Photochromic compound as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photochromic materials, and provides a photochromic compound as well as a preparation method and application thereof. The structural formula of the photochromic compound is # imgabs0, wherein R1, R2, R7 and R8 are independently hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl; r3 and R4 are independently hydrogen, halogen, hydroxyl, alkyl, heterocyclic alkyl, alkoxy, aryl or heteroaryl; r is hydrogen, alkyl, cycloalkyl or aryl; x is N-R9, O or S; and R9 is hydrogen, alkyl, aryl or heteroaryl. The photochromic compound disclosed by the invention can realize a color changing effect under an illumination condition, and can be in a colorless and transparent state when returning to a room or a dark place; by introducing a benzoheterocycle electron withdrawing structure into a parent structure and prolonging a conjugated structure, a charge transfer effect can be generated in the photochromic compound even in a near-infrared region, a color changing effect is realized, and meanwhile, heat exchange can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photochromic materials, and in particular to a photochromic compound and a preparation method and application thereof. Background Art

[0002] With the improvement of building energy-saving standards and the increasing demand for a more comfortable living and working environment, the infrared absorption function has gradually expanded to many fields such as architectural glass, automotive glass, and electronic equipment protective glass. Glass itself is a transparent material. Traditional glass has limited ability to absorb infrared rays, especially near-infrared rays. During the glass production process, specific absorption materials are usually added to enhance the glass's ability to absorb infrared rays. The absorption material is evenly dispersed in the glass matrix, so that the glass can effectively absorb infrared rays within a specific wavelength range, thereby achieving the purpose of heat insulation or reducing infrared penetration. Commonly used absorption materials include metal oxides (such as iron oxides, cobalt oxides, etc.) and rare earth element compounds.

[0003] Photochromic materials can automatically adjust the transparency of glass according to changes in ambient light. Under strong light or strong ultraviolet rays, the photochromic material will change its structure, making the glass darker and reducing the transmittance of visible light and infrared rays; when the light weakens, the photochromic material returns to its initial structure, making the glass transparent again. The function of photochromic materials to adaptively adjust according to light intensity can effectively reduce the problem of indoor light glare and improve visual comfort.

[0004] Therefore, developing photochromic materials with a wide absorption range and applying them to glass or interlayers to improve people's comfort has broad application prospects. Summary of the invention

[0005] The purpose of the present invention is to provide a photochromic compound and a preparation method and application thereof in view of the deficiencies in the prior art.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a photochromic compound, the structural formula of the photochromic compound is:

[0008]

[0009] wherein R1, R2, R7, and R8 are independently hydrogen, halogen, hydroxy, alkyl, alkoxy, amino, aryl, or heteroaryl;

[0010] R3 and R4 are independently hydrogen, halogen, hydroxy, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl;

[0011] R is hydrogen, alkyl, cycloalkyl or aryl;

[0012] X is N-R9, O or S;

[0013] R9 is hydrogen, alkyl, aryl or heteroaryl.

[0014] Preferably, the photochromic compound is any one of the following structural formulas:

[0015]

[0016]

[0017] The present invention also provides a method for preparing the photochromic compound, comprising the following steps:

[0018] (1) subjecting compound A, [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride, bipyraclostrobin, potassium acetate, toluene and water to a Miyaura borylation reaction to obtain an intermediate product;

[0019] (2) subjecting the intermediate product, compound B, tetrakis(triphenylphosphine)palladium, potassium carbonate solution and tetrahydrofuran to a Suzuki coupling reaction to obtain compound C;

[0020] (3) Compound C, a Grignard reagent and tetrahydrofuran are mixed and reacted to obtain compound D;

[0021] (4) subjecting compound D, pyridinium p-toluenesulfonate and chloroform to a cyclization reaction to obtain compound E;

[0022] (5) cross-coupling compound E, compound F, tris(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water to obtain compound G;

[0023] (6) subjecting compound G, boron tribromide and chloroform to a demethylation reaction to obtain compound H;

[0024] (7) Compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane are mixed and reacted to obtain a photochromic compound.

[0025] Preferably, the structural formula of the compound A in step (1) is Wherein, R3 and R4 are independently hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl;

[0026] The molar ratio of compound A, [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium and diboronic acid pinacol ester in step (1) is 48-52:1:58-63, and the molar mass ratio of compound A, potassium acetate, toluene and water is 48-52mmol:1-2g:120-180g:10-15g; the temperature of the Miyaura boronation reaction is 70-90°C, and the time of the Miyaura boronation reaction is 20-28h.

[0027] Preferably, the structural formula of the compound B in step (2) is Wherein, X is N-R9, O or S, and R9 is hydrogen, alkyl, aryl or heteroaryl;

[0028] The molar ratio of the compound B in step (2), tetrakis(triphenylphosphine)palladium and the compound A in step (1) is 75-80:2:48-52, the mass molar ratio of the potassium carbonate solution, tetrahydrofuran and the compound A in step (1) is 48-52g:200-300g:48-52mmol, and the concentration of the potassium carbonate solution is 1.5-2.5mol / L; the temperature of the Suzuki coupling reaction is 50-70°C, and the time of the Suzuki coupling reaction is 12-24h.

[0029] Preferably, the structural formula of the Grignard reagent in step (3) is R-Mg-Br, wherein R is hydrogen, alkyl, cycloalkyl or aryl;

[0030] In step (3), the molar volume ratio of compound C, Grignard reagent and tetrahydrofuran is 32-38 mmol:72-78 mmol:250 mL; the reaction temperature is 20-30° C., and the reaction time is 14-24 h;

[0031] The molar ratio of the pyridinium p-toluenesulfonate in step (4) to the compound C in step (3) is 12-16:32-38, and the molar volume ratio of the pyridinium p-toluenesulfonate to chloroform is 12-16 mmol:100 mL; the temperature of the cyclization reaction is 20-30° C., and the time of the cyclization reaction is 1-3 h.

[0032] Preferably, the structural formula of the compound F in step (5) is wherein R7 and R8 are independently hydrogen, halogen, hydroxy, alkyl, alkoxy, amino, aryl or heteroaryl;

[0033] In step (5), the molar mass ratio of compound E, compound F, tri(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water is 15-20 mmol: 25-30 mmol: 0.5-1.5 mmol: 34-38 mmol: 250 g: 20-30 g; the temperature of the cross-coupling reaction is 90-110° C., and the time of the cross-coupling reaction is 16-24 h.

[0034] Preferably, in step (6), the molar volume ratio of compound G, boron tribromide and chloroform is 10-15 mmol:15-20 mmol:10-25 mL; the temperature of the demethylation reaction is 20-30° C., and the time of the demethylation reaction is 16-24 h.

[0035] Preferably, the structural formula of the compound J in step (7) is Wherein, R1 and R2 are independently hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl;

[0036] In step (7), the molar volume ratio of compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane is 2-5 mmol: 3-6 mmol: 1-4 mmol: 100 mL; the reaction temperature is 35-45° C., and the reaction time is 4-10 h.

[0037] The invention also provides application of the photochromic compound in photochromic products.

[0038] The beneficial effects of the present invention include the following:

[0039] 1) The photochromic compound of the present invention can achieve a color-changing effect under light conditions, and can return to a colorless and transparent state when returned to the room or in a dark place.

[0040] 2) The present invention introduces the electron-withdrawing structure of the benzoheterocycle into the parent structure and extends the conjugated structure, so that the charge transfer effect can occur inside the photochromic compound even in the near-infrared region, thereby achieving a color-changing effect and effectively reducing heat exchange. DETAILED DESCRIPTION

[0041] The present invention provides a photochromic compound, the structural formula of the photochromic compound is:

[0042]

[0043] wherein R1, R2, R7, and R8 are independently hydrogen, halogen, hydroxy, alkyl, alkoxy, amino, aryl, or heteroaryl;

[0044] R3 and R4 are independently hydrogen, halogen, hydroxy, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl;

[0045] R is hydrogen, alkyl, cycloalkyl or aryl;

[0046] X is N-R9, O or S;

[0047] R9 is hydrogen, alkyl, aryl or heteroaryl.

[0048] In the present invention, the photochromic compound is preferably any one of the following structural formulas:

[0049]

[0050] The present invention also provides a method for preparing the photochromic compound, comprising the following steps:

[0051] (1) subjecting compound A, [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride, bipyraclostrobin, potassium acetate, toluene and water to a Miyaura borylation reaction to obtain an intermediate product;

[0052] (2) subjecting the intermediate product, compound B, tetrakis(triphenylphosphine)palladium, potassium carbonate solution and tetrahydrofuran to a Suzuki coupling reaction to obtain compound C;

[0053] (3) Compound C, a Grignard reagent and tetrahydrofuran are mixed and reacted to obtain compound D;

[0054] (4) subjecting compound D, pyridinium p-toluenesulfonate and chloroform to a cyclization reaction to obtain compound E;

[0055] (5) cross-coupling compound E, compound F, tris(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water to obtain compound G;

[0056] (6) subjecting compound G, boron tribromide and chloroform to a demethylation reaction to obtain compound H;

[0057] (7) Compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane are mixed and reacted to obtain a photochromic compound.

[0058] In the present invention, the synthesis route of the photochromic compound is preferably:

[0059]

[0060] In the present invention, the structural formula of compound A in step (1) is Wherein, R3 and R4 are independently preferably hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl;

[0061] The molar ratio of compound A, [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride and diboric acid pinacol ester in step (1) is preferably 48-52:1:58-63, more preferably 49-51:1:59-62, and more preferably 50.8:1:61; the molar mass ratio of compound A, potassium acetate, toluene and water is preferably 48-52 mmol:1-2 g:120-180 g:10-15 g, more preferably 49 ~51mmol:1.25~1.75g:135~165g:11~14g, more preferably 50.8mmol:1.5g:150g:12~13.5g; the temperature of the Miyaura borylation reaction is preferably 70~90℃, more preferably 75~85℃, more preferably 80℃; the time of the Miyaura borylation reaction is preferably 20~28h, more preferably 22~26h, more preferably 24h.

[0062] In the present invention, the Miyaura boronation reaction in step (1) is preferably carried out in nitrogen, and stirring is preferably performed during the Miyaura boronation reaction; the stirring speed is preferably 150 to 250 rpm, and more preferably 200 rpm.

[0063] In the present invention, after the Miyaura borylation reaction in step (1) is completed, it is preferably cooled to room temperature first and then subjected to rotary evaporation concentration; the vacuum degree of the rotary evaporation concentration is preferably -0.05 to -0.01 MPa, more preferably -0.03 to -0.02 MPa; the temperature of the rotary evaporation concentration is preferably 45 to 55°C, more preferably 50°C; the time of the rotary evaporation concentration is preferably 20 to 40 min, more preferably 30 min.

[0064] In the present invention, the structural formula of the intermediate product in step (1) is: Among them, R3 and R4 are preferably independently hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl.

[0065] In the present invention, the structural formula of compound B in step (2) is Wherein, X is preferably N-R9, O or S, and R9 is hydrogen, alkyl, aryl or heteroaryl;

[0066] The molar ratio of the compound B in step (2), tetrakis(triphenylphosphine)palladium and the compound A in step (1) is preferably 75-80:2:48-52, more preferably 76.2-79:2:49-51, and more preferably 77-78:2:50.8; the mass molar ratio of the potassium carbonate solution, tetrahydrofuran and the compound A in step (1) is preferably 48-52g:200-300g:48-52mmol, more preferably 49-51g:220-280g:49- 51mmol, more preferably 50g:250g:50.8mmol; the concentration of the potassium carbonate solution is preferably 1.5-2.5mol / L, more preferably 1.75-2.25mol / L, more preferably 2mol / L; the temperature of the Suzuki coupling reaction is preferably 50-70°C, more preferably 55-65°C, more preferably 60°C; the time of the Suzuki coupling reaction is preferably 12-24h, more preferably 16-20h, more preferably 18h.

[0067] In the present invention, the Suzuki coupling reaction in step (2) is preferably carried out in nitrogen, and stirring is preferably performed during the Suzuki coupling reaction; the stirring speed is preferably 150 to 250 rpm, and more preferably 200 rpm.

[0068] In the present invention, after the Suzuki coupling reaction in step (2) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into hydrochloric acid first, and then diluted, washed, dried, concentrated by rotary evaporation and subjected to silica gel column chromatography in sequence; the volume molar ratio of the hydrochloric acid to the compound A in step (1) is preferably 180-220 mL:48-52 mmol, more preferably 190-210 mL:49-51 mmol, more preferably 200 mL:50.8 mmol, and the concentration of the hydrochloric acid is preferably 1.5-2.5 mol / L, more preferably 2 mol / L; the dilution is preferably carried out using ether, and the volume molar ratio of ether to compound A is preferably 480-520 mL:48-52 mmol, more preferably 490-210 mL:49-51 mmol, more preferably 200 mL:50.8 mmol. 510mL: 49~51mmol, more preferably 500mL: 50.8mmol; the washing is preferably carried out on the organic layer obtained after dilution, and the reagents used for washing are preferably water and sodium chloride solution in sequence, and the mass concentration of the sodium chloride solution is preferably 10~27%, and more preferably 26.5%; the drying is preferably carried out using anhydrous sodium sulfate; the vacuum degree of the rotary evaporation concentration is preferably -0.05~-0.01MPa, and more preferably -0.03~-0.02MPa, and the temperature of the rotary evaporation concentration is preferably 30~60℃, and more preferably 40℃; the reagents used for silica gel column chromatography are preferably n-hexane and dichloromethane, and the volume ratio of n-hexane to dichloromethane is preferably 6~9:3, and more preferably 7~8:3.

[0069] In the present invention, the structural formula of the compound C in step (2) is: Among them, R3 and R4 are independently preferably hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; X is preferably N-R9, O or S, and R9 is preferably hydrogen, alkyl, aryl or heteroaryl.

[0070] In the present invention, the structural formula of the Grignard reagent in step (3) is R-Mg-Br, wherein R is preferably hydrogen, alkyl, cycloalkyl or aryl;

[0071] The molar volume ratio of compound C, Grignard reagent and tetrahydrofuran in step (3) is preferably 32-38 mmol: 72-78 mmol: 250 mL, more preferably 33-37 mmol: 73-77 mmol: 250 mL, more preferably 34.9-36 mmol: 75 mmol: 250 mL; the reaction temperature is preferably 20-30° C., more preferably 22-28° C., more preferably 25° C.; the reaction time is preferably 14-24 h, more preferably 16-20 h, more preferably 19 h;

[0072] The molar ratio of the pyridinium p-toluenesulfonate in step (4) to the compound C in step (3) is preferably 12-16:32-38, more preferably 13-15:33-37, and more preferably 14:34.9-36; the molar volume ratio of the pyridinium p-toluenesulfonate to chloroform is preferably 12-16 mmol:100 mL, more preferably 13-15 mmol:100 mL, and more preferably 14 mmol:100 mL; the temperature of the cyclization reaction is preferably 20-30°C, more preferably 22-28°C, and more preferably 25°C; the time of the cyclization reaction is preferably 1-3 h, more preferably 1.5-2.5 h, and more preferably 2 h.

[0073] In the present invention, the reaction in step (3) is preferably carried out in nitrogen, and stirring is preferably performed during the reaction; the stirring speed is preferably 150 to 250 rpm, and more preferably 200 rpm.

[0074] In the present invention, in step (3), compound C and tetrahydrofuran are preferably first mixed, and then a solution of a Grignard reagent is added dropwise; the time for the addition is preferably 20 to 40 minutes, and more preferably 30 minutes; the solvent used for the solution of the Grignard reagent is preferably ether, and the concentration of the Grignard reagent in the solution of the Grignard reagent is preferably 0.8 to 1.2 mol / L, and more preferably 1 mol / L.

[0075] In the present invention, after the reaction in step (3) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into hydrochloric acid first, and then diluted, washed, dried, concentrated by rotary evaporation and chromatographed on a silica gel column in sequence; the volume molar ratio of the hydrochloric acid to the compound C is preferably 180-220 mL: 32-38 mmol, more preferably 190-210 mL: 33-37 mmol, more preferably 200 mL: 34.9-36 mmol, and the concentration of the hydrochloric acid is preferably 1.5-2.5 mol / L, more preferably 2 mol / L; the dilution is preferably carried out using ether, and the volume molar ratio of ether to compound C is preferably 480-520 mL: 32-38 mmol, more preferably 490-510 mL: 33-37 mmol, more preferably 50 0mL:34.9~36mmol; the washing is preferably carried out on the organic layer obtained after dilution, and the reagents used for washing are preferably water and sodium chloride solution in sequence, and the mass concentration of the sodium chloride solution is preferably 10~27%, and more preferably 26.5%; the drying is preferably carried out using anhydrous sodium sulfate; the vacuum degree of the rotary evaporation concentration is preferably -0.05~-0.01MPa, and more preferably -0.03~-0.02MPa, the temperature of the rotary evaporation concentration is preferably 30~60℃, and more preferably 40℃, and the time of the rotary evaporation concentration is preferably 20~40min, and more preferably 30min; the reagents used for the silica gel column chromatography are preferably n-hexane and dichloromethane, and the volume ratio of n-hexane to dichloromethane is preferably 5~7:4, and more preferably 6:4.

[0076] In the present invention, the structural formula of the compound D in step (3) is: Among them, R3 and R4 are independently preferably hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; R is preferably hydrogen, alkyl, cycloalkyl or aryl; X is preferably N-R9, O or S, and R9 is preferably hydrogen, alkyl, aryl or heteroaryl.

[0077] In the present invention, stirring is preferably performed during the cyclization reaction in step (4); the stirring speed is preferably 150 to 250 rpm, more preferably 200 rpm.

[0078] In the present invention, after the cyclization reaction in step (4) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into water and stirred to obtain an organic layer, and the organic layer is sequentially washed, dried, concentrated by rotary evaporation, and chromatographed on a silica gel column; the volume molar ratio of the water to the compound C in step (3) is preferably 200-1000 mL:32-38 mmol, more preferably 400-600 mL:33-37 mmol, and more preferably 500 mL:34.9-36 mmol, the stirring speed is preferably 100-400 rpm, more preferably 200 rpm, and the stirring time is preferably 5-15 min, more preferably 10 mi n; the reagent used for the washing is preferably sodium chloride solution, and the mass concentration of the sodium chloride solution is preferably 10-27%, and more preferably 26.5%; the drying is preferably carried out using anhydrous sodium sulfate; the vacuum degree of the rotary evaporation is preferably -0.05-0.01MPa, and more preferably -0.03MPa, the temperature of the rotary evaporation is preferably 35-45°C, and more preferably 40°C, and the time of the rotary evaporation is preferably 20-40min, and more preferably 30min; the reagents used for the silica gel column chromatography are preferably n-hexane and dichloromethane, and the volume ratio of n-hexane to dichloromethane is preferably 92-98:5, and more preferably 95:5.

[0079] In the present invention, the structural formula of the compound E in step (4) is: Among them, R3 and R4 are independently preferably hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; R is preferably hydrogen, alkyl, cycloalkyl or aryl; X is preferably N-R9, O or S, and R9 is preferably hydrogen, alkyl, aryl or heteroaryl.

[0080] In the present invention, the structural formula of the compound F in step (5) is Wherein, R7 and R8 are independently preferably hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl;

[0081] The molar mass ratio of compound E, compound F, tri(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water in step (5) is preferably 15-20 mmol: 25-30 mmol: 0.5-1.5 mmol: 34-38 mmol: 250 g: 20-30 g, more preferably 16-18.2 mmol: 27.2-29 mmol: 0.7-1.2 mmol: 35-37 mmol: 250 g: 22-28 g, more preferably 17 mmol: 28 mmol: 0.9 mmol: 36.5 mmol: 250 g: 25 g; the temperature of the cross-coupling reaction is preferably 90-110° C., more preferably 95-105° C., more preferably 100° C.; the time of the cross-coupling reaction is preferably 16-24 h, more preferably 18-22 h, more preferably 20 h.

[0082] In the present invention, the cross-coupling reaction in step (5) is preferably carried out in nitrogen, and stirring is preferably performed during the cross-coupling reaction; the stirring speed is preferably 200 to 300 rpm, and more preferably 250 rpm.

[0083] In the present invention, after the cross-coupling reaction in step (5) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into water, and diluted, washed, dried, concentrated by rotary evaporation and chromatographed on a silica gel column in sequence; the volume molar ratio of water to compound E is preferably 200-1000 mL: 15-20 mmol, more preferably 400-600 mL: 16-18.2 mmol, and more preferably 500 mL: 17 mmol; the dilution is preferably carried out using dichloromethane, and the volume molar ratio of dichloromethane to compound E is preferably 30-200 mL: 15-20 mmol, more preferably 50-100 mL: 16-18.2 mmol, and more preferably 80 mL: 17 mmol; the washing is preferably carried out using a slurry of 1% ethanol and 1% ethanol; The organic layer obtained after dilution is washed, and the reagents used for washing are preferably water and sodium chloride solution in sequence, and the mass concentration of the sodium chloride solution is preferably 10-27%, and more preferably 26.5%; the drying is preferably carried out using anhydrous sodium sulfate; the vacuum degree of the rotary evaporation concentration is preferably -0.05 to -0.01 MPa, and more preferably -0.03 to -0.02 MPa, the temperature of the rotary evaporation concentration is preferably 30 to 60°C, and more preferably 40°C, and the time of the rotary evaporation concentration is preferably 20 to 40 min, and more preferably 30 min; the reagents used for the silica gel column chromatography are preferably n-hexane and dichloromethane, and the volume ratio of n-hexane to dichloromethane is preferably 92 to 98:5, and more preferably 95:5.

[0084] In the present invention, the structural formula of the compound G in step (5) is:

[0085] Among them, R3 and R4 are preferably independently hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; R7 and R8 are preferably independently hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl; R is preferably hydrogen, alkyl, cycloalkyl or aryl; X is preferably N-R9, O or S, and R9 is preferably hydrogen, alkyl, aryl or heteroaryl.

[0086] In the present invention, the molar volume ratio of compound G, boron tribromide and chloroform in step (6) is preferably 10-15 mmol: 15-20 mmol: 10-25 mL, more preferably 11-14 mmol: 16-19 mmol: 13-20 mL, more preferably 12-13 mmol: 18 mmol: 18 mL; the temperature of the demethylation reaction is preferably 20-30°C, more preferably 22-28°C, more preferably 25°C; the time of the demethylation reaction is preferably 16-24 h, more preferably 18-22 h, more preferably 20 h.

[0087] In the present invention, stirring is preferably performed during the demethylation reaction in step (6); the stirring speed is preferably 150 to 250 rpm, more preferably 200 rpm.

[0088] In the present invention, after the demethylation reaction in step (6) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into a saturated sodium bicarbonate solution, and diluted, extracted, washed, dried, concentrated by rotary evaporation and chromatographed on a silica gel column in sequence; the volume molar ratio of the saturated sodium bicarbonate solution to the compound G is preferably 20-100 mL: 10-15 mmol, more preferably 40-60 mL: 11-14 mmol, and more preferably 50 mL: 12 mmol; the dilution is preferably carried out using dichloromethane, and the volume molar ratio of dichloromethane to the compound G is preferably 20-100 mL: 10-15 mmol, more preferably 40-60 mL: 11-14 mmol, and more preferably 50 mL: 12 mmol; the dilution is preferably carried out by stirring, and the stirring speed is preferably 100-400 rpm, and more preferably 200 rpm. The stirring time is preferably 5-15 min, and more preferably 10 min; the extraction is preferably carried out on the water layer obtained after the dilution, and the extraction agent used for the extraction is preferably dichloromethane. Chloromethane, the number of extractions is preferably 2 to 4 times, more preferably 3 times, the volume molar ratio of the extractant used in each extraction to compound G is preferably 20 to 100 mL: 10 to 15 mmol, more preferably 40 to 60 mL: 11 to 14 mmol, more preferably 50 mL: 12 mmol; the washing is preferably to wash the organic layer obtained after the extraction, and the reagents used for washing are preferably water and sodium chloride solution in sequence, and the mass concentration of the sodium chloride solution is preferably 10 to 27%, more preferably 26.5%; the drying is preferably carried out with anhydrous sodium sulfate; the vacuum degree of the rotary evaporation concentration is preferably -0.05 to -0.01 MPa, more preferably -0.03 MPa, the temperature of the rotary evaporation concentration is preferably 20 to 30 ° C, more preferably 25 ° C, and the time of the rotary evaporation concentration is preferably 20 to 40 min, more preferably 30 min; the reagents used for the silica gel column chromatography are preferably n-hexane and dichloromethane, and the volume ratio of n-hexane to dichloromethane is preferably 4 to 6:5, more preferably 5:5.

[0089] In the present invention, the structural formula of the compound H in step (6) is: Among them, R3 and R4 are preferably independently hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; R7 and R8 are preferably independently hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl; R is preferably hydrogen, alkyl, cycloalkyl or aryl; X is preferably N-R9, O or S, and R9 is preferably hydrogen, alkyl, aryl or heteroaryl.

[0090] In the present invention, the structural formula of compound J in step (7) is Wherein, R1 and R2 are independently preferably hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl;

[0091] The molar volume ratio of compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane in step (7) is preferably 2-5 mmol: 3-6 mmol: 1-4 mmol: 100 mL, more preferably 3-4 mmol: 4-5 mmol: 2-3 mmol: 100 mL, more preferably 3.8 mmol: 4.7 mmol: 2.8 mmol: 100 mL; the reaction temperature is preferably 35-45°C, more preferably 38-42°C, more preferably 40°C; the reaction time is preferably 4-10 h, more preferably 6-8 h, more preferably 7 h.

[0092] In the present invention, the reaction in step (7) is preferably carried out in nitrogen, and stirring is preferably performed during the reaction; the stirring speed is preferably 100 to 200 rpm, and more preferably 150 rpm.

[0093] In the present invention, after the reaction in step (7) is completed, a mixed solution is obtained, and the mixed solution is preferably poured into ice water, and then extracted to obtain an organic phase, and the organic phase is sequentially subjected to rotary evaporation concentration and silica gel column chromatography; the volume molar ratio of the ice water to the compound H is preferably 50-250 mL:2-5 mmol, more preferably 100-200 mL:3-4 mmol, and more preferably 150 mL:3.8 mmol; the extractant used in the extraction is preferably toluene, the number of extractions is preferably 2-4 times, more preferably 3 times, and the volume molar ratio of the extractant used for a single extraction to the compound H is preferably 150-250 mL: 2~5mmol, further preferably 170~220mL:3~4mmol, more preferably 200mL:3.8mmol; the vacuum degree of the rotary evaporation concentration is preferably -0.05~-0.01MPa, further preferably -0.03~-0.02MPa, the temperature of the rotary evaporation concentration is preferably 30~60℃, further preferably 40℃, the time of the rotary evaporation concentration is preferably 20~40min, further preferably 30min; the reagents used in the silica gel column chromatography are preferably petroleum ether and dichloromethane, and the volume ratio of petroleum ether to dichloromethane is preferably 0.5~2:1, further preferably 1:1.

[0094] The invention also provides application of the photochromic compound in photochromic products.

[0095] In the present invention, the use of the photochromic compound in the photochromic product preferably comprises preparing the photochromic compound into a photochromic composition, and then preparing the photochromic product.

[0096] In the present invention, the photochromic composition preferably comprises the photochromic compound and an organic polymer, and the organic polymer preferably comprises one or more of polystyrene, poly(meth)acrylate, polycarbonate, polyureaurethane, epoxy resin, polyethylene glycol, polyurethane, polysiloxane, polyether, polyamide, polyester, polyacrylonitrile, copolymer containing vinyl or / and vinyl alcohol, cellulose acetate, cellulose acetate butyrate and polyvinyl butyral, as well as homopolymers and / or copolymers derived from the above compounds.

[0097] In the present invention, the photochromic composition preferably further comprises one or more of a surfactant, a photoinitiator, a thermal initiator, an inhibitor, a solvent, a light stabilizer, a thermal stabilizer, a release agent, a defoamer, a rheology control agent, a leveling agent, a free radical scavenger and an adhesion promoter.

[0098] In the present invention, the photochromic product preferably comprises eyeglass lenses, optical lens products, glass products or electronic consumer products; the optical lens products preferably comprise magnifying lenses, camera lenses or dimming lenses, the glass products preferably comprise color-changing laminated glass, color-changing window glass or color-changing automobile film, and the electronic consumer products preferably comprise display screens, display back panels, security elements, anti-counterfeiting originals, decorative products, clothing or accessories.

[0099] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0100]

[0101] 50.8mmol 1-bromo-4-methoxy-2-naphthoic acid methyl ester, 1mmol [1,1'-bis(diphenylphosphino)ferrocene] dichloropalladium, 61mmol biboric acid pinacol ester, 150g toluene, 13.5g water and 1.5g potassium acetate were mixed, nitrogen was replaced and the temperature was raised to 80°C, and the reaction was stirred at 200rpm for 24h to obtain a mixed solution. The mixed solution was cooled to room temperature and concentrated by rotary evaporation at -0.01MPa and 50°C for 30min to obtain an intermediate product. The intermediate product, 76.2mmol 4,7-dibromo-2,1,3-benzothiadiazole, 2mmol tetrakis(triphenylphosphine)palladium, 50g potassium carbonate aqueous solution (the concentration of potassium carbonate aqueous solution is 2mol / L) and 250g tetrahydrofuran were mixed, nitrogen was replaced and the temperature was raised to 60°C, and the reaction was stirred at 200rpm for 18h to obtain a mixed solution. The mixed solution was poured into 200 mL of 2 mol / L hydrochloric acid, and 500 mL of ether was added to dilute it to obtain an organic layer. The organic layer was washed with water and a sodium chloride solution with a mass concentration of 26.5% in sequence, and then dried with anhydrous sodium sulfate, and then rotary evaporated for 20 min at -0.01 MPa and 40°C. The product after rotary evaporation was chromatographed on a silica gel column (silica gel particle size of 200-300 mesh) using n-hexane and dichloromethane with a volume ratio of 7:3 to obtain compound C: 1-(7-(bromobenzothiadiazole)-4-methoxy-2-naphthoic acid methyl ester. Compound C is a yellow crystal with a mass of 16.3 g and a two-step yield of 75%. Mass spectrometry data: MS (ESI, m / z): [M+H] + calcd for(C 19 H 13 BrN2O3S),429.0; found,429.0.

[0102]

[0103] 34.9mmol 1-(7-(bromobenzothiadiazole)-4-methoxy-2-naphthoic acid methyl ester and 250mL ultra-dry tetrahydrofuran were added to a three-necked flask, and nitrogen was replaced. 75mL of methylmagnesium bromide ether solution (the concentration of methylmagnesium bromide in the ether solution of methylmagnesium bromide was 1mol / L) was added dropwise to the three-necked flask. The addition was completed over 30min, and the reaction was stirred at 200rpm at 25°C for 19h to obtain a mixed solution. The mixed solution was poured into 200mL of 2m ol / L hydrochloric acid, add 500mL of ether to dilute, stir at 200rpm for 10min to obtain an organic layer. The organic layer was washed with water and a sodium chloride solution with a mass concentration of 26.5% in sequence, then dried with anhydrous sodium sulfate, and then rotary evaporated at -0.01MPa and 40°C for 20min. The product after rotary evaporation was chromatographed on a silica gel column (silica gel particle size is 200-300 mesh) using n-hexane and dichloromethane with a volume ratio of 6:4 to obtain compound D. Compound D, 100mL of chloroform, and 14mmol of pyridinium p-toluenesulfonate were mixed, stirred at 200rpm for 2h at 25°C to obtain a mixed solution. The mixed solution was poured into 500mL of water, stirred at 200rpm for 10min to obtain an organic layer, washed with a sodium chloride solution with a mass concentration of 26.5%, then dried with anhydrous sodium sulfate, and then rotary evaporated at -0.01MPa, 40°C for 20min. The product was concentrated by rotary evaporation at 40°C for 30 min. The product was subjected to silica gel column chromatography (silica gel particle size was 200-300 mesh) using n-hexane and dichloromethane in a volume ratio of 95:5 to obtain compound E: 4-bromo-8-methoxy-6,6-dimethyl-6H-indeno[5,6]thiadiazole. Compound E was a light orange solid with a mass of 7.6 g and a two-step yield of 53%. Mass spectral data: MS (ESI, m / z): [M+H]+calcd for (C 20 H 15 BrN2OS),411.0; found,411.0.

[0104]

[0105] 18.2mmol 4-bromo-8-methoxy-6,6-dimethyl-6H-indeno[5,6]thiadiazole, 0.9mmol tri(dibenzylideneacetone)dipalladium, 36.5mmol cesium carbonate, 27.2mmol diphenylamine, 250g toluene and 25g water were mixed, the nitrogen was replaced and the temperature was raised to 100°C, and the reaction was stirred at 250rpm for 20h to obtain a mixed solution. The mixed solution was cooled to room temperature, poured into 500mL water, 80mL dichloromethane was added, and the organic layer was obtained by stirring at 250rpm for 10min. The organic layer was washed with water and a sodium chloride solution with a mass concentration of 26.5% in sequence, then dried with anhydrous sodium sulfate, and then concentrated by rotary evaporation at -0.01MPa and 40°C for 20min. The product after rotary evaporation and concentration was subjected to silica gel column chromatography (silica gel particle size was 200-300 mesh) using n-hexane and dichloromethane in a volume ratio of 95:5 to obtain compound G: 8-methoxy-6,6-dimethyl-4-diphenylamino-6H-indeno[5,6]thiadiazole. Compound G was off-white, with a mass of 6.1 g and a yield of 67%. Mass spectrometry data: MS (ESI, m / z): [M+H]+calcd for (C 32 H 25 N3OS),500.6;found,500.4.

[0106]

[0107] Mix 12mmol 8-methoxy-6,6-dimethyl-4-diphenylamino-6H-indeno[5,6]thiadiazole and 18mL chloroform, add 18mL dichloromethane solution of boron tribromide at a rate of 0.6mL / min (the concentration of boron tribromide in the dichloromethane solution of boron tribromide is 1mol / L), and stir at 200rpm at 25℃ for 20h to obtain a mixed solution. Pour the mixed solution into 50mL saturated sodium bicarbonate solution, add 50mL dichloromethane, and stir at 200rpm for 10min to obtain a water layer. Extract the water layer with 50mL dichloromethane each time, extract 3 times, and obtain an organic layer. The organic layer was washed with water and a sodium chloride solution with a mass concentration of 26.5% in sequence, and then dried with anhydrous sodium sulfate, and then rotary evaporated and concentrated at -0.01MPa and 25°C for 30 minutes. The product after rotary evaporated and concentrated was subjected to silica gel column chromatography (silica gel particle size of 200-300 mesh) using n-hexane and dichloromethane with a volume ratio of 5:5 to obtain compound H: 8-hydroxy-6,6-dimethyl-4-diphenylamino-6H-indeno[5,6]thiadiazole. Compound H was gray, with a mass of 5g and a yield of 86%. Mass spectrum data: MS (ESI, m / z): [M+H]+calcd for (C 31 H 23N3OS), 486.2; found, 486.1.

[0108]

[0109] 4.7mmol 1-(4-diphenylaminophenyl)-1-phenylprop-2-ynol, 3.8mmol 8-hydroxy-6,6-dimethyl-4-diphenylamino-6H-indeno[5,6]thiadiazole and 100mL dichloromethane were mixed, and 2.8mmol p-toluenesulfonic acid pyridinium salt was added, nitrogen was replaced, the temperature was raised to 40°C, and the reaction was stirred at a speed of 150rpm for 6h to obtain a mixed solution. The mixed solution was poured into 200mL ice water, and extracted with 200mL toluene each time, and the organic phase was obtained by extraction 3 times. The organic phase was placed in -0.01MPa, 40 ° C for 20 minutes of rotary evaporation concentration, and the product after rotary evaporation concentration was subjected to silica gel column chromatography (silica gel particle size is 200-300 mesh) using petroleum ether and dichloromethane with a volume ratio of 1:1 to obtain a photochromic compound: 3-(4-diphenylaminophenyl)-3-phenyl-13,13-dimethyl-11-diphenylamino-dihydroindeno[8,9]thiadiazole. The mass of the photochromic compound is 960 mg, the yield is 29%, the purity is 99.5%, and the mass spectrum data is: MS (ESI, m / z): [M+H] + calcd for(C 58 H 42 N4OS), 844.1; found, 844.1. Proton spectrum data: 1 H NMR(400MHz, CDCl3)δ8.71(d,1H),8.49(d,1H),8.17(d,1H),7.63(d,1H),7.59–7.49(m,5H),7.43–7.38(m,4H),7 .34-7.30(m,2H),7.29–7.24(m,5H),7.24–7.18(m,6H),7.14–7.06(m,8H),6.89(d,1H),6.28(d,1H),2.10(s,6H).

[0110] Example 2

[0111] The 1-bromo-4-methoxy-2-naphthoic acid methyl ester in Example 1 was replaced by 1-bromo-4,6,7-trimethoxy-2-naphthoic acid methyl ester, diphenylamine was replaced by 4,4-dimethoxydiphenylamine, 1-(4-diphenylaminophenyl)-1-phenylprop-2-ynol was replaced by 1-(4-di(4-methoxyphenyl)aminophenyl)-1-phenylprop-2-ynol, and the rest was the same as Example 1.

[0112] Mass spectral data of the photochromic compound prepared in this example: MS (ESI, m / z): [M+H] + calcd for(C 64 H 54 N4O7S),1023.4; found,1023.4.

[0113] The structural formula of the photochromic compound prepared in this embodiment is:

[0114]

[0115] Example 3

[0116] The 4,4-dimethoxydiphenylamine in Example 2 was replaced by 4,4-bis(N,N-dimethylamino)diphenylamine, and the rest was the same as Example 2.

[0117] Mass spectral data of the photochromic compound prepared in this example: MS (ESI, m / z): [M+H] + calcd for(C 66 H 60 N6O5S),1050.3; found,1050.3.

[0118] The structural formula of the photochromic compound prepared in this embodiment is:

[0119]

[0120] Example 4

[0121] The methylmagnesium bromide in Example 1 was replaced by phenylmagnesium bromide, and the rest was the same as in Example 1.

[0122] Mass spectral data of the photochromic compound prepared in this example: MS (ESI, m / z): [M+H] + calcd for(C 68 H 46 N4OS), 967.3; found, 967.3.

[0123] The structural formula of the photochromic compound prepared in this embodiment is:

[0124]

[0125] Example 5

[0126] The 4,7-dibromo-2,1,3-benzothiadiazole in Example 1 was replaced by 4,7-dibromo-2,1,3-benzoxadiazole, and the 1-bromo-4-methoxy-2-naphthoic acid methyl ester was replaced by 1-bromo-4,6,7-trimethoxy-2-naphthoic acid methyl ester. The rest was the same as in Example 1.

[0127] Mass spectral data of the photochromic compound prepared in this example: MS (ESI, m / z): [M+H]+calcd for (C 62 H 50 N4O6), 947.4; found, 947.4.

[0128] The structural formula of the photochromic compound prepared in this embodiment is:

[0129]

[0130] Example 6

[0131] The 4,7-dibromo-2,1,3-benzothiadiazole in Example 1 was replaced by 4,7-dibromo-2-(n-butyl)-2H-benzo[D][1,2,3]triazole, diphenylamine was replaced by 4,4-diethylaminodiphenylamine, 1-(4-diphenylaminophenyl)-1-phenylprop-2-ynol was replaced by 1-(4-di(4-diethylaminophenyl)aminophenyl)-1-phenylprop-2-ynol, and the rest was the same as in Example 1.

[0132] Mass spectral data of the photochromic compound prepared in this example: MS (ESI, m / z): [M+H] + calcd for(C 88 H 91 N9O), 1290.7; found, 1290.7.

[0133] The structural formula of the photochromic compound prepared in this embodiment is:

[0134]

[0135] Comparative Example 1

[0136] The structural formula of the photochromic compound is:

[0137] Application Example 1

[0138] In parts by mass, 25 parts of polyvinyl butyral resin, 6 parts of dibutyl phthalate, 65 parts of ethyl acetate, 2 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, 1 part of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 0.5 parts of butylated hydroxytoluene and 0.5 parts of the photochromic compound prepared in Example 1 were mixed, mechanically stirred at a speed of 1000 rpm for 2 hours and then allowed to stand for 1 hour to obtain a mixture. The mixture was placed in an extruder, extruded at 140° C., and then hot-pressed at 140° C. and 1.0 MPa to form a film with a thickness of 3.6 μm, and naturally cooled to room temperature to obtain a photochromic interlayer film.

[0139] Take two pieces of 10cm×10cm transparent white glass, place the photochromic interlayer film between the two pieces of transparent white glass, pre-press them under a roller pressing device (pre-pressing temperature is 70℃, pressure is 0.1MPa), and initially expel bubbles; then press them at 130℃ and 0.8MPa for 90min, press them into shape, and then naturally cool them to room temperature to obtain laminated double-layer glass.

[0140] Application Comparative Example 1

[0141] The photochromic compound in Application Example 1 was replaced by the photochromic compound in Comparative Example 1, and the rest was the same as in Application Example 1.

[0142] Laminated double-layer glass was subjected to irradiation test according to GB / T 5137.3-2020; laminated double-layer glass was subjected to near-infrared (wavelength range 780-2500nm) absorption test according to ISO 9050:2017. The test results are shown in Table 1.

[0143] Table 1 Irradiation and near infrared absorption test results of laminated double-layer glass

[0144]

[0145] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A photochromic compound, characterized in that: The structural formula of the photochromic compound is: wherein R1, R2, R7, and R8 are independently hydrogen, halogen, hydroxy, alkyl, alkoxy, amino, aryl, or heteroaryl; R3 and R4 are independently hydrogen, halogen, hydroxy, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; R is hydrogen, alkyl, cycloalkyl or aryl; X is N-R9, O or S; R9 is hydrogen, alkyl, aryl or heteroaryl.

2. The photochromic compound according to claim 1, characterized in that The photochromic compound is any one of the following structural formulas:

3. The method for preparing the photochromic compound according to claim 1 or 2, characterized in that: The following steps are included: (1) subjecting compound A, [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride, bipyraclostrobin, potassium acetate, toluene and water to a Miyaura borylation reaction to obtain an intermediate product; (2) subjecting the intermediate product, compound B, tetrakis(triphenylphosphine)palladium, potassium carbonate solution and tetrahydrofuran to a Suzuki coupling reaction to obtain compound C; (3) Compound C, a Grignard reagent and tetrahydrofuran are mixed and reacted to obtain compound D; (4) subjecting compound D, pyridinium p-toluenesulfonate and chloroform to a cyclization reaction to obtain compound E; (5) cross-coupling compound E, compound F, tris(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water to obtain compound G; (6) subjecting compound G, boron tribromide and chloroform to a demethylation reaction to obtain compound H; (7) Compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane are mixed and reacted to obtain a photochromic compound.

4. The preparation method according to claim 3, characterized in that: The structural formula of compound A in step (1) is Wherein, R3 and R4 are independently hydrogen, halogen, hydroxyl, alkyl, heterocycloalkyl, alkoxy, aryl or heteroaryl; The molar ratio of compound A, [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium and diboronic acid pinacol ester in step (1) is 48-52:1:58-63, and the molar mass ratio of compound A, potassium acetate, toluene and water is 48-52mmol:1-2g:120-180g:10-15g; the temperature of the Miyaura boronation reaction is 70-90°C, and the time of the Miyaura boronation reaction is 20-28h.

5. The preparation method according to claim 3 or 4, characterized in that: The structural formula of compound B in step (2) is Wherein, X is N-R9, O or S, and R9 is hydrogen, alkyl, aryl or heteroaryl; The molar ratio of the compound B in step (2), tetrakis(triphenylphosphine)palladium and the compound A in step (1) is 75-80:2:48-52, the mass molar ratio of the potassium carbonate solution, tetrahydrofuran and the compound A in step (1) is 48-52g:200-300g:48-52mmol, and the concentration of the potassium carbonate solution is 1.5-2.5mol / L; the temperature of the Suzuki coupling reaction is 50-70°C, and the time of the Suzuki coupling reaction is 12-24h.

6. The preparation method according to claim 5, characterized in that: The structural formula of the Grignard reagent in step (3) is R-Mg-Br, wherein R is hydrogen, alkyl, cycloalkyl or aryl; In step (3), the molar volume ratio of compound C, Grignard reagent and tetrahydrofuran is 32-38 mmol:72-78 mmol:250 mL; the reaction temperature is 20-30° C., and the reaction time is 14-24 h; The molar ratio of the pyridinium p-toluenesulfonate in step (4) to the compound C in step (3) is 12-16:32-38, and the molar volume ratio of the pyridinium p-toluenesulfonate to chloroform is 12-16 mmol:100 mL; the temperature of the cyclization reaction is 20-30° C., and the time of the cyclization reaction is 1-3 h.

7. The preparation method according to claim 6, characterized in that: The structural formula of the compound F in step (5) is wherein R7 and R8 are independently hydrogen, halogen, hydroxy, alkyl, alkoxy, amino, aryl or heteroaryl; In step (5), the molar mass ratio of compound E, compound F, tri(dibenzylideneacetone)dipalladium, cesium carbonate, toluene and water is 15-20 mmol: 25-30 mmol: 0.5-1.5 mmol: 34-38 mmol: 250 g: 20-30 g; the temperature of the cross-coupling reaction is 90-110° C., and the time of the cross-coupling reaction is 16-24 h.

8. The preparation method according to claim 6 or 7, characterized in that: In step (6), the molar volume ratio of compound G, boron tribromide and chloroform is 10-15 mmol: 15-20 mmol: 10-25 mL; the temperature of the demethylation reaction is 20-30° C., and the time of the demethylation reaction is 16-24 h.

9. The preparation method according to claim 8, characterized in that: The structural formula of compound J in step (7) is Wherein, R1 and R2 are independently hydrogen, halogen, hydroxyl, alkyl, alkoxy, amino, aryl or heteroaryl; In step (7), the molar volume ratio of compound H, compound J, pyridinium p-toluenesulfonate and dichloromethane is 2-5 mmol: 3-6 mmol: 1-4 mmol: 100 mL; the reaction temperature is 35-45° C., and the reaction time is 4-10 h.

10. Use of the photochromic compound according to claim 1 or 2 in photochromic products.

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