JPH03240783A - Hydrocumarin derivative - Google Patents

Abstract

NEW MATERIAL:A compound expressed by the formula (R<1> is 1-18C alkyl; X is single bond, O, COO or CH2O, etc.; Z is COO or CH2O; A<1> and A<2> are H, F, Cl, CH3 or CH3, etc.; R<2> is 1-16C alkyl; R<3> is H, F or CH3; p and q are 0 or 1; * is position of asymmetric carbon). EXAMPLE:(3R,1'R)-3-(1'-methylbutoxy) carbonyl-7-(4''-n-octyloxy)benzoyl oxycumarin. USE:Used as a mixing component for a ferroelectric liquid crystal having excellent responsibility. PREPARATION:For instance, 2,4-dihydroxybenzaldehyde is reacted with (R) malonic acid di-1-methyl butyl and reacted with 4-octyloxybenzoyl chloride, then subjected to catalytic hydrogenation using a platinum oxide catalyst to obtain (3RS,1'R)-3-(1'-methylbutoxy) carbonyl-7-(4''-n-octyloxy)benzoyl oxyhydrocumarin, thus resultant compound is treated with an optical resolution agent to afford the aimed compound expressed by the formula.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to novel optically active compounds.

(Prior art) Currently, liquid crystals are widely used as display materials, and although this liquid crystal is a nematic liquid crystal and has characteristics such as being light-receiving type, it does not cause eye strain and consumes very little power. , the response is slow, and the display cannot be seen depending on the viewing angle.

Ferroelectric liquid crystals are attracting attention because they have these characteristics, such as not tiring the eyes and extremely low power consumption, and also have high-speed response and high contrast comparable to light-emitting display elements.

Ferroelectric liquid crystal was developed in 1975 by Mayer (R, B, Me
yer) et al. (J, Physique 36.L-69 (197
5)), which has a chiral smectic phase such as chiral smectic C phase (hereinafter abbreviated as Sc'' phase).

Ferroelectric liquid crystal molecules have their long axes almost aligned, and the centers of gravity of the molecules are on almost the same plane, and these planes overlap periodically to form layers. The alignment direction is tilted at a constant angle determined by the liquid crystal, called the tilt angle, with respect to the vertical direction of the layer, and the tilt direction is slightly different for each layer while keeping the tilt angle constant, creating a helical structure.

When using a ferroelectric liquid crystal as a liquid crystal element, it must exhibit ferroelectricity in a wide temperature range including room temperature, have a long helical pitch in a helical structure, have an appropriately large spontaneous polarization, have a low viscosity, and have a suitable It is difficult to satisfy all of these conditions by using a single ferroelectric liquid crystal compound as it is, but by mixing multiple types of liquid crystal compounds. Attempts have been made to satisfy these conditions.

One of the promising methods among these attempts is to add an optically active compound to a non-chiral liquid crystal composition that has low viscosity and exhibits a smectic C phase (hereinafter abbreviated as Sc phase). Materials that exhibit ferroelectricity by themselves are used, and materials that do not exhibit ferroelectricity by themselves are also used.

In order to obtain a liquid crystal composition with a high response speed using the above method, it is necessary to use an optically active substance in which the asymmetric carbon of the optically active group is close to a permanent dipole, and the dipole rotates around the asymmetric carbon. Preferably one that can suppress this.

From this point of view, the present applicant has previously proposed an optically active substance having a δ-valerolactone ring as an optically active moiety, with a carbonyloxy group connecting this and an aromatic ring which is a mesogen. (Unexamined Japanese Patent Publication No. 199959) (Problem to be solved by the invention) However, in this case, free rotation is possible between the δ-valerolactone ring and the adjacent aromatic ring, and it is desirable to increase the response speed. It was inconvenient for that purpose.

(Means for Solving the Problems) In view of the above circumstances, the present inventors have conducted intensive studies and have found that hydrocoumarin is used as a substance capable of inhibiting free rotation between the valerolactone ring and the adjacent aromatic ring. We have come up with this possibility and have arrived at the present invention.

That is, the gist of the present invention is an optically active hydrocoumarin derivative represented by general formula (1).

(In formula (1), R1 represents an alkyl group having 1 to 18 carbon atoms, X is a single bond, -〇-・-COO--OCO-
or -ocoo-, Y is a single bond, -COO--0
CO--0CH2- or -〇H*O-, Z is -C
OO- or -cH*o-, A' and A2 each independently represent H%F, CI2, methyl group, trifluoromethyl group, or cyano group, and R8 is a linear or branched chain having 1 to 16 carbon atoms. represents an alkyl group having branches, Rs represents H, F, or a methyl group; p and q represent a combination of O, Oll, and O, or 1 and 1; * indicates that the carbon to which it is attached is an asymmetric carbon; Show that something is true. ) In the present invention, in the formula (1), the number of carbon atoms in R1 of the compound is 1
If it is 9 or more, the viscosity of this compound tends to become high, which is not preferable. Any number of carbon atoms in R1 can be used as long as it is in the range of 1 to 18, but 6
~14, the melting point of this compound is lowered and the temperature range of the Se'' phase when made into a composition is not narrowed,
The alkyl group R', which is preferable because it also has a relatively low viscosity, may be a straight-chain alkyl group or a branched alkyl group. Straight chain ones are preferable because they tend to lower the viscosity than the corresponding branched ones, and branched alkyl groups are preferable because they tend to lower the melting point compared to the corresponding straight chain ones. Specific examples include n-hexyl group, n-hebutyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group,
n-dodecyl group, n-tridecyl group, n-tetradecyl group, 4-methylhexyl group, 5-methylhebutyl group, 6
-methyloctyl group, 7-methylnonyl group, 8-methyldecyl group, 9-methylundecyl group, lO-methyldodecyl group, 11-methyltridecyl group, etc.

R2 is an alkyl group having 1 to 16 carbon atoms, and may be linear or branched. If it has a branch, it may be a racemate or it may have an asymmetric carbon. If the number of carbon atoms in R2 is 17 or more, the viscosity of the compound tends to increase, which is not preferable. From the viewpoint of viscosity, R2 preferably has 1 to 14 carbon atoms. It is preferable that R2 is a straight chain because it tends to lower the viscosity, and it is preferable that R2 has a branch chain because it tends to lower the melting point, and when it has an asymmetric carbon, this is used. When used as a composition, it tends to lengthen the helical pitch of the chiral smectic layer, which is preferable from the viewpoint of orientation. Preferred examples of R2 include optically active 1-methyldecyl group, ■-methylnonyl group, l-methyloctyl group, 1-methylhebutyl group, 1-methylhexyl group, l-methylpentyl group, 1
-methylethyl group, 1-methylpropyl group, 1-methylethyl group, and 2-methylbutyl group.

R3 is H, F or a methyl group, but it is preferable that R3 is F or a methyl group because racemization is less likely to occur. A
' and A2 are each independently selected from H, F, CI2, a methyl group, a trifluoromethyl group, and a cyano group, and it is preferable that A2 is hydrogen because it tends to improve liquid crystallinity. When A2 is fluorine, it has the effect of improving the orientation of a liquid crystal composition using this compound, and from this point of view, it is preferable that A2 is fluorine.Also, ferroelectric liquid crystals are usually heated at a higher temperature than the Se'' phase. It has a chiral nematic phase (hereinafter abbreviated as N° phase) in the region, and when creating liquid crystals, the liquid crystals are aligned and the helical pitch is adjusted during the process of lowering the temperature from the molten state. N
It is preferable that the temperature range in which the 0 phase is exhibited is wide, since it is easier to adjust the pitch and obtain uniform alignment.From this point of view, when A1 is hydrogen in the optically active substance of the present invention, the chiral nematic phase of the liquid crystal composition using this compound is improved. This is preferable because it tends to widen the temperature range of liquid crystal materials, and if A1 or A2 is a bulky group such as a fluorine group, a chlorine group, a methyl group, a trifluoromethyl group, or a cyano group, it is compatible with other liquid crystal materials. This is preferable because it tends to increase the

Furthermore, electron-withdrawing groups such as fluorine, chlorine, trifluoromethyl, and cyano groups are preferred because they tend to widen the temperature range of the Sc' phase when used in liquid crystal compositions.

It is more preferable that the A1 and A snows are each independently hydrogen or fluorine, since those with liquid crystallinity, orientation, and low viscosity can be obtained.

The combination of p and q is 0, 0.1 and 0 or 1 and 1
Any combination of O and O or l may be used as long as it is a combination of
A combination of and 0 tends to lower the viscosity and lower the melting point, so it is preferable, and a combination of 1 and 0 is more preferable.

In the optically active substance of the present invention, X is 10- or -C
If it is O〇-, it is preferable in that it increases the upper limit of the temperature range in which a smectic phase is exhibited, and if X is a single bond, it lowers the lower limit in the temperature range in which a smectic phase is exhibited, and also reduces the viscosity of the liquid crystal composition. It is preferable.

It is preferable that Y is a single bond, -COO- or -CO-, since the temperature range in which liquid crystallinity is exhibited tends to be widened. In particular, it is preferable that Y is a single bond because the viscosity also tends to decrease.

When Y is 10CHx- or -0H*O-, the viscosity tends to decrease and the response speed increases. It has excellent effects as an optically active substance for use in ferroelectric liquid crystal compositions.

The compound represented by general formula (1) can be synthesized by the following route.

(a) When Z in general formula (1) is -COO- (b) When Z in general formula (1) is -CH, O- Obtained by the reaction immediately before the final stage of (a) It can be obtained by performing the following reaction using the product, and when Rs is a methyl group, it can be synthesized by the following method.

When R1 is fluorine, a method can be adopted in which a predetermined position is brominated with bromine and then replaced with fluorine using mercury fluoride.

The compound of the present invention may exhibit ferroelectricity by itself, or may not exhibit ferroelectricity by itself, but may be mixed with a compound exhibiting Sc phase to form a ferroelectric liquid crystal composition, or It can be blended with other ferroelectric liquid crystal compounds or compositions to produce liquid crystal compositions with excellent response speed.

Any compound exhibiting an Sc' phase and a compound exhibiting an Sc phase can be used as compounds that can be mixed with the compound of the present invention to form a ferroelectric liquid crystal composition.

When the compound of the present invention is mixed into a non-chiral liquid crystal composition exhibiting an Sc phase, the liquid crystal composition preferably has a nematic phase (abbreviated as N phase) in a higher temperature region than the Sc phase. It is more preferable to have a smectic A phase in a higher temperature region than the Sc phase, and further to have an N phase in a higher temperature region.

(Example) Example 1 3R1'R-3-1'-methylbutoxy
Carbonyl-7-4"-n-octyloxy benzoyloxyhydrocoumarin and 3S 1°R-3-1'-
6.7 g of malonyl chloride was added dropwise to a solution of 8.4 g of L-(-)-pentanol dissolved in 40 mβ of methyanhydrous benzene while cooling in a water bath, and then 1
Stirring was continued for 4 hours, then 10 ml2 of pyridine was added thereto, and stirring was continued for an additional 1 hour.

Next, this solution was poured into 150 mβ of 1N hydrochloric acid, and the reaction product was extracted with ether, washed with water and saturated brine, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain (R)-malonic acid. Di-1-methylbutyl 10.5g
I got it.

Add 5.2,4-dihydroxybenzaldehyde to this total amount.
7 g of piperidine, 0.4 mβ of piperidine, 1 drop of acetic acid and 15 mβ of absolute ethanol were added, and the mixture was refluxed for 6 hours. Then, 20+nj2 of boiling water was added and cooled to precipitate crystals. (R)-3-(1'-methylbutoxy)carbonyl-7-hydroxycoumarin was purified by silica gel column chromatography and recrystallized from methanol.
2g was obtained.

0.43 g of 4-octyloxybenzoic acid and 0.43 g of phosphorus pentachloride.
4-octyloxybenzoyl chloride obtained by heating with 33g and distilling off the produced phosphorus oxychloride under reduced pressure and (R)-3-(1°-methylbutoxy)carbonyl-7-hydroxycoumarin obtained above. 0.44g
was dispersed in 15 mβ of anhydrous benzene, 20 mβ of pyridine was added dropwise thereto, and the mixture was reacted at room temperature for 15 hours.
Heated at 60°C for 2 hours, poured into ice water, extracted the reaction product with chloroform, washed twice each with 1N cold hydrochloric acid, water, and saturated saline, dried over anhydrous magnesium sulfate, and washed with the solvent. was removed. The resulting residue was subjected to silica gel column chromatography using chloroform as a developing solvent to separate the target product, which was then recrystallized from a mixed solvent of ethanol-hexane to obtain (R)-3-(1'-methylbutoxy)carbonyl-7- 0.60 g of (4''-n-octyloxy)benzoyloxycoumarin was obtained.

This was dissolved in ethyl acetate and quantitatively (3R3,
1°R)-3-(1”-methylbutoxy)carbonyl-
7-(4”-〇-octyloxy)benzoyloxyhydrocoumarin was obtained.
(3R, 1°R)-3-(1°
-methylbutoxy)carbonyl-7-(4"-n-octyloxy)benzoyloxyhydrocoumarin (optical rotation (-)) and (3S, loR)-3-(1'-methylbutoxy)carbonyl-7-(4 ”-n-octyloxy)benzoyloxyhydrocoumarin (optical rotation (+))
I got it.

(3RS, 1'R)-3 obtained in the same manner as in Example 1
-(1'-methylbutoxy)carbonyl-7-(4”-
0.1 g of 〇-octyloxy)benzoyloxyhydrocoumarin and 0.03 g of methyl iodide were dissolved in acetone, and 0.06 g of anhydrous potassium carbonate was added thereto. After refluxing for 6 hours, it was cooled and dissolved in ice water. After extracting the reaction product with chloroform, the extract was dried over anhydrous magnesium sulfate, the solvent was distilled off, and the residue was purified by silica gel column chromatography using hexane-ethyl acetate as the developing solvent. (3R3,l'R)-3-(1°-
methylbutoxy)carbonyl-3-methyl-7-(4”
-n-octyloxy)benzoyloxyhydrocumarin 0.07 g was obtained. (3R5,l'R)-3-(1°-methylbutoxy ) Carbonyl-3-methyl-7-(4”-n-octyloxy)benzoyloxyhydrocoumarin (optical rotation (+
)) and (3RS, 1′R)-3-(1′-methylbutoxy)carbonyl-3-methyl-7-(4”-n
-octyloxy)benzoyloxyhydrocoumarin (
Optical rotation (-)) was obtained.

Examples 3 to 5 The optically active hydrocoumarin derivative obtained in Example 1.2 was mixed into an alkoxyphenylpyrimidine liquid crystal mixture having the following phase transition temperature so that the concentration of the derivative was as shown in Table 1. The phase transition temperature and 0-50% response speed (25°C, E=5V/μm) of the mixture were measured.

Phase transition temperature of alkoxyphenylpyrimidine liquid crystal mixture Table 1 (Effects of the invention) As is clear from its chemical structure, the optically active substance of the present invention is chemically stable, has excellent photostability, and has a large spontaneous activity. It is extremely useful as a compounding component for ferroelectric liquid crystals that exhibit polarization and excellent responsiveness.

The results are shown in Table 1.

Claims (1)

[Claims] 1) An optically active hydrocoumarin derivative represented by general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In formula (1), R^1 represents an alkyl group having 1 to 18 carbon atoms, and X is a single bond, -O-, -COO-, -OC
O- or -OCOO-, Y is a single bond, -COO-
, -OCO-, -OCH_2- or -CH_2O-, Z represents -COO- or -CH_2O-, A^1
and A^2 each independently represent H, F, Cl, a methyl group, a trifluoromethyl group, or a cyano group, R^2 represents a linear or branched alkyl group having 1 to 16 carbon atoms, and R
^2 represents H, F or methyl group, p and q are 0, 0, 1
and 0 or 1 and 1, and * indicates that the carbon to which it is attached is an asymmetric carbon. )