JPS6377850A - Fluorine-containing propanenitrile compound - Google Patents

Abstract

NEW MATERIAL:The compound of formula I (R is alkyl). EXAMPLE:3-[p-(4-trans-n-propylcyclohexyl)-phenyl]-tetrafluoropropaneni trile. USE:A component of a liquid crystal composition. It can be used in combination with conventional liquid crystal compound, is stable to moisture, air, light, heat, etc., exhibits liquid crystal state over a wide temperature range, has low viscosity and gives high response speed. PREPARATION:The compound of formula I can be produced by using the compound of formula II (trans-isomer) as a starting substance, converting the substance to the compound of formula III and reacting with a dehydration agent such as phosphorus pentoxide at 100-250 deg.C.

Description

[Detailed description of the invention] [Field of use in business a] The present invention relates to a novel fluorine-containing compound.

Specifically, the present invention relates to a novel fluorine-containing propanenitrile compound that can be used as a component of a liquid crystal composition.

[Background of the Invention] Since liquid crystal compounds were used in electro-optical display devices, many liquid crystal compounds have been synthesized, and nematic liquid crystals or nematic-cholesteric liquid crystals are used to create twisted nematic mode display elements, displays using the cholesteric-nematic phase change phenomenon, etc. It is widely used in display devices that utilize the guest-host effect. A liquid crystal display using night crystals is also being considered.

These liquid crystal compounds are required to be stable against moisture, air, light, heat, etc., and are not only in a liquid crystal state at room temperature, but also in a liquid crystal state over a wide temperature range from low to high temperatures. , and a fast response speed is desired.

[Structure of the Invention] An object of the present invention is to provide a novel compound that provides a liquid crystal composition that satisfies such requirements.

That is, the present invention is based on the general formula [Eco (In the formula, R represents alkyl di.) A fluorine-containing propanenitrile compound represented by The main points are as follows.

The fluorine-containing propanenitrile compound of the present invention can be used in combination with an appropriate known liquid crystal compound, and can be used as a liquid crystal composition that exhibits low viscosity and high-speed response.

The present invention will be explained in detail below.

The fluorine-containing propanenitrile compound of the present invention is represented by the above general formula [II, in which the substituent R represents an alkyl group, and preferably R represents an alkyl group having 1 to 8 carbon atoms.

Such a fluorine-containing propanenitrile compound of the present invention can be obtained, for example, by a synthetic method using the following reactions (1) to (2).

■ [IV j + [V] □ n (In addition, R in the general formulas [II], [rV] to [■ has the same meaning as in the general formula [II]). , dimethylformamide, N-
It can be carried out in an organic solvent such as methylpyrrolidone in the presence of copper powder at a temperature of, for example, 100 to 200°C.

The reaction (2) can be carried out, for example, in an alcoholic solvent such as ethanol in the presence of zinc at a temperature of, for example, 70°C to 100°C.

The reaction (2) can be carried out, for example, by oxidizing with potassium permanganate at -10°C to 50°C in a ketone solvent such as acetone.

The reaction (2) is carried out in the presence of organic solvents such as aromatic solvents such as benzene and toluene, chlorine solvents such as carbon tetrachloride and chloroform, and ether solvents such as dioxane and tetrahydrofuran, or in the absence of these solvents. The reaction can be carried out using a chlorinating agent such as , thionyl chloride, etc., at a reaction temperature of, for example, 50 to 10°C.

The reaction (2) is carried out using, for example, -
It can be carried out at a reaction temperature of 10°C to 100°C.

The reaction (2) can be carried out using a dehydrating agent such as phosphorus pentoxide at a reaction temperature of, for example, 100 to 250°C.

When forming a liquid crystal composition using the fluorine-containing propanenitrile compound of the present invention, it can be used in combination with an appropriate known liquid crystal compound. Examples include azoxy, azo, Schiff, pyrimidine, biphenyl, phenylcyclohexane, cyclohexylcyclohexane, bicyclooctane, dioxane, and polycyclic compounds consisting of benzene and cyclohexane rings. Can be mentioned. Furthermore, when forming a liquid crystal composition using the compound of the present invention, additives such as known dichroic dyes or thinners can also be used in combination.

[Examples] Next, the present invention will be specifically explained using Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 Prior to the 3-(P-(4-1-lanse-n-propylcyclohexyl)-phenyl)-tetrafluoropropanenitrile reaction, 100 g of copper sulfate was dissolved in 350 mu of warm water, and after bringing the temperature to room temperature, 35 g of zinc was added. I added slowly. This causes copper to precipitate. This was washed by decantation five times with 200 al of water, and then washed with 100 al of 5% diluted hydrochloric acid.
The remaining zinc was dissolved and removed in mj2 to obtain precipitated copper.

4-(4-trans-lopropylcyclohexyl)-iodobenzene [: II al2.539
g (7,74
1531] g (2,15 x 10'-2 mo λ), 4.9586 g of the above precipitated copper (7,8 x 10'-2 mo
The mixture was heated and stirred at ℃ for 24 hours. After the reaction was completed, 100 ml of water was added to the reaction solution, filtered under suction, and the filtrate was extracted with diethyl ether (150 mfl x 5 times), washed with saturated brine (50 mu x Z times), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. An oil was obtained. Separate impurities by column chromatography (silica gel; hexane),
1-(:1.4~dichloroperfluorobutyl)-4
-(4-trans-rhopropylcyclohexyl)-benzene [rVal and 1-(3-perfluorobutenyl)
-4-(4-trans-lopropylcyclohexyl)
- 2.2245 g of a mixture with benzene [Val was obtained.

This imitation was confirmed by the following NMR and HIGH↑JASS results.

'H-N M Rδ=7. BO~7.05 (DI
4H) (CDCIls/TMS) 2.70~
0.79 (m 171()E A M S
M/2 PCELEIJENTSHIG)I MA
SS (70eV) 454 1.6 C+9H2+h
Cu+CJZτ452 1.4 Cl, H2+F7CJ
12382 13.9 Cl9821F7 251 100 Cl8H21F2 201 4.7 Cl5H2, 1534B, 6 C2HsF2 127 26.2 C2HsF2 (ii) [rVa]+ [Va] -n [■a] obtained in reaction (i) and [V al A mixture of 2.
0.995g of zinc in 225g (1,52x 10-”
After adding 20 mu of 99*tanol and heating under reflux for 1 hour, column chromatography (silica gel;
Excess zinc was removed with dichloromethane) and concentrated under reduced pressure to obtain 2.373 g of [Val.

To 2.373 g of [Val obtained in reaction (ii), 5.437 g of potassium permanganate (3,46 x 10”
``moi'' and 20 mfl of acetone were added, cooled to 0°C in an ice-salt bath, and stirred at that temperature for 16 hours. After the reaction was completed, 42 methanol of methanol was added to the reaction solution to remove excess potassium permanganate. mal, 10% F hydrochloric acid 10 mJ11 diethyl ether 100 m ft, and a small amount of common salt and sodium bisulfite were added.A slight amount of crystals had precipitated, so they were removed by filtration, extracted with diethyl ether (200 mu x 5 times), and anhydrous sulfuric acid. After drying with sodium, it was concentrated under reduced pressure to obtain a crystalline product. This was purified by column chromatography (silylated silica gel: hexane: benzene = 2 + 1) for 1 minute, and recrystallized from benzene-hexane to obtain white needle-like crystals. 3-(
p-(4-trans-n-propylcyclohexyl)-
phenyl)-tetrafluoropropionic acid [VIalo
, 712 g (2,05 x 10-3 mojl) were obtained.

[VIal had liquid crystallinity and the phase inversion point was as shown below.

Crystal-11-S m--→N e-m--1s.

145℃ 166℃ 169℃Also, NM
The results of R, IR, and elemental analysis were as shown below.

'H-N M Rδ=9.83 <s Il+)
(CDCj23/TMs) 7.48 (
d 2HJ・6.611z) 7.19 (d
2HJ-16,611z) 2.50~0.79 (m
17H)IR(KBr)cm-': 3400 (m, broad), 2945 (S), 2
850 (z) 1760 (S), 1615
(m), 1440 (m) 1300 (m),
1140 (S), 920 (m) 830 (α) Elemental analysis value (%) C: 82.42 H: 6.
Calculated value (%) as 40C+aH22F40□C:6
2.46H26.31 [V obtained in (ii) above to anhydrous benzene 5InA
IalO, 526g (1,52x IP3moJl)
and 3 drops of anhydrous dimethylformamide, and 3 drops of thionyl chloride.
．． 5ml (4°82x10'-'!11ofL) was dissolved and heated under reflux for 24 hours. Thereafter, benzene and excess thionyl chloride were distilled off under reduced pressure at the same temperature. This was returned to room temperature, further cooled, and anhydrous diethyl ether 1
After adding 5 mA and cooling with water, ammonia gas was
It blew for a minute. Add 50+nf of saturated saline to this reaction solution.
L and 30 mu of diethyl ether were added, extracted with diethyl ether (3001°C x 5 times), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain a crystalline product. The obtained crystals were recrystallized from benzene-hexane to give 3-(p-(
4-r+-propylcyclohexylolopropionic acid amide [■a] 0.389 g (1.
12 x 10-'moJl) were obtained (yield 74 leopards).

This compound has a transition temperature from crystal to nematic liquid crystal of 1
At 78°C, the transition temperature from nematic liquid crystal to isotropic liquid was 190°C.

1.600 g of niline pentoxide (1.39x
3-(p-(4-n-propylcyclohexyl)- obtained in (iv))
phenyl)-tetrafluoropropionic acid amide [■a
lO. 278g (8.Ox to'moλ) was added. After nitrogen was blown into the reaction system to make the reaction system anhydrous, the reaction system was heated at 200° C. for 1 hour in a silicone oil bath under reduced pressure. After the reaction is complete, add 30 ml of diethyl ether to the flask.
mft and water 50mJ! I poured it slowly. The extract was extracted with diethyl ether (30 ml x 3), dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to obtain an oil. This oily substance was separated and purified by column chromatography (silica gel; hexane), and a colorless and transparent oily substance 3- (p- (
4-n-propylcyclohexyl)-phenyl)-tetrafluoropropane nitrile [I alo. 179g
(5.47X 10-'mou) was obtained (yield: 68 pieces).

The physical properties of the obtained compound [1a] were as follows.

Melting point 6-7℃'H-NMR δ=7.53 (d
2H J-9. OHz) (CDCjl 3/TMS
) 7.32 (d 2H J・9.0H
z) 2,69~0.82 Import 1 7 II) I R
(Ilf) cm-': 2950 (S), 2880 (m), 2270 (m)
1820(m), 1450(m), 1160(S)
830 (m) Elemental analysis value (%) l;:61i. IS)I:8.
49 N: 4.19 Calculated value (%) as CIJ21F4N C: 66.04 H: 6.47 N: 4.2
8 Example 2 The fluorine-containing compound obtained in Example 1 was treated with E. Merck
10% by weight was mixed into a mixed liquid crystal commercially available as ZLI-1132 (transition fJ temperature from crystal to nematic liquid crystal: -6℃, transition temperature from nematic liquid crystal to isotropic liquid crystal: 70℃) from the company. , the transition temperature from nematic liquid crystal to isotropic liquid was 60.8°C. Note that it was difficult to measure the temperature at which the phase transition from crystal to nematic phase occurred because the sample was difficult to crystallize due to the supercooling phenomenon.

[Effects of the Invention] As detailed above, the fluorine-containing propanenitrile compound of the present invention is a novel compound that can be used as a component of a liquid crystal composition, and can be used in combination with a known liquid crystal compound. ■ Stable against moisture, air, light, heat, etc.

■ Exhibits liquid crystal state over a wide temperature range.

■Low viscosity and high response speed.

It has the following effects and is extremely useful industrially.

Claims (1)

[Claims] A fluorine-containing propanenitrile compound represented by the general formula [I] ▲Mathematical formula, chemical formula, table, etc.▼...[I] (In the formula, R represents an alkyl group.) (2) The fluorine-containing propanenitrile compound according to claim 1, wherein in the general formula [I], R is an alkyl group having 1 to 8 carbon atoms.