A 2-(ethoxymethylene)-1,3-dione dithiophene vinyl derivative, its preparation method and application

Abstract

A 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative, its preparation method, and its application. The 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative has the chemical formula shown in Formula I: where R represents C6-C6. 15 Phenyl. This derivative exhibits photochromic properties, and its molecular structure can be altered by ultraviolet-visible light stimulation. Under 313 nm ultraviolet light irradiation, it transitions from an open-ring to a closed-ring structure; after reaching a photosteady state, it reverts to its open-ring structure under 650 nm visible light irradiation. This system allows for the control of dynamic conjugated addition-elimination reactions via light, enabling regulation of reaction rate and yield. The hydrophilic / hydrophobic contact angle of the glass surface is controlled through the reactivity of the 1,3-diketonedithiophene ethylene derivative with a mercapto group.

Description

Technical Field

[0001] This application relates to a 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative, its preparation method and application, belonging to the field of organic chemistry. Background Technology

[0002] Photocontrolled chemical processes offer high spatiotemporal resolution and are currently widely used in research on molecular assembly, surface modification, and biotransmission. Irradiation can overcome energy barriers that are difficult to overcome in reactions, enabling reactions that are difficult to occur in the ground state. Photochromic molecules acquire high-energy metastable structures in a photostable state after illumination, which can be used to drive chemical reactions. In recent years, some photo-switching molecules, such as azobenzene, diarylethylene, and spiropyran, have attracted attention due to their excellent photochromic properties. Among them, dithiophene ethylene, which combines thermal stability and fatigue resistance, has wide applications in anti-counterfeiting inks, photochromic glasses, and cell imaging.

[0003] Dynamic covalent chemistry, through the reversible formation, breaking, and exchange of covalent bonds, allows for thermodynamic control of products, exhibiting characteristics such as self-adaptation, self-repair, and degradability, playing a crucial role in the construction of functional molecules and materials. Common dynamic covalent reactions include imine bond formation, disulfide bond exchange, and reversible conjugated addition reactions. Achieving controllability in dynamic covalent reactions has become a research hotspot in this field. By combining the reversibility of dynamic covalent reactions with the photoresponsiveness of photoswitches, and utilizing light to regulate the extent and rate of the reaction, new regulatory mechanisms can be provided for dynamic covalent systems. Summary of the Invention

[0004] According to the first aspect of this application, a 2-(ethoxymethylene)1,3-diketone dithiopheneethylene derivative is provided, obtained by introducing ethoxymethylene 1,3-diketone into dithiopheneethylene. Its 1,4-conjugated addition-elimination reaction with nucleophiles, such as thiols and amines, can be modulated by UV-Vis light. The dithiopheneethylene moiety exhibits photochromic properties, and its molecular structure can be altered by UV-Vis light stimulation. Due to the photocyclization of dithiopheneethylene, the conjugation of the 1,3-diketone moiety is also altered, resulting in different reactivity with nucleophiles. This type of molecule combines the photostimulation responsiveness and reactivity of the compound, achieving photodynamic and thermodynamic control of its addition-elimination reaction with nucleophiles. This strategy can be used for the controlled modification of glass surfaces and has potential applications in organic functional materials.

[0005] A 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative, said 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative having the chemical formula shown in Formula I below: Formula I; Where R represents C6~C 15 Phenyl.

[0006] Optionally, R is selected from any one of the following groups: .

[0007] According to a second aspect of this application, a method for preparing a 2-(ethoxymethylene)1,3-diketone-dithiophene ethylene derivative is provided. In the condensation process, the solvent added is a mixture of triethyl orthoformate and glacial acetic acid in a volume ratio of 1:1 to 1:1.5. This provides good solubility of the compound, and the acetic acid provides acidic conditions to catalyze the reaction.

[0008] The preparation method of the 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative described above includes the following steps: (S1) Contains 3,4-dibromo-N-methylmaleimide, arylboronic acid, PdCl2(PPh3)2, and BnEt3N + Cl - A mixture of cesium fluoride aqueous solution and toluene, reacted in reaction I to yield dithiophene maleimide as shown in formula II. Formula II; (S2) A mixture containing the above-mentioned dithiophene maleimide, ethanol, and sodium hydroxide is reacted with reaction II to obtain the dithiophene maleic anhydride shown in formula III; Formula III; (S3) A mixture containing the aforementioned dithiophene maleic anhydride compound, ethoxyformylmethylene triphenylphosphine, and solvent I is reacted in reaction III to obtain a compound having the structure shown in formula IV. Formula IV; (S4) A mixture containing sodium methoxide and solvent II is added to (S3), and reaction IV is carried out to obtain the dithiophene ethylene 1,3-dione compound represented by formula V. Formula V; (S5) A mixture containing the aforementioned dithiophene ethylene 1,3-diketone compound, triethyl orthoformate, and glacial acetic acid is reacted in reaction V to obtain the 2-(ethoxymethylene) 1,3-diketone dithiophene ethylene derivative shown in formula VI. Formula VI.

[0009] Optionally, in step (S1), the arylboronic acid has the following structure: ; R is a phenyl group.

[0010] Optionally, in step (S1), the amount of 3,4-dibromo-N-methylmaleimide is 0.3 to 0.5 equivalents; The amount of arylboronic acid is 1 to 1.5 equivalents; The PdCl2(PPh3)2 is 0.005 equivalent to 0.01 equivalent. BnEt3N + Cl - It is 0.005 equivalent to 0.01 equivalent.

[0011] Optionally, in step (S1), the conditions for reaction I are as follows: The temperature is 90℃ ~ 100℃; The time is 5 to 6 hours.

[0012] Optionally, in step (S2), the solid-liquid ratio of the dithiophene maleimide and the ethanol is 1:10 to 1:20; The solid-liquid ratio of the dithiophene maleimide and the sodium hydroxide is 1:2 to 1:3.

[0013] Optionally, in step (S2), the conditions for reaction II are as follows: The temperature is 20℃ ~ 30℃; The time is 0.2 h ~ 0.5 h.

[0014] Optionally, in step (S3), solvent I is selected from at least one of toluene and THF; Optionally, in step (S3), the solid-solid ratio of the dithiophene maleic anhydride compound and ethoxyformylmethylene triphenylphosphine is 1:2 to 1:3.

[0015] Optionally, in step (S3), the solid-liquid ratio of the dithiophene maleic anhydride compound and solvent I is 1:20 to 1:30.

[0016] Optionally, in step (S3), the conditions for reaction III are as follows: The temperature is 20℃ ~ 30℃; The time is 12 h to 15 h.

[0017] Optionally, in step (S3), reaction III is carried out under an inactive atmosphere; The inactive atmosphere is selected from at least one of nitrogen and argon.

[0018] Optionally, in step (S3), after reaction III is completed, excess solvent is removed.

[0019] Optionally, in step (S4), the equivalent of sodium methoxide is 1.5 to 2.

[0020] Optionally, in step (S4), the concentration of sodium methoxide is 5 M to 6 M.

[0021] Optionally, in step (S4), solvent II is selected from at least one of methanol and ethanol.

[0022] Optionally, in step (S4), the conditions for reaction IV are as follows: The temperature is 20℃ ~ 30℃; The time is 0.1 h ~ 0.2 h.

[0023] Optionally, in step (S4), reaction IV is carried out under an inactive atmosphere; The inactive atmosphere is selected from at least one of nitrogen and argon.

[0024] Optionally, in step (S4), after reaction IV, the reaction is quenched and neutralized.

[0025] Optionally, in step (S5), the volume ratio of triethyl orthoformate to glacial acetic acid is 1:1 to 1:1.5.

[0026] Optionally, in step (S5), the volume ratio of triethyl orthoformate to glacial acetic acid is independently selected from any value of 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5 or any range between the two.

[0027] Optionally, in step (S5), the solid-liquid ratio of the dithiophene ethylene 1,3-diketone compound to the triethyl orthoformate is 1:20 to 1:30.

[0028] Optionally, in step (S5), the conditions for reaction V are as follows: The temperature is 100℃ ~ 120℃; The time is 1 to 2 hours.

[0029] Optionally, in step (S5), after reaction V, the reaction is quenched, extracted, and dried.

[0030] According to a third aspect of this application, an application of a 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative is provided.

[0031] The above-described 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative and / or the 2-(ethoxymethylene)1,3-dione dithiophene ethylene derivative obtained by the above-described preparation method are used in photochromism, regulation of dynamic covalent chemical reactions, and glass surface modification.

[0032] Optionally, the 2-(ethoxymethylene)1,3-dionedithiophene ethylene derivative undergoes cyclization under ultraviolet light irradiation at 300 nm to 400 nm. After being irradiated to a steady state, it is irradiated back to its open-loop structure by visible light at 600 nm ~ 700 nm.

[0033] The beneficial effects that this application can produce include: 1) The 2-(ethoxymethylene)1,3-diketonedithiophene ethylene derivative provided in this application has photochromic properties and its molecular structure can be changed by ultraviolet-visible light stimulation. Under ultraviolet light irradiation at 313 nm, it changes from an open-ring structure to a closed-ring structure; after irradiation to a photosteady state, it returns to its open-ring structure when irradiated with visible light at 650 nm.

[0034] 2) The 2-(ethoxymethylene)1,3-dionedithiophene ethylene derivative provided in this application can be controlled by light to dynamically control the conjugate addition-elimination reaction, thereby achieving regulation of the reaction rate and yield.

[0035] 3) The 2-(ethoxymethylene)1,3-diketonedithiophene ethylene derivative provided in this application achieves the contact angle of the glass surface through the reactivity of the 1,3-diketonedithiophene ethylene derivative with mercapto groups. Glass with a specific contact angle can be adjusted simply by applying or removing ultraviolet light, which is quite convenient.

[0036] 4) The preparation method provided in this application has the characteristics of simple reaction and high yield, and is suitable for industrial application. Attached Figure Description

[0037] Figure 1 This is the 1H NMR spectrum of compound 5 in deuterated dimethyl sulfoxide.

[0038] Figure 2 This is the 1H NMR spectrum of compound 6 in deuterated acetonitrile.

[0039] Figure 3 The deuterated acetonitrile solution of compound 6 (a) reaches photosteady state after 1.5 h of 313 nm light irradiation (b), and is then subjected to 2 h of 650 nm light irradiation (c) and its 1H NMR spectrum.

[0040] Figure 4 In the diagram, Figure A represents the compound. o- Figure B shows the 1H NMR spectra of a 6% deuterated acetonitrile solution (a) after the addition of 3 equivalents of n-propanethiol (b) for 20 days (c) and 35 days (c). Figure B is a detailed kinetic curve of the process.

[0041] Figure 5In the diagram, Figure A represents the compound. c- Figure B shows the 1H NMR spectra of a 6% deuterated acetonitrile solution (a) after the addition of 3 equivalents of n-propanethiol (b) for 40 minutes (c) and after 90 minutes (c). Figure B is a detailed kinetic curve of the process.

[0042] Figure 6 In the diagram, Figure A represents the compound. o- Figure B shows the 1H NMR spectra of a 6% deuterated acetonitrile solution (a) after the addition of 1.5 equivalents of aniline (b) for 10 hours (c) and after 26 hours (c). Figure B is a detailed kinetic curve of the process.

[0043] Figure 7 It is a compound c- The 1H NMR spectrum of a 6-deuterated acetonitrile solution (a) after reacting for 10 minutes with 1.5 equivalents of aniline (b).

[0044] Figure 8 The ring-open form of compound 7, obtained by in-situ preparation, was followed by the addition of 1.5 equivalents of n-propylthiol (a), and its changes were tracked by 1H NMR spectroscopy (bh). Figure A is a magnified view of a local area, and Figure B is the full view.

[0045] Figure 9 The closed-ring form of compound 7 was prepared in situ. After adding 1.5 equivalents of n-propylthiol (a), its changes were tracked by 1H NMR spectroscopy (bg), where A is a magnified view of a local area and B is the full view.

[0046] Figure 10 This is a graph showing the exchange kinetics of compound 7 and benzyl mercaptan before and after light exposure, where red represents... o -7 and 1.5 equivalents of n-propanethiol reaction kinetics curve, black represents c -7 and 1.5 equivalents of n-propanethiol reaction kinetics curves. Detailed Implementation

[0047] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0048] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0049] The analysis method in the embodiments of this application is as follows: The proton nuclear magnetic resonance spectra were analyzed using a 400 MHz Bruker Biospin avance III.

[0050] Kinetic analysis was performed using the obtained hydrogen NMR spectrum.

[0051] The yield is calculated as (molar amount of product / molar amount of reactants) × 100%.

[0052] Preparation route and method of 2-(ethoxymethylene)1,3-dione dithiophene vinyl derivative The preparation route is shown in Equation 2: Formula 2 Dithiophene vinyl anhydride compounds can be prepared by Suzuki coupling and imide hydrolysis. Then, 1,3-diketodithiophene vinyl compounds are obtained by deionization and hydrolysis via the Wittig-Horner reaction. Finally, condensation with triethyl orthoformate yields 2-(ethoxymethylene)1,3-diketodithiophene vinyl compounds. The specific preparation process can be found in Example 1.

[0053] Example 1 Synthesis of intermediate 3: 1 equivalent of 3,4-dibromo-N-methylmaleimide was dissolved in 50 mL of toluene in a two-necked round-bottom flask. Then, 3 equivalents of arylboronic acid, 0.05 equivalents of PdCl2(PPh3)2, and 0.05 equivalents of BnEt3N were added. + Cl - A reflux apparatus was installed, and the reaction was carried out under nitrogen protection. 50 mL of a 4-equivalent cesium fluoride aqueous solution was added to the reaction system using a syringe. The mixture was heated to 90 °C and reacted until no imide feedstock remained as monitored by TLC. After cooling, the mixture was extracted three times with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, and the solvent was removed by a vacuum rotary evaporator. The mixture was then separated by column chromatography (SiO2) with petroleum ether:ethyl acetate = 100:1 as the eluent. Dithiophene maleimide 3 was obtained in 85% yield.

[0054] Synthesis of intermediate 4: Compound 3 was weighed into a 100 mL round-bottom flask, dissolved in 30 mL of ethanol, and then slowly adjusted to pH 12 by adding 2 M sodium hydroxide solution. After stirring for 1 hour, 2 M dilute hydrochloric acid was added to adjust to pH 4. After extraction three times with ethyl acetate, the organic phase was dried over anhydrous sodium sulfate, the solvent was removed by vacuum rotary evaporation, and the mixture was separated by column chromatography (SiO2) with petroleum ether:ethyl acetate = 10:1 as the eluent. Dithiophene maleic anhydride 4 was obtained in 90% yield.

[0055] Synthesis of intermediate 5: Compound 4 was placed in a 100 mL double-necked round-bottom flask, 2 equivalents of ethoxyformylmethylenetriphenylphosphine were added, and 50 mL of anhydrous toluene was added under nitrogen protection. The mixture was stirred at room temperature for 12 hours. After the reaction was completed, excess solvent was removed by rotary evaporator.

[0056] Intermediate 6: In the preparation of intermediate 5, after removing excess solvent, 50 mL of anhydrous methanol was added. Then, under nitrogen protection, 2 equivalents of sodium methoxide methanol solution (5.4 M) were slowly added dropwise through a rubber stopper. After stirring at room temperature for 30 minutes, water was added to quench the reaction. The solvent was then removed by rotary evaporation. 50 mL of 2 M hydrochloric acid aqueous solution was added to the reaction, and a reflux apparatus was set up. The mixture was refluxed at 110°C for 2 hours. After the reaction cooled, it was extracted three times with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, and the solvent was removed by vacuum rotary evaporation. The mixture was then separated by column chromatography (SiO2) with petroleum ether:ethyl acetate = 5:1 as the eluent. Compound 5, 1,3-dione of dithiopheneethylene, was obtained in 64% yield.

[0057] The proton NMR spectrum of compound 5: 1 H NMR (DMSO-d6): δ = 7.55 (d, J = 7.2 Hz, 4H), 7.41 (t, J = 7.2 Hz, 4H), 7.31 (t, J = 7.2 Hz, 2H), 7.28 (s, 2H), 3.31 (s, 2H), 2.01 (s, 6H). See attached spectrum for details. Figure 1 .

[0058] Synthesis of target product 6: Compound 5 was placed in a 100 mL two-necked flask, and 10 mL of triethyl orthoformate was added. Then, 10 mL of glacial acetic acid was slowly added dropwise. After the compound was completely dissolved, the reaction was carried out in an 80°C oil bath. TLC monitoring was performed until the starting material 5 was completely consumed. After cooling, water was added to quench the reaction, followed by extraction three times with ethyl acetate. The combined organic phases were dried over anhydrous sodium sulfate, and the solvent was removed by a vacuum rotary evaporator. Separation was then performed by column chromatography (SiO2) with petroleum ether:ethyl acetate = 2:1 as the eluent. 2-(ethoxymethylene)-1,3-diketone-dithiophene ethylene 6 was obtained in 90% yield.

[0059] The proton NMR spectrum of compound 6: 1 H NMR (CD3CN): δ = 7.62 (s, 1H), 7.58 (d, J = 7.2Hz, 4H), 7.40 (t, J = 7.2 Hz, 4H), 7.32 (t, J = 7.2 Hz, 2H), 7.26 (d, J = 7.2 Hz, 2H), 4.45 (q, J= 7.2 Hz, 2H), 2.06 (s, 3H), 1.43 (t, J = 7.2 Hz, 3H). See attached spectrum for details. Figure 2 .

[0060] The above method can be used to obtain ethoxymethylene 1,3-diketone dithiophene ethylene derivatives, and the compounds can be characterized by nuclear magnetic resonance, mass spectrometry and other means.

[0061] Example 2 Reaction with thiols before light exposure: Compound 6 was prepared into a 5 mM acetonitrile standard solution and its 1H NMR spectrum was measured. Three equivalents of n-propanethiol were added to the solution and the reaction progress was tracked by 1H NMR spectrum.

[0062] Reaction with thiols after light irradiation: Compound 6 was prepared into a 5 mM acetonitrile standard solution and brought to a photosteady state under 313 nm ultraviolet xenon lamp irradiation to obtain compound c-6. 3 equivalents of n-propanethiol were added to the solution, and the reaction process was tracked by 1H NMR spectroscopy.

[0063] Example 3 Reaction with aniline before light exposure: Compound 6 was prepared into a 5 mM acetonitrile standard solution and its 1H NMR spectrum was measured. 1.5 equivalents of aniline were added to the solution and the reaction progress was tracked by 1H NMR spectrum.

[0064] Reaction with aniline after light irradiation: Compound 6 was prepared into a 5 mM acetonitrile standard solution and brought to a photosteady state under 313 nm ultraviolet xenon lamp irradiation to obtain compound c-6. 1.5 equivalents of aniline were added to the solution and the reaction process was tracked by 1H NMR spectroscopy.

[0065] Example 4 In-situ preparation of compound 7: 3 equivalents of n-propanethiol and 5 mM of deuterated acetonitrile solution of compound c-6 were reacted completely to obtain c-7. The compound was then irradiated with visible light at 650 nm using a xenon lamp. Irradiation was stopped when the compound was completely converted to its open-ring form o-7.

[0066] Exchange of compound 7 with benzyl thiol before light exposure: 3 equivalents of benzyl thiol were added to compound o-7 prepared in situ, and the exchange reaction process was tracked by 1H NMR spectroscopy.

[0067] Compound 7 was exchanged with benzyl thiol after light exposure: 3 equivalents of benzyl thiol were added to compound c-7 prepared in situ, and the exchange reaction was tracked by 1H NMR spectroscopy.

[0068] Example 5 Preparation of thiol-modified glass surfaces: Glass slides were immersed in a Pirahana solution (15 mL of a 30% hydrogen peroxide solution and 35 mL of a concentrated sulfuric acid solution) for 1 hour, followed by ultrasonic cleaning twice with deionized water. The cleaned glass slides were then dried in a vacuum oven at 120°C for 12 hours. After drying, the glass slides were immersed in a 10% (v / v) mercaptotrimethylsilane-toluene solution for 20 hours, then cleaned with dried toluene, and finally ultrasonically cleaned twice to remove free mercaptotrimethylsilane. The contact angle was measured to be 92 degrees. Modification of glass surfaces by photoswitches: Thiol-modified glass surface sheets were placed in a dry acetonitrile solution containing 10% photoswitches by mass. After reacting for 1.5 hours, the free photoswitches were washed away with dry acetonitrile and dried at room temperature. The contact angles of the sheets were then measured.

[0069] The photochromic properties of this type of molecule can be controlled by ultraviolet-visible light.

[0070] Taking compound 6 as an example, under ultraviolet light irradiation at 313 nm, compound 6 undergoes photo-cyclization from the open-ring o-6 form to the c-6 form in deuterated acetonitrile. After irradiation to a photosteady state, it can be re-illuminated back to its open-ring structure o-6 by visible light at 650 nm, as shown in Equation 3. The NMR results of the light-illuminated NMR are shown in Equation 3. 1 H NMR as attached Figure 3 As shown, the specific experimental process can be found in Example 2.

[0071] The addition reactivity of this type of molecule with amines and alcohols can be modulated by ultraviolet-visible light (taking n-propylthiol and aniline as an example). The UV-Vis light modulates the reaction of this type of molecule with n-propylthiol as shown in Equation 4:

[0072] The ring-opening form of compound 6, o-6, was reacted in situ with n-propylthiol. The reaction process was monitored by 1H NMR spectroscopy. After 35 days of monitoring, the reaction reached equilibrium with a compound conversion rate of 38%, displacing an equal amount of ethanol. The process is shown in the attached figure. Figure 4 As shown. When its halo form c-6 undergoes the same reaction, its reaction rate is significantly increased, and the reaction is complete after 90 minutes, as shown in the attached figure. Figure 5 As shown in the figure. The specific process can be found in Example 2.

[0073] The ultraviolet-visible light modulates the reaction of this type of molecule with aniline, as shown in Equation 4:

[0074] The open-ring form o-6 and the halo-ring form c-6 of compound 6 were reacted in situ with aniline in deuterated acetonitrile. The reaction process was monitored in situ by 1H NMR spectroscopy. For the open-ring form o-6, the reactants were completely reacted after 26 hours of monitoring, displacing an equal amount of ethanol. The process is shown in the attached figure. Figure 5 As shown. For its cycloidal form c-6, the reaction is complete 10 minutes after the addition of aniline, as shown in the attached figure. Figure 6 As shown in the figure. These results indicate a significant difference in reactivity before and after ultraviolet light irradiation, as detailed in Example 3.

[0075] The dynamic exchange properties of this type of molecule can be modulated using ultraviolet-visible light.

[0076] To verify that this system is also applicable to the dynamic exchange regulation method, the open-ring form (o-7) and closed-ring form (c-7) of compound 7, prepared in situ, were subjected to nucleophilic exchange reactions with benzyl mercaptan in deuterated acetonitrile, and the reaction process was monitored by 1H NMR spectroscopy. For the open-ring form (o-7), the exchange reached equilibrium after 12 days of monitoring, with a ratio of 52:48 between o-7 and o-9. This process is shown in the attached figure. Figure 7 As shown. For the closed-loop configuration c-7, after tracking for 120 minutes, the exchange reached equilibrium, and the ratio between c-7 and c-9 remained at 52:48. This process is illustrated in the attached diagram. Figure 8 As shown in the attached figure, the kinetic exchange curves between benzyl thiol and thiols before and after illumination are... Figure 10 As shown in the figure. The specific process can be found in Example 4.

[0077] Surface modification of this type of molecule was regulated by ultraviolet-visible light. The light-controlled modification of glass surfaces by these molecules is shown in Equation-7:

[0078] Formula 7 Because compound 6 exhibits different reactivity with thiols before and after light irradiation, it was reacted with the thiol-modified surface before and after light irradiation. Under the same reaction time, form o-6 before light irradiation did not react with the surface, and the contact angle remained unchanged before and after modification. Conversely, for form c-6 after light irradiation, the contact angle of the glass surface increased to 110.4 degrees, indicating that the reaction occurred. The specific experimental process can be seen in Example 5.

[0079] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A 2-(ethoxymethylene)-1,3-dione dithiophene vinyl derivative, characterized in that, The 2-(ethoxymethylene)-1,3-dione-dithiophene vinyl derivative has the chemical formula shown in Formula I below: Equation I; Where R is a phenyl group.

2. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 1, characterized in that, The preparation method includes the following steps: (S1) Contains 3,4-dibromo-N-methylmaleimide, arylboronic acid, PdCl2(PPh3)2, and BnEt3N + Cl - A mixture of cesium fluoride aqueous solution and toluene, reacted in reaction I to yield dithiophene maleimide as shown in formula II. Formula II; (S2) A mixture containing the above-mentioned dithiophene maleimide, ethanol, and sodium hydroxide is reacted with reaction II to obtain the dithiophene maleic anhydride shown in formula III; Formula III; (S3) A mixture containing the aforementioned dithiophene maleic anhydride compound, ethoxyformylmethylene triphenylphosphine, and solvent I is reacted in reaction III to obtain a compound having the structure shown in formula IV. Formula IV; (S4) A mixture containing sodium methoxide and solvent II is added to (S3), and reaction IV is carried out to obtain the dithiophene ethylene 1,3-dione compound represented by formula V. Formula V; (S5) A mixture containing the aforementioned dithiophene ethylene 1,3-diketone compound, triethyl orthoformate, and glacial acetic acid is reacted in reaction V to obtain the 2-(ethoxymethylene) 1,3-diketone dithiophene ethylene derivative shown in formula VI. Formula VI.

3. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 2, characterized in that, In step (S1), the arylboronic acid has the following structure: ； The scope of R is the same as that described in claim 1; In step (S1), the conditions for reaction I are as follows: The temperature is 90℃ ~ 100℃; The time is 5 to 6 hours.

4. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 2, characterized in that, In step (S2), the solid-liquid ratio of the dithiophene maleimide and the ethanol is 1:10 to 1:20; The solid-liquid ratio of the dithiophene maleimide and the sodium hydroxide is 1:2 to 1:

3. In step (S2), the conditions for reaction II are as follows: The temperature is 20℃ ~ 30℃; The time is 0.2 h ~ 0.5 h.

5. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 2, characterized in that, In step (S3), solvent I is selected from at least one of toluene and THF; In step (S3), the solid-liquid ratio of the dithiophene maleic anhydride compound and the ethoxyformylmethylene triphenylphosphine is 1:2 to 1:3; In step (S3), the solid-liquid ratio of the dithiophene maleic anhydride compound and solvent I is 1:20 to 1:30; In step (S3), the conditions for reaction III are as follows: The temperature is 20℃ ~ 30℃; The time is 12 h ~ 15 h; In step (S3), reaction III is carried out under an inert atmosphere; The inactive atmosphere is selected from at least one of nitrogen and argon; In step (S3), after reaction III is completed, excess solvent is removed.

6. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 2, characterized in that, In step (S4), the concentration of sodium methoxide is 5 M to 6 M; In step (S4), solvent II is selected from at least one of methanol and ethanol; In step (S4), the conditions for reaction IV are as follows: The temperature is 20℃ ~ 30℃; The time is 0.1 h ~ 0.2 h; In step (S4), reaction IV is carried out under an inert atmosphere; The inactive atmosphere is selected from at least one of nitrogen and argon; In step (S4), after reaction IV, quenching and neutralization occur.

7. The method for preparing the 2-(ethoxymethylene)-1,3-dione dithiophene ethylene derivative according to claim 2, characterized in that, In step (S5), the volume ratio of triethyl orthoformate to glacial acetic acid is 1:1 to 1:1.5; In step (S5), the solid-liquid ratio of the dithiophene ethylene 1,3-diketone compound to the triethyl orthoformate is 1:20 to 1:30; In step (S5), the conditions for reaction V are as follows: The temperature is 100℃ ~ 120℃; The time is 1 to 2 hours; In step (S5), after reaction V, the reaction is quenched, extracted, and dried.

8. The application of the 2-(ethoxymethylene)1,3-dionedithiophene ethylene derivative of claim 1 or the 2-(ethoxymethylene)1,3-dionedithiophene ethylene derivative obtained by the preparation method of any one of claims 2 to 7 in photochromism, regulation of dynamic covalent chemical reactions, and glass surface modification.

9. The application according to claim 8, characterized in that, The 2-(ethoxymethylene)1,3-dione dithiophene vinyl derivative undergoes cyclization under ultraviolet light irradiation at 300 nm to 400 nm. After being irradiated to a steady state, it is irradiated back to its open-loop structure by visible light at 600 nm ~ 700 nm.

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