JPS5910551A - Novel nematic liquid crystal compound - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [R and R' are 1-7C straight chain alkyl; two cyclohexane rings are respectively in the trans (equatorialequatorial) configuration]. USE:A material for nematic liquid cyrstals, having a weak negative dielectric anisotropy, and capable of increasing the phase transition temperature between the nematic phase and the isotropic liquid phase remarkably by mixing with another nematic liquid crystal compound. PROCESS:p-Methoxybiphenyl is reacted with a compound of formula II and anhydrous aluminum chloride to give a compound of formula III, which is then reacted with hydrazine and potassium hydroxide, further with aqueous hydrogen bromide or hydrogen iodide and then a compound of formula IV to afford the aimed compound of formula I .

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel nematic liquid crystal compounds of cyclohexanecarboxylic acid derivatives useful as electro-optic display materials.

The novel nematic liquid crystal compound provided by the present invention has the general formula (1).
8ehadt) etc. [APPLIED pnysxcs
LETrERslg 127-12B (1971)) or the field effect mode cell proposed by Gel Heilmeier et al. [PROCEE
J) ING OF T) IE I, E, E, E,
561162-1171 (196B))
mode Φ cell) or GH e Beilmeyer (G
11) IHe eyes yleier) etc. [APPLIED P
HYSIC8LFJ'r'rERs 13,91(19
6B)) Or D L White (D Lw
hsts+) etc. (JOURNAL OF APPLIE
There is a guest-host type cell proposed by D PHYSIC 845, 471B (1974).

The liquid crystal materials used in these liquid crystal display cells are required to have various properties, but having a nematic phase over a wide temperature range, including room temperature, is an important property that is commonly required for all types of display cells. . Many of the practical drugs having such IF characteristics are usually made by mixing several or more components consisting of a compound having a nematic phase near room temperature and a compound having a nematic phase in a temperature range higher than room temperature. Prepared by. Most of the above-mentioned mixed liquid crystals currently in practical use are at least 160C~+
It is required to have a nematic phase over the entire temperature range of 65U. In order to meet such requirements, 4
．． 4'-substituted terphenyl, 4,4'-substituted biphenylcyclohexane, 4,4'-ran J@benzoyloxybenzoic acid phenyl ester, crystal phase-nematic phase transition temperature of about 10 DC (e-N point) and a nematic phase-isotropic liquid phase transition temperature (N-
Compounds having point I) are often used.

Recently, as liquid crystal display cells have been used for multiple purposes such as outdoors, there has been a need for cells with a nematic humidity range higher than +65U. For this purpose, the nematic phase-isotropic liquid phase transition temperature (N-I point) is required to be higher than that of conventional compounds. : A compound with is required.

The compound of formula (I) according to the present invention satisfies this requirement and can significantly increase the nematic phase-isotropic liquid phase transition temperature (N-I point) by mixing a small amount into known liquid crystal mixtures. be able to. Furthermore, the compound of formula (1) is a 4,4'-substituted cyclohexylcarboxylic acid phenyl ester which the present applicant reported in JP-A-54-86694 as a nematic liquid crystal material with excellent time-division driving characteristics. Since they have extremely good compatibility with these compounds, even better mixed liquid crystals can be obtained by mixing them with these compounds.

The compound of formula (I) according to the present invention can be produced according to the following production method.

(1) First step---P-methoxybiphenyl is reacted with a compound of formula (II) and anhydrous aluminum chloride in binary carbon or nitrobenzene to produce a compound of formula (III).

Step 2 - 1 - The compound of formula (III) produced in the first step is reacted with hydrazine and potassium hydroxide in diethylene glycol or triethylene glycol to produce a compound of formula (IV).

Step 6 - 1 The compound of formula (1v) produced in the second step is reacted with aqueous hydrogen bromide or aqueous hydrogen iodide in water or acetic acid to produce a compound of formula (V).

Step 4 - 1 The compound of formula (V) produced in step 6 is prepared using the formula (■
) is reacted to produce the compound of formula (I) according to the present invention.

The conversion temperatures of the deceptively prepared compounds of formula (1) are listed in Table 1.

In Table 1, C represents a crystalline phase, S represents a smectic phase, N represents a nematic phase, and l represents an isotropic liquid phase.

Does the compound of formula (I) according to the present invention have weak negative dielectric constant anisotropy? is a nematic liquid crystal compound having, thus, for example,
It can be used as a material for dynamic light scattering display cells in a mixture with other nematic liquid crystal compounds with negative or weak positive dielectric anisotropy, and also has strong positive dielectric anisotropy. It can be used as a material for field effect display cells in the form of a mixture with other nematic liquid crystal compounds.

Thus, preferred representative examples that can be used in combination with the compound of formula (I) include f+1, for example 4,4
'-Substituted benzoic acid phenyl ester, 4.4'-substituted cyclohexanecarboxylic acid phenyl ester, 4.4'-
t% cyclohexanecarboxylic acid biphenyl ester, 4
(4-filcyclohexanecarbonyloxy)benzoic acid 4'-substituted phenyl ester 4(4-substituted cyclohexyl)benzoic acid 4'-substituted phenyl ester, 4(4-
(substituted cyclohexyl)benzoic acid 4'-substituted cyclohexyl ester, 4.4'-biphenyl, 4.4'-phenylcyclohexane, 4.4'-substituted terphenyl, 4.
Examples include 4'-biphenylcyclohexane and 2(4'-fi substituted phenyl)5-substituted pyrimidine.

Table 2 shows the 90x111 base liquid crystal (A), which is currently widely used as a nematic liquid crystal material with excellent time-division driving characteristics.
% and compound 41 of formula (1) shown in Table 1, /I62,
The N-I points determined for each mixed liquid crystal consisting of 10 layers of 6, 4,5.7 g, and 66 are posted, and for comparison, the NI points determined for the base liquid crystal (A) itself are shown. The N-I points are displayed. In addition, the mother liquid crystal (
A) consists of 8 parts, 1%, 8 parts by weight, 8 parts by weight, 8 parts by weight, 8 parts by weight.

/' , /' Table 2 From the data posted in Table 2, the compound of formula (I) is 10
The N-I point of the mixed liquid crystal (A) is increased by about 2% by weight.
It is understood that the temperature can be increased by ℃. The high practical value of the compound of formula (I) is that the upper limit of the operating temperature range can be raised by addition of such a small amount.

The effect of Hon@8 Ming is also clarified by the following comparative experiment. The known compounds a) (&), which are widely used for the purpose of increasing the N-I point of mixed liquid crystals, were mixed in the above-mentioned base liquid crystal (A) in a uniform ratio. Similarly, one of the compounds according to the invention, namely...
...(41) was mixed in various proportions with the base liquid crystal (A).

Regarding the two types of mixed liquid crystals obtained in this way, each N
! - Point I was measured. Based on these measurement results, the relationship between the NI point and the amount added is shown in the vK1 diagram of the attached drawing. From these facts, it can be understood that the compound of formula CI) according to the present invention has a much greater increase in the N-I point with respect to the amount added than typical known similar compounds.

Examples: 100% carbon sulfide and 16% anhydrous aluminum chloride. ol
l.

(0,120 mol) and stirring at room temperature, trans-4-n-propylcyclohexyl acetic acid chloride 20.3J7 (0,100 mol) was added dropwise thereto, and the mixture was further stirred at room temperature for 1 hour. After cooling this to 5C, P
-Methoxybifu thousandnyl 18.4Ji' (0,100mo
l)? ! 'Dissolved in carbon divalent 1001/? , gradually dripped. Completion of dropping i1 Reaction was carried out at DC for 6 hours. The reaction mixture was added to ice water and heated to distill off carbon dioxide, followed by stirring at 60 U for 1 hour. After cooling, the reaction product was extracted with toluene, the extract was washed with water, and after drying, toluene was distilled off from this liquid. The obtained reaction product was purified by recrystallization with ether to obtain the lower Me compound 15.89 (0,
0451 mol) was obtained.

This compound contains triethylene glycol 180rue, 8
0% hydrazine hydride 7.88g (0,126m
ol) and 85% potassium hydroxide 10.111 (0,1
53 mol)', and while stirring these, the temperature was gradually raised and the reaction was carried out at 180 t:' for 5 hours.

After cooling, 200 ml of water (200 111ξ10% hydroxide) and 801 ml of Illumium liquor were added, and the reaction product was extracted with ether. After washing the extract with water, distill the ether from this liquid,
Add to this ioomz of glacial acetic acid and 17cc of 47% hydrogen bromide water.
were added, and these were reacted at reflux temperature for 8 hours. After the reaction was completed, the mixture was cooled, water was added at 200 m/s, and the reaction product was extracted with ether. Wash the extract with water and sulfuric anhydride)
After drying with IJum, the ether was distilled off from this solution, and the resulting reaction product was purified by recrystallization from In-hexane to obtain the following compound 1.0.6J7 (0,0529 mol).
) was obtained.

10.69 (0,0329 mol) of the above compound was dissolved in 70% toluene, and 5.20 Fl of pyridine was added to this.
(0,0658 mol) and 6.2 Cl (0,0658 mol) of trans-4-propylene clohexane chloride was added dropwise while stirring at room temperature. After the completion of the dropwise addition, the reaction was carried out at reflux for 6 hours, and after the completion of the reaction, the reaction product was extracted with toluene. After washing the extract with water and drying, toluene was distilled off from this liquid, and the resulting reaction product was recrystallized from acetone to obtain F combination compound 12.7. ! i
'(0,0268 mol) Y was obtained.

Yield 26.8% Transition temperature 174U (C10) 195C (SdN) 2BIC(NdI) Example 2 The following compound was obtained in the same manner as in Example fI11.

Yield 25.5% Transition temperature 1670 (C10) 170C (SdN) 270 C (xi Miko) Example 6 The following compound was obtained in the same manner as in Example 1.

Yield 26.2% Transition temperature 170C (C-age 5) 195C (SdN) 2721:” (NdI) Example 4 The following compound was obtained in the same manner as in Example 1.

Yield 25.7% Transition temperature 164C (C10) 222U (SIN) 252C (NiI) Example 5 An F combination compound was obtained in the same manner as in Example 1.

Yield 27.1% Transition humidity 172U (C→S) 2.03U (S:il’:N) 270U (Njil) Example 6 The following compound was obtained in the same manner as in Example 1.

Yield 26.5% Transition temperature 170C (C→5) 1B2C (SIN) 274C (NdI)

[Brief explanation of drawings]

Figure 1 shows the N of each mixed liquid crystal obtained by adding compound 1, which is one of the compounds related to the present invention, and known compound (a) to the currently widely used base liquid crystal (A). - It is a chart showing the relationship between the I point and the amount added.

Claims (1)

[Claims] general formula A compound represented by