JPH0819026B2 - Optically active compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel optically active compound. More specifically, it relates to an optically active compound useful as an intermediate for a novel optically active liquid crystal compound.

[Conventional technology]

At present, various liquid crystal display devices have been put into practical use. Above all, TN (Twisted Nematic) using nematic liquid crystal
The type display system has excellent performance in that it consumes very little power and is widely used. However, this display method has a drawback that the response speed is slow.

Recent advances in industrial technology strongly demand high-speed response for liquid crystal display elements, and various attempts have been made by improving liquid crystal materials to meet such requirements. In order to meet the above demand, a display device utilizing an optical switching phenomenon of a ferroelectric liquid crystal using an optically active smectic liquid crystal has already been proposed (Applied Physics Letter (Appl.Phys.Lett., 36 , 899). (1980)).

[Problems to be solved by the invention]

As a representative of known ferroelectric liquid crystals, there is one shown in Table 1.

However, these compounds have an unstable element that causes isomerization by light within a short period of time, and causes hydrolysis due to moisture so as not to show a liquid crystal phase, which is not preferable as a display element. Also, spontaneous polarization is about 1-5 nC / cm ²
And the response time is slow at about 1 msec. The subject of the present invention is photochemical and chemical stability that eliminates such unstable elements. And to provide a novel compound useful as an intermediate of a ferroelectric liquid crystal having a large spontaneous polarization and a high response speed.

[Means for solving problems]

The present inventors have arrived at the present invention by searching various compounds in order to solve the above problems.

That is, the invention has the general formula (I) (In the formula, R is an alkyl group having 1 to 10 carbon atoms, and * indicates an asymmetric carbon atom.)

The compound of formula (I) can be produced by various methods, but typically, it is produced by the following synthetic route.

That is, 6-benzyloxy-2-naphthol (a) and optically active 1- (p-toluenesulfonoxy) -2- (tetrahydro-2'-pyranyloxy) propane are added in the presence of a base (for example, sodium hydride). Reacted to give optically active 6-benzyloxy-2- [2 '
-(Tetrahydro-2 "-pyranyloxy) propoxy] naphthalene (b).

By making (b) more acidic, optical activity-
6-Benzyloxy-2- (2'-hydroxypropoxy) naphthalene (c). After reacting (c) with an alkyl halide present in the presence of a base (eg, alkyl iodide) to give optically active 6-benzyloxy-2- [2 '-(alkyloxy) propoxy] naphthalene (d), then (d) ) In the presence of a catalytic amount of palladium / carbon, reduction and debenzylation are carried out, and optically active-6-hydroxy-2 [2'-
(Alkyloxy) propoxy] naphthalene (I) is obtained.

[Operation of the invention]

The compound of the present invention is very useful as an intermediate in the production of an optically active liquid crystal compound.

The compound of the present invention has an optically active group in the molecule and is particularly useful as an intermediate in the production of ferroelectric liquid crystal and chiral nematic liquid crystal.

Further, by introducing the compound of the present invention into a polymer liquid crystal, a polymer liquid crystal exhibiting an electro-optical effect can be produced.

〔The invention's effect〕

The compound produced by using the compound of the present invention as an intermediate product becomes a very excellent ferroelectric liquid crystal, and the ferroelectric liquid crystal has a large spontaneous polarization and is very optically and chemically stable.

In general, a liquid crystal compound has a rod-like structure composed of a nucleus portion including a benzene ring, a heterocyclic ring, a cyclohexane ring and the like, and an alkyl chain and the like. It is well known that those having an alkyl chain having a certain number of carbon atoms or more tend to show a smectic phase.

That is, the compound represented by the general formula (I) can be prepared by, for example, alkylcarboxylic acid, alkoxycarboxylic acid, 4-alkylbenzoic acid, 4-alkoxybenzoic acid, 4-alkylcarbonyloxybenzoic acid, 4-alkoxycarbonylbenzoic acid, 4 -Alkoxycarbonyloxybenzoic acid, 6
-Alkyl-naphthalene-2-carboxylic acid, 6-alkoxy-naphthalene-2-carboxylic acid, 6-alkylcarbonyloxy-naphthalene-2-carboxylic acid, 6-alkoxycarbonyl-naphthalene-2-carboxylic acid, 6-
Alkoxycarbonyloxy-naphthalene-2-carboxylic acid, 4- (4'-alkylphenyl) benzoic acid, 4-
(4'-alkoxyphenyl) benzoic acid, 4- (4'-
Alkylcarbonyloxy) benzoic acid, 4- (4'-alkoxycarbonyl) benzoic acid, 4- (4'-alkoxycarbonyloxy) benzoic acid, trans-4- (4 '
-Alkylphenyl) cyclohexylcarboxylic acid, trans-4- (4'-alkoxyphenyl) cyclohexylcarboxylic acid, trans-4- (4'-alkylcarbonyloxyphenyl) cyclohexylcarboxylic acid, trans-4- (4'-alkoxycarbonyl) Phenyl) cyclohexylcarboxylic acid, trans-4- (4'-alkoxycarbonyloxyphenyl) cyclohexylcarboxylic acid, 4- (trans-4'-alkylcyclohexyl) benzoic acid, 4- (5'-alkylpyrimidine-2-
Il) benzoic acid, 4- (5′-alkoxypyrimidine)
2-yl) benzoic acid, 4- (trans-5'-alkyl-1,3-dioxan-2-yl) benzoic acid, 4- (trans-5'-alkyl-1,3-dithiaoxan-2-yl) Benzoic acid, 4- (trans-5'-alkyl-1,3)
-Dithian-2-yl) benzoic acid, 4- (5'-alkyl-1,3,2-dioxaborinan-2-yl) benzoic acid,
Or a halogen atom, a cyano group, a nitro group, a methyl group on the ring of the benzene ring or naphthalene of these compounds,
A very useful ferroelectric liquid crystal can be obtained by reacting with a derivative having an ethyl group substituted.

For example, a compound represented by the general formula (II) produced from the compound (I) of the present invention and 4-alkoxybenzoic acid (In the formula, R ¹ is an alkyl group having 1 to 16 carbon atoms, R ₂ is 1 carbon atom
~ 10 alkyl groups are shown. ) Indicates a chiral smectic C phase in a temperature range relatively close to room temperature as shown in Table 2, and has a very large spontaneous polarization. That is, in Table ^2, it was revealed that the spontaneous polarization of the compound shown in Example 3 was very high at 25 nC / cm ² and the response speed was very fast at 40 μsec.

In Table 2, C represents a crystalline phase, Sc ^* represents a chiral smectic C phase, SA represents a smectic A phase, and I represents an isotropic liquid.
The-mark and the number on the right side of each phase indicate the transition temperature from the phase to the phase on the right side, and the-mark means that the phase is not indicated. The value of spontaneous polarization was obtained at a temperature 10 ° C lower than the Sc ^* -SA transition temperature.

[Examples] The compounds of the present invention are described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 (s) -6-hydroxy-2 [2 '-(ethyloxy)
Propoxy] naphthalene (in the general formula (I), R = C ₂
Preparation of H ₅ compound (i) Preparation of (s) -6-benzyloxy-2- [2 ′-(tetrahydro-2 ″ -pyranyloxy) propoxy] naphthalene N, N-dimethylformamide 20 ml to 60% sodium hydride After suspending 3.5 g, 17 g of 6-benzyloxy-2-naphthol dissolved in 120 ml of N, N-dimethylformamide was added to this solution at room temperature for 20 minutes, and then 10 minutes at room temperature. After stirring in the literature (Jar of American Chemical Society J. Am. Chem. Soc,
95 , 4987 (1973)) (s)
25 g of -1- (p-toluenesulfonoxy) -2-propanol was added, and the mixture was stirred at 40 ° C for 48 hours.

After N, N-dimethylformamide was distilled off under reduced pressure, 100 ml of water and 300 ml of benzene were added to the residue, and then the benzene layer was separated. The benzene solution was dried over anhydrous magnesium sulfate, and then evaporated under reduced pressure. The residue is benzene
After elution with ethyl acetate (95: 5 v / v) and purification using silica gel column chromatography, the solid obtained was recrystallized from ethanol to give 13 g of colorless plate crystals (s) -6-benzyloxy. 2- [2 '-(Tetrahydro-2 "-pyranyloxy) propoxy] naphthalene was obtained. Yield 49%, melting point 84.0-87.0 ° C The elemental analysis values were in good agreement with the theoretical values as follows.

Theoretical value (as C ₂₅ H ₂₈ O ₄ ) Analytical value C 76.50% 76.71% H 7.19% 7.20% (ii) (s) -6-benzyloxy-2- [2′-hydroxypropoxy] naphthalene (i) Produced by (s) -6-benzyloxy-2-
[2 '-(Tetrahydro-2 "-pyranyloxy) propoxy] naphthalene 20g and Diaion (manufactured by Mitsubishi Kasei)
Sulfonic acid ion exchange resin 3g in 500ml methanol at 50 ℃
And stirred for 3 hours. Then, the reaction mixture is hot filtered, methanol is distilled off under reduced pressure, and the residue is washed with methanol to obtain 14.5 g of colorless plate crystals (s) -6.
-Benzyloxy-2- [2'-hydroxypropoxy] naphthalene was obtained. Yield 92% Melting point 141-143 ° C Elemental analysis values were in good agreement with theoretical values as follows.

Theoretical value (C ₂₀ H ₂₀ O ₃ as) analysis C 77.90% 78.00% H 6.54% 6.50% (iii) 6- Benzyloxy-2- [2 '- (ethyloxy) propoxy] 60% sodium hydride producing naphthalene A solution of 6 g of 6-benzyloxy-2- (2'-hydroxypropoxy) naphthalene prepared in (ii) in N, N-dimethylformamide (60 ml) in N, N-dimethylformamide (20 ml) in which 1.0 g was suspended. Was added, and the mixture was stirred at room temperature for 10 minutes. Then, 5 ml of ethyl iodide was added, and the mixture was stirred at 40 ° C. for 2 hours, N, N-dimethylformamide was distilled off under reduced pressure, 20 ml of water and 100 ml of benzene were added to separate the benzene layer, and the benzene solution was added. Was dried over anhydrous magnesium sulfate.

Benzene was distilled off under reduced pressure, the residue was purified by silica gel column chromatography using benzene-ethyl acetate (20: 1 v / v) as an eluent, and the obtained solid was recrystallized from ethanol to give 5 g of colorless plate crystals. As a result, the desired 6-benzyloxy-2- [2 '-(ethyloxy) propoxy] naphthalene was obtained.

 Yield 76% Melting point 66.3-67.5 ° C Elemental analysis values were in good agreement with theoretical values as follows.

Was obtained in the theoretical value (C ₂₂ as H ₂₄ O ₃₎ analysis C 78.54% 78.57% H 7.19% 7.20% (iv) (iii) (s) -6- Benzyloxy-2
-[2 '-(Ethyloxy) propoxy] naphthalene 4.
8 g was absorbed in 40 ml of ethanol in the presence of 0.5 g of 5% palladium / carbon at 40 ° C. for 2 hours to absorb 320 ml of hydrogen. After the palladium / carbon was filtered off, ethanol was distilled off under reduced pressure and the residue was recrystallized from ethanol to give 3.0 g of colorless needle crystals of the desired (s) -6-hydroxy-2- [2 '-(ethyloxy). Propoxy] naphthalene was obtained. 85% yield
Melting point 148 to 150 ° C. The elemental analysis values were in good agreement with the theoretical values as shown in Table 3.

Examples 2 to 10 (iii) of Example 1 except that various alkyl iodides were used in place of ethyl iodide in (iii) of Example 1.
Various (s) -6-benzyloxy-2- [2 '-(alkyloxy) propoxy] naphthalene were prepared according to the method described in 1.

Further, in (iv) of Example 1, (s) -6-benzyloxy-2- [2 '-(ethyloxy) propoxy]
According to the method described in (iv) of Example 1, except that various (s) -6-benzyloxy-2- [2 '-(alkyloxy) propoxy] naphthalene was used instead of naphthalene, (s) -6. -Hydroxy-2- [2 '-(alkyloxy) propoxy] naphthalene was prepared.

 The elemental analysis values of each compound are shown in Table 3.

Claims (1)

[Claims] 1. A general formula (I) (In the formula, R is an alkyl group having 1 to 10 carbon atoms, and * indicates an asymmetric carbon atom).