Process for the purification of a class of compounds containing an arylphosphine oxide group

Abstract

This invention belongs to the technical field of organic semiconductor materials applications and discloses a purification and preparation method for a class of compounds containing arylphosphoxy groups, the structural formula of which is shown in Formula I. The main purification and preparation process of this class of compounds includes: (1) coupling reaction of halogenated arylphosphoxy groups (X = Cl, Br and I) with arylboronic acid R2-B(OH)2 or arylboronic esters; (2) for the crude coupling product obtained in (1), through the synergistic effect of a "peroxide" oxidant and a base, the residual arylboronic acid or boronic ester derivatives are converted into easily separable phenolic derivatives (R2 is not oxidized by the peroxide oxidant; the polarity of R2-OH must be less than that of X = Cl, Br and I). This purification and preparation method is simple and easy to implement and has important application prospects.

Description

Technical Field

[0001] This invention belongs to the technical field of organic optoelectronic materials, and specifically relates to a method for purifying and preparing a class of compounds containing arylphosphoxy groups. Background Technology

[0002] Arylphosphine oxides, due to their rigid, stereochemical molecular structure and strong polarity, can be conveniently used to construct high-purity, amorphous organic functional materials, and they also exhibit reversible electrochemical reduction properties. This invention discloses a method for purifying and preparing a class of compounds containing arylphosphine oxide groups, the structural formula of which is shown in Formula I.

[0003]

[0004] Functional compounds containing arylphosphoxy groups (Formula 1) can be conveniently synthesized by coupling reactions of haloarylphosphoxy groups with aryl Suzuki reagents. It should be noted that residual arylboronic acid derivatives are usually present at the end of the reaction. These derivatives may originate from unreacted arylboronic acid, hydrolysis of arylboronic ester raw materials, or dehydration of residual arylboronic acid to form potential oligomers. The residual arylboronic acid derivatives have similar polarity to the target aromatic phosphoxy product (Formula 1), making separation difficult. Therefore, it is necessary to provide a method for removing residual arylboronic acid derivatives from the product to achieve the preparation of high-purity arylphosphoxy compounds. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the primary objective of this invention is to provide a method for preparing compounds containing arylphosphino groups. This invention utilizes the synergistic effect of a peroxide oxidant and a base to rapidly convert residual arylboronic acid derivatives into easily separable, correspondingly less polar phenolic derivatives R2-OH (R2 is not oxidized by the peroxide oxidant; the polarity of R2-OH is less than...). X = Cl, Br and I), and this purification and preparation method is simple and easy to implement, and has important application prospects.

[0006] Another object of the present invention is to provide high-purity compounds containing arylphosphoxy groups prepared by the above method.

[0007] The objective of this invention is achieved through the following solution:

[0008] A purification and preparation method for a class of compounds containing arylphosphine groups is described below:

[0009]

[0010] Where X is Cl, Br, or I;

[0011] The high-purity arylphosphoxy group-containing compound prepared according to the above purification and preparation route is shown in Formula I:

[0012]

[0013] Among them, R1 and R2 are aryl, heteroaryl, substituted aryl or substituted heteroaryl;

[0014] m = 1-6; when m ≥ 2, R1 can be the same or different; R2 is not oxidized by peroxide oxidants; the polarity of R2-OH must be less than 6. (X = Cl, Br and I).

[0015] More preferably, R1 is any one of the following representative structural units:

[0016]

[0017] Preferably, R2 is aryl, heteroaryl, substituted aryl, or substituted heteroaryl;

[0018] Further preferably, R2 is any one of the following representative structural units:

[0019]

[0020] The purification and preparation method described above includes the following steps:

[0021] (1) Using diphenyl (monohaloaryl)phosphine as raw material, diphenyl (monohaloaryl)phosphine oxide intermediate was obtained by oxidation with hydrogen peroxide;

[0022] (2) The diphenyl (monohaloaryl) phosphine oxide obtained in step (1) is reacted with arylboronic acid derivatives or arylboronic ester derivatives via a Suzuki coupling reaction to obtain a crude product containing arylphosphine oxides.

[0023] (3) For the crude product containing arylphosphine oxide obtained above, the compound was separated by rapid column chromatography, dissolved in an organic solvent, and then a peroxide oxidant / base was added to convert the residual arylboronic acid derivative into the corresponding phenolic derivative.

[0024] (4) The product obtained in step (3) above is subjected to further post-processing, including column chromatography, solvent washing, recrystallization and sublimation, to obtain high-purity compounds containing arylphosphoxy groups.

[0025] Preferably, the molar ratio of diphenyl (monohaloaryl)phosphine to hydrogen peroxide in step (1) is 1:3 to 6;

[0026] Preferably, the molar ratio of the diphenyl (monohaloaryl)phosphine oxide to the arylboronic acid derivative or arylboronic ester derivative in step (2) is 1 to 3:1;

[0027] Preferably, the temperature of the Suzuki coupling reaction in step (2) is 70–100°C, and the reaction time is 1–24 h;

[0028] Preferably, the specific process of step (3) is as follows: the crude product obtained after rapid column chromatography is dissolved in an organic solvent, then an alkaline solution is added and stirred, and then a peroxide oxidant is added and stirred.

[0029] Preferably, the organic solvent in step (3) is dichloromethane or a mixture of dichloromethane and an alcohol, wherein the alcohol is at least one of ethanol, methanol, and isopropanol;

[0030] Preferably, in step (3), the molar ratio of the arylphosphine-containing compound to the base is 1:1 to 20; the molar ratio of the peroxide oxidant to the base is 1:1 to 20.

[0031] Preferably, the peroxide oxidant used in step (3) is hydrogen peroxide, sodium peroxide, potassium peroxide, di-tert-butyl peroxide, peracetic acid, benzoyl peroxide, etc.; the base used is a hydroxide, such as sodium hydroxide or potassium hydroxide.

[0032] Preferably, the column chromatography eluent in step (4) is dichloromethane or a mixed solvent of toluene, xylene and ethyl acetate, methanol, ethanol and isopropanol;

[0033] Preferably, the sublimation in step (4) is purified by gradient temperature sublimation, with the gradient temperature sublimation ranges being 100-300℃ and 250-400℃, respectively.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0035] (1) The purification and preparation method of halo-containing arylphosphine oxide compounds disclosed in this invention converts the difficult-to-remove residual arylboronic acid derivatives into phenolic derivatives with weaker polarity, thereby achieving the purpose of separation and purification.

[0036] (2) The purification and preparation method of the halo-containing arylphosphine oxide compound disclosed in this invention uses the synergistic effect of "peroxide" oxide and strong base to quantitatively convert arylboronic acid derivatives into corresponding phenolic derivatives, with a conversion yield of 100% or close to 100%.

[0037] (3) With appropriate molecular design, the reaction raw materials containing halogenated arylphosphine oxides can be removed by solvent washing, such as alcohol solvents, recrystallization and vacuum sublimation; the purification and preparation method provided by the present invention can realize the large-scale synthesis of high-purity arylphosphine oxide compounds. Attached Figure Description

[0038] Figure 1 The HRMS spectrum of 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl]-1,3,5-triazine after alkali treatment;

[0039] Figure 2 HRMS spectrum of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol;

[0040] Figure 3 The NMR spectrum of TPOAN-DP, a compound containing arylphosphine oxide in Example 1 of this invention, after purification, is shown in deuterated dichloromethane as the solvent.

[0041] Figure 4 The HPLC spectrum of TPOAN-DP, a compound containing arylphosphine oxides in Example 1 of the present invention, after purification;

[0042] Figure 5 The image shows the purified NMR spectrum of the arylphosphine oxide compound TPO-m-TRZ in Example 2 of this invention, with deuterated dimethyl sulfoxide as the solvent.

[0043] Figure 6 The image shows the HPLC spectrum of the arylphosphine oxide-containing compound TPO-m-TRZ in Example 2 of this invention after purification. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0045] Experimental Investigation 1:

[0046] 2,4-Diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl]-1,3,5-triazine (500 mg, 1.15 mmol) was dissolved in dichloromethane (80 mL) and ethanol (5 mL). Then, an aqueous sodium hydroxide solution (3 eq. 2 M, 3.45 mmol) was added, and the mixture was stirred and refluxed for 4 h. After the reaction was stopped, the organic layer was first extracted with dichloromethane and then back-extracted with water. The resulting organic layer was dried over anhydrous magnesium sulfate and filtered. HRMS (ESI, negative ion mode) analysis of the product revealed that under strong alkali conditions, 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl]-1,3,5-triazine hydrolyzed to boric acid and partially dehydrated to form oligomers (such as...). Figure 1 (As shown).

[0047] Table 1. Partial hydrolysis products and molecular weights of 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl]-1,3,5-triazine after alkali treatment (ESI, negative ion mode).

[0048]

[0049] Experimental Investigation Process 2:

[0050]

[0051] 2,4-Diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxacyclopentaborane-2-yl)phenyl]-1,3,5-triazine (500 mg, 1.15 mmol) was dissolved in dichloromethane (80 mL), and an aqueous solution of hydrogen peroxide (15 eq. 17.25 mmol, 2 mL) and ethanol (5 mL) were added. The mixture was stirred at room temperature. Subsequently, an aqueous solution of sodium hydroxide (45 eq. 3 M, 51.75 mmol) was added. The borate ester was then undetectable by TLC. After the reaction was stopped, an aqueous solution of sodium bisulfite was added to quench excess hydrogen peroxide. The organic layer was first extracted with dichloromethane and then back-extracted with water; the resulting organic layer was dried over anhydrous magnesium sulfate, filtered, and subjected to reduced pressure to remove the solvent before column chromatography separation. Using dichloromethane as the eluent, the Rf value of 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)phenyl]-1,3,5-triazine was 0.8, while the Rf value of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenylboronic acid was 0. In contrast, the Rf value of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol was 0.2. Using dichloromethane as the eluent, 350 mg of a white solid of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol was obtained, with a yield of 94%. HRMS (ESI, negative ion mode) m / z: calcd. For C 21 H 14 N3O[MH + ] - ,324.1137; Found,324.1171(100%)

[0052] Figure 2 ESI-MS mass spectrum (negative ion mode) of 3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenol.

[0053] The chemical formulas of the two compounds prepared by the purification method of this invention are as follows:

[0054]

[0055] The specific purification and preparation steps of compound TPOAN-DP in Example 1 are as follows:

[0056] Step 1: Preparation of (3-bromophenyl)diphenylphosphine oxide (Compound 1)

[0057]

[0058] Hydrogen peroxide (15 mL) and ethanol (15 mL) were added to a solution of (3-bromophenyl)diphenylphosphine (12.3 g, 36 mmol) in dichloromethane (60 mL). The reaction was stirred overnight at room temperature. After the reaction was complete, an aqueous solution of sodium sulfite was added to the reaction mixture to reduce the excess hydrogen peroxide. Subsequently, the organic layer was first extracted with dichloromethane and then back-extracted with water; the resulting organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. Column chromatography was then performed, using a mixture of dichloromethane and ethanol as the eluent, to give a white solid in 97% yield (12.5 g).

[0059] 1 H NMR (400MHz, DMSO) δ7.86 (d, J = 7.8Hz, 1H), 7.74 (d, J = 11.7Hz, 1H), 7.49–7.67 (m, 12H).

[0060] Step 2: Preparation of compound TPOAN-DP

[0061]

[0062] Under a nitrogen atmosphere, tetrakis(triphenylphosphine)palladium (32 mg, 0.028 mmol) was added to a reaction mixture of (10-([1,1'-biphenyl]-4-yl)anthracene-9-yl)boric acid (1.35 g, 3.6 mmol), (3-bromophenyl)diphenylphosphine oxide (1 g, 2.8 mmol), sodium carbonate aqueous solution (2 M, 8.4 mmol), toluene (40 mL), and ethanol (9 mL). The reaction was heated to 100 °C and stirred overnight. After cooling to room temperature, water was added, the organic layer was separated, and then back-extracted with water. The obtained organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. Column chromatography was then performed, using a mixture of dichloromethane and ethanol as the eluent. For the sample separated by column chromatography, further washing with an alcohol solvent yielded a white solid (1.2 g).

[0063] 1 H NMR(500MHz,Methylene Chloride-d2, Figure 3 )δ8.66(m,1H),8.58(m,2H),8.53–8.40(m,11H),8.37–8.32(m,2H),8.31–8.17(m,10H),8.16–8.12(m,1H),8.08(m,4H).

[0064] Step 3: Purification and refining process of compound TPOAN-DP:

[0065] (1) Chemical treatment process: The crude product obtained in step two above was dissolved in dichloromethane (100 mL), and hydrogen peroxide aqueous solution (1 eq.) and ethanol (5 mL) were added and stirred at room temperature. Then, sodium hydroxide aqueous solution (3 eq. 3 M) was added. Subsequently, under ultraviolet light irradiation, TLC could not detect the characteristic blue light emitted by the boric acid derivative. Using dichloromethane as the developing solvent, 10-(4-(phenylphenyl)-9-anthraboric acid had an Rf value of 0.15 and exhibited a very bright blue light with severe tailing, while 10-(4-(phenylphenyl)-9-anthraphenol had an Rf value of 0.8 and did not emit light. After stopping the reaction, sodium bisulfite aqueous solution was added to quench the excess hydrogen peroxide, followed by extraction with dichloromethane, collection of the organic layer, and back-extraction with water; the obtained organic layer was dried with anhydrous magnesium sulfate and filtered.

[0066] (2) Column chromatography separation: After removing the solvent under reduced pressure, column chromatography was performed, with dichloromethane, dichloromethane and ethanol as the eluents in sequence, to remove residual 10-(4-(phenylphenyl)-9-anthraphenol, yielding a white solid. The product obtained from column chromatography was dissolved in dichloromethane, and then an appropriate amount of ethanol was added to precipitate the solid. Subsequently, the mixture was heated and stirred under reflux overnight, filtered while hot, and the resulting filter cake was dried.

[0067] (3) Sublimation purification. The obtained filter cake was subjected to gradient temperature sublimation to further remove residual (3-bromophenyl)diphenylphosphine oxide, yielding the product TPOAN-DP. HPLC analysis showed its purity to be 99.99%. Figure 4 ).

[0068] Example 2

[0069] The purification and preparation steps of the compound TPO-m-TRZ described in Example 2 are as follows:

[0070] Step 1: The preparation of (3-bromophenyl)diphenylphosphine oxide (compound 1) is the same as the preparation steps in Example 1.

[0071] Step 2: Preparation of compound TPO-m-TRZ

[0072]

[0073] Under a nitrogen atmosphere, tetra(triphenylphosphine)palladium (23 mg) was added to a mixture of 2,4-diphenyl-6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxoboronyl-2-yl)phenyl)-1,3,5-triazine (1.04 mg, 2.4 mmol), (3-bromophenyl)diphenylphosphine oxide (715 mg, 2 mmol), ethanol (3 ml), and sodium carbonate aqueous solution (2 M, 3 ml) in toluene (30 ml). The mixture was stirred at 90 °C for 12 hours. After the reaction was complete, water was added to the reaction mixture, and the toluene layer was separated and back-extracted with water. The resulting organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure. Column chromatography was performed using a mixture of dichloromethane and ethanol (100:1 v / v) as the eluent to give a white solid compound TPO-m-TRZ in 71.8% (840 mg).

[0074] 1 H NMR (500MHz, DMSO-d6), Figure 5 )δ8.83(t,J=1.8Hz,1H),8.79–8.69(m,5H),8.08(m,1H),8.00–7.92(m,2H),7.81–7.70(m,9H),7.70–7.64(m,6H),7.64–7.58(m,4H).

[0075] Step 3: Purification and refining process of compound TPO-m-TRZ

[0076] (1) Chemical treatment process: The crude product obtained from column chromatography was dissolved in dichloromethane (80 mL), and hydrogen peroxide aqueous solution (1 eq.) and ethanol (3 mL) were added, and the mixture was stirred at room temperature. Subsequently, sodium hydroxide aqueous solution (3 eq. 3 M) was added. The borate ester raw material was then undetectable by TLC. Using dichloromethane as the developing solvent, the Rf value of 2,4-diphenyl-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaneborane-2-yl)phenyl]-1,3,5-triazine was 0.8, while the Rf value of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenylboronic acid was 0. In contrast, the Rf value of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol was 0.2. After the reaction was stopped, sodium bisulfite aqueous solution was added to quench excess hydrogen peroxide. The organic layer was then extracted with dichloromethane and collected, followed by back-extraction with water. The resulting organic layer was dried with anhydrous magnesium sulfate and filtered.

[0077] (2) Column chromatography separation: After removing the solvent under reduced pressure, column chromatography was performed using a mixed solvent of dichloromethane and ethanol as the eluent to remove residual 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol, yielding a white solid. Using dichloromethane:ethanol (100:1 v / v) as the developing solvent, the Rf value of 3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenol was 0.8, while the Rf value of TPO-m-TRZ was 0.2.

[0078] (3) Sublimation purification: The obtained filter cake was subjected to gradient temperature sublimation to further remove residual (3-bromophenyl)diphenylphosphine oxide, yielding the product TPO-m-TRZ. HPLC analysis showed its purity to be 99.95%. Figure 6 ).

[0079] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for purifying and preparing a class of compounds containing arylphosphine groups, characterized in that, The purification and preparation method is as follows: Where X is Cl, Br, or I; m = 1–6; when m ≥ 2, R1 can be the same or different; R2 is not oxidized by the oxidizing agent; the polarity of R2-OH is less than that of the oxidizing agent. R1 can be any of the following structural units: R2 can be any of the following structural units: The alkali is a hydroxide; The oxidant is at least one of hydrogen peroxide, sodium peroxide, potassium peroxide, di-tert-butyl peroxide, peracetic acid, and benzoyl peroxide.

2. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 1, characterized in that, Includes the following steps: (1) with Using hydrogen peroxide as raw material, it is oxidized to obtain (2) The result obtained in step (1) and The crude product was obtained via Suzuki coupling reaction. (3) The crude product obtained above is separated by rapid column chromatography, dissolved in an organic solvent, and oxidant and alkali are added to convert the residual arylboronic acid derivative into the corresponding phenolic derivative. (4) The product obtained in step (3) above is subjected to further post-processing, including column chromatography, solvent washing, recrystallization and sublimation, to obtain a compound containing an arylphosphoxy group.

3. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2, characterized in that: The steps described in step (1) The molar ratio with hydrogen peroxide is 1:3 to 6.

4. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2, characterized in that: The steps described in step (2) and The molar ratio is 1 to 3:

1.

5. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2, characterized in that: The temperature of the Suzuki coupling reaction in step (2) is 70-100°C and the reaction time is 1-24 h.

6. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2, characterized in that: The specific process of step (3) is as follows: the crude product obtained after rapid column chromatography separation The compound is dissolved in an organic solvent, then an alkaline solution is added and stirred, followed by the addition of an oxidizing agent and stirring. The organic solvent is dichloromethane or a mixture thereof with an alcohol, wherein the alcohol is at least one of ethanol, methanol, and isopropanol.

7. A method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2 or 6, characterized in that: The alkali mentioned in step (3) is at least one of sodium hydroxide and potassium hydroxide; The oxidant mentioned in step (3) is at least one of hydrogen peroxide, sodium peroxide, potassium peroxide, di-tert-butyl peroxide, peracetic acid, and benzoyl peroxide.

8. A method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2 or 6, characterized in that: In step (3) The molar ratio with alkali is 1:1 to 20.

9. A method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2 or 6, characterized in that: The molar ratio of oxidant to alkali in step (3) is 1:1 to 20.

10. The method for purifying and preparing a class of compounds containing arylphosphino groups according to claim 2, characterized in that: The column chromatography eluent mentioned in step (4) is dichloromethane or a mixed solvent of toluene, xylene and ethyl acetate, methanol, ethanol and isopropanol; The sublimation described in step (4) is a purification process using gradient temperature sublimation.

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