / V A = Extraction effect in the range of 1 / 5 to 5 / 1, compared with V o / V A The extraction system was added to the above lithium-containing alkaline solution and shaken for 10 minutes. The results showed that compared with V O / V A =5 / 1, the extraction effect is the best, and the lithium extraction rate is 80%.

[0184] Embodiment 18

[0185] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0186] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0187] Co-extractant: di(2-ethylhexyloxy)phenyl phosphate (BPPO);

[0188] Diluent: cyclohexane;

[0189] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BPPO is 0.054 mol / L.

[0190] The extraction system is used to extract lithium from lithium-containing alkaline solution, and a series of sodium hydroxide concentrations C NaOH is 2.0mol / L, the lithium ion concentration C Li +The lithium-containing alkaline solution is in the range of 0.3 g / L to 3 g / L, and the influence of the lithium ion concentration in the lithium-containing alkaline solution on the extraction effect is tested.

[0191] According to the comparison V O / V A =1 / 1 The extraction system was added to lithium-containing solutions with lithium ion concentrations of 0.3g / L, 0.6g / L, 0.9g / L, 1.2g / L, 1.5g / L, 1.8g / L, 2.1g / L, 2.4g / L, 2.7g / L, and 3.0g / L, respectively, and the shaking time was 10min. The test results showed that the lithium ion concentration C Li + The extraction effect is best when the concentration is 0.3g / L, and the lithium extraction rate is 50%.

[0192] Embodiment 19

[0193] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0194] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0195] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0196] Diluent: cyclohexane;

[0197] Among them, the concentration of extractant OHB is 0.126 mol / L, and the concentration of synergistic extractant BTPO is 0.054 mol / L.

[0198] The extraction system is used to extract lithium from lithium-containing alkaline solution, and a series of sodium hydroxide concentrations C NaoH is 2.0mol / L, the lithium ion concentration C Li + The lithium-containing alkaline solution is in the range of 0.3 g / L to 3 g / L, and the influence of the lithium ion concentration in the lithium-containing alkaline solution on the extraction effect is tested.

[0199] According to the comparison V O / V A =1 / 1 The extraction system was added to lithium-containing solutions with lithium ion concentrations of 0.3g / L, 0.6g / L, 0.9g / L, 1.2g / L, 1.5g / L, 1.8g / L, 2.1g / L, 2.4g / L, 2.7g / L, and 3.0g / L, respectively, and the shaking time was 10min. The test results showed that the lithium ion concentration C Li + The extraction effect was best when the concentration was 0.3 g / L, and the lithium extraction rate was 52%.

[0200] Embodiment 20

[0201] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0202] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0203] Co-extractant: di(2-ethylhexyloxy)phenyl phosphate (BPPO);

[0204] Diluent: Cyclohexane

[0205] Among them, the concentrations of the extractant and the synergistic extractant are as follows:

[0206] (1) The concentration of the extractant is 0.09 mol / L and the concentration of the synergist is 0.039 mol / L (i.e., OHB / BPPO = 0.09 / 0.039);

[0207] (2) The concentration of the extractant is 0.27 mol / L and the concentration of the co-extractant is 0.116 mol / L (i.e., OHB / BPPO = 0.27 / 0.116);

[0208] (3) Extractant concentration: 0.45 mol / L, synergist concentration: 0.193 mol / L (i.e., OHB / BPPO = 0.45 / 0.193);

[0209] The above three extraction systems are used to extract lithium from the lithium-containing alkaline solution. The sodium hydroxide concentration C in the lithium-containing alkaline solution is NaOH The lithium ion concentration is 2.0 mol / L. Li + It is 0.3g / L.

[0210] According to the comparison V O / V A =1 / 1 Add the extraction system to the lithium-containing alkaline solution and shake for 10 minutes. The results show that the ratio of synergistic extractant to lithium ions during extraction is BPPO / Li + =1 / 1.

[0211] Embodiment 21

[0212] This embodiment provides an extraction system for extracting lithium from an alkaline solution, the extraction system comprising:

[0213] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0214] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0215] Diluent: cyclohexane;

[0216] Among them, the concentrations of the extractant and the synergistic extractant are as follows:

[0217] (1) The concentration of the extractant is 0.09 mol / L and the concentration of the synergist is 0.039 mol / L (i.e., OHB / BTPO = 0.09 / 0.039);

[0218] (2) The concentration of the extractant is 0.27 mol / L and the concentration of the co-extractant is 0.116 mol / L (i.e., OHB / BTPO = 0.27 / 0.116);

[0219] (3) Extractant concentration 0.45 mol / L, synergist concentration 0.193 mol / L (i.e., OHB / BTPO = 0.45 / 0193);

[0220] The above three extraction systems are used to extract lithium from the lithium-containing alkaline solution. The sodium hydroxide concentration C in the lithium-containing alkaline solution is NaoH The lithium ion concentration is 2.0 mol / L. Li + It is 0.3g / L.

[0221] According to the comparison V O / V A =1 / 1 Add the extraction system to the lithium-containing alkaline solution and shake for 10 minutes. The results show that the ratio of synergistic extractant to lithium ions during extraction is BTPO / Li + =1 / 1.

[0222] Embodiment 23

[0223] This embodiment provides the extraction of lithium from lithium precipitation mother liquor using the following extraction system, and the composition of lithium precipitation mother liquor is shown in Table 1 below:

[0224] Table 1. Lithium precipitation mother solution composition

[0225] ion Li Na K Ca Mg pH <![CDATA[Concentration / g*L -1 > 2.743 40.90 0.682 0.002973 0.5018 11.5 <![CDATA[Concentration / mol*L -1 > 0.395 1.778 0.017 <![CDATA[7.425*10 -5 ]]> 0.206

[0226] The extraction system used is:

[0227] Extraction agent: n-octyl o-hydroxybenzoate (OHB);

[0228] Co-extractant: 4-methylphenyl di(2-ethylhexyloxy) phosphate (BTPO);

[0229] Diluent: cyclohexane;

[0230] The concentration of the extractant is 0.4 mol / L, and the concentration of the synergist is 0.17 mol / L (ie, OHB / BTPO=0.4 / 0.17).

[0231] The sodium hydroxide concentration in the lithium precipitation mother solution is adjusted by using sodium hydroxide, and the concentration range is 0 mol / L to 3.2 mol / L, and a series of samples with sodium hydroxide concentrations of 0 mol / L, 0.4 mol / L, 0.8 mol / L, 1.2 mol / L, 1.6 mol / L, 2.0 mol / L, 2.4 mol / L, 2.8 mol / L, and 3.2 mol / L are prepared;

[0232] According to the comparison V O / V A =1 / 1 Add the extraction system to the above sample and shake for 10 minutes. The results show that the sodium hydroxide concentration in the sample is C NaoH When the concentration is greater than or equal to 0.8 mol / L, the extraction effect is the best, and the lithium extraction rate can reach about 70%. Moreover, after three-stage countercurrent extraction, the lithium extraction rate can reach more than 93%.

[0233] The present invention also adopts infrared spectroscopy (KBr tablet method) to detect the configuration change of the extractant n-octyl o-hydroxybenzoate when the extraction system extracts lithium.

[0234] It was found that the structure of the extractant n-octyl o-hydroxybenzoate changes from keto to enol during extraction. The change from Keto to Enol configuration is accompanied by obvious spectral changes: when the Keto structure is present, the UV spectrum absorption peak is at 307nm, and there is no fluorescence; when the configuration changes to Enol, the UV spectrum absorption peak is at 340nm, and the fluorescence emission peak appears at 410nm, showing blue fluorescence. The extraction mechanism of the extraction system provided by the present invention is as follows:

[0235]

[0236] Taking the extraction system of n-octyl o-hydroxybenzoate (OHB) and 4-methylphenylphosphonic acid di(2-ethylhexyloxy) (BTPO) as an example, the present invention tests the infrared characteristic peaks of the extractants being keto (Keto) and enol (Enol), as shown in Table 2.

[0237] Table 2. Infrared characteristic peaks when Keto and Enol configurations change during extraction with mixed extraction system

[0238]

[0239] Figure 1 When the extraction agent is octyl o-hydroxybenzoate 1 H NMR spectrum changes. Figure 1It can be seen that as the Keto to Enol configuration changes, the H on the benzene ring shifts from 7.82ppm, 7.48ppm, 6.94ppm, and 6.91ppm to 7.71ppm, 7.20ppm, 6.69ppm, and 6.42ppm, the shielding effect is enhanced and the deshielding effect is weakened.

[0240] In summary, the present invention provides a method for synthesizing an aromatic phosphate diester compound by using a halogenated aromatic compound as a substrate, reacting with an organic lithium to undergo a lithium-halogen exchange reaction, and then reacting with a corresponding phosphoryl chloride to undergo a nucleophilic reaction; the synthetic method has relatively mild reaction conditions, a high yield of raw material preparation, and a rich variety of applicable substrates. The prepared aromatic phosphate diester compound can be used as a co-extractant for extracting lithium, and can be used in combination with an extractant, n-octyl o-hydroxybenzoate, to extract lithium from an alkaline lithium-containing solution. The extraction process of this type of extraction system is characterized by obvious characteristics, and a Keto-Enol configuration transition will occur.

[0241] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0242] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments with other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0243] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made without departing from the spirit and scope of the present invention and that the elements of the embodiments may be replaced by substantial equivalents. In addition, many modifications may be made without departing from the scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, it is not intended herein to limit the present invention to the disclosed specific embodiments for performing the present invention, but it is intended that the present invention will include all embodiments within the scope of the appended claims. In addition, unless specifically stated, any use of the terms first, second, etc. does not indicate any order or importance, but rather uses the terms first, second, etc. to distinguish one element from another.

Claims

1. An aromatic phosphate diester compound, characterized in that: The aromatic phosphate diester compound has a structure shown in Formula I: Wherein, R is at least selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkyne, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN; the number of substitutions of R on the benzene ring of the aromatic phosphate diester compound is 1 to 5, and the substitution position is ortho, meta or para; R1 and R2 are at least independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl, and R1 and R2 are the same or different.

2. The aryl phosphate diester compound according to claim 1, characterized in that: R is selected from H, substituted or unsubstituted alkyl of C1-C8 alkyl, substituted or unsubstituted olefin of C2-C8, substituted or unsubstituted alkynyl of C2-C8, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN; and / or, the substituents on R include one or more of a primary amino substituent, a secondary amino substituent, a tertiary amino substituent or a quaternary amino substituent substituted with a heterocycle; and / or, R1 and R2 are independently selected from H, C1-C8 substituted or unsubstituted alkyl, C2-C8 substituted or unsubstituted olefin, C2-C8 substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl; And / or, the substituent groups on R1 and R2 include one or more heteroatoms or heterocyclic groups.

3. A method for synthesizing an aromatic phosphate diester compound, characterized in that: include: Under inert atmosphere conditions, a first mixed reaction system containing a phosphoric diester compound raw material, thionyl chloride and a catalyst undergoes a first reaction to obtain a phosphoryl chloride compound; wherein the catalyst comprises N,N-dimethylformamide; Under inert atmosphere conditions, a halogenated benzene compound and an organic lithium are subjected to a lithium-halogen exchange reaction, and a second mixed reaction system containing the phosphoryl chloride compound and a product of the lithium-halogen exchange reaction is subjected to a nucleophilic reaction to obtain an aromatic phosphate diester compound.

4. The synthesis method according to claim 3, characterized in that: The phosphodiester compound raw material has a structure shown in Formula II: Wherein, R1 and R2 are at least independently selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl, and R1 and R2 are the same or different; The halogenated benzene compound has a structure shown in Formula III: Wherein, X is Br; R is at least selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted olefin, substituted or unsubstituted alkyne, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN; the number of substitutions of R on the benzene ring of the halogenated benzene compound is 1 to 5, and the substitution position is ortho, meta or para; Preferably, R is selected from H, substituted or unsubstituted alkyl of C1-C8 alkyl, substituted or unsubstituted olefin of C2-C8, substituted or unsubstituted alkynyl of C2-C8, alkoxy, alkylamino, substituted or unsubstituted phenyl, -F, -Cl, -Br, -I, -CF3 or -CN; Preferably, the substituents on R include one or more of a primary amino substituent, a secondary amino substituent, a tertiary amino substituent or a quaternary amino substituent substituted with a heterocycle; Preferably, R1 and R2 are independently selected from H, C1-C8 substituted or unsubstituted alkyl, C2-C8 substituted or unsubstituted olefin, C2-C8 substituted or unsubstituted alkynyl, substituted or unsubstituted phenyl; Preferably, the substituent groups on R1 and R2 include one or more heteroatoms or heterocyclic groups.

5. The synthesis method according to claim 3, characterized in that: The first reaction time is 6 to 8 hours; and / or, the molar ratio of the phosphodiester compound to thionyl chloride is 1:1 to 2:3; and / or, the organic lithium comprises n-butyl lithium; and / or, the temperature of the lithium-halogen exchange reaction is -20°C to -110°C, and after the lithium-halogen exchange reaction is completed, the temperature is naturally raised to carry out the nucleophilic reaction; And / or, the lithium halogen exchange reaction time is 5 to 120 minutes, and the nucleophilic reaction time is 1 to 18 hours.

6. The synthesis method according to claim 3, characterized in that Specifically include: Under inert atmosphere conditions, a first mixed reaction system containing a phosphodiester compound raw material, thionyl chloride, a catalyst and a first solvent is heated to the reflux temperature of the first solvent to carry out the first reaction to obtain a phosphorus oxychloride compound; preferably, the first solvent comprises one or more of dichloromethane, 1,2-dichloroethane and carbon tetrachloride, and more preferably, the first solvent comprises dichloromethane; And / or, under inert atmosphere conditions, the halogenated benzene compound is dispersed in a second solvent, and the temperature is controlled at -20°C to -110°C, and it is mixed with organic lithium to carry out the lithium halogen exchange reaction; the phosphorus oxychloride compound is added to the product of the lithium halogen exchange reaction in batches to obtain the second mixed reaction system; the temperature of the second mixed reaction system is controlled at -20°C to -110°C and maintained for 10 to 80 minutes, and then the second mixed reaction system is naturally heated to carry out the nucleophilic reaction; preferably, the second solvent includes diethyl ether and / or tetrahydrofuran, more preferably includes tetrahydrofuran.

7. An aromatic phosphate diester compound, characterized in that: The method is prepared by the method described in any one of claims 3 to 6.

8. Use of the aryl phosphate diester compounds described in claims 1, 2 and 7 in extracting lithium from an alkaline lithium-containing solution.

9. An extraction system for extracting lithium from an alkaline lithium-containing solution, comprising an extractant and a synergist, characterized in that: The synergistic extractant comprises the aromatic phosphate diester compound according to claims 1, 2, and 7; Preferably, the extractant comprises n-octyl o-hydroxybenzoate; Preferably, the molar ratio of the extractant to the co-extractant is 1:9 to 9:1; Preferably, the extraction system further comprises a diluent, and the diluent makes the total concentration of the extractant and the co-extractant in the extraction system be 0.1 to 3 mol / L. More preferably, the diluent comprises a combination of one or more of kerosene, sulfonated kerosene, n-hexane, cyclohexane, benzene, toluene, xylene, chlorobenzene, disubstituted chlorobenzene, dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, and ethyl acetate.

10. A method for extracting lithium from an alkaline lithium-containing solution, characterized in that: include: Mixing and fully contacting the extraction system of claim 9 with an alkaline lithium-containing solution to extract lithium; Preferably, the concentration of hydroxide ions in the alkaline lithium-containing solution is 0.01 mol / L to 4 mol / L; Preferably, the extraction system is mixed with the alkaline lithium-containing solution in a ratio of 1:10 to 10:1; Preferably, the method comprises: using the extraction system to perform multi-stage countercurrent extraction on the alkaline lithium-containing solution, wherein the multi-stage countercurrent extraction is three-stage or more countercurrent extraction; Preferably, the method further comprises: after the extraction is completed, stripping with acid to release lithium ions. More preferably, the concentration of hydrogen ions in the acid is 0.01 mol / L to 6 mol / L.

Images