JP3899964B2 - Novel photochromic compound, its production method and its use - Google Patents

Description

【０００６】
はじめに、1-アリールブタジエン化合物を構成するアリール基について説明する。
Ｘは硫黄原子、酸素原子またはアルキル置換窒素原子である。アルキル置換窒素原子のアルキル基を構成する炭素数は1から１８が好ましく、さらに好ましくは１から６が最も望ましい。メチル基、エチル基、n-プロピル基、iso-プロピル基、n-ブチル基、iso-ブチル基、ter-ブチル基が例示される。
【０００７】
Ｒ₁は置換基を有していても良いアルキル基であって、炭素数が１から６のアルキル基が好ましく、メチル基、エチル基、n-プロピル基、iso-プロピル基、n-ブチル基、iso-ブチル基、ter-ブチル基が好ましく例示される。この場合メトキシメチル基のように修飾基が結合していてもよい。
【０００８】
Ｒ₂およびＲ₃は各々独立してアルキル基、アルコキシ基、アミノ基、シアノ基もしくはニトロ基、または置換基を有していてもよい芳香族基もしくは複素環式芳香族基であるか、あるいは共同して形成される芳香環を意味する。アルキル基の炭素数は１から６が好ましく、メチル基、エチル基が特に好ましく例示される。また、アルコキシ基としてはメトキシ基、エトキシ基が、アミノ基としてはジメチルアミノ基、ジエチルアミノ基、ピロリジノ基、イミダゾリル基が、置換基を有していてもよい芳香族としてはフェニル基、メトキシフェニル基、ニトロフェニル基、シアノフェニル基がそれぞれ好ましい。またＲ₂およびＲ₃が共同して芳香環を形成する場合としては、アリール基全体としてベンゾチオフェン、ベンゾフラン、インドールを基本骨格に有するアリール基が好ましく例示される。
【０００９】
アリール基の具体例としては2,4,5-トリメチルチオフェン、 2,4-ジメチル-5-フェニルチオフェン、2,4-ジメチル-5-(p-ジメチルアミノフェニル)チオフェン、2,4-ジメチル-5-(p-メトキシフェニル)チオフェン、2,4-ジメチル-5-(4'-ピリジル)チオフェン、2,4-ジメチル-5-ナフチルチオフェン、2,4,5-トリメチルフラン、1,2,4,5-テトラメチルピロール、1,2-ジメチル-5-シアノピロール、2-メチルベンゾチオフェン、1,2-ジメチルインドール、1,2-ジメチル-5-メトキシインドール、2-メチル-6-ニトロベンゾチオフェンなどが挙げられる。
【００１０】
次に、1-アリールブタジエン化合物を構成するビニル基について説明する。
Ｒ₄は置換基を有していてもよい芳香族基である。置換基はアミノ基、アルコキシ基、シアノ基、ニトロ基等であってよく、また、芳香族基は多環式であってよい。
【００１１】
具体例としてはベンゼン、p-ジメチルアミノベンゼン、p-シアノベンゼン、p-メトキシベンゼン、m-ニトロベンゼン、p-ニトロベンゼン、ナフタレン、3-ニトロナフタレン、4-シアノナフタレンなどが挙げられる。
【００１２】
Ｒ₅およびＲ₆は、置換基を有していてもよいアルキル基であるか、または共同して単環もしくは多環を形成する脂肪族環を意味し、1-アリールブタジエン化合物の分子内部において大きな立体障害を発現させるものが望ましい。アルキル基の炭素数は１から６が好ましく、メチル基、エチル基が特に好ましく例示される。また、脂肪族環の炭素数はＲ₅およびＲ₆ に直結する二重結合炭素を含めて５から１５が好ましく、単環式の脂肪族環としてはシクロペンタン、シクロヘキサン、シクロヘプタンが特に好ましく例示され、一方、多環式の脂肪族環としてはアダマンチル、ノルボルニリルが特に好ましく例示される。。
【００１３】
ところで、式[I]で示される1-アリールブタジエンに紫外光照射すると、下記式[II]で示される1-アリールブタジエンの閉環体が得られる。
【化５】

ここで、Ｒ₁ないしＲ₆は前掲と同じ基を表す。但しＲ₅およびＲ₆が共同して脂肪族環を形成する場合には、シクロヘキサジエン環と合わせ全体としてスピロ環を形成する。
【００１４】
当該閉環体は一定の着色を有し、可視光を照射することでもとの開環体、即ち1-アリールブタジエンに戻すことができる。熱安定な化合物であるので、暗所で保存する限り、もとの開環体に戻ることはない。
【００１５】
開環体と閉環体は両者間において下記のような熱不可逆なホトクロミズムを示す。
【化６】

【００１６】
次に本発明である1-アリールブタジエン化合物の製造法について説明する。
1-アリールブタジエン化合物は、下記式で示されるビニルハライド［IV］およびアリールハライド［V］を予めブチルリチウムによりリチオ化して得られたアニオンと、オクタフルオロシクロペンテン[III]とを逐次反応させることにより製造される。
【化７】

【化８】

【００１７】
反応順序は問わないが、ビニルハライドのアニオンを先に反応させ、次いでアリールハライドのアニオンを反応させるのが好ましい。下記式は先にビニルハライドを反応させている場合である。
【化９】

【００１８】
ここで、オクタフルオロシクロペンテンは市販品を利用することができる。また、ビニルハライド、アリールハライドにブチルリチウムを反応させてアニオンとする方法は公知である。例えば、ビニルハライド、アリールハライドを適当な溶媒に溶かし込み、そこへヘキサン等の溶媒に溶かしたブチルリチウムを加えることで調製できる。ブチルリチウムとしては通常n-ブチルリチウム、sec-ブチルリチウム、t-ブチルリチウムが用いられる。反応は好ましくは無水THFなどエーテル系無水溶媒中において低温で行うことができる。
【００１９】
本発明の1-アリールブタジエンは透明な光学用樹脂に混合してフィルム化すれば、光発色材料、調光材料、光記録材料とすることが可能である。好適な樹脂の例としてはポリメチルメタクリレート（ＰＭＭＡ）、ポリカーボネート、ポリウレタン、アートン、ゼオネックスなどが挙げられる。このような樹脂と混合したフィルムにおいても着色体である光閉環体は熱安定である。
【００２０】
【発明の実施の形態】
以下に実施例を挙げてこの発明を具体的に説明する。この1-アリールブタジエン[I]および閉環体[II]の化学構造は核磁気共鳴スペクトル（H-NMR、 分解能400 MHzおよび、270MHz使用、内部標準としてトリメチルシリルエーテル使用）、高分解能質量分析スペクトル（HRMS）、低分解能質量分析スペクトル（LRMS）、赤外吸収スペクトル（IR）、紫外-可視吸光スペクトルにより決定した。
【００２１】
【実施例１】
1-(アダマンチリデンベンジル)ヘプタフルオロシクロペンテンの合成
100ml二つ口ナシ型フラスコにアダマンチリデンブロモベンジル465 mg (1.54 mmol)を入れて窒素置換し、無水ＴＨＦ30mlに溶かした。溶液をドライアイス/イソプロパノール浴で−78℃以下に冷却し、n-ブチルリチウムのヘキサン溶液 1.2 ml(1.84 mmol)を加えた。 この溶液オクタフルオロシクロペンテン 0.6 ml (4.60 mmol)を加え15時間攪拌した。
反応溶液に水を加えて反応を終了させ、酢酸エチルステルで３回抽出した。有機層を飽和食塩水で洗浄し、無水硫化ナトリウムで乾燥したのちに溶媒を減圧留去した。残渣をシリカゲルフラッシュクロマトグラムで精製して1-(アダマンチリデンベンジル)ヘプタフルオロシクロペンテン 513 mgを収率92％で得た。
¹H-NMR (270 MHz，CDCl₃, TMS) δ/ppm: 1.57-2.00 (12H,m), 2.50 (1H,s), 2.73 (1H, s), 7.13-7.35 (5H,m)
IR (KBr) ν/cm-1: 3028 (Ph-H), 2903 (C-H), 1447 (C-H), 713 (C-H)
【００２２】
【実施例２】
1-(アダマンチリデンベンジル)-2-(2',5'-ジメチルチエ-3'-ニル)ヘキサフルオロシクロペンテンの合成
100ml二つ口ナシ型フラスコに3-ブロモ-2,5-ジメチルチオフェン 274 mg (1.43 mmol)を入れて窒素置換し、ＴＨＦ10mlに溶かした。溶液をドライアイス/イソプロパノール浴で−78℃以下に冷却し、n-ブチルリチウムのヘキサン溶液 1 ml(1.57 mmol)を加えた。この溶液を別に調整した1-(アダマンチリデンベンジル)ヘプタフルオロシクロペンテン 560 mg (1.34 mmol)のTHF（15 ml）溶液が入っている100 ml二つ口フラスコに滴下して24時間攪拌した。
反応溶液に水を加えて反応を終了させ、酢酸エチルステルで３回抽出した。有機層を飽和食塩水で洗浄し、無水硫化ナトリウムで乾燥したのちに溶媒を減圧留去した。残渣をシリカゲルフラッシュクロマトグラムで精製して1-(アダマンチリデンベンジル)-2-(2',5'-ジメチルチエ-3'-ニル)ヘキサフルオロシクロペンテン 194 mgを収率28％で得た。
この化合物はトルエン中で313nmに紫外吸収極大を示した。この溶液に313 nmの紫外光を照射すると新たに450 nmに吸収極大をもつ吸収が現れるホトクロミズムを示した。
¹H-NMR(400 MHz,CDCl₃, TMS)δ/ppm: 1.62-1.92 (12H，br)，2.05 (3H,s), 2.34 (3H,s), 2.62 (2H,br), 6.33 (1H,s), 6,95-6.98 (2H,m), 7.21-7.24 (3H,m)
m.p.=103-105 ℃
【００２３】
実施例１および実施例２の双方を通した反応式を次に示す。
【化１０】

【００２４】
【実施例３】
アリールブタジエンのポリメチルメタクリレートフィルム
ポリメチルメタクリレート（PMMA）ペレット 0.216 gをジクロロメタン4 mlに溶解し、実施例２で合成した1-(アダマンチリデンベンジル)-2-(2',5'-ジメチリチエ-3-ニル)ヘキサフルオロシクロペンタン1.27 mgを溶かしてキャステイングフィルムを得た。
このフィルムに波長313 nmの紫外光を30分照射したところ、赤色に着色し455 nmに吸収極大を示した。この着色フィルムに波長455 nmの光を照射したところ速やかに消色した。同様にこのフィルムに波長313 nmの紫外光を30分照射して赤色に着色させたフィルムを暗所において80℃に保った場合には消色は起こらなかった。図１にこのフィルムを80℃に保った場合の455 nmにおける吸光度変化を示した。
【００２５】
【実施例４】
1-(2-メチル-1−フェニルプロペニル)ヘプタフルオロペンテンの合成
100 ml二つ口ナシ型フラスコに1-ブロモ-2-メチル-1-ｐヘニルプロペン 506 mg (2.36 mmol)を入れて窒素置換し、無水THF 30 mlに溶かした。溶液をドライアイス／イソプロパノール浴で-78℃以下に冷却し、1.56 mol/dm3 n-ブチルリチウムのヘキサン溶液 1.82 ml (2.84 mmol)を加え30分攪拌した。この反応液にオクタフルオロシクロペンテン 0.79 ml (5.65 mmol)を加えて15時間攪拌した。
反応溶液に水を加えて反応を終了させ、酢酸エチルエステルで３回抽出した。有機層を飽和食塩水で洗浄し、無水硫化ナトリウムで乾燥した後に溶媒を減圧留去した。残査をシリカゲルクロマトグラムで精製して1-(2-メチル-1−フェニルプロペニル）ヘプタフルオロペンテン 503 mg を収率６６％で得た。
¹H-NMR (270MHz, CDCl₃, TMS) δ/ppm： 1.78 (3H, s), 1.84 (3H, s), 7.13 (2H, d, J/Hz=6.27), 7.32-7.45 (3H, m).
【００２６】
【実施例５】
2-(2-メチル-1−フェニルプロペニル）-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテンの合成
100 ml二つ口ナシ型フラスコに4-ブロモ-2,3,5-トリメチルチオフェン 306 mg (1.54 mmol)を入れて窒素置換し、無水THF 10 mlに溶かした。溶液をドライアイス／イソプロパノール浴で-78℃以下に冷却し、1.56 mol/dm3 n-ブチルリチウムのヘキサン溶液 1.1 ml (1.72 mmol)を加え30分攪拌した。この反応液を100 ml二つ口ナシ型フラスコに調整した 1-(2-メチル-1−フェニルプロペニル）ヘプタフルオロペンテン 500 mg (1.54 mmol)の無水THF溶液 15 mlに滴下し、５時間反応させた。
反応溶液に水を加えて反応を終了させ、酢酸エチルエステルで３回抽出した。有機層を飽和食塩水で洗浄し、無水硫化ナトリウムで乾燥した後に溶媒を減圧留去した。残査をシリカゲルクロマトグラムで精製して2-(2-メチル-1−フェニルプロペニル）-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテン 160 mgを収率24%で得た。
¹H-NMR (270MHz, CDCl₃, TMS) δ/ppm: 1.43 (3H, s), 1.59 (3H, s), 1.73 (3H, s), 1.90 (3H, s), 2.19 (3H, s), 6.69 (2H, m), 7.13-7.16 (3H, m).
【００２７】
実施例４および実施例５の双方を通した反応式を次に示す。
【化１１】

【００２８】
【実施例６】
2-(2-メチル-1−フェニルプロペニル）-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテンのホトクロミズム
2-(2-メチル-1−フェニルプロペニル）-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテンはトルエン中３５０ nm以下に末端吸収を示すのみであるが、313 nm光照射により6π電子系環化反応を示し450 nmに吸収極大を示す着色体となる。313 nm光照射時の開環体から閉環体への光反応量子収率（ψ）は0.42、閉環体から開環体への量子収率は0.14であった。閉環体は熱安定であり、405 nm光照射により開環体に異性化した。その量子収率は0.16であった。
【００２９】
【実施例７】
2-(2-メチル-1−フェニルプロペニル）-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテンのPMMAフィルム
2-(2-メチル-1−フェニルプロペニル)-1-(2,4,5-トリメチル-3-チエニル)-ヘキサフルオロペンテンのトルエン溶液にPMMAを溶かしキャスティングにより膜厚約50 μmのフィルムを得た。フィルムに313 nmの紫外光を照射して着色体とした後、暗所において80℃に３０日間保ったが吸光度に変化はなく、閉環体は極めて熱安定であることが示された。また、着色・消色のサイクルを１０回繰り返したが、着・消色物性の劣化は観測されなかった。
【００３０】
【発明の効果】
本発明の1-アリールブタジエン化合物の光閉環体は熱安定であり室温では開環せず、光応答が長期に渡って極めて安定であることが大きな特徴である。
【図面の簡単な説明】
【図１】 1-アリールブタジエン/PMMAフィルムのホトクロミック着色の熱安定性を示す。
（313 nmの紫外光を30分照射した直後の455 nmの吸光度をA0として規格化して、測定日の吸光度をA/A0で示した。）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a 1-arylbutadiene compound which is a novel photochromic material, a method for producing the same, and use thereof. More specifically, the present invention relates to a 1-arylbutadiene compound that gives a thermally stable colored ring closure by a photocyclization reaction, a synthesis method thereof, a photochromic material, a light control material, and an optical recording material.
[0002]
[Prior art]
A compound whose color is changed by light is called a photochromic compound, and has utility as a photochromic material, a light control material and an optical recording material. Among them, a compound that is thermally stable by coloring is particularly preferable as an optical recording material.
To date, photochromism compounds such as fulgide and diarylethene have been known as photochromic compounds that exhibit ring-closing and ring-opening reactions from hexatriene to cyclohexadiene according to the Woodward-Hoffman rule (Photochromism, p489 (1990)). Heinz Durr, Henri Bouas-Laurent, Elsever, JP 3-135977, etc.).
[0003]
[Problems to be solved by the invention]
Frugide uses an alkylidene group as a condensed adamantylidene group having a large steric hindrance to suppress side reactions such as a transfer reaction and an oxidation reaction, thereby obtaining a thermally stable ring-closed product. However, in fulgide, the succinic anhydride site is unstable with respect to the acid base, and there is a problem in the long-term stability of the photochromic properties.
In addition, diarylethene has the advantage that the perfluorocyclopentene ring is chemically very stable and the introduction of an aryl group is easy, but it is susceptible to oxidation and is not sufficiently durable.
[0004]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention introduces an aryl group at the 1-position of perfluorocyclopentene and an arylvinyl group having a large steric hindrance at the 2-position, which makes it easy to synthesize and chemically stable. A heat-stable photochromic 1-arylbutadiene compound was obtained.
[0005]
That is, the present invention relates to a 1-arylbutadiene compound which is a novel photochromic compound represented by the following formula [I].
[Formula 4]

[0006]
First, the aryl group constituting the 1-arylbutadiene compound will be described.
X is a sulfur atom, an oxygen atom or an alkyl-substituted nitrogen atom. The number of carbon atoms constituting the alkyl group of the alkyl-substituted nitrogen atom is preferably 1 to 18, more preferably 1 to 6. Examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group and ter-butyl group.
[0007]
R ₁ is an alkyl group which may have a substituent, and is preferably an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group. And iso-butyl group and ter-butyl group are preferred. In this case, a modifying group may be bonded like a methoxymethyl group.
[0008]
R ₂ and R ₃ are each independently an alkyl group, an alkoxy group, an amino group, a cyano group or a nitro group, or an optionally substituted aromatic group or heterocyclic aromatic group, or An aromatic ring formed jointly. The alkyl group preferably has 1 to 6 carbon atoms, and a methyl group and an ethyl group are particularly preferable. Further, the alkoxy group is a methoxy group, an ethoxy group, the amino group is a dimethylamino group, a diethylamino group, a pyrrolidino group, an imidazolyl group, and the aromatic group that may have a substituent is a phenyl group, a methoxyphenyl group , A nitrophenyl group, and a cyanophenyl group are preferable. In the case where R ₂ and R ₃ together form an aromatic ring, an aryl group having benzothiophene, benzofuran, and indole in the basic skeleton as the whole aryl group is preferably exemplified.
[0009]
Specific examples of the aryl group include 2,4,5-trimethylthiophene, 2,4-dimethyl-5-phenylthiophene, 2,4-dimethyl-5- (p-dimethylaminophenyl) thiophene, 2,4-dimethyl- 5- (p-methoxyphenyl) thiophene, 2,4-dimethyl-5- (4'-pyridyl) thiophene, 2,4-dimethyl-5-naphthylthiophene, 2,4,5-trimethylfuran, 1,2, 4,5-tetramethylpyrrole, 1,2-dimethyl-5-cyanopyrrole, 2-methylbenzothiophene, 1,2-dimethylindole, 1,2-dimethyl-5-methoxyindole, 2-methyl-6-nitro Examples include benzothiophene.
[0010]
Next, the vinyl group constituting the 1-arylbutadiene compound will be described.
R ₄ is an aromatic group that may have a substituent. The substituent may be an amino group, an alkoxy group, a cyano group, a nitro group or the like, and the aromatic group may be polycyclic.
[0011]
Specific examples include benzene, p-dimethylaminobenzene, p-cyanobenzene, p-methoxybenzene, m-nitrobenzene, p-nitrobenzene, naphthalene, 3-nitronaphthalene, 4-cyanonaphthalene and the like.
[0012]
R ₅ and R ₆ are an alkyl group which may have a substituent, or an aliphatic ring which jointly forms a monocyclic ring or a polycyclic ring, and in the molecule of the 1-arylbutadiene compound Those that cause a large steric hindrance are desirable. The alkyl group preferably has 1 to 6 carbon atoms, and a methyl group and an ethyl group are particularly preferable. The number of carbon atoms in the aliphatic ring is preferably 5 to 15 including the double bond carbon directly bonded to R ₅ and R ₆ , and cyclopentane, cyclohexane and cycloheptane are particularly preferred as the monocyclic aliphatic ring. On the other hand, adamantyl and norbornyl are particularly preferred as the polycyclic aliphatic ring. .
[0013]
By the way, when 1-arylbutadiene represented by the formula [I] is irradiated with ultraviolet light, a 1-arylbutadiene ring-closure represented by the following formula [II] is obtained.
[Chemical formula 5]

Here, R ₁ to R ₆ represent the same groups as described above. However, when R ₅ and R ₆ jointly form an aliphatic ring, they together with the cyclohexadiene ring form a spiro ring as a whole.
[0014]
The ring-closed body has a certain color and can be returned to the original ring-opened body, that is, 1-arylbutadiene by irradiation with visible light. Since it is a thermostable compound, it does not return to the original ring-opened form as long as it is stored in the dark.
[0015]
The ring-opened body and the ring-closed body show the following heat irreversible photochromism between them.
[Chemical 6]

[0016]
Next, a method for producing the 1-arylbutadiene compound according to the present invention will be described.
The 1-aryl butadiene compound is obtained by sequentially reacting an anion obtained by lithiation of vinyl halide [IV] and aryl halide [V] represented by the following formula with butyl lithium in advance and octafluorocyclopentene [III]. Manufactured.
[Chemical 7]

[Chemical 8]

[0017]
Although the reaction order is not limited, it is preferable to react the vinyl halide anion first and then the aryl halide anion. The following formula is a case where vinyl halide is reacted first.
[Chemical 9]

[0018]
Here, a commercially available product can be used as octafluorocyclopentene. A method for reacting vinyl halide and aryl halide with butyl lithium to form an anion is known. For example, it can be prepared by dissolving vinyl halide or aryl halide in a suitable solvent and adding butyllithium dissolved in a solvent such as hexane. As butyl lithium, n-butyl lithium, sec-butyl lithium and t-butyl lithium are usually used. The reaction can be preferably carried out at a low temperature in an ether-based anhydrous solvent such as anhydrous THF.
[0019]
If the 1-arylbutadiene of the present invention is mixed with a transparent optical resin to form a film, a photochromic material, a light control material, and an optical recording material can be obtained. Examples of suitable resins include polymethyl methacrylate (PMMA), polycarbonate, polyurethane, arton, ZEONEX and the like. Even in a film mixed with such a resin, the photocyclic ring, which is a colored body, is thermally stable.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be specifically described below with reference to examples. The chemical structures of 1-arylbutadiene [I] and ring-closed compound [II] are nuclear magnetic resonance spectra (H-NMR, using 400 MHz and 270 MHz resolution, using trimethylsilyl ether as internal standard), high-resolution mass spectrometry spectrum (HRMS) ), Low resolution mass spectrometry spectrum (LRMS), infrared absorption spectrum (IR), ultraviolet-visible absorption spectrum.
[0021]
[Example 1]
Synthesis of 1- (adamantylidenebenzyl) heptafluorocyclopentene
A 100 ml two-neck pear-shaped flask was charged with 465 mg (1.54 mmol) of adamantylidene bromobenzyl, purged with nitrogen, and dissolved in 30 ml of anhydrous THF. The solution was cooled to −78 ° C. or lower in a dry ice / isopropanol bath, and 1.2 ml (1.84 mmol) of a hexane solution of n-butyllithium was added. To this solution, 0.6 ml (4.60 mmol) of octafluorocyclopentene was added and stirred for 15 hours.
Water was added to the reaction solution to terminate the reaction, and the mixture was extracted 3 times with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfide, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel flash chromatogram to give 513 mg of 1- (adamantylidenebenzyl) heptafluorocyclopentene in 92% yield.
¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ / ppm: 1.57-2.00 (12H, m), 2.50 (1H, s), 2.73 (1H, s), 7.13-7.35 (5H, m)
IR (KBr) ν / cm-1: 3028 (Ph-H), 2903 (CH), 1447 (CH), 713 (CH)
[0022]
[Example 2]
Synthesis of 1- (adamantylidenebenzyl) -2- (2 ', 5'-dimethylthie-3'-nyl) hexafluorocyclopentene
In a 100 ml two-neck pear-shaped flask, 274 mg (1.43 mmol) of 3-bromo-2,5-dimethylthiophene was placed, and the atmosphere was purged with nitrogen, and dissolved in 10 ml of THF. The solution was cooled to −78 ° C. or lower with a dry ice / isopropanol bath, and 1 ml (1.57 mmol) of a hexane solution of n-butyllithium was added. This solution was added dropwise to a separately prepared 100 ml two-necked flask containing 1- (adamantylidenebenzyl) heptafluorocyclopentene 560 mg (1.34 mmol) in THF (15 ml), and stirred for 24 hours.
Water was added to the reaction solution to terminate the reaction, and the mixture was extracted 3 times with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfide, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel flash chromatogram to obtain 194 mg of 1- (adamantylidenebenzyl) -2- (2 ′, 5′-dimethylthie-3′-nyl) hexafluorocyclopentene in 28% yield.
This compound showed an ultraviolet absorption maximum at 313 nm in toluene. When this solution was irradiated with ultraviolet light of 313 nm, a new photochromism was observed in which absorption with an absorption maximum at 450 nm appeared.
¹ H-NMR (400 MHz, CDCl ₃ , TMS) δ / ppm: 1.62-1.92 (12H, br), 2.05 (3H, s), 2.34 (3H, s), 2.62 (2H, br), 6.33 (1H , s), 6,95-6.98 (2H, m), 7.21-7.24 (3H, m)
mp = 103-105 ℃
[0023]
The reaction formulas through both Example 1 and Example 2 are shown below.
[Chemical Formula 10]

[0024]
[Example 3]
1- (Adamantylidenebenzyl) -2- (2 ′, 5′-dimethylethylite) synthesized in Example 2 was prepared by dissolving 0.216 g of polymethyl methacrylate (PMMA) pellets of arylbutadiene in polymethyl methacrylate (PMMA) pellets in 4 ml of dichloromethane. A casting film was obtained by dissolving 1.27 mg of 3-nyl) hexafluorocyclopentane.
When this film was irradiated with ultraviolet light having a wavelength of 313 nm for 30 minutes, it was colored red and exhibited an absorption maximum at 455 nm. When this colored film was irradiated with light having a wavelength of 455 nm, it quickly disappeared. Similarly, when this film was irradiated with ultraviolet light having a wavelength of 313 nm for 30 minutes and colored in red at a temperature of 80 ° C. in the dark, no decoloration occurred. FIG. 1 shows the change in absorbance at 455 nm when this film was kept at 80 ° C.
[0025]
[Example 4]
Synthesis of 1- (2-methyl-1-phenylpropenyl) heptafluoropentene
1-Bromo-2-methyl-1-p-henylpropene 506 mg (2.36 mmol) was placed in a 100 ml two-neck pear-shaped flask, and the atmosphere was purged with nitrogen, and dissolved in 30 ml of anhydrous THF. The solution was cooled to −78 ° C. or lower in a dry ice / isopropanol bath, and 1.82 ml (2.84 mmol) of a hexane solution of 1.56 mol / dm 3 n-butyl lithium was added and stirred for 30 minutes. To this reaction solution, 0.79 ml (5.65 mmol) of octafluorocyclopentene was added and stirred for 15 hours.
Water was added to the reaction solution to terminate the reaction, and the mixture was extracted 3 times with acetic acid ethyl ester. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfide, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatogram to obtain 503 mg of 1- (2-methyl-1-phenylpropenyl) heptafluoropentene in a yield of 66%.
¹ H-NMR (270 MHz, CDCl ₃ , TMS) δ / ppm: 1.78 (3H, s), 1.84 (3H, s), 7.13 (2H, d, J / Hz = 6.27), 7.32-7.45 (3H, m ).
[0026]
[Example 5]
Synthesis of 2- (2-methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene
4-Bromo-2,3,5-trimethylthiophene (306 mg, 1.54 mmol) was placed in a 100 ml two-necked pear-type flask, purged with nitrogen, and dissolved in anhydrous THF (10 ml). The solution was cooled to −78 ° C. or lower with a dry ice / isopropanol bath, 1.1 ml (1.72 mmol) of a hexane solution of 1.56 mol / dm 3 n-butyllithium was added, and the mixture was stirred for 30 minutes. This reaction solution was added dropwise to 15 ml of an anhydrous THF solution of 500 mg (1.54 mmol) of 1- (2-methyl-1-phenylpropenyl) heptafluoropentene prepared in a 100 ml two-neck pear flask and allowed to react for 5 hours. It was.
Water was added to the reaction solution to terminate the reaction, and the mixture was extracted 3 times with acetic acid ethyl ester. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfide, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel chromatogram to obtain 160 mg of 2- (2-methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene in 24% yield. Obtained.
¹ H-NMR (270MHz, CDCl ₃ , TMS) δ / ppm: 1.43 (3H, s), 1.59 (3H, s), 1.73 (3H, s), 1.90 (3H, s), 2.19 (3H, s) , 6.69 (2H, m), 7.13-7.16 (3H, m).
[0027]
The reaction formulas through both Example 4 and Example 5 are shown below.
Embedded image

[0028]
[Example 6]
Photochromism of 2- (2-methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene
2- (2-Methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene only shows terminal absorption in toluene below 350 nm, but 313 nm It becomes a colored product that exhibits a 6π electron cyclization reaction upon irradiation with light and exhibits an absorption maximum at 450 nm. The photoreaction quantum yield (ψ) from the ring-opened product to the ring-closed product upon irradiation with 313 nm light was 0.42, and the quantum yield from the ring-closed product to the ring-opened product was 0.14. The closed ring was thermally stable and isomerized to the open ring by irradiation with 405 nm light. Its quantum yield was 0.16.
[0029]
[Example 7]
PMMA film of 2- (2-methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene
PMMA is dissolved in a toluene solution of 2- (2-methyl-1-phenylpropenyl) -1- (2,4,5-trimethyl-3-thienyl) -hexafluoropentene, and a film with a thickness of about 50 μm is obtained by casting. It was. After irradiating the film with ultraviolet light of 313 nm to form a colored body, the film was kept at 80 ° C. for 30 days in the dark. In addition, the coloring / decoloring cycle was repeated 10 times, but no deterioration of the wearing / decoloring properties was observed.
[0030]
【The invention's effect】
The photocyclic ring of the 1-arylbutadiene compound of the present invention is heat-stable, does not open at room temperature, and has a great feature that the photoresponse is extremely stable over a long period of time.
[Brief description of the drawings]
FIG. 1 shows the thermal stability of photochromic coloring of 1-arylbutadiene / PMMA films.
(The absorbance at 455 nm immediately after irradiating 313 nm ultraviolet light for 30 minutes was normalized as A0, and the absorbance on the measurement day was indicated as A / A0.)

Claims (6)

A 1-arylbutadiene compound represented by the following formula [I].

(In the formula, X represents a sulfur atom, an oxygen atom or an alkyl-substituted nitrogen atom. R ₁ represents an alkyl group which may have a substituent. R ₂ and R ₃ each independently represents an alkyl group, an alkoxy group. group refers to an amino group, a cyano group or a nitro group or have a substituent is also an aromatic group or heterocyclic aromatic group, or jointly aromatic ring formed by, .R ₄ Is an aromatic group which may have a substituent, R ₅ and R ₆ are alkyl groups which may have a substituent, or a fatty acid which forms a monocyclic ring or a polycyclic ring together Means a family ring.) A photocyclized product of a 1-arylbutadiene compound represented by the following formula [II].

(In the formula, X, R ₁ to R ₄ are the same groups as those described above. R ₅ and R ₆ are alkyl groups which may have a substituent, or a monocyclic or polycyclic group together. Means an aliphatic ring that forms 2. The 1-arylbutadiene according to claim 1, wherein an anion of vinyl halide [IV] and aryl halide [V] represented by the following formula, which has been previously lithiated with butyllithium, is sequentially reacted with octafluorocyclopentene. Compound preparation.

A photochromic material comprising the 1-arylbutadiene compound [I] shown in claim 1 or the photocyclized compound [II] shown in claim 2 as a photochromic compound. A light-modulating material comprising the 1-arylbutadiene compound [I] shown in claim 1 or the photocyclized compound [II] shown in claim 2 as a photochromic compound. An optical recording material comprising the 1-arylbutadiene compound [I] shown in claim 1 or the photocyclized compound [II] shown in claim 2 as a photochromic compound.

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