JPH01113329A - Optically active biphenyl ether compound - Google Patents

Abstract

NEW MATERIAL:The optically active biphenyl ether compound of formula (R is H or 1-11C straight-chain alkyl; X is H or Cl; n is 3-5; * represents asymmetric carbon atom). EXAMPLE:(S,S)-4,4'-bis(6''-methyldecyloxy)-biphenyl. USE:Useful as a component of a liquid crystal composition for liquid crystal display element. It has low transition temperature between crystal and liquid crystal phase. In the case of giving a cholesteric phase, it has high phase- transition temperature between liquid crystal and isotropic liquid, short helix pitch and small temperature dependency. PREPARATION:The objective compound of formula can be produced e.g. by reacting (A) an optically active alkyl halide or chloroalkyl halide with (B) p-toluenesulfonic acid of an optically active alcohol or chloroalcohol and (C) 4,4'-dihydroxydiphenyl in the presence of an alkaline compound.

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 in displays such as watches and calculators. Most of the liquid crystal display elements currently in practical use utilize the dielectric alignment effect of twisted nematic liquid crystals and cholesteric liquid crystals. However, recently, other liquid crystal display methods have been actively developed, and STN methods, cholesteric nematic phase transition display methods, and the like are also being used.

The liquid crystal compositions used in these liquid crystal display devices are adjusted to have respective helical pitches by introducing optically active substituents into nematic liquid crystals or by adding optically active substances.

For example, p-alkoxybenzaldehyde and (+) −
Schiff base type liquid crystals made from p-amino-2-methylbutylbenzene are known. In addition, the optically active substance to be added is 4-(2-methylbutyloxy)-
Although 4°-cyanobiphenyl is known, this compound has a long twist pitch in choleslic liquid crystals, so it has the disadvantage that it requires a large amount to be blended in order to obtain desired physical properties.

The present inventors have discovered that crystals useful as components of the liquid crystal mixture for display devices have a low crystal-liquid crystal phase transition temperature, and when providing a cholesteric phase, have a high liquid crystal-isotropic liquid phase transition temperature and have a short helical pitch. As a result of intensive studies to find a compound, we found that an optically active biphenyl ether compound represented by the following general formula has a significantly low crystal-liquid crystal phase transition temperature, and when the compound gives a cholesteric phase, it has a liquid crystal-liquid crystal phase transition temperature.
It has been found that due to its high isotropic liquid phase transition temperature, it is an extremely suitable compound for use for the above purpose.

(In the formula, R represents a hydrogen atom or a straight chain 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 2 is, for example, an alkali compound of optically active alkyl halide or chloroalkyl halide, or optically active alcohol or p-toluenesulfonic acid ester of chloroalcohol, and 4,4'-dihydroxydiphenyl. It can be easily produced by reacting in the presence of

Next, the present invention will be explained by examples.

Example 1 1.86 g of 4,4'-biphenol and 0.84 g of finely ground sodium hydroxide in 50 ml of methyl ethyl ketone
After charging and reacting under reflux for 1 hour, p4 luenesulfonic acid ester of 6-methyl-1-decanol 6.
86 g was added and reacted under reflux for 12 hours.

The reaction mixture was poured into a large amount of 5% aqueous hydrochloric acid solution, the precipitated solid was filtered, washed with water, and recrystallized from ethanol to obtain highly pure (S,5)-4,4'-(6''-methyldecyloxy)biphenyl. As a result of infrared spectroscopic analysis at a melting point of 75 to 76°C, the obtained product had the following characteristic absorption, which confirmed that it was the desired product.3050 cm-' (vw), 2975 cm-' (
s), 2940cm-' (s), 2870cm-'
(m), 1610cm-' (m), 1570c
m-' (vw), 1505 cm-' (s), 147
0cm-' (m), 1395cm-' (w),
1380cm-' (W), 1325cm-' (v
w), 1275cm-' (s), 1250cm-'
(s), 1180cm-' (m), '1041
04O' (m), 825cm-' (s), 7
30 cm-' (vw) Also, the optical rotation of the obtained product is shown below.

[α], -±0.53° (29'C, C=1, chloroform solution) Example 2 1.86 g of 4,4'-biphenol and 0.84 g of finely ground sodium hydroxide in 50 ml of methyl ethyl ketone
After charging and reacting under reflux for 1 hour, (S)-4-
5.53 g of methyldodecyl bromide was added, and the mixture was reacted under reflux for 15 hours. The same treatment as in Example 1 was carried out to obtain highly pure (S,5)-4,4''-bis-(4''-methyldodecyloxy)-biphenyl. Melting point 125~
As a result of 126°C infrared spectroscopy, the obtained product had the following characteristic absorption, confirming that it was the desired product.
50cm-' (vw), 2975cm-' (s)
, 2940cm-' (s), 2870cm-'
(m), 1610cm-' (m), 1560cm-
'(vw), 1500cm-' (s), 1470c
m-' (m), 1390cm-' (w), 13
80cm-' (w), 1325cm-' (vw),
1270cm-' (s), 1245cm-' (
s), 1180cm-' (m), 105105O'
(m), 825cm-' (s), 720cm
-'(vw) Also, the optical rotation of the obtained product is shown below.

[α), = +1.02° (27”C, C=1, chloroform solution) This compound was added to Merck's nematic liquid crystal ZL.
I-1565 was mixed at 10% and the pitch was measured in a cup wedge cell and the results are shown in the table below.
- As a comparative example, C-15 manufactured by BDH was used.

Pitch (μm) 30°C40”C50°C60°C
The above compound 5.8 5.8 5.9 6.0BD1
The above compound C-157, 27, 68, 08, 5 manufactured by Manufacturer 1 has a shorter helical pitch and less temperature dependence than the comparative example C-15.

Example 3 86 g of 4,4'-biphenol in 30 ml of methyl ethyl ketone and 0.84 g of finely ground sodium hydroxide
After charging g and reacting under reflux for 1 hour, [α], =
Add 6.40 g of P-toluenesulfonic acid ester derived from (R)-6-chloro-4-methylhexanol at -3.76°C (27°C5C=2, chloroform solution) and keep at 82°C for 12 hours. Stirred.

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

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorption, confirming that it was the target product.
, 2880cm-' (w), 1605cm-'
(m), 1565cm-' (vw), 1500cm-
' (s), 1470cm-' (m), 1385
cm-' (w), 1270 cm-' (s), 1
240cm-' (s), 1180cm-' (w
), 1120cm-' (vw), 105105O'
(w), 100100O' (w), 920cm-
'(vw), 825cm-' (s), 725cm
-' (w) 650cm-' (w), 60
0 cm-' (vw), 520 cm-' (w) Also, the optical rotation of the obtained product is shown below.

[α]. =+7.72@ (28°C, c=i, 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.

Pitch (μm) 30°C40°C50°C60°C
The above compound 2.6 2.6 2.6 2.6BD1
Company 1 C-15 7.2 7.6 8.0 8.5 The above compound has a shorter helical pitch and less temperature dispersion than the comparative example C-15.

Example 4 (R,R)-4,4'-bis-(6''-chloro-42
-U of methyloctyloxy)biphenyl [α)o=+o, ρ-upper syl of (R)-6-chloro-4-methyloctatool at 75"C (28°CXC=1, chloroformn volume 7 nights) Synthesis was carried out in the same manner as in Example 3 except that ensulfonic acid ester was used to obtain a white powder with a melting point of 65.2°C.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorptions, which confirmed that it was the desired product.
m), 2880cm-' (w), 1605cm-'
(m), 1565cm-' (vw), 1500c
m-' (s), 1465cm-' (m), 13
85cm-' (w), 1270cm-' (s)
, L240cn+-' (s), 1180cm-'
(w), 1130cm-' (vw), 1045cm
-' (w), 995cm-' (w), 92
0cm-' (vw), 825cm-' (s),
660cm-'(vw) 600cm-'(w
), 515CTl+-' (w) Further, the optical rotation of the obtained product is shown below.

[α')n = +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.

Pitch (μm)' 30°C40°C50°C60°
C above compound 5.9 5.8 5.8 5.8BD
11 Company C-157,27,68,08,5 Example 5 [α), = -1, (17)-6-chloro-4- at 95°C (26°C, C = 1, chloroform solution) Synthesis was carried out in the same manner as in Example 3 except that p-)luenesulfonic acid ester of methyldecanol was used to obtain a white powder with a melting point of 82.4°C.

As a result of infrared spectroscopic analysis, the obtained product had the following characteristic absorptions, which confirmed that it was the desired product.
s), 2870cm-' (m), 1605cm-'
(m), 1570cm-' (vw), 1500c
m-' (s), 1470 cm-' (s), 13
80cm-' (w), 1270cm-' (s)
, 1240cm-' (s), 1180cm-'
(w), 1120cm-' (vw), 105105O
' (w), 100100O' (w),
925cm-' (vw), 820cm-'
(s), 730cm-'(vw) 665cm
-'(vw), 605cm-'(w): 515
cm-' (w) Also, the optical rotation of the obtained product is shown below.

[α) o=+1.65' (27°C, C=1, chloroform solution)

Claims (1)

[Claims] An optically active biphenyl ether compound represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R represents a hydrogen atom or a straight chain alkyl group having 1 to 11 carbon atoms, X represents a hydrogen atom or a chlorine atom, and n represents 3 to 5. , * indicates an asymmetric carbon atom.)