JP2869684B2 - Stimuli-responsive cholesterol compounds - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cholesterol compound, and more particularly to a novel cholesterol compound which exhibits a unique property in response to external stimuli such as light and can be used as a switching element or a display element. .

[0002]

2. Description of the Related Art A large number of cholesterol compounds containing a cholesterol group in the basic structure have been known so far, but their applications are very few, and there are only a few cholesterol alkyl fatty acid esters. Only an application example of a derivative as a thermometer is known (using detection of a change in pitch that fluctuates with a change in temperature as an external stimulus as a change in color).

Recently, Lin and Weiss et al. Have found that some anthracene derivatives based on cholesterol form gels in organic solvents and reversible sol-gels due to temperature changes as external stimuli. It is reported that optical properties such as fluorescence and intensity of circular dichroism spectrum (CD spectrum) change with the transition (J. Am. Chem. So
c., 111 , 5542 (1989)). Such a property is conceived for application to switching elements and display elements utilizing stimulus responsiveness, but in fact, the sol-gel transition of the cholesterol-based compound is not sharp, but is 10 to 20 ° C. Responsiveness, such as a change in the CD spectrum intensity, which occurs gradually with a temperature range, is not sufficient, and is not practical.

Further, other liquid crystal compounds such as nematic and smectic are widely used as display elements of various electric appliances and measuring instruments, but these compounds change the molecular arrangement of liquid crystal molecules exclusively by using an electric field as an external stimulus. Therefore, it cannot be applied to a display element having a large area such as a large display element or a window shutter.

[0005]

[Means for Solving the Problems and Effects of the Invention] As the inventors of the present invention have been conducting research on cholesterol compounds, they have not only properties as liquid crystals but also are not found in conventional cholesterol compounds. A cholesterol compound having a unique stimulus responsiveness was found.

That is, the present invention provides a compound represented by the following general formula:
A cholesterol compound represented by the formula:

[0007]

Embedded image R ₁ −φ−N = N−φ−R ₂ −Cho

In the above formula, Cho represents a cholesterol group, and φ represents a benzene ring. That is, the compound of the present invention is a cholesterol derivative having azobenzene. In the formula, R ₁ represents — (CH ₂ ) _n CH ₃ , —O (C
H ₂ ) _n CH ₃ , —N [(CH ₂ ) _n CH ₃ ] ₂ , a piperidino group, or —H. Further, R ₂ is, - (CH ₂₎ m
Represents COO— or —O (CH ₂ ) _m COO—. N and m in R ₁ and R ₂ are each an integer of 0 to 10, preferably 0 to 8. As understood from the above formula, the azobenzene moiety and the cholesterol moiety are linked via an ester bond. Also, C
As the cholesterol moiety represented by ho, it is also possible to use a partially modified derivative. In addition, the piperidino group is a functional group represented by the following formula [Formula 2].

[0009]

Embedded image

One of the features of the compound of the present invention is that it forms a gel reversibly or thermoreversibly in response to light or a temperature change as an external stimulus to an organic solvent, and undergoes a sol-gel transition. Along with this, the light transmittance, the CD spectrum or the absorption spectrum is significantly changed. Preferred as such a gelling compound is the above-mentioned general formula [Chemical formula 1]
In the formula, R ₁ represents — (CH ₂ ) _n CH ₃ , —O (CH ₂ ) _n
CH ₃ and —N [(CH ₂ ) _n CH ₃ ] ₂ , wherein n is 0 to 5
And m is 0 or 1, and particularly preferably, R ₁ is-(CH ₂ ) _n CH ₃ (n = 0 to 5), -O
(CH ₂ ) _n CH ₃ (n = 0 to 5) or —N [(CH ₂ )
_n CH ₃ ] ₂ (n = 0 to 3) and R ₂ is —COO— or —OCH ₂ COO—.

The following are some specific examples of the cholesterol compound of the present invention that gels an organic solvent.

[0012]

Embedded image CH ₃ O-φ-N = N-φ-COO-Cho

[0013]

Embedded image C ₂ H ₅ O-φ-N = N-φ-COO-Cho

[0014]

Embedded image C ₃ H ₇ O-φ-N = N-φ-COO-Cho

[0015]

Embedded image C ₄ H ₉ O-φ-N = N-φ-COO-Cho

[0016]

Embedded image C ₅ H ₁₁ O-φ-N = N-φ-COO-Cho

[0017]

[CH ₃ ] ₂ N-φ-N = N-φ-COO-Ch
o

[0018]

Embedded image _{[C 2 H 5] 2 N} -φ-N = N-φ-COO-C
ho

[0019]

[C ₃ H ₇ ] ₂ N-φ-N = N-φ-COO-
Cho

[0020]

Embedded image CH ₃ -φ-N = N-φ-OCH ₂ COO-C
ho

[0021]

Embedded image C ₂ H ₅ -φ-N = N-φ-OCH ₂ COO-
Cho

In these compounds, φ and Cho represent a benzene ring and a cholesterol group, respectively, as described above. Therefore, the compound of the formula [Chemical formula 3] can be specifically represented as the following [Chemical formula 13].

[0023]

Embedded image

The compound of the formula [Chemical formula 9] can be represented by the following formula [Chemical formula 14].

[0025]

Embedded image

The organic solvent that forms a gel with the cholesterol compound of the above general formula [Chemical Formula 1] according to the present invention varies depending on the type of the compound, but hydrocarbons such as benzene, cyclohexane, methylcyclohexane, hexane and heptane; Alcohols such as ethanol, propanol, butanol and dodecane, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, halogens such as carbon tetrachloride, and a mixed solvent thereof are used. The mixing ratio of the compound and the solvent for forming the gel varies depending on the type of the compound or the solvent to be used, but generally, 0.01 part by weight or more with respect to 100 parts by weight of the solvent.
Preferably, 0.05 parts by weight or more of a cholesterol compound is used.

For example, the compound represented by the above formula [Chemical Formula 3] is not less than 1 part by weight per 100 parts by weight of a solvent for cyclohexane, methylcyclohexane, propanol, or a mixed solvent of cyclohexane / benzene, and Forms a gel at room temperature at a rate of 0.05 parts by weight or more and 0.1 parts by weight or more with respect to hexane.

As described above, the cholesterol-based compound represented by the general formula [Formula 1] forms a photoreversible and thermoreversible gel with an organic solvent, and has an optical property corresponding to the gel formation. Changes significantly. Thus, the present invention provides, as another aspect, a gelling composition comprising the cholesterol-based compound represented by the general formula [Chemical Formula 1] and an organic solvent in the above-described ratio. Since the gelling composition has unique properties, it can be used as various functional elements.

In particular, this gelling composition can be obtained by appropriately selecting the concentration of the gelling agent so that visible light-ultraviolet light-
By alternating the light irradiation like visible light,
The structural change between gel-sol-gel reversibly occurs even in the room temperature range, and exhibits a unique property that the light transmittance, absorption coefficient, intensity and shape of the CD spectrum are remarkably changed accordingly. Such a feature suggests that the gelling composition according to the present invention can be suitably used as a new optical switching device or display device. The expression of such properties in the compound or the gelling composition of the present invention is caused by the fact that the azobenzene unit contained in the cholesterol-based compound represented by the general formula [Chemical Formula 1] undergoes cis-trans change, and accordingly, -Presumed to be caused by a change in gel structure.

The concentration of the photoreversible cholesterol-based compound varies depending on the type of the compound and the solvent used.
The cholesterol compound is used in an amount of 1 to 30 parts by weight, preferably 0.05 to 20 parts by weight. However, even if a gel is formed in the cis structure, the spectrum intensity of the cis state and the trans state is significantly different in the CD spectrum. It can be used as a switch system. Also,
These cholesterol compounds can be used in combination with other cholesterol-based compounds or other liquid crystal compounds as long as the effects of the present invention are not impaired.

The gel-sol change in the gelling composition according to the present invention is characteristically caused by irradiation with visible light-ultraviolet light, but the gel-sol can also be changed by changing the temperature or the concentration. Can be changed. It can be used for a switching element or a display element based on a change in light transmittance or CD spectrum caused by a change in the state of the gel-sol corresponding to such an external stimulus.

The compound of the present invention is not only used as a gelling composition together with an organic solvent, but also exhibits a cholesteric liquid crystal structure in a specific temperature range corresponding to each compound. This compound exhibits different light transmittance and CD spectrum characteristics depending on the liquid crystal phase-crystal phase-isotropic phase. In particular, the CD spectrum of the liquid crystal phase forms a large excitation CD spectrum and exhibits a remarkably large spectral intensity different from the crystal phase and the isotropic phase. Therefore, when a phase change is caused by an appropriate external stimulus, it is suitably used as an optical switch element or the like. As the external stimulus, in addition to an electric field and a thermal stimulus (temperature change) as generally performed with a liquid crystal, alternate light irradiation of ultraviolet light and visible light is also performed.
Such light irradiation causes a cis-trans change between the liquid crystal structures, and the CD spectrum intensity is higher in the trans state than in the cis state. Thus, the liquid crystal compound of the present invention can provide a new switch system for detecting a state change between a liquid crystal phase, a crystal phase, and an isotropic phase or a state change between liquid crystal phases by a signal called a CD spectrum. The temperature range in which the state change (phase transition) occurs varies depending on each compound, but generally, the transition temperature from the crystal to the liquid crystal is 0 to 300 ° C, and the transition from the liquid crystal to the isotropic phase is 20 to 300 ° C. Occurs at 320 ° C.

For example, in the case of the cholesterol compound according to the present invention represented by the following formula [Formula 15], the transition from crystal to liquid crystal is about 172 ° C., the transition from liquid crystal to isotropic liquid is about 212 ° C.,
The isotropic phase → liquid crystal A transition occurs at about 213 ° C., the liquid crystal A → liquid crystal B transition occurs at about 132 ° C., and the liquid crystal B → crystal transition occurs at about 118 ° C. As another example, in the case of the compound represented by the formula [Formula 8], the crystal → liquid crystal transition is about 82 ° C., the liquid crystal → isotropic phase transition is about 225 ° C., and the isotropic phase → liquid crystal transition is about 292 ° C. , LCD →
A crystal transition occurs at 193 ° C.

[0034]

Embedded image φ-N = N-φ-C ₂ H ₄ COO-Cho

The compounds of the present invention are synthesized by devising various conventionally known reactions. Basically, the compound of the present invention is represented by the general formula [R ₁ -φ
-N = N-φ-R ₂ -H] and [Cho-OH] by ester bond. For example, a method in which thionyl chloride is added dropwise to a carboxyphenylazobenzene derivative (or a carboxyalkylphenylazobenzene derivative or a carboxyalkyloxyphenylazobenzene derivative) and dehydrated pyridine, acid-chlorinated, then cholesterol is added and esterified, A method in which an azobenzene derivative (or a carboxyalkylphenylazobenzene derivative or a carboxyalkyloxyphenylazobenzene derivative) is stirred with cholesterol and triphenylphosphine in a solvent such as tetrahydrofuran, and diethylazodicarboxylate is added dropwise to cause a reaction. Is mentioned. As a method of obtaining a portion of [R ₁ -φ-N = N-φ-R ₂ -H], for example, R ₁ is C _n H _{2n + 1} -O-, R
For ₂ COO-, 4-After the amino acid with phenol and diazo coupling, a method of O- alkylated, R ₂ is _{[C n H 2n + 1]} 2 -N-, R 2 is a COO- In this case, it can be obtained by a method of diazo coupling between 4-aminobenzoic acid and N, N dialkylaniline.

Hereinafter, the present invention will be described specifically, but the present invention is not limited to only these examples.

[0037]

EXAMPLES Example 1 : Synthesis of 4-methoxy- (4'-cholesteryloxycarbonyl) azobenzene (compound represented by the above formula [3]; abbreviated as 1a) 12 g of sodium nitrite in 50 ml of water Dissolved in water 3
00 ml, concentrated hydrochloric acid 30 ml, 4-aminobenzoic acid 12 g
Was added dropwise to the solution. After stirring for 10 minutes, a small amount of sulfamic acid was added. On the other hand, 250 ml of water, 8 g of sodium hydroxide and 18 g of phenol were added and dissolved, and then 39 g of sodium carbonate was added. The diazonium salt solution described above was added dropwise thereto to obtain 4- (4′-hydroxyphenylazo) benzoic acid. 15 g of the obtained hydroxyphenylazobenzoic acid was added to 250 ml of dimethylformamide (DMF).
And 100 g of potassium carbonate was added. To this, 71 g of methyl iodide was added dropwise, and the mixture was heated and reacted at 65 ° C. for 16 hours. The product was concentrated, washed with aqueous hydrochloric acid of pH 2, dissolved in ethanol-water, heated and stirred, and 4- (4′-methoxyphenyl) was added. Azo) benzoic acid ethyl ester was obtained. 200 ml of 7 g of the obtained ethyl ester and 3 g of potassium hydroxide
Of ethanol and 100 ml of water, stirred at room temperature for 16 hours, and neutralized with dilute hydrochloric acid to obtain 4- (4′-methoxyphenylazo) benzoic acid. Furthermore, benzoic acid 4
g was placed in 300 ml of benzene and 1 g of pyridine, and 1 g of thionyl chloride was added dropwise with stirring under heating and reflux, and the mixture was reacted for 8 hours. Further, equimolar amounts of cholesterol, 300 ml of benzene and 1 g of pyridine were added, and the mixture was reacted for 12 hours.
I got Nuclear magnetic resonance absorption (NMR) and infrared absorption spectrum (IR) were performed to confirm that the product was the desired product. NMR
, The chemical shift (δ) of the azobenzene portion (8 hydrogen (H) components) with respect to tetramethylsilane is 7.0.
To 8.4 ppm, the 45H portion of the cholesterol portion to 0.3 to 2.6 ppm, and the methyl portion (3H) to 3.9 ppm.
At ~ 4.0 ppm, the 2H content of the cholesterol moiety is 4.0.
It was observed between 7 and 5.6 ppm. In IR, the absorption of CＣO is 1710 cm ⁻¹ and the absorption of C—O is 1250 cm ^−1.
Was observed. In the elemental analysis, H was calculated to be 9.0.
8.98% of measured value and 38.8% of calculated value for 3%
The measured value is 79.98% and the calculated value N is 4.4 with respect to 0%.
It was 4.55% against 8%. The crystal-liquid crystal formation temperature obtained from a differential scanning calorimeter (DSC) was 135 ° C.
Liquid crystal-isotropic temperature was 152 ° C.

The compound 1a was evaluated for characteristics as shown in the following Examples, and its suitability as a switching element or a display element was confirmed.

Example 2 A gelation test of the compound 1a obtained in Example 1 was performed. Gelation was carried out with cyclohexane, a mixed solvent of methylcyclohexane / benzene (3: 1), hexane, propanol and butanol. Gel concentration for butanol
0.2 wt%, 0.5 wt% in the case of hexane, 6 wt% in the case of the mixed solvent, and 2 wt% in the other cases. In addition, when these gels were irradiated with ultraviolet light (UV) using a color filter, the gels collapsed and became an isotropic (isotropic) solution. Further, upon irradiation with visible light (VIS), a gel was formed again and a sol-gel transition occurred reversibly.

The light source used was a 400 W high-pressure mercury lamp, and the color filter was D-3 for UV.
5 (made by Toshiba) for VIS L-42 (made by Toshiba)
Was used. All measurements were performed at room temperature.

Example 3 The light transmittance of a 1a-butanol gel was examined. The gel concentration was 0.2% by weight. Measurement is 700nm
, And UV and VIS were alternately irradiated to examine the change in light transmittance. The transmission coefficient of the gel before UV irradiation is 95
%Met. By UV irradiation, the gel disappeared and became a solution, and a transmittance of almost 100% was obtained. Furthermore,
The gel was formed by VIS irradiation, and the transmittance became 95% again. The UV-VIS irradiation test was repeated 10 times, but there was almost no variation in transmittance, and a constant transmittance was obtained. It can be seen that the light transmittance changes with the photoreversible sol-gel transition. All measurements are performed at room temperature.
Also, when the light transmittance was measured by changing the temperature,
The transmittance gradually changed from 95% to 100% from 35 to 45 ° C.

As a visible-ultraviolet absorption spectrometer, UV-2200 manufactured by Shimadzu Corporation was used.

Example 4 Circular dichroism spectra were measured using 1a-butanol-based and 1a-hexane-based gels. The gel concentration was 0.2 wt% for butanol and 0.5 wt% for hexane. In each case, the gel state
An exciton interaction was observed in which the sign of the CD spectrum was suddenly reversed at 10 nm. The maximum value and the minimum value of the spectrum (molecular ellipticity: deg · cm ² · dmol ⁻¹ ) are about 1.5 × 10 ⁵ (320 nm) and −1.3 × 1 in the butanol system.
0 ⁵ (300 nm) and about 5 × 10 ⁴ (33
0 nm) and -1.4 × 10 ⁵ (300 nm).
Next, UV and VIS were alternately irradiated, and the CD spectrum was measured. In each case, irradiation with UV light significantly reduced the spectral intensity to 10 ^-3 or less. In addition, the reversal of the spectrum did not occur.
Further, by continuously irradiating VIS, a spectrum almost similar to that before UV irradiation was formed. Although the above experiment was performed five times continuously, similar results were obtained. In addition, for the butanol system, the CD spectrum change was measured while changing the temperature. The spectrum intensity (maximum value was 1.5 × 10 ⁵ to 10 ⁻³ or less) ^gradually decreased from 35 to 45 ° C.

The circular dichroism spectrum used was J-720 manufactured by JASCO Corporation. The measurement was performed at room temperature.

Example 5 : 4- (N, N-di-n-methylamino)-(4'-cholesteryloxycarbonyl) azobenzene (compound represented by the above formula [Chemical Formula 8]: hereinafter abbreviated as 1b) 4 g of aminobenzoic acid and 3 g of sodium nitrite are placed in 60 ml of an 8% aqueous hydrochloric acid solution and stirred for about 2 hours.
5.2 g of N, N-di-n-methylalanine in 40 ml of acetic acid was added dropwise, stirred for about 10 hours, and 4- (4'-
N, N-Di-n-propylaminophenylazo) benzoic acid (B) was obtained. Compound (B) (2 g), cholesterol (2.5 g), and triphenylphosphine (3.8 g) were dissolved in tetrahydrofuran (THF) (150 ml), stirred for about 2 hours, and diethyl azocarboxylate diluted in 20 ml of THF was added dropwise. Stir for about 24 hours. After removing the solvent, the target product 1b was separated and purified by column chromatography using toluene. NMR as in Example 1,
The compound was confirmed by IR and elemental analysis. NMR
The chemical shift (δ) of the azobenzene portion (8H) with respect to tetramethylsilane is 6.0 to 8.0 p.
In pm, the amount of 45H of the cholesterol portion is 0.3-2.
At 8 ppm, the 6H content of the methylamino moiety is 3.0 to 3.0 ppm.
In 5 ppm, the 2H content of the cholesterol portion is 4.0-4.0.
Observed at 5.5 ppm. In IR, absorption of CＣO was observed at 1710 cm ⁻¹ . In elemental analysis, H
Is calculated value 9.32%, measured value 9.22%, C is calculated value 79.08%, measured value 78.78%, N
Was 6.51% with respect to the calculated value of 6.58%. The molecular weight obtained by mass spectrometry was 638 compared to the calculated value of 637.95. The crystal-liquid crystal formation temperature determined by DSC was 82 ° C, and the liquid crystal-isotropic phase temperature was 225 ° C.

The properties of this compound 1b were evaluated as shown in the following examples, and its applicability as a switching element was confirmed.

Example 6 Compound 1b obtained according to Example 5 in the same manner as in Example 2.
Was subjected to a gelation test. Gelation was performed using cyclohexane and a mixed solvent of cyclohexane / benzene (8: 2). The gel concentration was 1.0 wt%. When these gels were irradiated with UV, the gels collapsed and turned into sols. Further, upon irradiation with VIS, a gel was formed again, and sol-gel transition occurred reversibly. The measurement was performed at room temperature.

Example 7 The same light transmittance as in Example 3 was examined using 1b-cyclohexane gel. The gel concentration was 1 wt%.
The measurement was performed in a wavelength region of 700 nm, and irradiation with UV and VIS was performed alternately, and a change in light transmittance was examined. The transmission coefficient of the gel before UV irradiation was 80%. The gel was extinguished by UV irradiation and became a liquid, and a transmittance of about 98% was obtained. Further, the gel was formed by the VIS irradiation, and the transmittance became 80% again. 10 UV-VIS irradiation tests
The measurement was repeated continuously, but there was almost no variation, and a constant transmittance was obtained. The light transmittance changed with the photoreversible sol-gel transition. The measurement was performed at room temperature.

Example 8 Using 1b-cyclohexane gel, a CD spectrum similar to that of Example 4 was measured. The concentration of 1b was 1 wt%. Exciton interaction is observed around 375 nm, with a maximum value of 3 × 10 ⁴ (deg · cm ² / dmol) and a minimum value of −2 × 10 ⁴ (d
eg · cm ² / dmol). Gel was irradiated with UV gel disappeared, CD spectrum was not observed at all [Maximum value even minimum even 10 ² or less. Further, upon irradiation with VIS, a gel was formed again, and almost the same spectrum as before UV irradiation was obtained. The same measurement was repeated five times, and the same result was obtained.

Example 9 Synthesis of 4-butoxy- (4'-cholesteryloxycarbonyl) azobenzene (compound represented by the above formula [Chemical Formula 6]; hereinafter abbreviated as 1c) Butyl bromide was used instead of methyl iodide. Using this, the same reaction as in Example 1 was performed to obtain the target product 1c. NMR,
IR was performed to confirm that the product was the target product. In NMR,
The chemical shift (δ) of the azobenzene portion (8 hydrogen (H) components) based on tetramethylsilane is 7.0 to 8.0.
At 4 ppm, the 45H portion of the cholesterol portion and the 7H portion of the butyl portion were at 0.3 to 2.6 ppm, and 2% of the butyl portion.
The H content was observed at 3.0 to 4.0 ppm, and the 2H content of the cholesterol portion was observed at 4.7 to 5.6 ppm. In IR, the absorption of C = O is in 1710 cm ^-1, absorption of C-O was observed at 1250 cm ^-1. The crystal-liquid crystalization temperature obtained by DSC is 105 ° C, and the liquid crystal-isotropic temperature is 134 ° C.
Met.

The properties of this compound 1a were evaluated as shown in the following examples, and its suitability as a switching element or a display element was confirmed.

Example 10 A gelation test of the compound 1c obtained in Example 9 was performed. Gelation was performed with cyclohexane, a mixed solvent of methylcyclohexane / benzene (5: 1), hexane, propanol, and butanol. Gel concentration is 1 wt% for butanol and hexane, 8 wt% for mixed solvent, and 5 wt% for others.
%. In addition, upon irradiation with UV, the gel collapsed and became an isotropic solution. Further, upon irradiation with VIS, a gel was formed again, and sol-gel transition occurred reversibly.

Example 11 The light transmittance of a 1c-cyclohexane gel was examined. The gel concentration was 4% by weight. Measurement is 700nm
, And UV and VIS were alternately irradiated to examine the change in light transmittance. The gel has a transmission coefficient of 73 before UV irradiation.
%Met. The gel was extinguished by UV irradiation and became a solution, and a transmittance of 96% was obtained. In addition, VIS
Irradiation resulted in 72%. The UV-VIS irradiation test was repeated 10 times, and similar results were obtained.

Example 12 Using a 1c-butanol system, a circular dichroism spectrum was measured. The gel concentration was 1 wt%. At room temperature, the gel was in a gel state, and an exciton interaction was observed in which the sign of the CD spectrum was suddenly reversed around 310 nm. The maximum value and the minimum value of the spectrum are about 1.0 × 10 ⁵ (330
nm) and about −0.8 × 10 ⁵ (300 nm).
Next, UV and VIS were alternately irradiated, and the CD spectrum was measured. Irradiation with UV significantly reduced the spectral intensity to 10 ^-3 or less. In addition, the reversal of the spectrum did not occur. Further, by continuously irradiating VIS, a spectrum almost similar to that before UV irradiation was formed. Although the above experiment was performed five times continuously, similar results were obtained.

Example 13 The UV absorption spectrum of a 1a-butanol gel was measured. The concentration of 1a was 0.2 wt%. In the gel state at room temperature, about 1.2 × 10 ⁴ (1 / cm · mo
l), the absorption band at 310 nm disappeared in the solution state at 50 ° C. (about 0.4 × 10 ⁴ (1 / cm 2)).
・ Mol)) About 1.2 × 10 ⁴ (1 / cm ・ m
ol) appeared. In addition, UV is applied to the gel at room temperature.
Irradiated, the absorption band at 310 nm disappeared (reduced to about 0.7 × 10 ⁴ (1 / cm · mol)).

Continued on the front page (72) Inventor Masayoshi Aoki 222-57 Corp.Tainii II 207, Ojiri, Chikushino-shi, Fukuoka (72) Inventor Seiji Shinkai 1860-1 Mitoma, Higashi-ku, Fukuoka, Fukuoka (58) Cl. ⁶ , DB name) C07J 41/00

Claims (1)

(57) [Claims] 1. A cholesterol compound represented by the structural formula [Chemical Formula 1]. R ₁ -φ-N = N-φ-R ₂ -Cho (where R ₁ is — (CH ₂ ) _n CH ₃ , —O (CH ₂ )
_{n CH 3, -N [(CH} 2) n CH 3] 2, piperidino group or -H, R _{2 is,, - (CH 2) m} COO-, or -O
(CH ₂ ) _m COO—, n and m are each an integer of 0 to 10, Cho represents a cholesterol group, and φ represents a benzene ring. )