JPH0791207B2 - Optically active biphenyl ether compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a specific optically active biphenyl ether compound, and more particularly to a biphenyl ether compound having an asymmetric carbon atom-containing alkoxy group.

Liquid crystals have been applied as various electro-optical elements and have been put to practical use for displays such as watches and calculators. Most of the currently practically used liquid crystal display devices utilize the dielectric alignment effect of twisted nematic liquid crystals and cholesteric liquid crystals. However, recently, other types of liquid crystal display methods have been actively developed, and STN methods and cholesteric / nematic phase transition type display methods are also used.

The liquid crystal compositions used in these liquid crystal display devices are adjusted to have respective helical pitches by introducing an optically active substituent into nematic liquid crystal or by adding an optically active substance. For example, a Schiff base type liquid crystal made of p-alkoxybenzaldehyde and (+)-p-amino-2-methylbutylbenzene is known. The optically active substance added is 4- (2
-Methylbutyloxy) -4'-cyanobiphenyl is known, but since this compound has a long twist pitch of the cholesteric liquid crystal, it has a drawback that a large amount of compound is required to obtain desired physical properties. It was

The present inventors have found that the crystal-liquid crystal phase transition temperature useful as a component of the liquid crystal mixture for a display element is low, and the liquid crystal-isotropic liquid phase transition temperature is high when giving a cholesteric phase, and the helical bitch is short. As a result of repeated intensive studies to find a compound, the optically active biphenyl ether compound represented by the following general formula has a crystal-liquid crystal phase transition temperature extremely low,
When the compound gives a cholesteric phase, a liquid crystal
Since the isotropic liquid phase transition temperature is high, it has been found that the compound is extremely suitable for use for the above purpose.

(In the formula, R represents a hydrogen atom or a linear alkyl group having 1 to 11 carbon atoms, X represents a hydrogen atom or a chlorine atom,
n represents 3 to 5, and * represents an asymmetric carbon atom. The compound represented by the above general formula is, for example, an optically active alkyl halide or chloroalkyl halide or an optically active alcohol or p-toluenesulfonic acid ester of chloroalcohol and 4,4′-dihydroxydiphenyl of an alkaline compound. By reacting in the presence, it can be easily produced.

Next, the present invention will be described with reference to examples.

Example 1 (S, S) -4,4'-bis- (6 "-methyldecyloxy)
-Preparation of biphenyl 1.86 g of 4,4'-biphenol in 50 ml of methyl ethyl ketone
And 0.84 g of finely pulverized sodium hydroxide were charged and reacted under reflux for 1 hour, then 6.86 g of p-toluenesulfonic acid ester of 6-methyl-1-decanol was added and reacted under reflux for 12 hours. . The reaction mixture was poured into a large amount of 5% hydrochloric acid aqueous solution, the precipitated solid was filtered, washed with water, and recrystallized from ethanol to give a highly pure (S, S) -4,4'-
(6 ″ -methyldecyloxy) biphenyl was obtained, melting point
As a result of infrared spectroscopic analysis at 75 to 76 ° C, the obtained product had the following characteristic absorption and was confirmed to be the target product: 3050cm ^-1 (vw), 2975cm ^-1 (s), 2940cm ^{-1 (s), 2870cm -1 (} m), 1610cm -1 (m), 1570cm -1 (vw), 1505cm -1 (s), 1470cm -1 (m), 1395cm -1 (w), 1380cm - ^{1 (w), 1325cm -1 (} vw), 1275cm -1 (s), 1250cm -1 (s), 1180cm -1 (m), 1040cm -1 (m), 825cm -1 (s), 730cm -1 (Vw) The optical rotation of the obtained product is shown below.

[Α] _D = + 0.53 ° (29 ° C., C = 1, chloroform solution) Example 2 Preparation of (S, S) -4,4′-bis- (4 ″ -methyldodecyloxy) biphenyl 50 ml of methyl ethyl ketone 1,4 g of 4,4'-biphenol
Then, 0.84 g of finely pulverized sodium hydroxide was charged, the mixture was reacted under reflux for 1 hour, 5.53 g of (s) -4-methyldodecyl bromide was added, and the mixture was reacted under reflux for 15 hours. High-purity (S, S) -4,4′-bis- (4 ″ -methyldodecyloxy) -biphenyl was obtained by the same treatment as in Example 1. Melting point 125-126 ° C. Infrared spectroscopic analysis result The obtained product had the following characteristic absorption and was confirmed to be the target product: 3050cm ^-1 (vw), 2975cm ^-1 (s), 2940cm ^-1 (s), 2870cm ^-1 ( ^{m), 1610cm -1 (m)} , 1560cm -1 (vw), 1500cm -1 (s), 1470cm -1 (m), 1390cm -1 (w), 1380cm -1 (w), 1325cm -1 (vw ^{), 1270cm -1 (s),} 1245cm -1 (s), 1180cm -1 (m), 1050cm -1 (m), 825cm -1 (s), also 720cm ^-1 (vw), the product obtained The optical rotation of is shown below.

[Α] _D = + 1.02 ° (27 ° C, C = 1, chloroform solution) This compound is a nematic liquid crystal ZL-1565 manufactured by Merck.
The pitch was measured with a cell in the shape of a wedge of Kano, and the results are shown in the table below.

As a comparative example, C-15 manufactured by BDH was used.

The above compound has a shorter helical pitch and less temperature heterogeneity than C-15 of Comparative Example.

Example 3 Preparation of (R, R) -4,4′-bis (6 ″ -chloro-4 ″ -methylhexyloxy) -biphenyl 1.86 g of 4,4′-biphenol in 30 ml of methyl ethyl ketone
Then, 0.84 g of finely pulverized sodium hydroxide was charged, and after reacting for 1 hour under reflux, [α] _D = + 3.76 ° (27 ° C, C =
2. Chloroform solution) was added with 6.40 g of P-toluenesulfonic acid ester derived from (R) -6-chloro-4-methylhexanol, and the mixture was stirred at 82 ° C for 12 hours.

The reaction mixture was poured into a large amount of 5% hydrochloric acid aqueous solution, and the precipitated solid was filtered. After washing with water and drying, the product was purified with a silica gel column using hexane / ethyl ether (90/10) as a developing solvent and recrystallized from ethanol to obtain a white powder having a melting point of 75.3 ° C.

As a result of infrared spectroscopic analysis, the obtained product had the following special absorption and was confirmed to be the target product: 3050 cm ^-1 (vw), 2925 cm ^-1 (m), 2880 cm ^-1 (w ), 1605cm ^-1 (m), 1565cm ^-1 (vw), 1500cm ^-1 (s), 1470cm ^-1 (m), 1385cm ^-1 (w), 1270cm ^-1 (s), 1240cm ^-1 (s) ^{, 1180cm -1 (w), 1120cm} -1 (vw), 1050cm -1 (w), 1000cm -1 (w), 920cm -1 (vw), 825cm -1 (s), 725cm -1 (w), 650 cm ^-1 (w) 600 cm ^-1 (vw), 520 cm ^-1 (w) Moreover, the optical rotation of the obtained product is shown below.

[Α] _D = + 7.72 ° (28 ° C., C = 1, chloroform solution) The pitch of this compound was measured in the same manner as in Example 2, and the results are shown in the table below.

The above compound has a shorter helical pitch and less temperature heterogeneity than C-15 of Comparative Example.

Example 4 Production of (R, R) -4,4′-bis- (6 ″ -chloro-4 ″ -methyloctyloxy) biphenyl [α] _D = + 0.75 ° (28 ° C., C = 1, chloroform Example 3 except that the solution of (R) -6-chloro-4-methyloctanol p-toluenesulfonic acid ester is used.
A white powder having a melting point of 65.2 ° C. was obtained by synthesizing in the same manner as.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorption and was confirmed to be the target product: 3040 cm ^-1 (vw), 2925 cm ^-1 (m), 2880 cm ^-1 (w ), 1605cm ^-1 (m), 1565cm ^-1 (vw), 1500cm ^-1 (s), 1465cm ^-1 (m), 1385cm ^-1 (w), 1270cm ^-1 (s), 1240cm ^-1 (s) , 1180cm ^-1 (w), 1130cm ^-1 (vw), 1045cm ^-1 (w), 995cm ^-1 (w), 920cm ^-1 (vw), 825cm ^-1 (s), 660cm ^-1 (vw), 600cm ^-1 (w), 515cm ^-1 addition (w), the following optical rotation of the resulting product.

[Α] _D = + 5.70 ° (28 ° C., C = 1, chloroform solution) The pitch of the above compound was measured in the same manner as in Example 2, and the results are shown in the table below.

Example 5 Production of (R, R) -4,4′-bis- (6 ″ -chloro-4 ″ -methyldecyloxy) biphenyl [α] _D = −1.95 ° (26 ° C., C = 1, chloroform solution) ) Of (R) -6-chloro-4-methyldecanol p
-A white powder having a melting point of 82.4 ° C was obtained by synthesis in the same manner as in Example 3 except that toluenesulfonic acid ester was used.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorption and was confirmed to be the target product: 3050 cm ^-1 (vw), 2920 cm ^-1 (s), 2870 cm ^-1 (m ), 1605cm ^-1 (m), 1570cm ^-1 (vw), 1500cm ^-1 (s), 1470cm ^-1 (m), 1380cm ^-1 (w), 1270cm ^-1 (s), 1240cm ^-1 (s) ^{, 1180cm -1 (w), 1120cm} -1 (vw), 1050cm -1 (w), 1000cm -1 (w), 925cm -1 (vw), 820cm -1 (s), 730cm -1 (vw), ^{665cm -1 (vw), 605cm -1} (w): 515cm -1 (w) Moreover, the following optical rotation of the resulting product.

[Α] _D = + 1.65 ° (27 ° C, C = 1, chloroform solution)

Claims (1)

[Claims] 1. An optically active biphenyl ether compound represented by the following general formula. (In the formula, R represents a hydrogen atom or a linear alkyl group having 1 to 11 carbon atoms, X represents a hydrogen atom or a chlorine atom,
n represents 3 to 5, and * represents an asymmetric carbon atom. )