JPH04112885A - Spiropyran compound and production thereof - Google Patents

Abstract

NEW MATERIAL:A compound shown by formula I [group shown by formula II is (substituted) 7-norbornylidene; group shown by formula III is (substituted) aromatic hydrocarbon or unsaturated heterocyclic ring; R1 and R2 are H, alkyl, aralkyl, aryl or substituted amino]. EXAMPLE:A compound shown by formula IV. USE:A photochromic material reversely changing from a colorless state to a colored state by ultraviolet rays such as sunlight or mercury lamp and showing excellent durability. PREPARATION:A compound shown by formula V is reacted with a compound shown by formula VI preferably 1:10-10:1 (molecular ratio) in the presence of a condensation agent (e.g. pyrrolidine) at 0-200 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is characterized in that the present invention changes from colorless to colored or darkly colored form with light including ultraviolet rays such as sunlight or light from a mercury lamp.
This invention relates to a novel spiropyran compound whose changes are reversible and which exhibits excellent durability.

(Prior Art and Problems to be Solved by the Invention) Photochromism is a phenomenon that has attracted attention over the past few years.When a certain compound is irradiated with light containing ultraviolet light, such as sunlight or light from a mercury lamp, photochromism immediately This is a reversible effect in which the color changes and returns to the original color when you stop exposing it to light and place it in a dark place. Compounds having this property are called photochromic compounds, and various compounds have been synthesized to date, but no particular common skeleton is recognized in their structures.

JP-A-63-66178 describes spiroadamancune compounds in which an adamantylidene group is present at the 2-position of a benzopyran ring or a naphthopyran ring. These spiroadamancun compounds are produced at around room temperature (
It is a compound that exhibits photochromic properties even at temperatures of 10 to 40°C, and is generally known to change color from colorless to yellow to orange.

However, these spiroadamancun compounds
This is thought to be due to its noble adamantylidene group,
The colored form is relatively stable and the rate of fading due to ambient temperature is not very fast.

Furthermore, JP-A-2-69471 describes a spironorbornane compound in which a 2-norbornylidene group is present at the 2-position of a benzopyran ring or a naphthopyran ring. These spironorbornane compounds are heated at around room temperature (10 to 4
It exhibits photochromic properties even at 0°C) and is a compound that fades quickly, changing from colorless to yellow to orange.

However, these spironorbornane compounds have poor durability, probably due to the presence of secondary carbon next to spirocarbon.

(Means for Solving the Problems) As a result of intensive research to further improve the photochromic properties of the above-mentioned compounds, the present inventors succeeded in synthesizing a novel spiropyran compound. It was discovered that the color fading rate is fast and the durability is good, leading to the completion of the present invention.

That is, the present invention provides - formula (I) R.

It is an aromatic hydrocarbon group or an unsaturated heterocyclic group which may be substituted, and R1 and R2 are the same or different hydrogen atoms, alkyl groups, aralkyl groups, aryl groups, or substituted amino groups, respectively. ] This is a spiropyran compound represented by

Represents a substituted 7-norbornylidene group. Specific examples of the substituent include, for example, hydroxy group; substituted amino groups such as methylamino group and diethylamino group; alkoxy groups having 1 to 4 carbon atoms such as methoxy group, ethoxy group, and tert-butoxy group; benzyloxy Aralkoxy groups having 7 to 15 carbon atoms such as groups; Aryloxy groups having 6 to 14 carbon atoms such as phenoxy groups and l-naphthoxy groups; Lower groups having 1 to 4 carbon atoms such as methyl groups, ethyl groups, and t-butyl groups. Alkyl group;
Halogen atoms such as fluorine, chlorine, and oxaline; cyano groups;
Carboxyl group: 2 or more carbon atoms such as ethoxycarbonyl group
10 alkoxycarbonyl groups; halogen-substituted alkyl groups having 1 or 2 carbon atoms such as trifluoromethyl groups; nitro groups; aryl groups such as phenyl groups and tolyl M; aralkyl groups such as phenylethyl groups and phenylpropyl groups, etc. In addition, these substituents are not only included as l-substituted products, but may also be included as polysubstituted products having two or more substituents, and furthermore, substituents in polysubstituted products There is no problem whether they are the same or different, and the position of the substituent can be changed depending on the purpose or use.

They are an aromatic hydrocarbon group or an unsaturated heterocyclic group, each of which may be substituted. More specific examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups derived from one benzene ring or 2 to 4 condensed rings thereof such as benzene ring, naphthalene ring, phenanthrene ring, toluene, xylene, etc. In addition, an alkoxy group, a hydroxyl group, a nitro group, a cyano group, a trifluoromethyl group, a substituted amino group, a halogen atom, or a heterocyclic group is added to the above aromatic hydrocarbon group.
Examples include substituted aromatic hydrocarbon groups substituted with one or more substituted aromatic hydrocarbon groups. In addition, the above-mentioned unsaturated heterocyclic group represented by α includes a 5-membered ring containing oxygen, sulfur, and nitrogen atoms;
Examples include a 6-membered ring or a heterocyclic group in which a benzene ring is fused to the 6-membered ring. Specifically, 2 derived from nitrogen-containing heterocycles such as pyridine ring, quinoline ring, and pyrrole ring; oxygen-containing heterocycles such as furan ring and benzofuran ring; and sulfur-containing heterocycles such as thiophene ring and benzothiophene ring. is a valent heterocyclic group. Furthermore, substituted unsaturated heterocyclic groups in which these unsaturated heterocyclic groups are substituted with the substituents described in the description of the aromatic hydrocarbon group described above are also employed without any limitations in the present invention.

Further, in the formula (I), the groups represented by RI and R2 are the same or different hydrogen atoms, alkyl groups, aralkyl groups, aryl groups, or substituted amino groups, respectively. The alkyl group mentioned above is not particularly limited, but generally an alkyl group having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms, is suitably used. The aralkyl group preferably has 7 to 16 carbon atoms, and the alkyl group contained therein generally has 1 carbon number.
~IO1, preferably 1 to 4 are suitable. More specific examples of these alkyl groups and aralkyl groups include methyl, ethyl, propyl, butyl, benzyl, phenylethyl, phenylpropyl, and phenylbutyl groups. Further, the aryl group preferably has 6 to 14 carbon atoms, and for example, phenyl group, tolyl group, xylyl group, naphthyl group, etc. are suitable.

Furthermore, in the above-mentioned formula (I), the groups R1 and R2 are:
Either one of R3 and R4 is a hydrogen atom and the other is an alkyl group, or each represents the same or different alkyl group. The alkyl group is not particularly limited, but specifically, the same groups as the above-mentioned examples of the alkyl group can be employed. Furthermore, R5 is an alkylene group having 3 to 6 carbon atoms such as a tetramethylene group or a pentamethylene group, CHzCHOCHz CHzOCHz
CHz-CH.

CH2CH20CH2CH2CH20(CH2)3-1
Oxyalkylene groups having 3 to 6 carbon atoms such as, CHz
SCHzCth CIh5(CHz) :ICH
CH having 3 to 6 carbon atoms, such as zCHzSCHzCHz-.

oalkylene group, CHJCHzCHz-number of atoms 3 to 6
Azoalkylene groups and the like are preferably employed.

The compound represented by the above general formula (I) of the present invention generally exists as a colorless or pale yellow solid or viscous liquid at room temperature and pressure, and can be prepared by the following means (a) to (c). You can check it here. 1 (a) By measuring proton nuclear magnetic resonance spectra ('H-NMR), it is possible to know the type and number of protons present in a molecule. That is, there is a peak based on aromatic protons around 67 to 8.5 ppm, and a peak at 61.2 to 2.5 ppm.
A broad peak based on protons derived from the 7-norbornylidene group near pm, 65.5 to 7.5 when R is a hydrogen atom. A peak based on protons appears near Oppm. Furthermore, by relatively comparing the respective δ peak intensities, the number of protons of each bonding group can be determined.

(0) Each weight percent of carbon, hydrogen, nitrogen, sulfur, and halogen can be determined by elemental analysis. Furthermore, the weight percent of oxygen can be calculated by subtracting the sum of the recognized weight percent of each element from 100. The composition of the corresponding product can therefore be determined.

(c) 13C-Nuclear Magnetic Resonance Spectrum ("C-N?I
By measuring R), the type of carbon present in the molecule can be known. 7- around δ27-52ρρm
A peak derived from the carbon of the norbornylidene group, a peak derived from the carbon of the alkyl group around 615 to 35 ppm when Rt and R2 are alkyl groups, 6110 to 15
A peak based on carbon of an aromatic hydrocarbon group or an unsaturated heterocyclic group appears near 0 ppm.

The method for producing the compound represented by the general formula (1) of the present invention is as follows:
It is not particularly limited and may be obtained by any synthesis method. Representative methods that are generally suitably adopted will be explained below.

A compound represented by the following general formula (II) and a norbornylidene group represented by the general formula (II[). ) In the presence of a condensing agent, R or R2 in formula (I) is a hydrogen atom or a substituted amino group, and at least one of the compounds is a substituted amino group. can be obtained.

Above - Compound represented by formula (I[) and general formula H(I[
The reaction with the compound represented by [) is carried out as follows. The reaction ratio of these two types of compounds can be adopted from a wide range, but is generally selected from the range of 1:10 to 10:1 (molar ratio).

The reaction temperature is usually preferably 0 to 200°C, and the solvent used is a polar aprotic solvent such as N-methylpyrrolidone, dimethylformamide, or tetrahydrofuran. In this reaction, a condensing agent typified by secondary amines such as pyrrolidine, piperidine, and morpholine is usually used in an amount of 0.1 to 10 mol per mol of the compound represented by general formula (II). The reaction can be completed by removing the water produced during the reaction. Water can be removed by using a Dean-Stark device to remove water from the reaction system, or by adding calcium chloride, calcium oxide, and zinc chloride to the reaction system and using these dehydrating agents to remove water from the reaction system. There are ways to remove the water that forms inside, and any of these methods may be used.

This reaction is similar to the following formula (IV) (1). ] A chromanone compound represented by the following is obtained. Then, if the above reaction is continued further, in the above-mentioned formula (1), R
, or the same as the following formula (V) (1) in which at least one of R2 is a substituted amine group. ] The chromanol compound represented by is obtained and then dehydrated using a dehydrating agent such as anhydrous copper sulfate, which is the same as the following formula (I), and R1 and R2 are the same or different hydrogen atoms or substituted hydrogen atoms, respectively. It is an amino group, and at least one of them is a substituted amino group. ] A compound represented by the following is obtained.

- In the above-mentioned formula (1), the compound in which both R and R2 are hydrogen atoms is obtained by reacting the chromanone compound represented by the above (IV) with a reducing agent such as sodium borohydride or lithium aluminum hydride. This is the same as the following formula (I). ] A compound represented by the following is obtained.

In the above formula (I), the compound in which R3 is an alkyl group, an aralkyl group, or an aryl group can be obtained by reacting a chromanone compound represented by the above formula (IV) with an organometallic compound such as an alkylmagnesium halide or an alkyllithium halide. , is the same as the following formula (I), and R+ is an alkyl group, an aralkyl group, or an aryl group. ] By obtaining a chromanol compound represented by and then dehydrating it using a dehydrating agent such as anhydrous copper sulfate, it is the same as the following formula (1), and R is an alkyl group, an aralkyl group, or an aryl group. be. ] A compound represented by the following is obtained.

Further, in the above-mentioned formula (1), R2 is an alkyl group,
Compounds that are an aralkyl group or an aryl group include the above (V)
The compound represented by the following formula (
VT) Same as (1), R2 is an alkyl group, an aralkyl group, or an aryl group. ] A chromanone compound represented by is obtained, reduced with a reducing agent similar to that described above, and further dehydrated using a dehydrating agent to obtain a compound having the same formula as shown below, where R2 is an alkyl group, an aralkyl group, or an aryl group. It is the basis. ] A compound represented by the following is obtained. Furthermore, by reacting the chromanone compound represented by the above (VI) with an organometallic compound such as alkylmagnesium halide in the same manner as described above, and then dehydrating it using a dehydrating agent, a compound similar to the following formula, R , and R2 are the same or different alkyl groups, aralkyl groups, and aryl groups, respectively. ] A compound represented by the following is obtained.

The spiropyran compound represented by the above formula (1) of the present invention is well soluble in common organic solvents such as toluene, chloroform, and tetrahydrofuran.

When the spiropyran compound represented by the general formula [I] is dissolved in such a solvent, the solution is generally almost colorless and transparent, but when exposed to sunlight or ultraviolet light, it quickly changes color or darkens, and when the light is blocked, the solution becomes almost colorless and transparent. It exhibits a good reversible photochromic effect that quickly returns to its original colorless state. Such a photochromic effect in the compound of formula (1) occurs even in a polymer solid matrix, and the reversible speed occurs on the order of seconds. Such a target polymer matrix includes the general formula CI of the present invention.
) can be uniformly dispersed, and optically preferable examples include polymethyl acrylate, polyethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polystyrene, polyacrylonitrile, and polyvinyl. Polymers such as alcohol, polyacrylamide, poly(2-hydroxyethyl methacrylate), polydimethylsiloxane, polycarbonate, poly(allyl diglycol carbonate), or the heptamers forming these polymers with each other or with other monomers. Polymers formed by copolymerizing with and the like are preferably used.

The photochromic action of the spiropyran compound of the present invention is particularly superior in fading speed compared to conventional spiroadamantane compounds.

In addition, it is particularly more durable than the above-mentioned spironorbornane compound.

Therefore, the spiropyran compound of the present invention can be widely used as a photochromic material, such as various storage materials in place of silver salt photosensitive materials, photographic materials, photoreceptors for printing, recording materials for cathode ray tubes, photosensitive materials for lasers, and holography. It can be used as a variety of recording materials such as photosensitive materials. In addition, the photochromic material using the spiropyran compound of the present invention can also be used as a material for photochromic lenses, optical filter materials, display materials, photometers, decorations, and the like. For example, when used in a photochromic lens, there is no particular restriction as long as the method provides uniform light control performance.A specific example is a polymer film formed by uniformly dispersing the photochromic material of the present invention. How to sandwich it into a lens, or
For example, by dissolving this compound in silicone oil,
There is a method in which the lens surface is impregnated at 0 to 200°C for 10 to 60 minutes, and then the surface is further coated with a curable substance to form a photochromic lens. Another possible method is to apply the above polymer film to the lens surface and coat the surface with a curable substance to make a photochromic lens.

When acting on such a photochromic lens, a photochromic material that develops a deep color when exposed to sunlight at around room temperature is preferable. Preferred compounds for such photochromine lenses are compounds that are divalent groups derived from the above-mentioned general threne ring, pyridine ring, or quinoline ring.

In particular, compounds in which both R3 and R2 are hydrogen atoms have the advantage of developing a particularly deep color and fading quickly.

Further, by selecting each substituent of R1 or R2 in the above-mentioned general formula (1), the fading rate of the compound of -Funenin (1) can be changed. For example, when R1 and R2 are alkyl groups, a fast color fading rate can be obtained, probably because it is difficult to take the trans form of the coloring state. Furthermore, when R1 is a substituted amino group, the trans form in the coloring state is stabilized by resonance, and while a high coloring density can be obtained, the fading rate is a little slow. Each substituent for R and R2 can be arbitrarily selected depending on the purpose.

〔effect〕

The spiropyran compound represented by the general formula (I) of the present invention is
In a solid polymer matrix, the type of the matrix does not affect the quality of the matrix, and although it is stable and colorless when fishing on a boat, it immediately develops a color when exposed to ultraviolet rays. When discontinued, it returns to its original colorless state at a fast fading rate on the order of seconds, and has the property of repeating these discolorations with good durability.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 10 g of 1,-hydroxy-2-acetonaphthone (0,0
54n+ol) 7-norbornalane 6,6 g (
0,06 mol) and pyrrolidine 8 g (0,113+
A solution was prepared by dissolving mol) in 300 cc of toluene. The mixture was boiled for 10 hours and the water was separated.

After the reaction was completed, toluene was removed under reduced pressure, and the remaining chromanone compound was crystallized from acetone. Next, this chromanone compound was dissolved in 200 cc of methanol,
Sodium borohydride was added slowly to give the chromanol compound. 7.47 g of this chromanol compound
with 4.5 g of anhydrous copper sulfate in a stream of carbon dioxide.
Heating at ˜160° C. for 10 minutes and purification of the brown viscous liquid by chromatography on silica gel yielded 6.3 g of a spiropyran compound of the following formula.

The elemental analysis values of this compound are CB6.93%, H6.8
9%, 06.18% and calculated value for Cl9H11IO C 87.02%, H6, 87%, 06
．． It was in very good agreement with 12%. In addition, when proton nuclear magnetic resonance spectrum (Fig. 1) was measured, it was found that 67.2
A peak of <6H based on the proton of the naphthalene ring around 8.3 ppm, a peak of <2H based on the proton of the alkene around 65.6 to 6.7 ppm, a peak of <2H based on the proton of the alkene around 65.6 to 6.7 ppm, 61.2 to 2.
A broad peak of <IOH based on the proton of 7-norbornylidene group was shown around 5 ppm. Furthermore, when we measured the 13c-nuclear magnetic resonance spectrum, we found that δ27~52p
A peak based on the carbon of the 7-norbornylidene group appears near p-, a peak based on the carbon of the naphthalene ring appears near 6110 to 160 ppm, and a peak based on the carbon of the double bond appears near 680 to 110 ppm. From the above results, it was confirmed that the isolated product was a compound represented by the above structural formula (1).

Example 2 1-acetyl-2-naphthol 10 g (0,054
mol ) and 7-norbornane 6,6 g (0,06
mol) and morpholine 8.7 g (0,1On+ol
) was dissolved in 300 cc of toluene to prepare a solution.

The mixture was boiled for 5 hours and the water was separated. After the reaction was completed, toluene was removed under reduced pressure, and the remaining chromanone compound was recrystallized from acetone. Next, this chromanone compound was dissolved in 200 cc of methanol, and lithium aluminum hydride was added to obtain a chromanol compound. 6.49 g of this chromanol compound was mixed with anhydrous copper sulfate in a carbon dioxide stream at 170-180°C for 10 minutes.
After heating for minutes, the brown viscous liquid was purified by chromatography on silica gel to obtain 5.1 g of a spiropyran compound of the following formula.

The elemental analysis values of this compound are C86,86%, H6,9
1%, 06.22% and calculated values for Cl9H1aO C 87.02%, H6, 87%, 06.
It was in very good agreement with 12%. In addition, when proton nuclear magnetic resonance spectrum was measured, 67.2 to 8.3 pp.
-A <6H peak based on the proton of the naphthalene ring near 65.9 to 7. <2H peak based on the alkene proton near Opp+m, 10H peak based on the 7-norbornylidene group proton near 61.2-2.5 ppm
showed a broad peak. Furthermore, when the l30-nuclear magnetic resonance spectrum was measured, a peak based on the carbon of the 7-norbornylidene group was observed at around 627 to 55 pp■, and a peak based on the carbon of the 61
Based on the carbon of the naphthalene ring (around 10 to 160 ppm)
A peak based on double bond carbon appears around 690 to 110 pp+n. From the above results, it was confirmed that the isolated product was a compound represented by the above structural formula (2).

Example 3 Chromanone compound represented by the following formula obtained in Example 2 2.
Dissolve 78 g (0.01 mol) in 50 cc of anhydrous ether,
Cool the solution to 0 °C and add freshly prepared Grignard reagent CHJgl (0,
012■01) was added dropwise into the solution over a period of about 1 hour.

After the addition was completed, the ether solution was stirred for another 2 hours at room temperature, the ether solution was gently poured into cold water, the product was extracted with ether, the solution was dried over magnesium sulfate, the ether was removed under reduced pressure, and the chromanone The compound was changed to a chromanol compound. This chromanol compound was then heated with anhydrous copper sulfate in a stream of carbon dioxide at 200"C for about 10 minutes, and the brown viscous liquid was purified by chromatography on silica gel to obtain spiropyran compound 2.24 g of the following formula: I got it.

Melt 1) and 7 Holin 8°, and after finishing, dissolve 7.5 Norbornane 6,6 g (0,06a+ol) and Morph g (0,10a+ol) in 300c of toluene.
The mixture was boiled for 15 hours and the water was separated. The reaction toluene was removed under reduced pressure, and the remaining product was recrystallized to obtain 3g of the following formula.

As in Example 2, by elemental analysis, proton nuclear magnetic resonance spectrum, and C-nuclear magnetic resonance spectrum measurements,
This compound was confirmed to be a compound represented by the above structural formula (3). Table 2 shows the elemental analysis values of this compound and the calculated values calculated from the compositional formula of compound (3).

Example 4 1-acetyl-2-naphthol 10 g (0,054
Next, 7.53 g of this compound was added to methanol at 100C.
By dissolving in C and reacting with methyl iodide,
6.95'g of a chromanone compound represented by the following formula was obtained.

Next, the produced chromanone compound was changed into a chromanol compound in the same manner as in Example 2, and a dehydration reaction was carried out. After separation and purification, a spiropyran compound 5.8 of the following formula was obtained.
4 g was obtained.

The elemental analysis value of the compound (4) and the calculated value calculated from the compositional formula of compound (4) are shown.

Examples 5-30 Various spiropyran compounds were synthesized from the raw materials shown in Table 1 in the same manner as in Examples 1-4. However, in Table 1, Examples 5 to 9 were conducted in the same manner as Example 4, Examples 1O to 25 were conducted in the same manner as Example 1, and Examples 26 to 30 were conducted in the same manner as Example 3 or 4. Ta.

As a result of structural analysis of the obtained product using the same structural confirmation method as in Example 1, it was confirmed that it was a compound represented by the structural formula shown in Table 1. Further, Table 2 shows the elemental analysis values of this compound and the calculated values obtained from the structural formula of each compound.

As in Example 2, this compound was confirmed to be a compound represented by the above structural formula (4) by elemental analysis, proton nuclear magnetic resonance spectrum, and 1''' C-nuclear magnetic resonance spectrum measurements. Table 2 shows Example 31 The compound of the following formula synthesized in Example 1 was dissolved and decomposed in polymethyl methacrylate using benzene, and a cast film was made on a slide glass (11.2×3.7Ω). The concentration of the above compound contained in this film was adjusted to 1.OX 10 mol/g, and the thickness was adjusted to 0.1 mm.

A mercury lamp 5HL-100 manufactured by Toshiba ■ was placed on this photochromic film at 25 ± 1°C and at a distance of 10C11.
The film was irradiated for a second to develop color, and its photochromic properties were measured. The photochromic properties were expressed as follows. The results are shown in Table 3.

Maximum absorption wavelength (λ□X); ■Hitachi spectrophotometer 2
The λm□ of this coloring film was determined using 2OA.

ε (60 seconds): Absorbance of this film at the maximum absorption wavelength after 60 seconds of light irradiation under the above conditions.

ε (0 seconds); Absorbance of the unirradiated film at the maximum absorption wavelength during light irradiation.

half-life I/Z, the time required for the absorbance of this film to decrease to 172 of (ε(60 seconds) ε(0 seconds)) after light irradiation for 6Ω seconds.

Lifespan TI/Z, Xenon Long Life Fade Meter FAL-250AX-HC' manufactured by Suga Test Instruments Co., Ltd. is used for the above photochromic film. 'The time required for the color density to decay to the initial level of 172 when irradiated with ultraviolet rays.

Examples 32 to 60 In the same manner as in Example 31, the photochromic properties of the compounds produced in Examples 2 to 30 were measured in the same manner as in Example 31. The results are shown in Table 3. For comparison, films were similarly prepared and measured for the photochromic properties of spiroadamancune compounds and spironorbornane compounds shown in (31) and (32) below.

4,

[Brief explanation of drawings]

Figure 1 shows the spiropyran compound obtained in Example 1. nuclear magnetic resonance spec Tor's cha It is Ru.

Claims (4)

[Claims] (1) The following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is an optionally substituted 7-norbornylidene group, and ▲ Numerical formulas, chemical formulas, tables, etc. ▼ is an optionally substituted aromatic hydrocarbon group or unsaturated heterocyclic group, and R_
1 and R_2 are the same or different hydrogen atoms, alkyl groups, aralkyl groups, aryl groups, or substituted amino groups, respectively. ] A spiropyran compound represented by (2) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ are respectively optionally substituted aromatic hydrocarbon groups or unsaturated heterocyclic groups . ] and the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is an optionally substituted 7-norbornylidene group.] The following formula ▲ includes mathematical formulas, chemical formulas, tables, etc.▼ [However, ▲ includes mathematical formulas, chemical formulas, tables, etc. ▼ may be substituted. It is a 7-norbornylidene group, and ▲ has a numerical formula, chemical formula, table, etc. ▼ is an optionally substituted aromatic hydrocarbon group or unsaturated heterocyclic group, and R_
1 and R_2 are the same or different hydrogen atoms or amino groups, respectively, and at least one is a substituted amino group. ] A method for producing a spiropyran compound. (3) General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ are respectively optionally substituted aromatic hydrocarbon groups or unsaturated heterocyclic groups . ] and the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ is an optionally substituted 7-norbornylidene group. ] In the presence of a condensing agent, a compound represented by the general formula [However, ▲ has a mathematical formula, a chemical formula, a table, etc. ▼ is an optionally substituted 7-norbornylidene group, and ▲ formula, There are chemical formulas, tables, etc. where ▼ is an optionally substituted aromatic hydrocarbon group or unsaturated heterocyclic group. ] The following formula, which is characterized by obtaining a compound represented by, then reducing this compound, and further dehydrating it ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ , is an optionally substituted 7-norbornylidene group, ▲ has a numerical formula, chemical formula, table, etc. ▼ is an optionally substituted aromatic hydrocarbon group or unsaturated heterocyclic group, R_
1 and R_2 are hydrogen atoms. ] A method for producing a spiropyran compound shown by. (4) A photochromic material comprising a spiropyran compound according to claim (1).