A method for synthesizing a spiropyran compound

Abstract

The application provides a synthesis method of a spiropyran compound and belongs to the technical field of organic synthesis chemistry, and aims at solving the technical problems of difficult synthesis of a spiro ring skeleton and complex steps. In the application, reactants, an oxazine compound, a 1,4-benzoquinone compound and a catalyst and an additive are added into a solvent to react under an inert atmosphere, and the spiropyran compound is prepared after the reaction is completed. In the application, the simple and easily obtained oxazine compound and the 1,4-benzoquinone compound are selected as the reactants, the construction of a novel spiro[5.5]heterocyclic skeleton containing a quaternary carbon center is realized through [3+3] in the action of a metal ruthenium catalyst, a simple and effective synthesis method for the construction of a complex spiro ring is provided, and the method has the characteristics of mild reaction condition, simple operation, atom economy, step economy and strong functional group tolerance.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthetic chemistry, and in particular relates to a method for synthesizing spiropyran compounds. Background Art

[0002] Spirocyclic compounds are a class of compounds with important application value and good biological activity, playing an important role in the fields of medicine, pesticides, dyes, catalysis, etc. (Chem. Rev. 2004, 104, 2751-2776; Chem. Rev. 2007, 107, 1011-1065). Therefore, scientists have conducted a lot of exploration on the synthesis methods of spirocyclic compounds. However, these synthesis methods are often faced with the problems of complex raw material synthesis, poor step economy, harsh conditions, etc. (ACS Catal. 2013, 3, 540-553; Eur. J. Org. Chem. 2017, 5316-5342). The above problems greatly limit the use of such compounds. At present, most of the research on spirocyclic compounds is to construct spirocarbon skeletons, while there are few studies on the synthesis of spiroheterocyclic skeletons. Among them, the construction methods of spiropyran compounds are extremely scarce. This is mainly because many spiropyran compounds have poor stability. How to efficiently and conveniently synthesize stable spiropyran compounds is a difficult problem in synthesizing spiroheterocyclic skeletons. We previously reported a case study of the construction of spiropyrans via C-H bond activation (Chem. Commun., 2022, 58, 5144-5147). This synthesis was achieved through a tandem reaction using a metal Rh catalyst. This synthetic method yielded a bicyclic product, making it difficult to control the activation of a single C-H bond to produce a single cyclized spiropyran product. Therefore, a more cost-effective method for controlling the production of a single C-H bond was sought.

[0003] Benzoxazine derivatives, widely found as endogenous substances in major crops such as corn, wheat, and rye, play a crucial role in crop defense. They serve as primary active ingredients in crop resistance to microbial and disease infections and are integral to crop defense systems (Int. Rev. Cytol., 2000, 198, 319-346; Molecules, 2017, 22, 1103). Several research groups have conducted bioactivity studies using these compounds against pathogens such as pepper anthracnose, wheat sheath blight, rice blast, sheath blight, brown spot, sclerotinia, gray mold, and fusarium head blight. These results demonstrate that these compounds exhibit moderate antibacterial activity against a variety of pathogens. Therefore, developing and structurally modifying benzoxazine derivatives could yield benzoxazine derivatives with enhanced antibacterial activity, which is of great significance for the development of novel benzoxazine fungicides for the control of crop diseases. SUMMARY

[0004] In order to solve the technical problems of complex steps and difficult synthesis of spiro ring skeleton, the application provides a synthesis method of spiro-pyrans compound.

[0005] In order to achieve the above-mentioned purposes, the technical scheme of the application is as follows:

[0006] The synthesis method of spiro-pyrans compound is synthesized by using oxazine compound and 1,4-benzoquinone compound as raw materials under the promotion of catalyst; the reaction formula is shown in the following formula:

[0007]

[0008] In the formula, R is any one of H, Me, F, Cl, Br or t-Bu; R1 is any one of Me, Cl, t-Bu or Ph; and Ar is any one of Me, OMe, Cl, Br, Ph or CF3 substituted benzene ring.

[0009] The specific steps are as follows: the reactants of oxazine compound, 1,4-benzoquinone compound, catalyst and additive are added into the solvent to react under inert atmosphere, and the spiro-pyrans compound is prepared after the reaction is completed.

[0010] According to the synthesis method of spiro-pyrans compound in claim 2, the molar ratio of the oxazine compound, 1,4-benzoquinone compound, catalyst and additive is 1:(1.1-2.2):(0.1-0.2):(1.1-2.2).

[0011] The concentration of the reactants in the solvent is 0.05M-0.1M.

[0012] The additive is any one or two or more of copper acetate, sodium acetate, lithium acetate or sodium bicarbonate.

[0013] The catalyst is composed of ruthenium catalyst / rhodium catalyst and silver salt, and the molar ratio of the ruthenium catalyst / rhodium catalyst and silver salt is 1:4.

[0014] The ruthenium catalyst is 2 dichlorobis(4-methylisopropylphenyl) ruthenium ([RuCl2(p-cymene)]2), the rhodium catalyst is dichloro(pentamethylcyclopentadienyl) rhodium(III) dimer, and the silver salt is silver hexafluoroantimonate (AgSbF6).

[0015] The solvent is any one of 1,2-dichloroethane, dichloromethane, ethylene glycol dimethyl ether or trifluorotoluene.

[0016] The inert atmosphere is a nitrogen atmosphere.

[0017] The reaction temperature of the reaction is 30-80 DEG C, and the reaction time is 12-24h.

[0018] At the same time, for the reaction mode of the reaction, the possible path is proposed, and the mechanism is verified by the corresponding experimental design, as shown in the following formula:

[0019] The benzoxazine generates a ring metal intermediate A under the action of a ruthenium catalyst and silver hexafluoroantimonate, 1,4-benzoquinone is inserted to generate an intermediate B, then metal removal occurs to obtain an intermediate C, and a hydroxyl attacks to generate a spiro compound D, and the reaction can effectively control the activation of a C-H bond to obtain a single ring-closing product D.

[0020] The beneficial effects of the present application: the present application selects simple and easily available oxazine compounds and 1,4-benzoquinone compounds as reactants, and under the action of a metal ruthenium catalyst, a new type of spiro[5.5]heterocyclic skeleton containing a quaternary carbon center is constructed by [3+3] one step, which provides a simple and effective synthesis method for the construction of complex spiro rings, and the method has the characteristics of mild reaction conditions, simple operation, atomic economy, step economy and strong functional group tolerance. The obtained product has wide industrial application prospect, and by introducing spiro-pyran structure in benzoxazolyl analogs, it can be used as bactericide, and the present application provides a new idea and method for the fields of medicine, natural product synthesis and luminescent materials. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below, and obviously, the drawings in the following description can only be some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0022] Figure 1 is the nuclear magnetic resonance spectrum of compound 3aa 1 H spectrum; Figure 2 is the nuclear magnetic resonance spectrum of compound 3aa 13 C spectrum.

[0023] Figure 3 is the nuclear magnetic resonance spectrum of compound 3ba 1 H spectrum; Figure 4 is the nuclear magnetic resonance spectrum of compound 3ba 13 C spectrum.

[0024] Figure 5 is the nuclear magnetic resonance spectrum of compound 3ca 1H spectrum; Figure 6 is the nuclear magnetic resonance spectrum of compound 3ca 13 C spectrum.

[0025] Figure 7 is the nuclear magnetic resonance spectrum of compound 3da 1 H spectrum; Figure 8 is the nuclear magnetic resonance spectrum of compound 3da 13 C spectrum.

[0026] Figure 9 is the nuclear magnetic resonance spectrum of compound 3ea 1 H spectrum; Figure 10 is the nuclear magnetic resonance spectrum of compound 3ea 13 C spectrum.

[0027] Figure 11 is the nuclear magnetic resonance spectrum of compound 3fa 1 H spectrum; Figure 12 is the nuclear magnetic resonance spectrum of compound 3fa 13 C spectrum.

[0028] Figure 13 is the nuclear magnetic resonance spectrum of compound 3ga 1 H spectrum; Figure 14 is the nuclear magnetic resonance spectrum of compound 3ga 13 C spectrum.

[0029] Figure 15 is the nuclear magnetic resonance spectrum of compound 3ha 1 H spectrum; Figure 16 is the nuclear magnetic resonance spectrum of compound 3ha 13 C spectrum.

[0030] Figure 17 is the nuclear magnetic resonance spectrum of compound 3ia 1 H spectrum; Figure 18 is the nuclear magnetic resonance spectrum of compound 3ia 13 C spectrum.

[0031] Figure 19 is the nuclear magnetic resonance spectrum of compound 3ja 1 H spectrum; Figure 20 is the nuclear magnetic resonance spectrum of compound 3ja 13 C spectrum.

[0032] Figure 21 is the nuclear magnetic resonance spectrum of compound 3ka 1 H spectrum; Figure 22 is the nuclear magnetic resonance spectrum of compound 3ka 13 C spectrum.

[0033] Figure 23 is the nuclear magnetic resonance spectrum of compound 3la 1 H spectrum; Figure 24 is the nuclear magnetic resonance spectrum of compound 3la 13 C spectrum.

[0034] Figure 25 is the1H NMR spectrum of compound 3ma; 1 H spectrum; Figure 26 is the1H NMR spectrum of compound 3ma; 13 C spectrum.

[0035] Figure 27 is the1H NMR spectrum of compound 3na; 1 H spectrum; Figure 28 is the1H NMR spectrum of compound 3na; 13 C spectrum.

[0036] Figure 29 is the1H NMR spectrum of compound 3ab; 1 H spectrum; Figure 30 is the1H NMR spectrum of compound 3ab; 13 C spectrum.

[0037] Figure 31 is the1H NMR spectrum of compound 3ac; 1 H spectrum; Figure 32 is the1H NMR spectrum of compound 3ac; 13 C spectrum.

[0038] Figure 33 is the1H NMR spectrum of compound 3ad; 1 H spectrum; Figure 34 is the1H NMR spectrum of compound 3ad; 13 C spectrum.

[0039] Figure 35 is the1H NMR spectrum of compound 3ad'; 1 H spectrum; Figure 36 is the1H NMR spectrum of compound 3ad'; 13 C spectrum.

[0040] Figure 37 is the picture of the antibacterial test of the preparation of spiropyran compounds in Example 1.

[0041] Figure 38 is the picture of the antibacterial test of the preparation of spiropyran compounds in Example 8. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0043] Example 1

[0044]

[0045] Oxazine compound la (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 2H,4H-spiro[benzo[b][1.4]oxazine-3,6’-benzo[c]chromen]-2’-ol (3aa) was obtained by silica gel column separation. All eluents were prepared in a ratio of 15:1:1 of petroleum ether and ethyl acetate and dichloromethane. Product data characterization: white solid, 83% yield, melting range: 125-126 °C. NMR spectra are shown in Figure 1 and 2 1 H NMR (400 MHz, CDCl3) δ 7.73 (d, J = 7.8 Hz, 1H), 7.54 (dd, J = 7.7, 1.4 Hz, 1H), 7.49 (td, J = 7.6, 1.4 Hz, 1H), 7.40 (td, J = 7.6, 1.3 Hz, 1H), 7.24 (d, J = 2.9 Hz, 1H), 6.95-6.86 (m, 3H), 6.81 (td, J = 7.6, 1.6 Hz, 1H), 6.75 (td, 2H), 4.79 (d, J = 2.2 Hz, 1H), 4.76 (s, 1H), 4.40 (dd, J = 11.3, 2.5 Hz, 1H), 3.87 (d, J = 11.3 Hz, 1H). 13 C NMR (101 MHz, CD3OD) δ 153.50, 146.33, 144.41, 133.72, 133.41, 132.21, 130.62, 129.50, 126.56, 123.50, 123.40, 122.76, 119.99, 119.95, 117.86, 116.97, 116.64, 110.11, 84.82, 68.62. HRMS: [M+H] + calculated for C 20 H 16 NO3 + :318.1125, found:318.1122.

[0046] Example 2

[0047]

[0048] ​Oxazine compound 1b (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added to a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 8-bromo-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ba) was obtained by silica gel column separation. All eluents were prepared in a ratio of 15:1:1 of petroleum ether and ethyl acetate and dichloromethane. Product data characterization: white solid, 73% yield, melting range: 133-134 °C. NMR spectra are shown in Figure 3 and 4 1 H NMR (400 MHz, CDCl3) δ 7.60 (d, J = 7.7 Hz, 1H), 7.43 (d, J = 7.5 Hz, 2H), 7.33 (t, 1H), 7.15 (d, J = 2.9 Hz, 1H), 7.02 (d, J = 7.8 Hz, 1H), 6.83 (d, J = 8.6 Hz, 1H), 6.75-6.60 (m, 3H), 5.19 (s, 1H), 4.92 (s, 1H), 4.47 (dd, J = 11.3, 2.4 Hz, 1H), 3.86 (d, J = 11.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 150.83, 145.29, 140.32, 132.32, 131.43, 130.59, 130.08, 128.85, 125.10, 123.83, 122.78, 122.63, 122.07, 119.61, 117.28, 115.02, 110.58, 109.55, 83.37, 68.25. HRMS: [M+H] + calculated for C 20 H 15 BrNO3 + : 396.0230, found: 396.0222.

[0049] Example 3

[0050]

[0051] ​Oxazine compound 1c (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 7-fluoro-2H,4H-spiro[benzo[b][1.4]oxazine-3,6’-benzo[c]chromene]-2’-ol (3ca) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. Product data characterization: white solid, 69% yield, melting range: 207-208 °C. NMR spectra are shown in Figure 5 and 6 1 HNMR (400 MHz, CD3OD) δ 7.74 (d, J = 7.8 Hz, 1H), 7.51 (d, J = 7.7 Hz, 1H), 7.44 (t, J = 7.6 Hz, 1H), 7.36 (t, J = 7.5 Hz, 1H), 7.23 (d, J = 2.9 Hz, 1H), 6.86-6.65 (m, 3H), 6.63-6.44 (m, 2H), 4.28 (d, J = 11.1 Hz, 1H), 3.73 (d, J = 11.2 Hz, 1H). 13 C NMR (101 MHz, MeOD) δ 157.70 (d, J = 234.7 Hz), 153.50, 146.19, 144.89 (d, J = 11.6 Hz), 133.45, 132.14, 130.65, 129.74 (d, J = 2.5 Hz), 129.49, 126.51, 123.46, 123.41, 119.88, 117.85, 116.71 (d, J = 9.1 Hz), 110.14, 108.61 (d, J = 22.7 Hz), 104.31 (d, J = 26.0 Hz), 84.46, 68.70. HRMS: [M+H] + calculated for C 20 H 15 FNO3 + : 336.1030, found: 336.1028.

[0052] Example 4

[0053]

[0054] ​Oxazine compound Id (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 7-methyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3da) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. Product data characterization: white solid, 78% yield, melting range: 129-130 °C. NMR spectra are shown in Figure 7 and 8 1 HNMR (400 MHz, DMSO-d6) δ 9.21-9.14 (m, 1H), 7.81 (d, J = 8.4 Hz, 1H), 7.56-7.47 (m, 2H), 7.42 (td, J = 7.4, 1.2 Hz, 1H), 7.27 (q, J = 2.6 Hz, 1H), 7.21 (t, J = 1.9 Hz, 1H), 6.77-6.72 (m, 1H), 6.72-6.67 (m, 2H), 6.64-6.58 (m, 2H), 4.22 (dt, J = 11.2, 2.1 Hz, 1H), 3.75 (dd, J = 11.1, 1.4 Hz, 1H), 2.18 (s, 3H). 13 C NMR (101 MHz, CD3OD) δ 153.42, 146.36, 144.24, 133.79, 132.16, 130.70, 130.55, 129.61, 129.45, 126.55, 123.50, 123.36, 123.19, 119.92, 117.81, 117.46, 116.56, 110.11, 84.90, 68.63, 20.72. HRMS: [M+H] + calculated for C 21 H 18 NO3 + : 332.1281, found: 332.1282.

[0055] Example 5

[0056]

[0057] ​Oxazine compound 1e (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 6-chloro-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ea) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a proportion of 15:1:1. Product data characterization: white solid, 84% yield, melting range: 212-213 °C. NMR spectra are shown in Figure 9 and 10 1 HNMR (400 MHz, DMSO-d6) δ 9.21 (s, 1H), 7.87-7.78 (m, 1H), 7.69 (d, J = 2.0 Hz, 1H), 7.56-7.47 (m, 2H), 7.47-7.41 (m, 1H), 7.27 (d, J = 2.7 Hz, 1H), 6.84-6.78 (m, 2H), 6.76 (d, J = 8.6 Hz, 1H), 6.68 (ddd, J = 11.2, 8.6, 2.6 Hz, 2H), 4.27 (dd, J = 11.3, 2.0 Hz, 1H), 3.83 (d, J = 11.3 Hz, 1H). 13 C NMR (101 MHz, DMSO-d6) δ 152.40, 143.81, 141.31, 133.73, 131.30, 130.24, 129.84, 128.48, 125.44, 125.07, 122.45, 121.58, 118.58, 117.59, 117.09, 117.01, 114.32, 109.29, 82.40, 67.14. HRMS: [M+H]+calculated for C 20 H 15 ClNO3 + : 352.0735, found: 352.0740.

[0058] Example 6

[0059]

[0060] ​Oxazine compound 1f (0.20 mmol), 1,4-benzoquinone compound 2a (0.22 mmol), [RuCl2(p-cymene)]2(3 mol% of oxazine compound), AgSbF6(12 mol% of oxazine compound), sodium acetate (0.22 mmol) and solvent dichloromethane (3.0 mL) were added into a 10 mL sealed tube, and the reaction was carried out in a reaction module at 50 °C for 24 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 6-tert-butyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3fa) was obtained by silica gel column separation. All eluents were prepared in a ratio of 15:1:1 of petroleum ether and ethyl acetate and dichloromethane. Product data characterization: white solid, 23% yield, melting range: 179-180 °C. NMR spectra are shown in Figure 11 and 12 1 H NMR (400 MHz, CDCl3) δ 7.74-7.63 (m, 1H), 7.54 (dd, J = 7.6, 1.4 Hz, 1H), 7.46 (td, J = 7.6, 1.4 Hz, 1H), 7.38 (td, J = 7.5, 1.3 Hz, 1H), 7.22 (d, J = 2.9 Hz, 1H), 6.91 (d, J = 8.6 Hz, 1H), 6.89-6.80 (m, 2H), 6.78 (d, J = 2.1 Hz, 1H), 6.71 (dd, J = 8.7, 2.9 Hz, 1H), 4.82 (d, J = 6.7 Hz, 1H), 4.77 (d, J = 2.4 Hz, 1H), 4.36 (dd, J = 11.3, 2.4 Hz, 1H), 3.82 (d, J = 11.3 Hz, 1H), 1.30 (s, 9H). 13 C NMR (101 MHz, CDCl3) δ 150.76, 145.82, 145.16, 141.08, 132.34, 130.75, 130.26, 129.91, 128.82, 125.41, 122.68, 122.32, 119.56, 117.27, 117.22, 116.16, 113.17, 109.57, 84.02, 67.73, 34.35, 31.66. HRMS: [M+H] + calculated for C 24 H 24 NO3 + : 374.1751, found: 374.1753.

[0061] Example 7

[0062] ​

[0063] Oxazine compound 1g (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 5-fluoro-2H,4H-spiro[benzo[b][1.4]oxazine-3,6’-benzo[c]chromene]-2’-ol (3ga) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a ratio of 15:1:1. Product data characterization: white solid, 61% yield, melting range: 166-167 °C. NMR spectra are shown in Figure 13 and 14 1 HNMR (400 MHz, CDC13) δ 7.69 (dd, J = 7.9, 1.2 Hz, 1H), 7.55 (dd, J = 7.6, 1.4 Hz, 1H), 7.47 (td, J = 7.6, 1.5 Hz, 1H), 7.39 (td, J = 7.5, 1.3 Hz, 1H), 7.22 (d, J = 2.9 Hz, 1H), 6.89 (d, J = 8.6 Hz, 1H), 6.76-6.68 (m, 4H), 4.97 (s, 1H), 4.85 (s, 1H), 4.41 (dd, J = 11.4, 2.5 Hz, 1H), 3.85 (d, J = 11.4 Hz, 1H). 13 C NMR (101 MHz, CDC13) δ 151.89 (d, J = 239.0 Hz), 150.86, 150.71, 145.50, 144.71 (d, J = 5.4 Hz), 131.70, 130.67, 130.12, 128.95, 125.39, 122.74, 122.26, 120.41 (d, J = 15.6 Hz), 119.45, 118.73 (d, J = 9.0 Hz), 117.28, 1112.13 (d, J = 2.8 Hz), 109.65, 108.30 (d, J = 18.3 Hz), 82.74, 67.81. HRMS: [M+H] + calculated for C 20 H 15 FNO3 + : 336.1030, found: 336.1027.

[0064] Example 8​

[0065]

[0066] Oxazine compound 1h (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 6,8-dichloro-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ha) was obtained by silica gel column separation. All eluents were prepared in a ratio of 15:1:1 of petroleum ether and ethyl acetate and dichloromethane. Product data characterization: white solid, 37% yield, melting range: 125-126 °C. NMR spectra are shown in Figure 15 and 16 1 H NMR (400 MHz, CDCl3) δ 7.71 (d, J = 7.8 Hz, 1H), 7.53-7.43 (m, 2H), 7.39 (t, J = 7.4 Hz, 1H), 7.22 (d, J = 2.9 Hz, 1H), 6.95-6.83 (m, 2H), 6.74 (dd, J = 8.7, 2.9 Hz, 1H), 6.64 (d, J = 2.5 Hz, 1H), 4.94 (d, J = 2.3 Hz, 1H), 4.73 (s, 1H), 4.51 (dd, J = 11.4, 2.4 Hz, 1H), 3.88 (d, J = 11.4 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 150.97, 145.22, 138.36, 133.04, 131.13, 130.64, 130.31, 129.00, 126.41, 125.03, 122.89, 122.11, 122.05, 120.55, 119.65, 117.35, 114.21, 109.57, 82.95, 68.25. HRMS: [M+H] + calculated for C 20 H 14 Cl2NO3 + : 386.0345, found: 386.0345.

[0067] Example 9

[0068] ​

[0069] Oxazine compound 1i (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol%), AgSbF6(16 mol%), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 8'-phenyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ia) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a ratio of 15:1:1. Product data characterization: white solid, 41% yield, melting range: 194-195 °C. NMR spectra are shown in Figure 17 and 18 as shown, 1 H NMR (400 MHz, CDCl3) δ 7.8-7.7 (m, 2H), 7.7 (dd, J = 8.2, 1.8 Hz, 1H), 7.7-7.6 (m, 2H), 7.5-7.4 (m, 2H), 7.4-7.4 (m, 1H), 7.2 (d, J = 3.0 Hz, 1H), 7.0-6.9 (m, 3H), 6.8 (td, J = 7.6, 1.7 Hz, 1H), 6.8-6.7 (m, 2H), 4.8 (d, J = 2.4 Hz, 1H), 4.8 (s, 1H), 4.4 (dd, J = 11.4, 2.5 Hz, 1H), 3.9 (d, J = 11.4 Hz, 1H). 13 CNMR (101 MHz, CDCl3) δ 150.71, 145.60, 143.33, 141.59, 139.99, 132.54, 130.94, 129.53, 128.97, 128.36, 127.84, 126.93, 123.85, 123.13, 121.94, 120.25, 119.39, 117.11, 116.63, 115.94, 109.40, 83.72, 67.69. HRMS [M+H] + calculated for C 26 H 20 NO3 + : 394.1438, found: 394.1447.

[0070] Example 10

[0071]

[0072] Oxazine compound 1j (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 8'-methoxy-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ja) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a proportion of 15:1:1. Product data characterization: white solid, 68% yield, melting range: 220-221 °C. NMR spectra are shown in Figure 19 and 20 1 H NMR (400 MHz, CD3OD) δ 7.71 (d, J = 8.6 Hz, 1H), 7.17 (d, J = 2.8 Hz, 1H), 7.12 (d, J = 2.7 Hz, 1H), 7.04 (dd, J = 8.6, 2.7 Hz, 1H), 6.85-6.80 (m, 2H), 6.80-6.74 (m, 2H), 6.72-6.66 (m, 1H), 6.64 (dd, J = 8.6, 2.8 Hz, 1H), 4.27 (d, J = 11.2 Hz, 1H), 3.85 (s, 3H), 3.72 (d, J = 11.2 Hz, 1H). 13 C NMR (101 MHz, CD3OD) δ 161.65, 153.49, 145.57, 144.45, 135.33, 133.38, 125.06, 124.95, 123.72, 122.74, 120.05, 119.72, 116.96, 116.72, 116.66, 116.32, 111.71, 109.59, 84.78, 68.40, 55.92. HRMS [M+H] + calculated for C 21 H 18 NO4 + : 348.1230, found: 348.1230.

[0073] Example 11

[0074]

[0075] ​Oxazine compound 1k (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 9'-trifluoromethyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ka) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. Product data characterization: white solid, 64% yield, melting range: 185-186 °C. NMR spectra as shown in Figure 21 and 22 1 H NMR (400 MHz, CDCl3) δ 7.92 (s, 1H), 7.69-7.59 (m, 2H), 7.24 (d, J = 2.9 Hz, 1H), 6.94 (d, J = 8.5 Hz, 2H), 6.91-6.81 (m, 2H), 6.77 (td, J = 8.2, 7.4, 2.3 Hz, 2H), 4.81 (d, J = 2.6 Hz, 1H), 4.73 (s, 1H), 4.39 (dd, J = 11.3, 2.6 Hz, 1H), 3.84 (d, J = 11.4 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 151.04, 145.73, 143.34, 135.34, 132.21 (q, J = 32.5 Hz), 131.61, 130.69, 126.20, 125.26 (q, J = 3.7 Hz), 122.57, 122.30, 121.00, 120.66, 119.77, 119.62 (q, J = 3.8 Hz), 118.32, 116.79, 116.25, 109.65, 83.69, 67.36. HRMS [M + H] + calculated for C 21 H 15 F3NO3 + : 386.0999, found: 368.1001.

[0076] Example 12

[0077]

[0078] ​Oxazine compound 1 1 (0.20 mmol), 1,4-benzoquinone compound 2a (0.3 mmol), [RuCl2(p-cymene)]2(2 mol% of oxazine compound), AgSbF6(8 mol% of oxazine compound), lithium acetate (0.44 mmol) and solvent trifluorotoluene (4.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 80 °C for 12 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 9'-chloro-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3la) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. Product data characterization: white solid, 29% yield, melting range: 123-124 °C. NMR spectra as shown in Figure 23 and 24 1 H NMR (400 MHz, CDC13) δ 7.62 (s, 1H), 7.43 (d, J = 8.2 Hz, 1H), 7.31 (d, J = 8.0 Hz, 1H), 7.13 (s, 1H), 6.99-6.78 (m, 4H), 6.78-6.59 (m, 2H), 4.86 (s, 1H), 4.80 (s, 1H), 4.35 (d, J = 11.0 Hz, 1H), 3.79 (d, J = 11.4 Hz, 1H). 13 C NMR (101 MHz, CDC13) δ 150.90, 145.90, 143.36, 136.21, 132.52, 130.84, 130.44, 128.64, 127.02, 122.81, 122.18, 121.09, 120.52, 119.70, 118.07, 116.77, 116.12, 109.60, 83.63, 67.58. HRMS [M+H] + calculated for C 20 H 15 ClNO3 + : 352.0735, found: 352.0736.

[0079] Example 13

[0080]

[0081] ​Oxazine compound 1m (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction, the solvent was removed under reduced pressure and the target product 9'-phenyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ma) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. Product data characterization: white solid, 65% yield, melting range: 159-160 °C. NMR spectra as shown in Figure 25 and 26 1 H NMR (400 MHz, CDCl3) δ 7.87 (s, 1H), 7.62 (d, J = 6.9 Hz, 2H), 7.57 (t, 2H), 7.48 (t, J = 7.5 Hz, 2H), 7.41 (t, J = 7.3 Hz, 1H), 7.32-7.27 (m, 1H), 6.96-6.89 (m, 2H), 6.87 (dd, J = 7.6, 1.6 Hz, 1H), 6.81 (td, J = 7.6, 1.6 Hz, 1H), 6.78-6.69 (m, 2H), 4.83 (d, J = 2.4 Hz, 1H), 4.74 (s, 1H), 4.42 (dd, J = 11.3, 2.5 Hz, 1H), 3.89 (d, J = 11.3 Hz, 1H). 13 C NMR (101 MHz, CDCl3) δ 150.81, 145.95, 143.47, 143.01, 140.49, 131.09, 129.12, 128.08, 127.59, 127.35, 125.88, 122.25, 122.09, 121.50, 120.34, 119.63, 117.37, 116.77, 116.00, 109.59, 83.71, 67.83. (Two carbon is not visible due to overlapping peaks). HRMS [M+H] + calculated for C 26 H 20 NO3 + : 394.1438, found: 394.1438.

[0082] Example 14 ​

[0083]

[0084] Oxazine compound 1n (0.20 mmol), 1,4-benzoquinone compound 2a (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 9'-methyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3na) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a ratio of 15:1:1. Product data characterization: white solid, 65% yield, melting range: 106-107 °C. NMR spectra are shown in Figure 27 and 28 1 H NMR (400 MHz, CDCl3) δ 7.48 (d, J = 1.7 Hz, 1H), 7.38 (d, J = 7.8 Hz, 1H), 7.22-7.14 (m, 2H), 6.92 (dd, J = 7.9, 1.5 Hz, 1H), 6.89-6.83 (m, 2H), 6.79 (td, J = 7.6, 1.6 Hz, 1H), 6.72 (dd, J = 7.6, 1.6 Hz, 1H), 6.68 (dd, J = 8.7, 2.9 Hz, 1H), 4.85 (s, 1H), 4.78 (d, J = 2.4 Hz, 1H), 4.36 (dd, J = 11.3, 2.4 Hz, 1H), 3.83 (d, J = 11.3 Hz, 1H), 2.41 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 150.71, 145.82, 143.38, 139.82, 131.17, 130.48, 129.58, 129.40, 125.23, 123.30, 122.33, 122.06, 120.21, 119.48, 117.07, 116.71, 115.92, 109.52, 83.67, 67.89, 21.60. HRMS [M+H] + calculated for C 21 H 18 NO3 + : 332.1281, found: 332.1280.

[0085] Example 15 ​

[0086]

[0087] Oxazine compound la (0.20 mmol), 1,4-benzoquinone compound 2b (0.44 mmol), dichloro(pentamethylcyclopentadienyl) rhodium (III) dimer (4 mol%), AgSbF6(16 mol%), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 3',4'-dimethyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ab) was obtained by silica gel column separation. All eluents were prepared in a ratio of 15:1:1 of petroleum ether and ethyl acetate and dichloromethane. Product data characterization: white solid, 45% yield, melting range: 185-186 °C. NMR spectra are shown in Figure 29 and 30 1 H NMR (400 MHz, CDCl3) δ 7.66 (dd, J = 7.8, 1.2 Hz, 1H), 7.51 (dd, J = 7.6, 1.4 Hz, 1H), 7.45 (td, J = 7.6, 1.4 Hz, 1H), 7.35 (td, J = 7.5, 1.3 Hz, 1H), 7.03 (s, 1H), 6.95-6.84 (m, 2H), 6.84-6.72 (m, 2H), 4.77 (d, J = 2.5 Hz, 1H), 4.52 (s, 1H), 4.34 (dd, J = 11.1, 2.5 Hz, 1H), 3.85 (d, J = 11.2 Hz, 1H), 2.18 (s, 3H), 2.08 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 148.68, 143.75, 143.71, 132.32, 131.41, 131.39, 129.79, 128.36, 128.21, 125.21, 125.00, 122.57, 121.77, 120.27, 119.39, 116.49, 116.18, 106.50, 83.56, 67.64, 12.33, 12.06. HRMS: [M+H] + calculated for C 22 H 20 NO3 + : 346.1438, found: 346.1441.

[0088] Example 16

[0089] ​

[0090] Oxazine compound la (0.20 mmol), 1,4-benzoquinone compound 2c (0.44 mmol), [RuCl2(p-cymene)]2(4 mol% of oxazine compound), AgSbF6(16 mol% of oxazine compound), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 3'-methoxy-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ac) was obtained by silica gel column separation. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in a ratio of 15:1:1. Product data characterization: white solid, 61% yield, melting range: 163-164 °C. NMR spectra are shown in Figure 31 and 32 1 H NMR (400 MHz, CDCl3) δ 7.62 (dd, J = 7.9, 1.2 Hz, 1H), 7.45 (qd, J = 7.7, 1.4 Hz, 2H), 7.34-7.27 (m, 2H), 6.93 (dd, J = 7.8, 1.5 Hz, 1H), 6.88 (td, J = 7.5, 1.6 Hz, 1H), 6.80 (td, J = 7.6, 1.7 Hz, 1H), 6.74 (dd, J = 7.7, 1.7 Hz, 1H), 6.57 (s, 1H), 5.35 (s, 1H), 4.80 (d, J = 2.4 Hz, 1H), 4.43 (dd, J = 11.2, 2.3 Hz, 1H), 3.86 (d, J = 11.3 Hz, 1H), 3.84 (s, 3H). 13 C NMR (101 MHz, CDCl3) δ 148.09, 145.64, 143.41, 141.08, 131.16, 131.02, 130.87, 129.96, 127.70, 125.16, 122.08, 122.05, 120.21, 116.72, 115.95, 113.86, 108.29, 101.67, 83.90, 67.83, 56.20. HRMS [M+H] + calculated for C 21 H 18 NO4 + : 348.1230, found: 348.1230.

[0091] Example 17

[0092] ​

[0093] Oxazine compound la (0.20 mmol), 1,4-benzoquinone compound 2d (0.44 mmol), [RuCl2(p-cymene)]2(4 mol%), AgSbF6(16 mol%), Cu(OAc)2(0.4 mmol) and solvent DCE (2.0 mL) were added into a 10 mL sealed tube and reacted in a reaction module at 30 °C for 16 h. After the reaction was completed, the solvent was removed under reduced pressure, and the target product 4'-tert-butyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ad) and 3'-tert-butyl-2H,4H-spiro[benzo[b][1.4]oxazine-3,6'-benzo[c]chromene]-2'-ol (3ad') were separated by silica gel column. All eluents were petroleum ether and ethyl acetate and dichloromethane prepared in the proportion of 15:1:1. 3ad product data characterization: white solid, 23% yield, melting range: 155-156 °C. NMR spectra as shown in Figure 33 and 34 1 H NMR (400 MHz, CDC13) δ 7.70 (d, J = 7.8 Hz, 1H), 7.54-7.43 (m, 2H), 7.38 (t, J = 7.5 Hz, 1H), 7.13 (d, J = 3.0 Hz, 1H), 6.92-6.75 (m, 4H), 6.70 (dd, 1H), 4.78 (d, 1H), 4.56 (s, 1H), 4.48 (dd, J = 11.2, 2.4 Hz, 1H), 4.04 (d, J = 11.1 Hz, 1H), 1.24 (s, 9H). 13 C NMR (101 MHz, CDC13) δ 149.74, 144.41, 143.24, 141.69, 131.82, 131.30, 130.96, 129.79, 128.52, 124.47, 123.24, 122.30, 121.85, 120.17, 116.67, 115.61, 115.57, 107.15, 83.09, 68.03, 34.97, 29.81. HRMS [M + H] + calculated for C 24 H 24 NO3 + : 374.1751, found: 374.1758. 3ad' product data characterization: white solid, 23% yield, melting range: 124-125 °C. NMR spectra as shown in Figure 35 and 36 ​shown, 1H NMR (400 MHz, CDC13) δ 7.65 - 7.58 (m, 1H), 7.50 (dd, J = 7.7, 1.4 Hz, 1H), 7.43 (td, J = 7.6, 1.4 Hz, 1H), 7.34 (td, J = 7.5, 1.2 Hz, 1H), 7.02 (s, 1H), 6.97 - 6.91 (m, 2H), 6.89 (td, J = 7.5, 1.5 Hz, 1H), 6.81 (td, J = 7.6, 1.6 Hz, 1H), 6.75 (dd, J = 7.7, 1.6 Hz, 1H), 4.79 (d, J = 2.3 Hz, 1H), 4.74 (s, 1H), 4.42 (dd, J = 11.2, 2.4 Hz, 1H), 3.85 (d, J = 11.3 Hz, 1H), 1.38 (s, 9H). 13 C NMR (101 MHz, CDC13) δ 149.43, 145.40, 143.36, 139.28, 131.71, 131.20, 130.52, 129.83, 128.36, 125.43, 122.14, 122.07, 120.18, 119.09, 117.34, 116.77, 115.92, 110.34, 83.68, 67.97, 34.92, 29.64. HRMS [M + H] + calculated for C 24 H 24 NO3 + : 374.1751, found: 374.1758.

[0094] Antifungal performance test

[0095] The antifungal effect of the spiropyran compound 3aa synthesized in Example 1 was determined by mycelial growth rate method, and the colony growth diameter (minus the fungus cake diameter) was measured by cross method, and the growth inhibition rate of the spiropyran compound on different strains was calculated according to the following formula.

[0096]

[0097] At the concentration gradient of 200, 100, 50, 25, 12.5, 6.25 μg·mL -1 (ppm), three parallel tests were repeated, CK was blank medium control group without adding drugs, the antifungal activity of the spiropyran compound was determined by mycelial growth rate method, and the antifungal test photos were as follows Figure 37, the results are shown in Table 1, the target compound has good fungicidal activity to the four pathogenic fungi measured, which can provide research ideas for the design and modification of spiropyrans; in addition, the fungistatic performance of compound 3ha synthesized in Example 8 on R. cornis (Rc) was further tested, and the fungistatic test photos are as follows Figure 38 , the results are shown in Table 2, compound 3ha exhibits higher fungistatic activity to Rc.

[0098] Table 1 Fungistatic rate of spiropyrans compound 3aa

[0099]

[0100] Table 2 Fungistatic rate of spiropyrans compound 3ha

[0101] Strain 200 ppm inhibition rate 100 ppm inhibition rate 50 ppm inhibition rate Rc (Lagenidium giganteum) 57.26％ 19.72％ 16.53％

[0102] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for synthesizing a spiropyran compound, characterized by, The reactants, oxazine compound, 1,4-benzoquinone compound and catalyst, additive are added into the solvent to react under inert atmosphere, and after the reaction, the spiropyran compound is prepared; The additive is any one of copper acetate, sodium acetate, lithium acetate or sodium bicarbonate; The catalyst is composed of a ruthenium catalyst / rhodium catalyst and a silver salt, and the molar ratio of the ruthenium catalyst / rhodium catalyst and the silver salt is 1:4; The ruthenium catalyst is [RuCl2(p-cymene)]2, the rhodium catalyst is dichloro(pentamethylcyclopentadienyl) rhodium(III) dimer, and the silver salt is silver hexafluoroantimonate; The reaction formula is shown as follows: ， wherein: R is H, Me, F, Cl, Br, or t R1is Me, Cl, or Br; and Ar is a phenyl ring substituted with any of Me, OMe, Cl, Br, or CF3. t R1is Me, Cl, or Br; and Ar is a phenyl ring substituted with any of Me, OMe, Cl, Br, or CF3.

2. The method of claim 1, wherein the spiropyran compound is represented by the following formula 1: ###0001### Formula 1 The molar ratio of the oxazine compound, 1,4-benzoquinone compound, catalyst and additive is 1:(1.1-2.2):(0.1-0.2):(1.1-2.2).

3. The method for synthesizing spiropyran compounds according to claim 2, wherein: The concentration of the oxazine compound in the solvent is 0.05 M-0.1 M.

4. The method of claim 3, wherein the spiropyran compound is represented by the following formula 1 : ###0001### Formula 1 The solvent is any one of 1,2-dichloroethane, dichloromethane, ethylene glycol dimethyl ether or trifluorotoluene.

5. The method of claim 4, wherein the spiropyran compound is represented by the following formula: ###0002### 5 The inert atmosphere is a nitrogen atmosphere.

6. The method for synthesizing spiropyran compounds according to claim 5, wherein: The reaction temperature is 30 ℃-80 ℃, and the reaction time is 12 h-24 h.

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