JPH0521107B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a new chemical substance, and in detail,
The present invention relates to a pyrimidine derivative which can be used by itself as a forced chiral smectic liquid crystal material and is also useful as a mixed material for liquid crystal compositions with various other liquid crystal compounds. (Summary of the invention) (Problems to be solved by the present invention) The compound provided by the present invention has the formula (1) or formula (2) (In the formula, m is an integer of 1 to 8, n is an integer of 5 to 14, *
indicates that the carbon atom is an asymmetric carbon atom, and s- or -s indicates that the alkyl group is linear. )
It is a pyrimidine derivative represented by This compound is a ferroelectric liquid crystal compound that exhibits a chiral smectic C phase in a wide temperature range including room temperature, and has excellent chemical stability and high electric field response. It also has excellent miscibility with other compounds. (Prior Art) (s)-2-Methylbutyl P-(pn-decyloxybenzylideneamino)cinnamate (DOBAMBC) is known as a liquid crystal compound exhibiting ferroelectricity. This Schiff base series liquid crystal compound was the subject of research on ferroelectric liquid crystals, and various compounds were synthesized. As an example, Compounds represented by the general formula (wherein X is H, Cl, CN, Y is Cl, and C ₂ H ₅ * indicates that the carbon atom is an asymmetric carbon atom) are known. However, this series of compounds cannot be used as liquid crystal materials at room temperature because the temperature at which they exhibit chiral smectic C phase is higher than room temperature, and because they are Schiff base compounds, they are easily decomposed by moisture. It has its drawbacks. As a compound devised to improve these (Ferroelectriics Vol. 24, p. 309 (1980)). Compounds of this type have attracted attention as compounds that exhibit a chiral smectic C phase over a wide temperature range including room temperature. Therefore, the formula It has been reported that a compound represented by the formula (in which n represents 9 or 10) exhibits a chiral smectic C phase in a temperature range relatively close to room temperature. Also, by HZ ASCHKE Some of the compounds represented by are introduced as exhibiting smectic phase. (J.Prakt
Chemic 317 617 (1975)) However, among these,
Chiral smectic liquid crystal compounds are neither described nor suggested. (Means for Solving the Problems) The compound provided by the present invention is produced as follows. (a) The compound represented by formula (1) can be produced as follows. That is, A compound represented by (-s indicates that the alkyl group is linear) in the presence of a condensing agent,
The compound represented by the formula (1) can be obtained by condensation in a solvent. Here X
is a halogen atom such as chloro, bromine, or iodo, or a mesyloxy group or a tosyloxy group, m is an integer of 1 to 8, and n is an integer of 5 to 14. Condensing agents used include alkali metals such as sodium and potassium, alkali metal hydrides such as sodium hydride, anhydrous alkali metal salts such as anhydrous sodium carbonate and anhydrous potassium carbonate, and solvents used include NN-dimethylformamide. , amide types such as NN-dimethylacetamide, ether types such as tetrahydrofuran and diethylene glycol dimethyl ether, aromatic types such as benzene, toluene, and xylene, and dimethyl sulfoxide. The reaction is carried out at room temperature to the reflux temperature of the solvent, preferably 50°C to 100°C. (b) The compound represented by formula (2) can be produced as follows. That is, With the compound shown by

It can be obtained by condensing a compound represented by the formula (-s indicates that the alkyl group is linear) in a solvent in the presence of a basic condensing agent. Examples of the solvent used here include alcohols such as methanol, ethanol, propanol, and isopropanol, benzene, toluene dimethylformamide, diethylene glycol dimethyl ether, and diethylene glycol ethyl ether. Examples of the basic condensing agent include the above-mentioned alkali metals and alkali metals. Examples include alcoholates, anhydrous alkali metal salts, and the like. The reaction can be carried out at room temperature to the reflux temperature of the solvent used, preferably at 50°C to 100°C. In (a) and (b) above, m is an integer of 1 to 8, n is an integer of 5 to 14, and * indicates that the carbon atom is an asymmetric carbon atom. Since the compound provided by the present invention contains an asymmetric carbon atom in its molecule, it has a pair of optical objects, both of which are included in the object compound of the present invention. The steric configuration is uniquely determined by that of the compound used as a raw material. Example 1 Synthesis of (s)-2-[4-(6-methyloctyloxy)phenyl]-5-[4-n-octylphenyl]pyrimidine Equipped with a cooling tube, a thermometer, a dropping funnel, and a calcium chloride tube. Add 0.6 g of sodium hydride (approximately 50% Oil Suspension) to a 50 ml three-necked flask.
5 ml of dimethylformamide was added. Then dry
NN-4 dissolved in 13 ml of dimethylformamide
3.75 g of -[5-n-octylphenyl)-2-pyrimidinyl]phenol was added dropwise and reacted at 100°C for 40 minutes. Next, activated amyl alcohol ([α] ²³ −5.8°
(neat)) 3.10 g of 4-methylbenzenesulfonic acid 6-methyloctyl ester, dried N.
13 ml of N-dimethylformamide was added dropwise at 80°C. After the dropwise addition, the reaction was further continued for 8 hours. After the reaction was completed, the mixture was poured into ice water to precipitate crystals, which were collected by filtration. The obtained crude product was purified by recrystallization (using ethyl alcohol as a recrystallization solvent) to give (s)-2-
[4-(6-methyloctyloxy)phenyl]-
5-[4-n-octylphenyl]pyrimidine 1.2
I got g. IR ν max (cm ^-1 ): 1610, 1585, 1440 1250, 800 I _H -NMR (60MHz, CDCl ₃ ) δ (ppm): 0.6-2.1 (m, 32H) 2.66 (t, 2H) 4.01 (t, 2H) 6.97 (d, 2H) 7.27 (d, 2H) 7.52 (d, 2H) 8.41 (d, 2H) 8.92 (s, 2H) Phase transition temperature (℃) C _ry 55 ―→ ←― *S _Y →S _X →S _C *156 ---→ S _A 165 ---→ I _SO (where, C _ry is crystal, S _c ^* is chiral smectic C phase, S _A is smectic A phase, and I _SO is isotropic liquid, S _X and S _Y indicate other smectic phases;
* indicates supercooling) Example 2 Synthesis of (s)-5-[4′-(6″-methyloctyloxy)phenyl]-2-(4-normal-octylphenyl)pyrimidine 4- Octylbenzamidine hydrochloride 1.02g(s)
-1-dimethylamino-3-dimethylimino-2
-[4-(6-methyloctyloxy)phenylpropene-1, 10.2 g of perchlorate, and 28% sodium methylate, a mixture of 17.4 g of methanol solution
After reacting under reflux for an hour, it was poured into ice water and the product was extracted with ethyl acetate. The organic layer was washed with dilute hydrochloric acid, sodium bicarbonate, and brine, dried over magnesium sulfate, the solvent was distilled off, and the residue was crystallized from methanol to give 0.94 g of (s)-5-[4'- (6″-methyloctyloxy)phenyl]-2-(4-octylphenyl)pyrimidine was obtained, which was further purified by recrystallization (using ethyl alcohol as the recrystallization solvent) to yield 0.64 g of pure IR ν max (cm ^-1 ); 1615, 1585, 1540 1445, 1250, 830 ¹ H-NMR (60MHz, CDCl ₃ ) δ (ppm): 0.6-2.0 (m, 32H) 2.65 (t , 2H) 3.95 (t, 2H) 6.93 (d, 2H) 7.23 (d, 2H) 7.48 (d, 2H) 8.30 (d, 2H) 8.88 (s, 2H) Phase transition temperature (℃) C _ry /65 - _{→ ←} ― _{* S Y} ⁷⁸ ― _{→ S} S _A is the smectic A phase, I _SO is the isotropic liquid, S _X and S _Y are the other smectic phases,
* indicates supercooling) The raw material compound used in the present invention was produced as follows. (stomach) Synthesis of Helbeca Himica Acta Volume 18, 279 (1960)
(Helv, Chim. Acta, XLll 279 (1960)). That is, active amyl alcohol, phosphorus tribromide,
Alcohol is obtained by halogenation with phosphorus trioxide, hydrobromic acid, etc., reaction with ethythyl malonate, saponification, decarboxylation, and reduction with lithium aluminum hydride. On the other hand, after halogenating s-amyl alcohol with the above-mentioned halogenating agent, a Grignard reagent is prepared by reaction with metal magnesium, and then reacted with carbon dioxide to obtain the corresponding carboxylic acid. This carboxylic acid can be reduced with lithium aluminum hydride to give the corresponding alcohol. If we display the chemical reaction equation, we can write it as follows.
Malonic acid ester synthesis method Grignard method (In the formula, X ₁ represents a halogen atom.) The alcohol thus obtained is converted into a corresponding halide by reacting with the above halogenating agent, or reacted with P-tosyl chloride or mesyl chloride in pyridine. If possible, it is converted to the corresponding tosylate and mesylate. When following the above malonic acid ester synthesis method,
It is possible to obtain an alcohol in which m has two more carbon atoms than the starting compound, and when the Grignard method is followed, an alcohol in which m has increased by one carbon number can be obtained. (B) (-s indicates that the alkyl group is linear.) This compound is produced by using a linear alkylbenzoic acid as a starting material, reducing it with _LiAlH4 , and then using a halogenating agent (e.g., thionyl chloride, concentrated hydrochloric acid). After halogenation, Grignard reagents were prepared and reacted with carbon dioxide to form linear alkyl phenyl acetic acids. This linear alkyl phenyl acetic acid is then
Horst Zaschke, Siegfried, Arndt, Vera;
Wagner, Hermann Shubert et al. (X.
Chem., 17 Jg (1977) Heft 8, 293-294). was synthesized. This perchlorate compound was synthesized by reacting P-hydroxybenzamidine hydrochloride in the presence of a metal alcoholate. An example of the synthesis of is shown by a chemical reaction formula. As shown in the examples above, the compound of the present invention has an S ^* c layer in a temperature range higher than room temperature, and is capable of producing a chiral smectic liquid crystal composition having an S ^* c layer up to high temperatures. is an effective compound.

Claims (1)

[Claims] 1 formula A pyrimidine derivative represented by the formula, where one of R ₁ and R ₂ is and the other is S−C _o H _2o+1 −
m is an integer of 1 to 8, n is an integer of 5 to 14, * indicates that the carbon atom is an asymmetric carbon atom, and s
- indicates that the alkyl group is linear.