An indeno-fused naphthopyran photochromic compound, and a preparation method and application thereof

Abstract

The application belongs to the field of photochromic materials, and relates to an indeno-fused naphthopyran photochromic compound and a preparation method and application thereof, a structure formula of which is shown in general formula I or general formula II: wherein R1 and R2 are independently selected from one of hydrogen and C1-C6 alkyl; R3, R4 and R5 are independently selected from one of hydrogen, hydroxyl, C1-C6 alkyl, methoxy, ethoxy, amino, halogen, formyl and acetyl. The indeno-fused naphthopyran photochromic compound provided by the application introduces trifluoromethyl-substituted diaryl into the indeno-fused naphthopyran compound, and adds triphenylphosphine as a dehydrating agent, so that the photochromic performance, color formation speed and color fading speed are adjusted, the formation of a pyran ring can be realized at room temperature with high yield, the method is easy to separate and purify, the yield is high, and the production cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of photochromic materials, and relates to an inden-fused naphthylpyran photochromic compound, its preparation method, and its application. Background Technology

[0002] Photochromism refers to the phenomenon where the molecular structure of certain compounds changes under the influence of light of specific wavelengths and intensities, resulting in a corresponding change in their absorption peak, i.e., their color. This change is generally reversible. Compounds exhibiting this property are called photochromic compounds. Photochromic materials are attracting attention due to their increasingly widespread applications in light energy conversion, optical lenses, automotive windshields, optical anti-counterfeiting, and decorative materials, as well as their significant potential applications in optical information storage, optical recording, and optical switches.

[0003] Naphthopyrans are an important class of organic photochromic materials. Under light irradiation, their absorption spectrum shifts from the ultraviolet region to the visible light region, displaying color. In darkness or under heat, the absorption spectrum shifts back to the ultraviolet region, reverting to a colorless state. Naphthopyrans can switch between these two states under light. Currently, naphthopyrans have wide applications in non-silver halide photosensitive materials, rewritable optical discs, organic photochromic resin mirrors, and anti-counterfeiting technologies. However, naphthopyrans suffer from slow fading rates and residual color in solid environments, hindering the rapid transition between their two stable states. Summary of the Invention

[0004] This invention addresses the problems existing in photochromic materials in the prior art by providing an indene-fused naphthylpyran photochromic compound, its preparation method, and its applications.

[0005] One objective of this invention is achieved through the following technical solution:

[0006] An indene-fused naphthopyran photochromic compound, the structural formula of which is shown in general formula I or general formula II:

[0007]

[0008] in,

[0009] R1 and R2 are each independently selected from hydrogen and C1 to C6 alkyl groups;

[0010] R3, R4, and R5 are each independently selected from one of the following: hydrogen, hydroxyl, C1-C6 alkyl, methoxy, ethoxy, amino, halogen, formyl, and acetyl.

[0011] Preferably, the halogen is F, Cl or Br.

[0012] Preferably, in one embodiment of the present invention, R1 and R2 can be the same.

[0013] Preferably, the structural formula of the indenoid-fused naphthylpyran photochromic compound is shown in formula SP1, SP2 or SP3 below:

[0014]

[0015] Another objective of this invention is achieved through the following technical solution:

[0016] A method for preparing an indene-fused naphthopyran photochromic compound, wherein the photochromic compound has the structural formula of general formula I and R2 is one of C1 to C6 alkyl groups, the preparation method of the photochromic compound is as follows:

[0017]

[0018] Includes the following steps:

[0019] (1) Reacting compound M1 with an acid yields compound M2;

[0020] (2) Compound M2 was reacted with an alkylating agent to obtain compound M3;

[0021] (3) Compound M3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were reacted in the presence of a dehydrating agent and a catalyst to obtain compound M4;

[0022] (4) Compound M4 was reacted with haloalkanes under alkaline conditions to obtain the target product of general formula I;

[0023] When the photochromic compound has the structural formula of general formula I and R2 is H, the preparation method of the photochromic compound is as follows:

[0024]

[0025] Includes the following steps:

[0026] (1) Reacting compound M1 with an acid yields compound M2;

[0027] (2) Compound M2 was reacted with an alkylating agent to obtain compound M3;

[0028] (3) Compound M3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were reacted in the presence of a dehydrating agent and a catalyst to obtain the target product of general formula I.

[0029] Preferably, in step (1), compound M1 reacts with an acid in a reaction solvent, the reaction solvent including one or more of dichloromethane, toluene, and xylene.

[0030] Preferably, the acid in step (1) includes one or more of trifluoroacetic acid, concentrated sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and polyphosphoric acid, wherein the mass fraction of the concentrated sulfuric acid is 95-98%.

[0031] Preferably, in step (1), the molar ratio of compound M1 to acid is 1:(0.1~1).

[0032] Preferably, the reaction temperature in step (1) is 25–100°C and the reaction time is 3–12 h.

[0033] Preferably, after the reaction in step (1) is completed, extraction is performed, the organic phases are combined and concentrated, and then eluted by acidic silica gel column chromatography to obtain compound M2.

[0034] Preferably, the extraction process involves at least three extractions using an extractant, which is ethyl acetate or dichloromethane, more preferably ethyl acetate. The extraction steps in the following preparation methods are similar.

[0035] Preferably, the acidic silica gel column chromatography elution parameters are PE:EA = 10:1 to 30:1, where PE is petroleum ether and EA is ethyl acetate. A mixed solution of PE and EA in a volume ratio of 10:1 to 30:1 is used as the elution solvent, and the compound is obtained by column chromatography separation. The acidic silica gel column chromatography elution steps in the following preparation methods are similar.

[0036] Preferably, in step (2), compound M2 reacts with an alkylating agent in a reaction solvent, the reaction solvent including one or more of tetrahydrofuran, anhydrous dichloromethane, diethyl ether, and 1,4-dioxane.

[0037] Preferably, the alkylating agent in step (2) includes one or more of alkyl lithium, alkyl magnesium chloride, and alkyl magnesium bromide.

[0038] Further preferably, the alkylating agent includes one or more of C1-C6 alkyllithium, C1-C6 alkylmagnesium chloride, and C1-C6 alkylmagnesium bromide.

[0039] Preferably, in step (2), the molar ratio of compound M2 to the alkylating agent is 1:(1-3).

[0040] Preferably, the reaction in step (2) is carried out under nitrogen protection, with the alkylating agent added dropwise to the M2 solution at a temperature of -30 to -45°C, and the reaction proceeding to room temperature for 3 to 10 hours.

[0041] Preferably, after the reaction in step (2) is completed, the reaction is quenched with water at -5 to 5°C, then acidified with 1 to 3M hydrochloric acid to pH 3 to 5, then extracted, the organic phase is collected and dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound M3.

[0042] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 20:1 to 10:1.

[0043] Preferably, in step (3), compound M3 reacts with 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol in a reaction solvent, wherein the reaction solvent includes one or more of dichloromethane, chloroform, toluene, and xylene.

[0044] Preferably, in step (3), the molar ratio of compound M3 to 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol is 1:(1-3).

[0045] Preferably, in step (3), a dehydrating agent and a catalyst are added to the reaction solution, and the mixture is stirred at 25–100°C for 0.5–5 h.

[0046] Preferably, the dehydrating agent is triphenylphosphine.

[0047] Preferably, the catalyst comprises one or more of p-toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridinium salt, trifluoromethanesulfonic acid, trifluoroacetic acid, and dodecylbenzenesulfonic acid, and more preferably p-toluenesulfonic acid.

[0048] Preferably, the molar ratio of compound M3 to the dehydrating agent is 1:(0.01~1).

[0049] Preferably, the molar ratio of compound M3 to catalyst is 1:(0.01~1).

[0050] Preferably, in step (3), after the reaction is complete, water is added, followed by extraction, and then the organic layer is dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the product is eluted by acidic silica gel column chromatography to obtain compound M4 or target product of general formula I (when R2 is H).

[0051] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 30:1 to 20:1.

[0052] Preferably, in step (4), compound M4 reacts with a basic compound and a haloalkane in a reaction solvent, wherein the reaction solvent is acetonitrile.

[0053] Preferably, the alkaline compound includes one or more of potassium carbonate, pyridine, and triethylamine.

[0054] Preferably, the haloalkane includes one of bromoalkanes, chloroalkanes, and iodoalkanes.

[0055] More preferably, the haloalkane includes one of brominated C1-C6 alkanes, chlorinated C1-C6 alkanes, and iodinated C1-C6 alkanes.

[0056] Preferably, the molar ratio of compound M4 to the basic compound is 1:(1-3).

[0057] Preferably, the molar ratio of compound M4 to haloalkane is 1:(1-3).

[0058] Preferably, in step (4), the reaction solution is heated under reflux for 2 to 20 hours.

[0059] Preferably, after the reaction in step (4) is completed, the mixture is cooled to room temperature, water is added and the mixture is extracted, the organic phases are combined, dried with anhydrous sodium sulfate, concentrated and evaporated, and purified by elution with an acidic silica gel column to obtain the target product of general formula I (when R2 is one of C1 to C6 alkyl groups).

[0060] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 30:1 to 10:1.

[0061] The third objective of this invention is achieved through the following technical solution:

[0062] A method for preparing an indenoid-fused naphthopyran photochromic compound, wherein when the structural formula of the photochromic compound is general formula II, the preparation method of the photochromic compound is as follows:

[0063]

[0064] Includes the following steps:

[0065] (1) Compound M1 was reacted with an alkylating agent to obtain compound M5;

[0066] (2) Compound M5 was reacted with an acid to obtain compound M6;

[0067] (3) Compound M6 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were reacted in the presence of a dehydrating agent and a catalyst to obtain the target product of general formula II.

[0068] Preferably, in step (1), compound M1 reacts with an alkylating agent in a reaction solvent, the reaction solvent including one or more of tetrahydrofuran, anhydrous dichloromethane, diethyl ether, and 1,4-dioxane.

[0069] Preferably, the alkylating agent in step (1) includes one or more of alkyl lithium, alkyl magnesium chloride, and alkyl magnesium bromide.

[0070] Further preferably, the alkylating agent includes one or more of C1-C6 alkyllithium, C1-C6 alkylmagnesium chloride, and C1-C6 alkylmagnesium bromide.

[0071] Preferably, in step (1), the molar ratio of compound M1 to alkylating agent is 1:(1-10).

[0072] Preferably, the reaction in step (1) is carried out under nitrogen protection, with the alkylating agent added dropwise to the M1 solution at a temperature of -30 to -45°C, and the reaction proceeding to room temperature for 3 to 10 hours.

[0073] Preferably, in step (1), after the reaction is complete, water is added at -5 to 5°C to quench the reaction, and then 1 to 3M hydrochloric acid is used to acidify to pH 3 to 5. Then, extraction is performed, the organic phase is collected and dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound M5.

[0074] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 20:1 to 10:1.

[0075] Preferably, in step (2), compound M5 reacts with an acid in a reaction solvent, which includes one or more of dichloromethane, toluene, and xylene.

[0076] Preferably, the acid in step (2) includes one or more of trifluoroacetic acid, concentrated sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and polyphosphoric acid, wherein the mass fraction of the concentrated sulfuric acid is 95-98%.

[0077] Preferably, in step (2), the molar ratio of compound M5 to acid is 1:(0.1~1).

[0078] Preferably, the reaction temperature in step (2) is 25–100°C and the reaction time is 3–12 h.

[0079] Preferably, after the reaction in step (2) is completed, extraction is performed, the organic phases are combined and concentrated, and then eluted by acidic silica gel column chromatography to obtain compound M6.

[0080] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 10:1 to 20:1.

[0081] Preferably, in step (3), compound M6 reacts with 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol in a reaction solvent, wherein the reaction solvent includes one or more of dichloromethane, chloroform, toluene, and xylene.

[0082] Preferably, in step (3), the molar ratio of compound M6 to 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol is 1:(1-3).

[0083] Preferably, in step (3), a dehydrating agent and a catalyst are added to the reaction solution, and the mixture is stirred at 25–100°C for 0.5–5 h.

[0084] Preferably, the dehydrating agent is triphenylphosphine.

[0085] Preferably, the catalyst comprises one or more of p-toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridinium salt, trifluoromethanesulfonic acid, trifluoroacetic acid, and dodecylbenzenesulfonic acid, and more preferably p-toluenesulfonic acid.

[0086] Preferably, the molar ratio of compound M6 to the dehydrating agent is 1:(0.01~1).

[0087] Preferably, the molar ratio of compound M6 to catalyst is 1:(0.01~1). Preferably, in step (3), after the reaction is complete, water is added, followed by extraction, and then the organic layer is dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the product is eluted by acidic silica gel column chromatography to obtain the target product of general formula II.

[0088] Preferably, the elution parameters for the acidic silica gel column chromatography are PE:EA = 40:1 to 20:1.

[0089] Optionally, the photochromic compound SP1 is prepared as follows:

[0090]

[0091] The preparation method of the photochromic compound SP1 includes the following steps:

[0092] (1) Compound 1-1 was reacted with acid at 25-100℃ for 3-12 h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and then eluted by acid silica gel column chromatography to obtain compound 1-2.

[0093] (2) Under nitrogen protection, CH3MgCl was added dropwise to solution 1-2 at -30 to -45℃. After the temperature was raised to room temperature, the reaction was carried out for 3 to 10 hours. After the reaction was completed, water was added at -5 to 5℃ to quench the reaction. Then, 1 to 3M hydrochloric acid was used to acidify the pH to 3 to 5. The organic phase was then collected, dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 1-3.

[0094] (3) Add dehydrating agent and catalyst to compounds 1-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25-100℃ for 0.5-5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain the target product SP1.

[0095] Optionally, the photochromic compound SP2 is prepared as follows:

[0096]

[0097] The preparation method of the photochromic compound SP2 includes the following steps:

[0098] (1) Compound 2-1 was reacted with acid at 25-100℃ for 3-12 h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and then eluted by acid silica gel column chromatography to obtain compound 2-2.

[0099] (2) Under nitrogen protection, CH3MgCl was added dropwise to 2-2 at -30 to -45℃. After the temperature was raised to room temperature, the reaction was carried out for 3 to 10 hours. After the reaction was completed, water was added at -5 to 5℃ to quench the reaction. Then, 1 to 3M hydrochloric acid was used to acidify the pH to 3 to 5. The organic phase was then extracted, dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 2-3.

[0100] (3) Add dehydrating agent and catalyst to compound 2-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25-100℃ for 0.5-5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain compound 2-4;

[0101] (4) Compounds 2-4 were reacted with CH3I under alkaline conditions and heated under reflux for 2-20 h. After the reaction was completed, the mixture was cooled to room temperature, water was added and the mixture was extracted. The organic phases were combined, dried with anhydrous sodium sulfate, concentrated and evaporated to dryness, and purified by elution with acidic silica gel column to obtain the target product SP2.

[0102] Optionally, the photochromic compound SP3 is prepared as follows:

[0103]

[0104] The preparation method of the photochromic compound SP3 includes the following steps:

[0105] (1) Under nitrogen protection, nBuLi was added dropwise to 3-1 at -30 to -45℃. After the temperature was raised to room temperature, the reaction was carried out for 3 to 10 hours. After the reaction was completed, water was added at -5 to 5℃ to quench the reaction. Then, 1 to 3M hydrochloric acid was used to acidify the pH to 3 to 5. The organic phase was then collected, dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 3-2.

[0106] (2) Compound 3-2 was reacted with acid at 25-100℃ for 3-12 h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and then eluted by acid silica gel column chromatography to obtain compound 3-3.

[0107] (3) Add dehydrating agent and catalyst to compound 3-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25-100℃ for 0.5-5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain the target product SP3.

[0108] Another objective of this invention is achieved through the following technical solution:

[0109] Application of an indene-fused naphthylpyran photochromic compound in photochromic glasses, photochromic films and anti-counterfeiting materials.

[0110] Compared with the prior art, the present invention has the following beneficial effects:

[0111] 1. The present invention provides an indenoid-fused naphthopyran photochromic compound. By exploring and improving its preparation method, triphenylphosphine is added as a dehydrating agent in the pyran ring forming step, so that the formation of pyran ring can be achieved in high yield at room temperature. This method is easy to separate and purify, has a high yield, and reduces production costs.

[0112] 2. In the preparation method of the indenoid-fused naphthopyran photochromic compound provided by the present invention, a trifluoromethyl-substituted diaryl group is introduced into the indenoid-fused naphthopyran compound, which can regulate the photochromic properties and has a fast coloring speed and fading speed.

[0113] 3. The compounds SP1, SP2, and SP3 obtained by the preparation method of the indenoid-fused naphthylpyran photochromic compound provided by the present invention can change from colorless to purple, yellow, or brown under ultraviolet irradiation. They have high chromaticity and the color can be controlled by changing the substituents on the compound skeleton. When ultraviolet irradiation is stopped, the compound can reversibly fade from the chromogenic form back to the colorless form. These compounds have rapid color change and decolorization rates and excellent fatigue resistance, and have broad application prospects. Attached Figure Description

[0114] Figure 1The results of color-changing performance tests are for solutions of photochromic compounds SP1, SP2 and SP3 prepared in Examples 2, 4 and 5 of this invention.

[0115] Figure 2 The A-λ achromatic curve of the photochromic compound SP2 solution prepared in Example 4 of this invention was measured by a UV-Vis absorption spectrometer.

[0116] Figure 3 The image shows the change in maximum absorbance in the visible light region of the solution of the photochromic compound SP2 prepared in Example 4 of this invention over time, represented by the at-decolorization curve.

[0117] Figure 4 This is a test image of the low-temperature color-changing effect of the photochromic compound SP2 prepared in Example 4 of the present invention. Detailed Implementation

[0118] The technical solution of the present invention will be further described below with reference to specific embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the accompanying drawings used herein are merely for better illustrating the content disclosed in the present invention and do not limit the scope of protection. It should also be understood that after reading the teachings of this invention, those skilled in the art can make various modifications or alterations to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0119] The pharmaceuticals and reagents used in the preparation methods of the following embodiments are all conventional materials in the art and can be obtained commercially.

[0120] Example 1

[0121] The preparation method of the photochromic compound in this embodiment is as follows:

[0122]

[0123] The preparation method of the above-mentioned photochromic compound includes the following steps:

[0124] (1) Dissolve 0.1 mol of compound 1-1 in 200 mL of dichloromethane, add 0.01 mol of trifluoroacetic acid, react at 50 °C for 5 h, add 300 mL of distilled water after the reaction is complete, extract with ethyl acetate, combine the organic phases and concentrate, then elute by acid silica gel column chromatography with PE:EA = 30:1 to obtain compound 1-2 (yield 90%).

[0125] (2) Under nitrogen protection, 0.09 mol of compound 1-2 was dissolved in 30 mL of tetrahydrofuran (dried in anhydrous Na2SO4). 58.5 mL of tetrahydrofuran solution of CH3MgCl (concentration 2 mol / L) was added dropwise at -30℃. The solution color changed from bright red to dark red. The reaction was carried out at low temperature for 1.5 h, then slowly raised to room temperature and continued for 3 h. 200 mL of distilled water was added at 0℃ to quench the reaction. The solution was then acidified with 1 M hydrochloric acid to pH 4. The solution was extracted three times with 20 mL of dichloromethane. The organic phase was collected and concentrated. The solution was eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain compound 1-3 (yield 70%).

[0126] (3) 0.063 mol of compound 1-3 and 0.069 mol of 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were dissolved in 250 mL of dichloromethane solvent. 0.003 mol of p-toluenesulfonic acid monohydrate and 0.003 mol of triphenylphosphine were added. The mixture was stirred at room temperature for 0.5 h. After the reaction was completed, 200 mL of distilled water was added. The mixture was extracted three times with 150 mL of ethyl acetate. The organic layer was dried with anhydrous sodium sulfate. The organic phase was collected and evaporated to dryness. The mixture was eluted by acid silica gel column chromatography with a PE:EA ratio of 30:1 to obtain the photochromic compound SP1 (yield 98%, HPLC purity 98.5%).

[0127] Example 2

[0128] The only difference between Example 2 and Example 1 is that the reaction process in step (3) of Example 2 is different.

[0129] The method for preparing the photochromic compound in this embodiment includes the following steps:

[0130] Steps (1) and (2) are the same as in Example 1;

[0131] (3) 0.1 mol of compound 1-3 and 0.11 mol of 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were dissolved in 100 mL of toluene solvent. 0.005 mol of p-toluenesulfonic acid monohydrate and 0.005 mol of triphenylphosphine were added. The reaction was stopped after stirring at 100 °C for 0.5 h. After cooling, 300 mL of distilled water was added. The mixture was extracted three times with 500 mL of ethyl acetate. The organic layer was then dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the mixture was eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain the photochromic compound SP1 (yield 98%, HPLC purity 98.5%).

[0132] The NMR data for the photochromic compound SP1 are as follows:

[0133] 1H NMR (500MHz, CDCl3) δ=8.38(t,J=7.6Hz,1H),8.15(d,J=9.8Hz,1H),7.92(t,J=6.9Hz,1H),7.55(s,1H),7.51–7.36(m,6H),7.27(d,J=7. 3Hz, 1H), 6.88 (t, J = 9.5Hz, 2H), 6.79 (t, J = 8.7Hz, 2H), 6.42 (s, 1H), 3.79 (d, J = 8.9Hz, 3H), 3.72 (d, J = 8.9Hz, 3H), 1.94 (d, J = 1.9Hz, 3H).

[0134] 19 F NMR (471MHz, CDCl3) δ = -76.33ppm, -76.97ppm.

[0135] Example 3

[0136] The preparation method of the photochromic compound in this embodiment is as follows:

[0137]

[0138] The preparation method of the above-mentioned photochromic compound includes the following steps:

[0139] (1) Dissolve 0.05 mol of compound 2-1 in 200 mL of toluene, add 0.005 mol of trifluoroacetic acid, react at 50 °C for 5 h, concentrate the reaction solution under reduced pressure after the reaction is complete, then adjust the pH to 10.5 with saturated sodium bicarbonate solution, extract with ethyl acetate, combine the organic phases and concentrate, then elute with acid silica gel column chromatography PE:EA = 30:1 to obtain compound 2-2 (yield 90%).

[0140] (2) Under nitrogen protection, 0.045 mol of compound 2-2 was dissolved in 150 mL of tetrahydrofuran (dried in anhydrous Na2SO4). 29.3 mL of tetrahydrofuran solution of CH3MgCl (concentration 2 mol / L) was added dropwise at -30 °C. The solution color changed from bright red to dark red. The reaction was carried out at low temperature for 1.5 h, then slowly raised to room temperature and continued for 3 h. After that, 150 mL of distilled water was added at 0 °C to quench the reaction. The solution was then acidified with 1 M hydrochloric acid to pH 4. The solution was extracted three times with 150 mL of dichloromethane. The organic phase was collected and concentrated. The solution was eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain compound 2-3 (yield 74%).

[0141] (3) 0.034 mol of compound 2-3 and 0.035 mol of 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were dissolved in 250 mL of dichloromethane solvent, and 0.0015 mol of p-toluenesulfonic acid monohydrate and 0.0015 mol of triphenylphosphine were added. The mixture was stirred at room temperature for 2 h. After the reaction was completed, the solvent was concentrated under reduced pressure, and 300 mL of distilled water was added. The mixture was extracted three times with 300 mL of ethyl acetate. The organic layer was then dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the mixture was eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain compound 2-4 (yield 95%).

[0142] (4) 0.032 mol of compound 2-4 and 0.065 mol of K2CO3 were added to 200 mL of acetonitrile, heated and stirred under reflux for 2 h, cooled to room temperature, and then 0.045 mol of CH3I was added. The mixture was stirred and refluxed for 12 h. After dissolving the inorganic salt in water, the mixture was extracted with dichloromethane. The organic fraction was eluted by silica gel column chromatography with a PE:EA ratio of 30:1 to obtain the photochromic compound SP2 (yield 85.0%, HPLC purity 98.5%).

[0143] Example 4

[0144] The only difference between Example 4 and Example 3 is that the reaction process in step (3) of Example 4 is different.

[0145] The method for preparing the photochromic compound in this embodiment includes the following steps:

[0146] Steps (1) and (2) are the same as in Example 3;

[0147] (3) 0.1 mol of compound 2-3 and 0.13 mol of 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were dissolved in 100 mL of toluene solvent. 0.01 mol of p-toluenesulfonic acid monohydrate and 0.008 mol of triphenylphosphine were added. The reaction was stopped after stirring at 100 °C for 0.5 h. After cooling, 300 mL of distilled water was added. The mixture was extracted three times with 500 mL of ethyl acetate. The organic layer was dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the mixture was eluted by acid silica gel column chromatography with a PE:EA ratio of 30:1 to obtain compound 2-4 (yield 98%).

[0148] Step (4) is the same as in Example 3, yielding the photochromic compound SP2 (yield 85.0%, HPLC purity 98.5%).

[0149] The NMR data of formula SP2 are as follows:

[0150] 1H NMR(500MHz, CDCl3)δ=8.35(t,J=7.6Hz,1H),8.05(d,J=9.8Hz,1H),7.94(t,J=6.9Hz,1H),7.73(s,1H),7.51–7.36(m,6H),7.27(d,J=7.3Hz,1H) ,6.88(t,J=9.5Hz,2H),6.79(t,J=8.7Hz,2H),6.17(dd,J=29.6,9.9Hz,1H),2.54(d,J=3.8Hz,3H),2.43(d,J=13.1Hz,3H),1.93(d,J=1.9Hz,3H).

[0151] 19 F NMR (471MHz, CDCl3) δ = -76.10ppm, -76.50ppm.

[0152] Example 5

[0153] The preparation method of the photochromic compound in this embodiment is as follows:

[0154]

[0155] The preparation method of the above-mentioned photochromic compound includes the following steps:

[0156] (1) Under nitrogen protection, 0.05 mol of compound 3-1 was dissolved in 200 mL of tetrahydrofuran (dried in anhydrous Na2SO4). 71 mL of nBuLi solution (concentration 2.82 mol / L) was slowly added at -45 °C. The temperature was gradually raised to room temperature, and the reaction was continued for 3 h. The reaction was quenched with water at 0 °C, acidified with 200 mL of 1 M hydrochloric acid, and extracted three times with 150 mL of ethyl acetate. The organic phase was collected and evaporated to dryness. The mixture was then eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain compound 3-2 (yield 78%).

[0157] (2) Dissolve 0.039 mol of compound 3-2 in 200 mL of dichloromethane, add 0.0039 mol of trifluoroacetic acid, stir at room temperature for 12 h, add 300 mL of distilled water after the reaction is complete, extract with ethyl acetate, combine the organic phases, concentrate and recrystallize by acid silica gel column chromatography with PE:EA = 10:1 to obtain compound 3-3 (yield 85%).

[0158] (3) 0.033 mol of compound 3-3 and 0.040 mol of 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol were dissolved in 220 mL of dichloromethane solvent. 0.00165 mol of p-toluenesulfonic acid monohydrate and 0.00165 mol of triphenylphosphine were added. The mixture was stirred at room temperature for 5 h. 100 mL of distilled water was added. The mixture was extracted three times with 200 mL of ethyl acetate. The organic layer was dried with anhydrous sodium sulfate. After rotary evaporation of the solvent, the mixture was eluted by acid silica gel column chromatography with a PE:EA ratio of 20:1 to obtain the photochromic compound SP3 (yield 95%, HPLC purity 98.5%).

[0159] The NMR data of SP3 are as follows:

[0160] 1 H NMR (400MHz, CDCl3) δ8.03(d,J=7.6Hz,1H),7.92(s,1H),7.73(s,1H),7.55(t,J=1.7Hz,1H),7.54(s,1H),7.46 (d,J=2.2Hz,1H),7.44(d,J=2.1Hz,1H),7.38(d,J=5.7Hz,2H),7.35(dd,J=3.7,2.4Hz,1H),7.34–7.30(m,3H), 7.29–7.27(m,1H),7.26(dd,J=3.5,1.6Hz,1H),7.24(d,J=3.6Hz,1H),2.34(s,3H),2.35(s,3H),2.27(d,J=5.1 Hz,2H),2.15–2.05(m,2H),1.09–0.96(m,4H),0.61(t,J=5.8Hz,4H),0.57(t,J=5.8Hz,3H),0.44–0.29(m,4H).

[0161] 19 F NMR (471MHz, CDCl3) δ = -77.10ppm, -77.30ppm.

[0162] The photochromic compounds SP1, SP2, and SP3 obtained in Examples 2, 4, and 5 were dissolved in acetonitrile to prepare a 50 μg / mL photochromic material acetonitrile solution, and the color-changing performance was tested.

[0163] The color-changing performance test used a 365nm ultraviolet lamp as the excitation light source, irradiated at a distance of 6cm from the photochromic material solution for 10s. The test results are shown below. Figure 1 .

[0164] Figure 1The results of color-changing performance tests are for solutions of photochromic compounds SP1, SP2 and SP3 prepared in Examples 2, 4 and 5 of this invention.

[0165] like Figure 1 As shown, solutions of compounds SP1, SP2, and SP3 were colorless before light irradiation, but rapidly changed color after irradiation. Specifically, solution SP1 changed from colorless to yellow, solution SP2 changed from colorless to purple, and solution SP3 changed from colorless to brown. The color-changing phenomenon indicates that the photochromic compounds prepared in this invention exhibit rapid color change, high chromaticity, rich colors, and can be controlled through the electronic effects of substituents and their substitution positions.

[0166] The decolorization rate of the acetonitrile solution of the photochromic compound SP2 prepared above was tested, and the test results are shown in […]. Figures 2-3 .

[0167] Figure 2 The A-λ achromatic curve of the photochromic compound SP2 solution prepared in Example 4 of this invention was measured by a UV-Vis absorption spectrometer.

[0168] Figure 3 The image shows the change in maximum absorbance in the visible light region of the solution of the photochromic compound SP2 prepared in Example 4 of this invention over time, represented by the at-decolorization curve.

[0169] like Figures 2-3 As shown in the decolorization curve, the photochromic compound SP2 prepared in this invention can rapidly decolorize from its colored state, which has strong practical value.

[0170] The acetonitrile solution of the photochromic compound SP2 prepared above was tested for its color-changing effect at low temperature. The test results are shown in […]. Figure 4 .

[0171] Figure 4 This is a test image of the low-temperature color-changing effect of the photochromic compound SP2 prepared in Example 4 of the present invention.

[0172] like Figure 4 As shown, the acetonitrile solution of the photochromic compound SP2 prepared by this invention still exhibits relatively fast color change and fading rates at low temperatures. This color change phenomenon indicates that it still has a good response rate at low temperatures. Therefore, it can be seen that the introduction of fluorine atoms has a significant impact on the fading performance of the material. Thus, the photochromic compound of this invention is expected to be used in low-temperature color-changing materials.

[0173] In summary, the indene-fused naphthopyran photochromic compound provided by this invention can achieve high yield at room temperature. Furthermore, the compounds SP1, SP2, and SP3 obtained using the preparation method of the indene-fused naphthopyran photochromic compound provided by this invention exhibit rapid color change and decolorization rates, high chromaticity, and their color can be controlled by changing the substituents on the compound skeleton. They also demonstrate excellent fatigue resistance and have broad application prospects.

[0174] All aspects, embodiments, and features of this invention should be considered illustrative in all respects and not limiting of the invention; the scope of the invention is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0175] In the preparation method of this invention, the order of the steps is not limited to the listed order. For those skilled in the art, variations in the order of the steps without creative effort are also within the scope of protection of this invention. Furthermore, two or more steps or actions can be performed simultaneously.

[0176] Finally, it should be noted that the specific embodiments described herein are merely illustrative examples of the invention and are not intended to limit the implementation of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them; it is neither necessary nor possible to exemplify all embodiments here. However, these obvious variations or modifications derived from the essential spirit of the invention still fall within the scope of protection of the invention, and interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. An indene-fused naphthylpyran photochromic compound, characterized in that, The structural formula of the photochromic compound is shown in formula SP1, formula SP2 or formula SP3: 。 2. A method for preparing an indenoid-fused naphthylpyran photochromic compound as described in claim 1, characterized in that, The photochromic compound has the structural formula SP1, and its preparation method includes: ， (1) Compound 1-1 was reacted with acid at 25~100℃ for 3~12h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and then eluted by acid silica gel column chromatography to obtain compound 1-2. (2) Under nitrogen protection, CH3MgCl was added dropwise to the solution of compound 1-2 at -30~-45℃. After the temperature was raised to room temperature, the reaction was carried out for 3~10h. After the reaction was completed, water was added at -5~5℃ to quench the reaction. Then, 1~3mol / L hydrochloric acid was used to acidify the pH to 3~5. Then, extraction was performed, the organic phase was collected and dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 1-3. (3) Add a dehydrating agent and a catalyst to compounds 1-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25~100℃ for 0.5~5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain the target product SP1; the dehydrating agent is triphenylphosphine; The catalyst is one or more of p-toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridine salt, trifluoromethanesulfonic acid, trifluoroacetic acid, and dodecylbenzenesulfonic acid.

3. A method for preparing an indenoid-fused naphthylpyran photochromic compound as described in claim 1, characterized in that, The photochromic compound has the structural formula SP2, and its preparation method includes: ， (1) Compound 2-1 was reacted with acid at 25~100℃ for 3~12h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and eluted by acid silica gel column chromatography to obtain compound 2-2. (2) Under nitrogen protection, CH3MgCl was added dropwise to compound 2-2 at -30~-45℃. After the temperature was raised to room temperature, the reaction was carried out for 3~10h. After the reaction was completed, water was added at -5~5℃ to quench the reaction. Then, 1~3M hydrochloric acid was used to acidify the pH to 3~5. Then, extraction was performed, the organic phase was collected and dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 2-3. (3) Add a dehydrating agent and a catalyst to compounds 2-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25~100℃ for 0.5~5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain compounds 2-4; the dehydrating agent is triphenylphosphine; (4) React compounds 2-4 with basic compounds and CH3I, heat under reflux for 2-20 h, cool to room temperature after the reaction is complete, add water and extract, combine the organic phases, dry with anhydrous sodium sulfate, concentrate and evaporate to dryness, elute and purify with acidic silica gel column to obtain the target product SP2. The catalyst is one or more of p-toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridine salt, trifluoromethanesulfonic acid, trifluoroacetic acid, and dodecylbenzenesulfonic acid.

4. A method for preparing an indenoid-fused naphthylpyran photochromic compound as described in claim 1, characterized in that, The photochromic compound has the structural formula SP3, and its preparation method includes: ， The preparation method of the photochromic compound SP3 includes the following steps: (1) Under nitrogen protection, n-butyllithium was added dropwise to compound 3-1 at -30~-45℃. After the temperature was raised to room temperature, the reaction was carried out for 3~10h. After the reaction was completed, water was added at -5~5℃ to quench the reaction. Then, 1~3M hydrochloric acid was used to acidify the pH to 3~5. Then, extraction was performed, the organic phase was collected and dried by rotary evaporation, and purified by acid silica gel column chromatography to obtain compound 3-2. (2) Compound 3-2 was reacted with acid at 25~100℃ for 3~12h. After the reaction was completed, the mixture was extracted, and the organic phases were combined, concentrated, and eluted by acid silica gel column chromatography to obtain compound 3-3. (3) Add a dehydrating agent and a catalyst to compound 3-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol, stir at 25~100℃ for 0.5~5h, add water after the reaction is complete, extract again, dry the organic layer with anhydrous sodium sulfate, evaporate the solvent by rotary evaporation and elute by acidic silica gel column chromatography to obtain the target product SP3; the dehydrating agent is triphenylphosphine; The catalyst is one or more of p-toluenesulfonic acid, methanesulfonic acid, p-toluenesulfonic acid pyridine salt, trifluoromethanesulfonic acid, trifluoroacetic acid, and dodecylbenzenesulfonic acid.

5. The preparation method according to any one of claims 2-4, characterized in that, The acid is one or more selected from trifluoroacetic acid, concentrated sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, and polyphosphoric acid, wherein the mass fraction of the concentrated sulfuric acid is 95-98%. The catalyst is p-toluenesulfonic acid.

6. The preparation method according to claim 2, characterized in that, Compound 1-1 reacts with an acid in a reaction solvent, wherein the reaction solvent is one or more of dichloromethane, toluene, and xylene; The molar ratio of compound 1-1 to acid is 1:(0.1~1). Compounds 1-2 react with CH3MgCl in a reaction solvent, which is one or more of tetrahydrofuran, anhydrous dichloromethane, diethyl ether, and 1,4-dioxane. The molar ratio of compounds 1-2 to CH3MgCl is 1:(1~3); Compounds 1-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol react in a reaction solvent, wherein the reaction solvent is one or more of dichloromethane, chloroform, toluene, and xylene; The molar ratio of compounds 1-3 to 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol is 1:(1~3). The molar ratio of compounds 1-3 to the dehydrating agent is 1:(0.01~1). The molar ratio of compounds 1-3 to the catalyst is 1:(0.01~1).

7. The preparation method according to claim 3, characterized in that, Compound 2-1 reacts with an acid in a reaction solvent, wherein the reaction solvent is one or more of dichloromethane, toluene, and xylene; The molar ratio of compound 2-1 to acid is 1:(0.1~1); Compound 2-2 reacts with CH3MgCl in a reaction solvent, which is one or more of tetrahydrofuran, anhydrous dichloromethane, diethyl ether, and 1,4-dioxane. The molar ratio of compound 2-2 to CH3MgCl is 1:(1~3); Compounds 2-3 and 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol react in a reaction solvent, wherein the reaction solvent is one or more of dichloromethane, chloroform, toluene, and xylene; The molar ratio of compounds 2-3 to 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol is 1:(1~3); The molar ratio of compound 2-3 to the dehydrating agent is 1:(0.01~1); The molar ratio of compound 2-3 to catalyst is 1:(0.01~1); The basic compound is one or more of potassium carbonate, pyridine, and triethylamine; The molar ratio of compounds 2-4 to the basic compounds is 1:(1~3). The molar ratio of compound 2-4 to CH3I is 1:(1~3).

8. The preparation method according to claim 4, characterized in that, Compound 3-1 reacts with n-butyllithium in a reaction solvent, which is one or more of tetrahydrofuran, anhydrous dichloromethane, diethyl ether, and 1,4-dioxane. The molar ratio of compound 3-1 to n-butyllithium is 1:(1~10). Compound 3-2 reacts with an acid in a reaction solvent, which is one or more of dichloromethane, toluene, and xylene. The molar ratio of compound 3-2 to acid is 1:(0.1~1); Compound 3-3 reacts with 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol in a reaction solvent, wherein the reaction solvent is one or more of dichloromethane, chloroform, toluene, and xylene; The molar ratio of compound 3-3 to 1,1'-bis(4-trifluoromethylphenyl)prop-2-yn-1-ol is 1:(1~3); The molar ratio of compound 3-3 to the dehydrating agent is 1:(0.01~1); The molar ratio of compound 3-3 to the catalyst is 1:(0.01~1).

9. The application of an indene-fused naphthylpyran photochromic compound as described in claim 1 in the fields of photochromic glasses, photochromic films, and anti-counterfeiting materials.

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