JPH0684380B2 - Photochromic compound and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel photochromic compound having a photochromic action and a method for producing the same.

(Problems to be Solved by Prior Art and Invention) Photochromism is a phenomenon that has been attracting attention for several years, and when a compound is irradiated with light including ultraviolet rays such as sunlight or the light of a mercury lamp, it is prompt. It is a reversible action that changes color and returns to the original color when the light is stopped and placed in the dark. A compound having this property is called a photochromic compound, and various compounds have been conventionally synthesized, but no special common structure is recognized in the structure.

In recent years, among these various photochromic compounds, the following general formula [However, Represents a substituted or unsubstituted adamantylidene group,
R'represents hydrogen, an aryl group, an aralkyl group, or a heterocyclic group, and X'is an oxygen atom or N-R "(wherein R" is hydrogen, an aryl group, an aralkyl group, or a heterocyclic group). .), Is an aromatic group or an unsaturated heterocyclic group. The fulgide compound represented by the formula [1] is a series of photochromic compounds having a high photosensitivity that absorbs ultraviolet rays to be colored and rapidly returns to white light. However, such compounds show a tendency to return to a colorless form in white light and are therefore not or hardly colored in sunlight.

Further, it is known that the above-mentioned fulgide compound becomes a photochromic compound having the following structure which is colored by sunlight when heated or irradiated with ultraviolet rays (JP-A-60-155179).

[In the formula R ′ and X ′ are the same as the above formula, Is an aromatic group or an unsaturated heterocyclic group. ] Since this compound has a cage-like adamantylidene group that is hard and strain-free, it weakens the single bond that forms part of the 6-membered ring, and facilitates electron-cyclic ring-opening by sunlight irradiation. And result in a colored form. However,
The above-mentioned colored form of the photochromic compound is thermally unstable, and a sufficient coloring density cannot be obtained at a temperature slightly higher than room temperature.

(Means for Solving the Problems) As a result of intensive studies to solve the above-mentioned problems, the present inventors have succeeded in synthesizing a novel photochromic compound, and the photochromic compound has a temperature higher than room temperature. However, it was found that the color was sufficiently developed, and the present invention was completed.

That is, the present invention has the general formula (I) [However, Is a substituted or unsubstituted adamantylidene group or a substituted or unsubstituted norbornylidene group, R ₁ is a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, and X is an oxygen atom. Or N—R ₂ (wherein R ₂ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group), Is a substituted or unsubstituted unsaturated heterocyclic group containing only one selenium atom as a heteroatom constituting the ring. ] It is a photochromic compound shown by these.

In the above general formula (I), Is an adamantylidene group or a substituted adamantylidene group, or a norbornylidene group or a substituted norbornylidene group. Examples of the substituent of the substituted adamantylidene group include a hydroxy group; a substituted amino group such as a methylamino group and a diethylamino group; an alkoxy group having 1 to 4 carbon atoms such as a tert-butoxy group; and a carbon number such as a benzyloxy group. 7-15 aralkoxy group; phenoxy group, 1-naphthoxy group, and other aryloxy group having 6-14 carbon atoms; methyl group,
Lower alkyl group having 1 to 4 carbon atoms such as ethyl group and tert-butyl group; halogen atom such as fluorine, chlorine and chlorine; cyano group; alkoxycarbonyl group having 2 to 10 carbon atoms such as carboxyl group and ethoxycarbonyl group A halogen-substituted alkyl group having 1 or 2 carbon atoms such as a trifluoromethyl group;
Examples thereof include nitro group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as phenylethyl group and phenylpropyl group. These substituents may be included not only as a mono-substituted product but also as a poly-substituted product having a plurality of 2- or more-substituted substituents. Furthermore, the substituents in the poly-substituted product may be the same kind. Also, there is no problem even if they are different, and the position of the substituent can be changed according to the purpose or application.

Further, the substituent of the substituted norbornylidene group is the same as the above-mentioned substituent of the adamantylidene group, and these substituents include not only those contained as a mono-substituted product but also those having two or more substituents. It may be included as a poly-substituted product having a number of substituents, further, the substituents in the poly-substituted product may be the same or different, and there is no problem.
The position of the substituent can also be changed depending on the purpose or application.

In the general formula (I), the hydrocarbon group represented by R ₁ may be aliphatic or aromatic. An alkyl group is preferable as the aliphatic hydrocarbon group, and an aryl group and an aralkyl group are preferable as the aromatic hydrocarbon group.

The above-mentioned alkyl group 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 alkyl group of the aralkyl group generally has 1 carbon atom.
-10, preferably 1-4 are suitable. More specific examples of these alkyl groups and aralkyl groups include a methyl group, an ethyl group, a propyl group, a butyl group, a benzyl group, a phenylethyl group, a phenylpropyl group and a phenylbutyl group. As the aryl group among the hydrocarbon groups represented by R ₁ , for example, a phenyl group, a tolyl group, a xylyl group, a naphthyl group and the like are preferable.

The substituent of these hydrocarbon groups is not particularly limited, and for example, the groups described above as the substituent of the adamantylidene group can be adopted.

Further, in the general formula (I), the heterocyclic group represented by R ₁ is a 5-membered ring, a 6-membered ring containing each atom of oxygen, sulfur, or nitrogen, or a heterocyclic group in which a benzene ring is condensed with these. Can be mentioned. Specifically, nitrogen-containing heterocyclic groups such as pyridyl group, quinolyl group, piperidyl group; oxygen-containing heterocyclic groups such as furyl group, benzofuryl group, oxolyl group; sulfur-containing heterocyclic groups such as thienyl group, benzothienyl group, etc. Is. As the substituents of these heterocyclic groups, the above-mentioned substituents of the adamantylidene group can be adopted without any limitation.

In the general formula (I), X is an oxygen atom or N—R ₂ , and R ₂ is a hydrogen atom or a substituted or unsubstituted hydrocarbon group. The hydrocarbon group represented by R ₂ may be aliphatic or aromatic. An alkyl group and a cycloalkyl group are preferable as the aliphatic hydrocarbon group, and an aryl group and an aralkyl group are preferable as the aromatic hydrocarbon group.

The above-mentioned alkyl group 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 alkyl group of the aralkyl group generally has 1 carbon atom.
-10, preferably 1-4 are suitable. More specific examples of these alkyl groups and aralkyl groups include a methyl group, an ethyl group, a propyl group, a butyl group, a benzyl group, a phenylethyl group, a phenylpropyl group and a phenylbutyl group. The cycloalkyl group is not particularly limited, but generally, a cycloalkyl group having 3 to 12 carbon atoms, preferably 5 to 7 carbon atoms is suitably used. More specific examples of these cycloalkyl groups include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and the like. Of the hydrocarbon groups represented by R ₂ , the aryl group is preferably a phenyl group, a tolyl group, a xylyl group, a naphthyl group, or the like.

Examples of the substituent of these hydrocarbon groups include fluorine,
Halogen atom such as chlorine and chlorine; cyano group; nitro group; group represented by -OR ₅ ; Etc. can be mentioned. However, in the above general formula, R ₅ ,
R ₇ and R ₈ are a hydrogen atom, a substituted or unsubstituted hydrocarbon group, and R ₆ is a substituted or unsubstituted hydrocarbon group.

As the hydrocarbon group of R ₅ , R ₆ , R ₇ and R _{8 in} the above formula and the substituents thereof, the groups described above for R ₁ are used. The substituent may be included not only as a mono-substituted product but also as a poly-substituted product having a plurality of 2- or more-substituted substituents. Further, the substituents in the poly-substituted product may be the same kind, There is no problem even if they are different, and the position of the substituent can be changed according to the purpose or application.

Furthermore, in the general formula (I), The group represented by is a substituted or unsubstituted unsaturated heterocyclic group containing only one atom of selenium as a hetero atom constituting the ring. More specifically exemplifying an unsaturated heterocyclic group containing selenium as a ring constituent element, And the like, and an unsaturated heterocyclic group containing only one atom of selenium as a hetero atom constituting the above-mentioned ring, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, a nitro group, a cyano group, an amino group, Alternatively, a substituted unsaturated heterocyclic group in which one or more halogen atoms are substituted can be given.

Among the compounds represented by the above general formula (I), particularly A compound in which is an adamantylidene group or a substituted adamantylidene group is excellent in thermal stability, and a compound in which X is oxygen or a compound in which R ₂ of NR ₂ is a substituted hydrocarbon group has a higher color density. Obtainable.

The photochromic compound represented by the above general formula (I) of the present invention generally exists as a pale yellow solid at room temperature, and is generally represented by the following general formula (I) by the following means (I) to (C). It can be confirmed that the compound is.

(B) ¹ H- by measuring the nuclear magnetic resonance spectra ⁽¹ H-NMR), it is possible to know the types and number of protons present in the molecule. That is, a peak based on aromatic protons around δ7-9ppm, δ1.2-2.5ppm
A broad peak based on the protons derived from the adamantylidene group or norbornylidene group in the vicinity, δ1.2 to 4.0
When R ₁ is an alkyl group, a peak due to the alkyl group appears around ppm. In addition, the relative number of δ peak intensities can be compared to determine the number of protons in each bonding group.

(B) By elemental analysis, each weight% of carbon, hydrogen, nitrogen, sulfur, selenium, and halogen can be determined. Further, by subtracting the sum of the recognized weight% of each element from 100, the weight% of oxygen can be calculated. Therefore, the composition of the corresponding product can be determined.

(C) by measuring the ¹³ C- nuclear magnetic resonance spectrum ⁽¹³ C-NMR), it is possible to know the type of carbon present in the molecule. Peaks derived from adamantylidene group or norbornylidene group around δ27-52ppm, δ15-35
When R ₁ is an alkyl group in the vicinity of ppm, a peak based on the alkyl group, δ 110 to 150 ppm, the peak based on the carbon of an aromatic hydrocarbon group or an unsaturated heterocyclic group, δ 160 to 170 pp
A peak based on C = O carbon appears near m.

The method for producing the compound represented by the above general formula (I) of the present invention is not particularly limited, and any synthetic method may be adopted. A typical method that is generally adopted is described below.

The following general formula (II) (In the formula, , R ₁ are the same as in formula (I). ) And a compound represented by the general formula (III) (In the formula, Is a substituted or unsubstituted adamantylidene group, or a substituted or unsubstituted norbornylidene group, R ₃ and R ₄
Are each the same or different alkyl group. ) Is reacted with a compound represented by the formula (1) to give an acid anhydride, and a cyclization reaction is carried out, or a method of carrying out a cyclization reaction after reacting an amine compound is employed.

The reaction between the compound represented by the general formula (II) and the compound represented by the general formula (III) is performed as follows.
The reaction ratio of these two compounds can be selected 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 -20 to 100 ° C, and the solvent is a polar aprotic solvent such as N-.
Methylpyrrolidone, dimethylformamide, toluene,
Tetrahydrofuran or the like is adopted. In this reaction, a condensing agent such as sodium hydride, potassium t-butoxide and sodium ethylate is generally used in the range of 0.1 to 10 mol per 1 mol of the compound represented by the general formula (II). . After the reaction, dicarboxylic acid is formed with a base such as 10% ethanolic potassium hydroxide, and the obtained dicarboxylic acid is cyclized with an appropriate dehydrating agent such as acetic anhydride or acetyl chloride to give an acid anhydride represented by the general formula (IV). The compound shown is obtained.

(In the formula R ₁ , and Is the same as in formula (I) or (III). ) The photochromic compound of the present invention is obtained by carrying out a cyclization reaction of the compound represented by the general formula (IV) thus obtained. The photochromic compound of the present invention can also be obtained by reacting the compound represented by the general formula (IV) with an amine compound and then subjecting the obtained product to a cyclization reaction. The amine compound is represented by the general formula (V) H ₂ N—R ₂ (V) [wherein R ₂ is the same as in the general formula (I). ] Is shown. The reaction ratio of the compound represented by the above general formula (IV) and the amine compound represented by the above (V) is adopted from a wide range, but is generally adopted from the range of 1:10 to 10: 1 (molar ratio). To be done.

As a method of the above cyclization reaction, generally, heating, a combination of heating and ultraviolet irradiation, or a method of contacting with a Lewis acid catalyst is adopted. Examples of the Lewis acid include SnCl
Known compounds such as ₄ , TiCl ₄ , SbCl ₅ and AlCl ₃ are generally used in the range of 0.01 to 1 mol per mol of the compound to be cyclized.

Further, among the photochromic compounds of the present invention, compounds in which X in the general formula (I) is other than an oxygen atom or NH can also be produced by the following method.

General formula (VI) [However, R ₁ , and Is the same as in the general formula (I). ] The compound shown by the following is reacted with an alkali metal, and then the general formula (VII) Br-R ₂ (VII) [wherein R ₂ is the same as the above general formula (I). ] It is the method of making it react with the bromine compound shown by these.

The alkali metals used in this method are metallic potassium,
Metallic sodium and metallic lithium are used. The reaction ratio of the alkali metal is generally selected from the range of 1.0 to 10 mol with respect to 1 mol of the compound represented by the general formula (VI). In addition, the reaction ratio of the bromine compound represented by the general formula (VII) is generally preferably selected from the range of 0.5 to 10 mol per mol of the compound after the reaction with the alkali metal.

The solvent used in this reaction is the same as that used in the above-mentioned method. The reaction temperature is usually preferably in the range of 0 to 100 ° C.

The photochromic compound of the present invention can be obtained by the above method.

The photochromic compound represented by the above general formula (I) of the present invention is well soluble in general organic solvents such as toluene, chloroform and tetrahydrofuran. When the photochromic compound represented by the general formula (I) is dissolved in such a solvent, the solution is generally colorless and transparent, and when irradiated with sunlight or ultraviolet rays, it rapidly changes to a colored or dark color and blocks light. Then, it exhibits a good reversible photochromic action that quickly returns to the original colorless state. The photochromic action in the compound of the general formula (I) also occurs in the polymer solid matrix, and the reversible speed occurs on the order of seconds to minutes. The target polymer matrix may be one in which the photochromic compound represented by the general formula (I) of the present invention is uniformly dispersed. Optically preferably, for example, polymethyl acrylate, polyacrylic acid Polymers such as ethyl, polymethylmethacrylate, polyethylmethacrylate, polystyrene, polyacrylonitrile, polyvinyl alcohol, polyacrylamide, poly (2-hydroxyethylmethacrylate), polydimethylsiloxane, polycarbonate, poly (allyl diglycol carbonate),
Alternatively, a polymer obtained by copolymerizing monomers forming these polymers or a copolymer of the monomer with another monomer is preferably used.

The photochromic action of the photochromic compound of the present invention is more excellent in thermal stability than conventional photochromic compounds, and sufficient color density can be obtained even at a high temperature of 30 to 40 ° C.

Therefore, the photochromic compound of the present invention can be widely used as a photochromic material. For example, various recording materials replacing silver salt photosensitive materials, copying materials, printing photoreceptors, cathode ray photosensitive recording materials, laser photosensitive materials, holography. It can be used as various recording materials such as a light-sensitive material. In addition, the photochromic material using the photochromic compound of the present invention can be used as a material for a photochromic lens material, an optical filter material, a display material, a photometer, a decoration and the like. For example, when used for a photochromic lens, it is not particularly limited as long as it is a method capable of obtaining uniform light control performance, and if it is specifically exemplified, a polymer film obtained by uniformly dispersing the photochromic material of the present invention. Is sandwiched in a lens, or this compound is dissolved in, for example, silicone oil and impregnated on the lens surface at 150 to 200 ° C. for 0 to 60 minutes, and the surface is further coated with a curing substance to form a photochromic lens. There is a method to do. further,
A method of applying the above polymer film on the lens surface to form a photochromic lens is also considered.

(Effect) The photochromic compound represented by the general formula (I) of the present invention is hardly affected by the kind of the matrix in the polymer solid matrix and exhibits stable colorless in a general state. , It develops color immediately when it is exposed to ultraviolet rays, returns to the original colorless state on the order of seconds to minutes when the irradiation of ultraviolet rays is stopped, and shows sufficient color density even at high temperatures of 30 to 40 ° C.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A solution was prepared by dissolving 4 g (0.0231 mol) of 3-acetylselenophene and 7.79 g (0.0254 mol) of diethyl adamantylidene succinate in 50 ml of toluene. Then, the above toluene solution was added dropwise to a solution prepared by dispersing 5 g of sodium hydride in 50 ml of toluene under a nitrogen atmosphere for 2 hours while keeping the liquid temperature at -10 ° C or lower. After the dropping was completed, the liquid temperature was kept at 0 ° C. or lower and the mixture was vigorously stirred for 10 hours.
Hydrolyze with an excess of 10% alcoholic potassium hydroxide solution, then hydrolyze with hydrochloric acid, acidify with hydrochloric acid to treat the dicarboxylic acid with 100 ml of acetyl chloride, and purify by chromatography on silica gel. Thus, 4 g of a fulgide compound represented by the following formula was obtained.

The resulting compound was refluxed in o-dichlorobenzene for 1 hour to be rearranged into the following photochromic compound (1).

The compound of (1) was precipitated as a solid by removing the o-dichlorobenzene. This solid was purified by recrystallization in a solution of chloroform and hexane. The elemental analysis values of this compound are C62.31%, H5.01%, Se19.95
%, And a O12.73%, C62.01% is calculated values for _{C 20 H 20 O 3 Se,} H5.20%, Se19.95%, and was extremely well matched to O12.41%. In addition, ¹ H-nuclear magnetic resonance spectrum was measured to find that the peak of 2 H based on the proton of the selenophene ring was around δ7.4 to 8.0 ppm, and the peak of 1-5 was around δ 4.0 ppm.
1H peak due to rearranged protons, around δ2.7ppm
3H peak based on C-CH ₃ bond protons, δ1.5-2.5p
A broad peak of 14H based on the adamantylidene proton was shown near pm. Further, ¹³ C-nuclear magnetic resonance spectrum ( ¹³ C-NMR) was measured, and it was found that the peak due to the carbon of the adamantylidene group and the carbon of the methylene chain was around δ27 to 52 ppm, and the carbon of the methyl group was around δ15.6 ppm. A peak due to the carbon of the selenophene ring appears in the vicinity of δ110 to 160 ppm, and a peak due to the carbon of the C═O bond appears in the vicinity of δ160 to 170 ppm. From the above results, it was confirmed that the isolated product was the compound represented by the structural formula (1).

Example 2 1 g of (3-selenophenyl) ethylidene-2-adamantylidene succinic anhydride of the following formula obtained in Example 1 (0.0025
8 mol) And 2 ml of the ethylamine solution were dissolved in 30 ml of acetone and refluxed for 30 minutes. After that, the solvent was removed, and the solution was treated with acetyl chloride for dehydration ring closure. The obtained photochromic compound was obtained by heating the obtained compound in o-dichlorobenzene for 6 hours. This compound was purified by chromatography on silica gel using chloroform and hexane as eluents and was obtained as needle crystals from ethanol in 15% yield. The elemental analysis value of this compound is C63.67%… H6.12%, N3.40%, O7.63%, Se19.18%
A is a calculated value for C ₂₂ H ₂₅ NO ₂ Se C63.76
%, H6.08%, N3.38%, O7.72%, Se19.05%. Further, when the ¹ H-nuclear magnetic resonance spectrum was measured, a peak of 2 H based on the proton of the selenophene ring near δ 7.4 to 8.0 ppm, a peak of 1 H based on the 1-5 rearranged proton near δ 4.0 ppm, and δ 2. A peak of 3H based on the proton of the C-CH ₃ bond is shown near 7 ppm, and a broad peak of 17H based on the proton of the adamantylidene group and the methyl group of the N-CH ₂ -CH ₃ bond is shown near δ1.5 to 2.5 ppm. , Δ3.5-4.0ppm
And a peak of 2H based on the protons of methylene N-CH ₂ -CH ₃ in the vicinity. From the above results, it was confirmed that the isolated product was a compound represented by the following structural formula (2).

Example 3 The following compound was obtained in the same manner as in Example 2 except that NH ₃ was used instead of ethylamine in Example 2.

6 g (0.0155 mol) of this compound was dissolved in tetrahydrofuran and metallic potassium was reacted at room temperature to obtain imide potassium.

This and benzoic acid-2-bromoethyl ester 3.6g (0.017m
ol) in dimethylformamide
The following photochromic compound (3) was obtained. This compound was purified by chromatography on silica gel using chloroform and hexane as eluents,
Obtained as needle crystals from ethanol in 55% yield. The elemental analysis values of this compound are C65.21%, H5.43%, N
2.58%, O11.98%, a Se14.80%, C65.17% is calculated values for _{C 29 H 29 NO 4 Se,} H5.47%, N2.62%, O11.
Very good agreement with 97% and Se 14.77%. The ¹ H-nuclear magnetic resonance spectrum was also measured and found to be 7 H based on the proton of the selenophene ring and the benzene ring in the vicinity of δ 7.4 to 8.0 ppm.
, A peak of 1H based on the 1-5 rearranged protons near δ4.0ppm, a peak of 3H based on the proton of the C-CH ₃ bond near δ2.7ppm, and an adamantylidene group near δ1.0 to 2.5ppm. Shows a broad peak of 14H based on the protons of
A peak of 4H based on the proton of the N-CH ₂ -CH ₂ -O bond was shown in the vicinity of δ 3.5 to 5.0 ppm. From the above results, it was confirmed that the isolated product was a compound represented by the following structural formula (3).

Examples 4 to 43 Various photochromic compounds were synthesized from the raw materials shown in Table 1 in the same manner as in Examples 1 to 3.

Elemental analysis, ¹ H-nuclear magnetic resonance spectrum, and ¹³ C-nuclear magnetic resonance spectrum of the obtained products were measured in the same manner as in Examples 1 to 3, and each compound shown in Table 1 was produced. It was confirmed.

Examples 44 to 86 0.005 parts by weight of the compounds represented by the structural formulas (1) to (43) prepared in Examples 1 to 43 were solvent-dispersed with 1 part by weight of polymethylmethacrylate and 3 parts by weight of benzene, and slide. A cast film was made on a glass (11.2 x 3.7 cm). The maximum absorption wavelength (λmax) and color density of this photochromic film were measured by a rapid scan spectrophotometer MPCD-100 (28C) manufactured by Otsuka Electronics Co., Ltd. The color density is defined as the light transmittance immediately after the photochromic film is excited by a xenon lamp and the excitation light is blocked.

The measurement results are shown in Table 2. For comparison, a film was similarly prepared for the photochromic compound represented by (44) below, and the maximum absorption wavelength and color density were measured.

[Brief description of drawings]

FIG. 1 shows the ¹ H-nuclear magnetic resonance spectrum of the photochromic compound of the present invention obtained in Example 1.

Claims (4)

[Claims] 1. A general formula [However, Is a substituted or unsubstituted adamantylidene group or a substituted or unsubstituted norbornylidene group, R ₁ is a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, and X is an oxygen atom. Or N—R ₂ (wherein R ₂ represents a hydrogen atom or a substituted or unsubstituted hydrocarbon group), Is a substituted or unsubstituted unsaturated heterocyclic group containing only one selenium atom as a heteroatom constituting the ring. ] The photochromic compound shown by these. 2. General formula [However, R ₁ is a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, Is a substituted or unsubstituted unsaturated heterocyclic group containing only one selenium atom as a heteroatom constituting the ring. ] And the general formula [However, Is a substituted or unsubstituted adamantylidene group or a substituted or unsubstituted norbornylidene group, R ₃ and R ₄
Are the same or different alkyl groups. ] The compound which is shown by these is made into an acid anhydride, and a cyclization reaction is performed, or a cyclization reaction is performed after making an amine compound react, Claim (1) characterized by the above-mentioned. A method for producing the described photochromic compound. 3. General formula [However, Is a substituted or unsubstituted adamantylidene group or a substituted or unsubstituted norbornylidene group, R ₁ is a substituted or unsubstituted hydrocarbon group or a substituted or unsubstituted heterocyclic group, Is a substituted or unsubstituted unsaturated heterocyclic group containing only one selenium atom as a heteroatom constituting the ring. ] After reacting the compound represented by the formula with an alkali metal, the following formula Br-R ₂ [wherein R ₂ represents a substituted or unsubstituted hydrocarbon group]. ] The manufacturing method of the photochromic compound of Claim (1) characterized by reacting the bromine compound shown by these. 4. A photochromic material comprising the photochromic compound according to claim (1).