A triphenylamine derivative, a preparation method and application thereof

Abstract

The present application relates to a kind of triphenylamine derivatives and its preparation method and application.The triphenylamine derivative provided by the present application has the structural formula as shown in (I), which is prepared by the reaction of 2-thiophene boronic acid and 2-halo-5-nitro pyridine, followed by halogenation, and then the halogenated product is reacted with 4-boronic acid triphenylamine.The triphenylamine derivative can be used as an organic small molecule probe to detect the water content in organic solvent, and can be very simply and conveniently, quickly used for the detection and analysis of water content in organic solvent, and has the advantages of high detection sensitivity and accuracy, good stability, wide pH application range.

Description

Technical Field

[0001] This invention belongs to the field of organic chemistry and analytical detection technology, specifically relating to a triphenylamine derivative, its preparation method, and its application. Background Technology

[0002] Currently, the conventional methods for quantitative analysis of water content in solvents include: the Karl Fischer method, electrochemical analysis, density measurement, and distillation.

[0003] The Karl Fischer method (KF) is a commonly used and effective method for detecting the water content of organic solvents. It is the most specific and accurate method for determining water content among various chemical methods, capable of measuring the water content in liquids, solids, and gases. It is a globally recognized industry standard analytical method, widely used in the petroleum, chemical, power, pharmaceutical, and pesticide industries, as well as in academic research. The following are the basic steps and principles of using mass spectrometry for detection:

[0004] Preparation phase: Ensure all instruments and reagents are ready and that the instruments are airtight. Required instruments include a Karl Fischer titrator, titration cell, magnetic stirrer, etc.

[0005] Sample preparation: Prepare the sample whose water content needs to be tested, which is usually in liquid form.

[0006] Reagent equilibration: A portion of Karl Fischer reagent is injected into the titration cell and equilibrated by magnetic stirring.

[0007] Sample preparation: Take an appropriate amount of sample and determine the appropriate injection volume based on the sample's properties and water content. If the sample contains substances that may react with Karl Fischer reagent, appropriate pretreatment measures may be necessary, such as heating or using an extraction solvent.

[0008] Spectral Acquisition: In an NMR spectrometer, the sample is exposed to a series of magnetic fields and radio frequency pulses. This causes the atomic nuclei in the sample (such as hydrogen and deuterium) to absorb energy and subsequently release it. These energy releases are detected and converted into spectra.

[0009] Titration process: The sample is injected into the equilibrated titration cell to begin the titration process. In the volumetric method, an electric piston burette is used to add a solution containing iodine for titration; in the coulometric method, iodine is generated by electrolysis, and the water content is determined based on the amount of electricity consumed during electrolysis.

[0010] Endpoint determination: During titration, the endpoint is determined by observing changes in color or potential. Volumetric titration typically uses visual inspection or potentiometric methods to determine the endpoint, while coulometric titration determines the endpoint by observing changes in electrolytic current.

[0011] Calculate the moisture content: Calculate the moisture content in the sample according to the formula based on the volume of Karl Fischer reagent consumed in titration or the amount of electricity consumed during electrolysis.

[0012] Although the Karl Fischer method has high accuracy in detecting the water content of solvents, as mentioned above, its operation is complex and cumbersome, requiring specialized equipment and well-trained professionals. Furthermore, it is limited by the testing instruments and the available space, making it unsuitable for portable testing. Summary of the Invention

[0013] Therefore, the purpose of this invention is to provide a simple, convenient, and rapid method for detecting the water content of organic solvents.

[0014] To achieve the above-mentioned objectives, the present invention includes the following technical solutions.

[0015] On the one hand, the present invention provides a triphenylamine derivative having the structure shown in formula (I) below.

[0016]

[0017] Secondly, the present invention provides a method for preparing the triphenylamine derivative, comprising the following steps:

[0018] (1) 2-Thiopheneboronic acid reacts with 2-halo-5-nitropyridine to give intermediate 1;

[0019] (2) Intermediate 1 reacts with a halogenated reagent to give intermediate 2;

[0020] (3) Intermediate 2 reacts with triphenylamine 4-boronic acid to obtain a triphenylamine derivative with the structure shown in formula (I);

[0021] The reaction formula is as follows:

[0022]

[0023] R and R' are each independently selected from halogens.

[0024] Thirdly, the present invention provides the application of the triphenylamine derivative in the detection of water content in organic solvents.

[0025] Fourthly, the present invention provides a method for detecting the water content in an organic solvent, comprising: adding the triphenylamine derivative described in the present invention to the organic solvent to be tested, and testing the ultraviolet absorption spectrum and / or fluorescence spectrum of the resulting mixed solution.

[0026] This invention designs and synthesizes a novel triphenylamine derivative. The derivative is prepared by reacting 2-thiopheneboronic acid with 2-halo-5-nitropyridine followed by halogenation, and then reacting the halogenated product with 4-boronic acid triphenylamine. This compound can be used as a small organic molecule probe to test the water content in organic solvents (especially acetone). By adding the triphenylamine derivative of this invention to an organic solvent, the presence and amount of water in the solvent can be determined by testing its ultraviolet absorption or fluorescence spectrum using simple equipment, thus enabling simple and rapid detection of water content in organic solvents. The triphenylamine derivative provided by this invention can be used very simply, conveniently, and quickly for the detection and analysis of water content in organic solvents, and has the advantages of high detection sensitivity and accuracy, good stability, and a wide pH range. Attached Figure Description

[0027] Figure 1 The image shows the 1H NMR spectrum of intermediate 1.

[0028] Figure 2 The image shows the 1H NMR spectrum of intermediate 2.

[0029] Figure 3 This is the 1H NMR spectrum of a triphenylamine derivative.

[0030] Figure 4 The fluorescence response of triphenylamine derivatives to acetone solvents with different water contents is shown.

[0031] Figure 5 The correlation between fluorescence intensity at 414 nm and water content of acetone solvent after the addition of triphenylamine derivative is shown.

[0032] Figure 6 The UV-absorbing spectra of triphenylamine derivatives in acetone solvents with different water contents are shown.

[0033] Figure 7 The fluorescence intensity of the triphenylamine derivative in PBS solutions at different pH values ​​is given. Detailed Implementation

[0034] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0035] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0036] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0037] Furthermore, as used herein, the term "or" is an inclusive "or" sign and is equivalent to the term "and / or" unless the context clearly specifies otherwise. The term "based on" is not exclusive and allows for basing on other factors not described unless the context clearly specifies otherwise. Additionally, throughout the specification, the meanings of "an," "a," and "the" include plural indicators. The meaning of "in" includes both "in" and "on."

[0038] To provide a simple, convenient, and rapid method for detecting the water content of organic solvents, the inventors of this invention designed and synthesized a novel triphenylamine derivative. This compound can be used as a small organic molecule probe to detect the water content of organic solvents, and has the advantages of high detection sensitivity and accuracy, good stability, and a wide pH range.

[0039] In one embodiment of the present invention, a triphenylamine derivative having the structure shown in formula (I) is provided:

[0040]

[0041] In another embodiment of the present invention, a method for preparing the triphenylamine derivative is provided, comprising the following steps:

[0042] (1) 2-Thiopheneboronic acid reacts with 2-halo-5-nitropyridine to give intermediate 1;

[0043] (2) Intermediate 1 reacts with a halogenated reagent to give intermediate 2;

[0044] (3) Intermediate 2 reacts with triphenylamine 4-boronic acid to obtain a triphenylamine derivative with the structure shown in formula (I);

[0045] The reaction formula is as follows:

[0046]

[0047] R and R' are each independently selected from halogens.

[0048] In the synthetic route of the present invention, R in the 2-halo-5-nitropyridine is a halogen, such as chlorine, bromine, etc.; that is, the 2-halo-5-nitropyridine can be 2-bromo-5-nitropyridine or 2-chloro-5-nitropyridine.

[0049] In the synthetic route of this invention, the halogenating agent can be a brominating agent or a chlorinating agent; the brominating agent can be N-bromosuccinimide, etc., and the chlorinating agent can be N-chlorosuccinimide, etc.

[0050] In some embodiments, the 2-thiopheneboronic acid described in step (1) reacts with 2-halo-5-nitropyridine in the presence of tetra(triphenylphosphine)palladium and a base.

[0051] The alkali can be an organic or inorganic alkali, preferably potassium carbonate or sodium carbonate; the alkali is preferably added to the reaction system as an alkaline solution (water as solvent), therefore, the solvent of the reaction may contain water. Preferably, the concentration of the alkali in the alkaline solution is 1.8 mol / L to 2.5 mol / L.

[0052] In some embodiments, the molar ratio of the 2-halo-5-nitropyridine to the tetra(triphenylphosphine)palladium is 1:0.08 to 0.15, preferably 1:0.09 to 0.12.

[0053] In some embodiments, the solvent for the reaction in step (1) is tetrahydrofuran and water, and the volume ratio of the tetrahydrofuran to the alkaline solution is preferably 2 to 6:1, more preferably 2 to 3:1.

[0054] In some embodiments, the molar ratio of 2-thiopheneboronic acid to 2-halo-5-nitropyridine in step (1) is 1.2 to 1.8:1, more preferably 1.4 to 1.6:1.

[0055] In some embodiments, the temperature of the reaction in step (1) is 80°C to 90°C, and the time is 40 hours to 56 hours, more preferably 45 hours to 50 hours.

[0056] In some embodiments, the molar ratio of intermediate 1 to halogenated reagent in step (2) is 1:1.1 to 1.5, preferably 1:1.1 to 1.3.

[0057] In some of these embodiments, the solvent for the reaction in step (2) is dichloromethane.

[0058] In some embodiments, the reaction in step (2) is carried out at a temperature of 20°C to 30°C for 12 hours to 24 hours, preferably 15 hours to 20 hours.

[0059] In some embodiments, intermediate 2 of step (3) reacts with triphenylamine 4-borate in the presence of tetra(triphenylphosphine)palladium and a base.

[0060] The alkali can be an organic or inorganic alkali, preferably potassium carbonate or sodium carbonate; the alkali is preferably added to the reaction system as an alkaline solution (water as solvent), therefore, the solvent of the reaction may contain water. Preferably, the concentration of the alkali in the alkaline solution is 1.8 mol / L to 2.5 mol / L.

[0061] In some embodiments, the molar ratio of intermediate 2 to tetra(triphenylphosphine)palladium is 1:1:0.08 to 0.15, preferably 1:0.09 to 0.11.

[0062] In some embodiments, the solvent for the reaction in step (3) is tetrahydrofuran and water, and the volume ratio of the tetrahydrofuran to the alkaline solution is preferably 1.5 to 3:1, more preferably 1.8 to 2.5:1.

[0063] In some embodiments, the molar ratio of intermediate 2 in step (3) to triphenylamine 4-boronic acid is 1:1.2 to 1.8, more preferably 1.4 to 1.6.

[0064] In some embodiments, the reaction temperature in step (3) is 80°C to 90°C and the time is 40 hours to 56 hours, more preferably 45 hours to 50 hours.

[0065] In another embodiment of the present invention, the application of the triphenylamine derivative in detecting the water content of organic solvents, wherein the organic solvent may be acetone, etc. The inventors have found that the triphenylamine derivative of the present invention can be used very simply, conveniently, and quickly to detect the water content in organic solvents, and has high detection sensitivity and accuracy.

[0066] In another embodiment of the present invention, a method for detecting the water content of an organic solvent is provided, the method comprising: adding the triphenylamine derivative of the present invention to the organic solvent to be tested, and testing the ultraviolet absorption spectrum and / or fluorescence spectrum of the resulting mixed solution.

[0067] The ultraviolet absorption spectrum of the tested mixed solution includes: the ultraviolet absorption wavelength and / or ultraviolet absorption intensity of the tested mixed solution;

[0068] The fluorescence spectrum of the obtained mixed solution includes: the fluorescence wavelength and / or fluorescence intensity of the obtained mixed solution.

[0069] The concentration of the triphenylamine derivative in the mixed solution is preferably 0.005 mmol / L-0.02 mmol / L, more preferably 0.008 mmol / L-0.015 mmol / L, and even more preferably 0.008 mmol / L-0.012 mmol / L.

[0070] By adding the triphenylamine derivative described in this invention to an organic solvent, the water content in the organic solvent can be determined by testing its ultraviolet absorption and fluorescence using simple equipment, thus enabling a simple and rapid detection of the water content in organic solvents. This detection method is simple to operate, requires simple equipment, and has high sensitivity and accuracy.

[0071] The present invention will be further described in detail below with reference to specific embodiments.

[0072] Example 1: Synthesis of the probe (triphenylamine derivative)

[0073] Step 1: Preparation of Intermediate 1

[0074]

[0075] 2-Thiopheneboronic acid (2 g, 15.6 mmol) and 2-bromo-5-nitropyridine (2.12 g, 10.4 mmol) were added to 200 mL of tetrahydrofuran solvent, followed by tetrakis(triphenylphosphine)palladium (1.2 g, 1.04 mmol) and 50 mL of 2 M potassium carbonate aqueous solution. The mixture was heated at 85 °C for 48 hours. After cooling to room temperature, the mixture was extracted with ethyl acetate and purified water, and evaporated to dryness by rotary evaporation. The extract was then purified by silica gel column chromatography with dichloromethane and n-hexane to give intermediate 1 (1.75 g, 81.67% yield).

[0076] 1 H NMR (600MHz, DMSO) δ9.35(dd,J=2.7,0.7Hz,1H),8.63(dd,J=8.8,2.7Hz,1H),8.19–7.79(m,2H),7.43(dd,J=3.5,0.8Hz,1H),6.78(dd,J=3.5,1.7Hz,1H).

[0077] Step 2: Preparation of Intermediate 2

[0078]

[0079] Intermediate 1 (0.5 g, 2.43 mmol) and N-bromosuccinimide (NBS) (0.48 g, 2.70 mmol) were added to 20 mL of dichloromethane solvent and reacted at room temperature for 18 hours. The mixture was then evaporated to dryness by rotary evaporation and purified by silica gel column chromatography with dichloromethane and n-hexane to give intermediate 2 (0.62 g, 90.17% yield).

[0080] 1 H NMR (600MHz, DMSO) δ9.52–9.17(m,1H),8.63(dd,J=8.8,2.7Hz,1H),8.19–7.75(m,1H),7.47(dd,J=3.6,0.9Hz,1H),6.91(dd,J=3.6,0.8Hz,1H).

[0081] Step 3: Preparation of triphenylamine derivatives

[0082]

[0083] Intermediate 2 (0.25 g, 0.88 mmol) and triphenylamine 4-borate (0.38 g, 1.32 mmol) were added to 100 mL of tetrahydrofuran solvent, followed by tetra(triphenylphosphine)palladium (0.1 g, 0.088 mmol) and 50 mL of 2 M potassium carbonate solution. The mixture was heated at 85°C for 48 hours. After cooling to room temperature, the mixture was extracted with ethyl acetate and purified water, and evaporated to dryness by rotary evaporation. The extract was then purified by silica gel column chromatography using dichloromethane and n-hexane to obtain the triphenylamine derivative (0.35 g, 89.40% yield).

[0084] 1 H NMR (400MHz, DMSO) δ9.38 (d, J=2.6Hz, 1H), 8.64 (dd, J=8.9, 2.7Hz, 1H), 8.07 (d, J=8.9Hz, 2H), 7.82 (d, J= 8.8Hz,2H),7.55(d,J=3.7Hz,1H),7.37(dd,J=8.4,7.3Hz,4H),7.24–7.08(m,6H),7.04(d,J=8.7Hz,2H).

[0085] Example 2: Response capability of organic molecular probe (triphenylamine derivative) to organic solvents with different water contents

[0086] 1. Fluorescence detection

[0087] The triphenylamine derivative prepared in Example 1 was dissolved in dimethyl sulfoxide to prepare a triphenylamine derivative solution with a concentration of 5 mmol / L.

[0088] Prepare mixed solutions of acetone and water with water contents of 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% (100% is pure water, and 0% is pure acetone). Add 2 μL of triphenylamine derivative solution (5 mmol / L) to each acetone solution (1 mL) with different water contents. After mixing evenly, observe the fluorescence changes under a fluorescence spectrophotometer (excitation wavelength 350 nm).

[0089] The results are as follows Figure 4 and Figure 5 As shown, the fluorescence intensity at 414 nm exhibits a good correlation with the water content of the acetone solvent within the water content range of 0% to 100%.

[0090] 2. Ultraviolet-absorption spectroscopy determination

[0091] The triphenylamine derivative prepared in Example 1 was dissolved in dimethyl sulfoxide to prepare a triphenylamine derivative solution with a concentration of 5 mmol / L.

[0092] Prepare mixed solutions of acetone and water with water contents of 0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100% (100% is pure water, and 0% is pure acetone). Add 2 μL of triphenylamine derivative solution (5 mmol / L) to each acetone solution (1 mL) with different water contents, mix thoroughly, and observe the changes in UV absorption intensity under an ELISA reader.

[0093] The results are as follows Figure 6 As shown, the UV absorption intensity at 402 nm gradually increases with the increase of water content in acetone, and the solvation effect is very obvious. Therefore, the triphenylamine derivative prepared in this invention can be used as a sensor for measuring the water content in organic solvents.

[0094] These results demonstrate that the triphenylamine derivatives prepared in this invention have sufficient sensitivity to quantitatively detect the water content of organic solvents, and the detection accuracy is high.

[0095] Example 3: Detection of organic solvents at different pH values

[0096] The triphenylamine derivative prepared in Example 1 was dissolved in dimethyl sulfoxide to prepare a triphenylamine derivative solution with a concentration of 5 mmol / L.

[0097] Two microliters of triphenylamine derivative solution were added to 1 mL of PBS buffer at pH 5, 6, 7, 8, and 9, respectively, and the fluorescence spectra of the PBS buffer solutions at different pH values ​​were measured using a fluorescence spectrophotometer.

[0098] The results are as follows Figure 7As shown, the fluorescence intensity (wavelength 414 nm) of the solution did not change significantly under weakly acidic and weakly alkaline conditions, indicating that the triphenylamine derivative organic molecular probe prepared in this invention has sufficient stability and is applicable to general acid and alkaline environments.

[0099] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A triphenylamine derivative having a structure represented by formula (I): ###0001### (I) comprising the steps of: （I）。 2. A method for preparing a triphenylamine derivative, characterized by, (1) reacting 2-thiopheneboronic acid with 2-halo-5-nitropyridine to obtain intermediate 1; (2) reacting intermediate 1 with a halogenating agent to obtain intermediate 2; (3) reacting intermediate 2 with 4-boronic acid triphenylamine to obtain the triphenylamine derivative represented by formula (I); wherein R and R' are each independently selected from halogen. The 2-halo-5-nitropyridine is 2-bromo-5-nitropyridine or 2-chloro-5-nitropyridine; and / or, The halogenating agent is N-bromosuccinimide or N-chlorosuccinimide.

3. The method for preparing the triphenylamine derivative according to claim 2, characterized in that, In step (1), the 2-thiopheneboronic acid and the 2-halo-5-nitropyridine are reacted in the presence of tetrakis(triphenylphosphine)palladium and a base; and / or, In step (1), the solvent for the reaction is tetrahydrofuran and water; and / or, 4. The method of producing a triphenylamine derivative according to claim 2 or 3, characterized by, In step (1), the molar ratio of the 2-thiopheneboronic acid to the 2-halo-5-nitropyridine is 1.2-1.8:1; and / or, In step (1), the reaction is carried out at a temperature of 80-90°C for a period of 40-56 hours. In step (1), the base is potassium carbonate or sodium carbonate. In step (1), the base is added to the reaction system in the form of a base solution, and the volume ratio of the tetrahydrofuran to the base solution is 2-6:

1.

5. The method for preparing the triphenylamine derivative according to claim 4, characterized in that, In step (1), the concentration of the base in the base solution is 1.8-2.5 mol / L.

6. The method for preparing the triphenylamine derivative according to claim 4, characterized in that, In step (1), the molar ratio of the 2-halo-5-nitropyridine to the tetrakis(triphenylphosphine)palladium is 1:0.08-0.

15.

7. The method for preparing the triphenylamine derivative according to claim 6, characterized in that, In step (2), the molar ratio of intermediate 1 to the halogenating agent is 1:1.1-1.5; and / or, 8. The method for preparing the triphenylamine derivative according to claim 4, characterized in that, In step (2), the solvent for the reaction is dichloromethane; and / or, 9. The method of producing a triphenylamine derivative according to claim 2 or 3, characterized by, In step (2), the reaction is carried out at a temperature of 20-30°C for a period of 12-24 hours. In step (3), intermediate 2 and 4-boronic acid triphenylamine are reacted in the presence of tetrakis(triphenylphosphine)palladium and a base; and / or, In step (3), the solvent for the reaction is tetrahydrofuran and water; and / or, 10. The method of producing a triphenylamine derivative according to claim 2 or 3, characterized by, In step (3), the molar ratio of intermediate 2 to 4-boronic acid triphenylamine is 1:1.2-1.8; and / or, In step (3), the reaction is carried out at a temperature of 80-90°C for a period of 40-56 hours. In step (3), the base is potassium carbonate or sodium carbonate. In step (3), the base is added to the reaction system in the form of a base solution, and the volume ratio of the tetrahydrofuran to the base solution is 1.5-3:

1.

11. The method for preparing the triphenylamine derivative according to claim 10, characterized in that, In step (3), the concentration of the base in the base solution is 1.8-2.5 mol / L.

12. The method for preparing the triphenylamine derivative according to claim 10, characterized in that, In step (3), the molar ratio of intermediate 2 to the tetrakis(triphenylphosphine)palladium is 1:0.08-0.

15.

13. The method for preparing the triphenylamine derivative according to claim 12, characterized in that, 15. Use of the triphenylamine derivative of claim 1 in detecting the water content of an organic solvent.

14. The method for preparing the triphenylamine derivative according to claim 10, characterized in that, The solvent is acetone. comprising:

16. The use according to claim 15, characterized in that, adding the triphenylamine derivative of claim 1 to the organic solvent to be tested, and testing the ultraviolet absorption spectrum and / or fluorescence spectrum of the resulting mixed solution.

17. A method of detecting the water content in an organic solvent, characterized by, The organic solvent is acetone. ​ 18. The method of claim 17, wherein the water content in the organic solvent is detected by the method. ​ 19. The method of claim 17, wherein the water content in the organic solvent is detected by the method. The ultraviolet absorption spectrum of the obtained mixed solution comprises: testing the ultraviolet absorption wavelength and / or ultraviolet absorption intensity of the obtained mixed solution.

20. The method of claim 19, wherein the water content in the organic solvent is detected by the method. The fluorescence spectrum of the obtained mixed solution comprises: testing the fluorescence wavelength and / or fluorescence intensity of the obtained mixed solution.

21. The method of claim 17, wherein the water content in the organic solvent is detected by the method. The concentration of the triphenylamine derivative in the mixed solution is 0.005 mmol / L to 0.02 mmol / L.

22. The method of claim 21, wherein the water content of the organic solvent is determined by the method of claim 20. The concentration of the triphenylamine derivative in the mixed solution is 0.008 mmol / L to 0.012 mmol / L.

23. The method of detecting the water content in an organic solvent according to any one of claims 17 to 22, wherein The fluorescence intensity of the mixed solution at 414 nm is tested; and / or The ultraviolet absorption intensity of the mixed solution at 402 nm is tested.

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