JPH06239839A - 5-fluoro-2-substituted pyrimidine derivative, its production and liquid crystal composition - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as a liquid crystal component having a low viscosity, high physicochemical stability and a stable nematic phase. CONSTITUTION:This compound is expressed by formula I [R is 1-10C alkyl; Q is single bond, ether bond, carboxylic acid ester bond, etc.; rings A and B are benzene or cyclohexyl ring; X and Y are single bond, methylenoxy bond, oxymethylene bond, etc.; (m) and (n) are 0-2]. The compound is obtained by catalytically reducing a compound expressed by formula II in the presence of magnesium oxide, etc., in an inert solvent such as methanol. The compound expressed by formula I is one component useful for preparing liquid crystal compositions used in a liquid crystal flat panel display, etc., good in compatibility with many other liquid crystal compounds and capable of increasing the N-I point or improving other physical properties by adding thereof to the liquid crystal compositions containing the liquid crystal compounds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel liquid crystal compound exhibiting a liquid crystal phase and having a low viscosity, a process for producing them, and a liquid crystal composition containing at least one of the compounds.

[0002]

2. Description of the Related Art Liquid crystal compounds exhibit dielectric anisotropy and optical anisotropy in the liquid crystal phase. The liquid crystal phase includes a nematic liquid crystal phase, a smectic liquid crystal phase, a cholesteric liquid crystal phase, etc. Among them, applied products using the nematic liquid crystal phase are most widely put into practical use. In other words, applied products that utilize these characteristics have been expanded to light control glass, sign displays, and flat panel displays such as calculators, watches, and word processors. With the recent advances in the electronics field, a wide variety of products (DS type) have been developed. , Twisted nematic type (TN type), super twisted nematic type (ST
N type), guest-host type (GH type) and the like.
The liquid crystal materials used for these are naturally physicochemically stable,
In particular, stability against heat, light, moisture, air, etc. is required. Further, the liquid crystal material has to exhibit a desired liquid crystal phase in a temperature range as wide as possible including room temperature, and physical properties such as operating voltage and responsiveness according to the purpose must be satisfied at a practical level. That is, it is generally preferable that the threshold voltage and the saturation voltage necessary for driving the liquid crystal display element are as low as possible, and that the viscosity of the liquid crystal material is as low as possible in order to increase the response speed. However, it is impossible to satisfy these physical properties with a single compound, and at present, several kinds of liquid crystal compounds and non-liquid crystal compounds are mixed to obtain the practically required properties. However, in order to construct a liquid crystal composition that satisfies these practically required properties, it is extremely important to develop a single compound having various properties as good as possible.

Under such circumstances, a compound having a nematic property is disclosed in, for example, JP-A-51-80870.

[0004]

[Chemical 14]

[Either one of R ¹ and R ² represents CN. ] And the like are described. However, these compounds do not satisfy the practically required properties.

[0006]

An object of the present invention is to provide a novel liquid crystal compound useful in developing such a practical liquid crystal composition.

[0007]

As a result of intensive studies to solve the above problems, the present inventors have succeeded in synthesizing a novel compound represented by the formula (I), and this compound ( It was discovered that I) had unexpectedly high physical and chemical stability and exhibited a stable nematic phase, and as a result of further studies, the present invention was completed.

That is, the present invention uses the formula (1)

[0009]

[Chemical 15]

[In the formula, R represents a linear or branched alkyl group having 1 to 10 carbon atoms, and Q represents a single bond, an ether bond, a thioether bond, a carboxylic acid ester bond or a thiocarboxylic acid ester bond. ,

[0011]

[Chemical 16]

M and n each represent 0, 1, 2 and X and Y each represent a single bond, a carboxylic ester bond, a thiocarboxylic ester bond, a methyleneoxy bond or an oxymethylene bond. However, when m is 0, at least one of Q and X represents a single bond, and when n is 0, at least one of X and Y represents a single bond, and both m and n are 0. Not shown. And a liquid crystal composition containing (3) compound (I) and (2) a method for producing compound (I).

Examples of the linear or branched alkyl group having 1 to 10 carbon atoms represented by R in the above formula (I) include, for example, methyl, ethyl, propyl,
Linear alkyl groups such as butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl and isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl , 1-methylpentyl, 2-methylpentyl, 5-methylhexyl, 2,3,5-trimethylhexyl, 2,
Branched alkyl groups such as 7,8-trimethyldecyl, 4-ethyl-5-methylnonyl and the like can be used. Of these, a linear alkyl group having 3 to 8 carbon atoms, such as propyl, butyl, pentyl, hexyl, heptyl, octyl and the like are preferable.

Q represents a single bond, an ether bond, a thioether bond, a carboxylic acid ester bond or a thiocarboxylic acid bond. In the carboxylic acid ester bond of the present invention,

[0015]

[Chemical 17]

As the substituent which may have, for example, a halogen atom (for example, fluorine, chlorine, bromine or iodine atom), a cyano group and the like are used, and a fluorine atom is particularly preferable. The number of substituents is about 1 to 3, preferably 2.

[0017]

[Chemical 18]

M and n each represent 0, 1 or 2, and preferably 0 or 1. X and Y each represent a single bond, a carboxylic acid ester bond, a thiocarboxylic acid ester bond, a methyleneoxy bond or an oxyethylene bond. Each of X and Y is preferably a single bond, a carboxylic acid ester bond or a thiocarboxylic acid ester bond, and particularly preferably a single bond or a carboxylic acid ester bond.

When m is 0, at least one of Q and X represents a single bond, and when n is 0, either X or Y represents a single bond, and both m and n are 0. Not shown. That is, when m is 0, the compound (I)
Is

[0020]

[Chemical 19]

(M'represents 1 or 2).

Preferred embodiments of the compound (I) of the present invention include the following.

[0023]

[Chemical 20]

Next, a method for producing the compound (I) of the present invention will be described.

Production Method (Part 1) [Compound (I) wherein Y = single bond: Production method of compound (Ia)]

[0026]

[Chemical 21]

The amidines which are the starting materials are easily produced from the corresponding nitriles by imino etherification and subsequent reaction with ammonia. This amidine is carried out in the presence of sodium alcoholate or an alkali metal, and a solvent that does not participate in the reaction, for example, alcohols such as methanol and ethanol, benzene, toluene, dimethylsulfoxide (DMSO), dimethylformamide (DMF) and the like are appropriately used. Can be selected and used. The reaction is usually carried out under heating, but it is preferably carried out at 50 ° to 150 ° C. The reaction time varies depending on the reaction temperature and the substrate, but is several minutes to several days, usually 10 minutes to several hours. The diol compound thus obtained is reacted with a halogenating agent such as phosphorus oxyhalide, phosphorus tri or pentahalide to convert it into a halogen-substituted compound. This reaction is usually carried out under reflux of these halogenating agents, and in this case, a basic catalyst such as N, N-dimethylaniline or pyridine is used, but N, N-diethylaniline is preferably used. The dihalogenate thus obtained is subjected to catalytic reduction in the presence of magnesium oxide, sodium acetate, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, etc. in a solvent inert to alcohols such as methanol and ethanol, ethyl acetate and chloroform. The desired compound (Ia) of the present invention can be obtained by subjecting the compound to catalytic reduction in a solvent such as tetrahydrofuran (THF).

The compound (Ia) of the present invention can be produced by a few synthetic methods other than the above-mentioned method. That is,
The manufacturing method (the 2), the manufacturing method (the 3), the manufacturing method (the 4), etc. which are mentioned below are mentioned.

Manufacturing method (2)

[0030]

[Chemical formula 22]

This production method is a method in which the 5-fluoropyrimidine ring-forming reaction of the above-mentioned production method (No. 1) is carried out at the stage of intermediate synthesis rather than the final step. That is, Q is -O-
In the case of, a phenol or alcohol having a 5-fluoro-2-pyrimidine ring and an alcohol (R-OH) as a side chain component or an active derivative thereof (for example, an organic sulfonic acid ester derivative, a halogen derivative) is suitable. It is a method for producing the desired compound (Ia) of the present invention by condensation in the presence of a condensing agent. Examples of the condensing agent include diazocarboxylic acid diethyl ester (DEAD), triphenylphosphine (PPh ₃ ), an inorganic base such as potassium carbonate and sodium hydride, and an organic strong base. Any reaction solvent may be used as long as it does not inhibit the reaction, and it may not be used.

Specifically, reaction solvents include hydrocarbons, halogenated hydrocarbons, ethers (diethyl ether, tetrahydrofuran, dioxane, etc.), ethyl acetate, acetonitrile, dimethylformamide (DM).
F), dimethylsulfoxide (DMSO), hexamethylphosphoric triamide (HMPA) and the like. The reaction temperature is usually -78 ° C to 150 ° C, and is appropriately selected, but 0 ° C to 80 ° C is preferably used. The reaction time varies depending on the reaction temperature and the substrate, but is a few minutes to a few
It is usually carried out for 10 minutes to a few hours for a day.

[0033]

[Chemical formula 23]

The invention compound (Ia) is produced by finally forming the intra-skeletal bond (X) by subjecting the skeleton component compound containing a 5-fluoro-2-pyrimidine ring and one skeleton component compound to a condensation reaction. There is also a method (manufacturing method 3). Further, the 5-position fluorine atom on the pyrimidine ring can be introduced by converting it from an amino group in addition to being derived from the fluorine atom-containing raw material compound as in the above method. So-called,
This is a method in which an amino group is diazotized and then converted to a fluorine atom by acting a fluorinating agent such as borofluoric acid (Production method 4). The reaction temperature in the above production method is -50 ° C to
It is carried out at about 150 ° C, but normally about -20 ° C to 80 ° C is preferably used. The reaction time varies depending on the reaction temperature and the substrate, but it is usually 2-3 minutes to 2-3 days, usually 10 minutes to 2-3.
Done in time.

The compound (I) in which Y is a methyleneoxy bond or a carboxylic acid ester bond is produced as follows.

[0036]

[Chemical formula 24]

Each raw material compound is a known compound or can be easily synthesized from a known compound. Specifically, one of the starting material compounds, 2-substituted-5-fluoropyrimidines, is produced by the following route.

[0038]

[Chemical 25]

Target product (I) produced by the above method
Can be separated and purified from the reaction solution using a commonly used separation and purification means such as extraction, phase transfer, column chromatography, liquid chromatography, recrystallization and the like.

The compound (I) obtained as described above has high physical and chemical stability and has a stable nematic phase. Therefore, it is useful for a liquid crystal composition used in a liquid crystal flat panel display or the like. It can be used as one component. The compound of the present invention can be used alone as a liquid crystal compound, and by adding it to another liquid crystal mixture, the liquid crystal activity of the other liquid crystal mixture can be enhanced. As a liquid crystal mixture to which the compound of the present invention can be added, for example, “Flussige Kristalle in Tabellen” I & IIVEB Verl
ag, Leipzig or "Liquid Crystal Device Handbook" (edited by Japan Society for the Promotion of Science, 142th Committee, Nikkan Kogyo Shimbun) or "Full Color Liquid Crystal Display Technology" (Trikeps Publishing Department,
The nematic liquid crystal described in Trikeps Co., Ltd., etc., and a commercially available nematic liquid crystal compound are also included. In this case, the amount of the compound of the present invention is usually 0.5% to
It is about 50%, preferably about 5% to 20%.

The present invention will be described in detail below with reference to examples, but these do not limit the scope of the present invention.

[0042]

【Example】

 Example 1

[0043]

[Chemical formula 26]

Dimethyl fluoromalonate 5.00 g
(0.028 mol) and 7.37 g (0.028 mol) of benzyloxybenzamidine hydrochloride were dissolved in 50 ml of 28% sodium methylate methanol solution, and the mixture was stirred at 80 ° C. overnight. 200 ml of 6N hydrochloric acid was added to the reaction solution, and the temperature was 60 ° C.
The resulting crystals were collected by filtration and washed with methanol to obtain 5.88 g of the desired product (yield 67.3%).

[0045]

[Chemical 27]

5.88 g (0.0) of the OH form obtained in i)
To 19 mol), 20 ml of phosphorus oxychloride and 7 ml of diethylaniline were added, and the mixture was heated under reflux overnight. The reaction solution is carefully poured into ice water, extracted with chloroform, and the organic layer is concentrated to dryness. Methanol was added to the residue, and the crystals that had crystallized were collected by filtration and well dried to obtain 4.66 g (71.0%) of the desired product.

[0047]

[Chemical 28]

4.66 g (0.
(013 mol) was dissolved in a mixed solution of 40 ml of ethanol, 150 ml of THF and 20 ml of water, 2 g of magnesium oxide and 0.4 g of 5% palladium carbon were added, and catalytic hydrogen reduction was carried out at room temperature and atmospheric pressure. After the catalyst and inorganic substances were collected by filtration, the filtrate was concentrated to dryness, and THF and 1N hydrochloric acid were added to the residue for liquid separation T
The HF layer is concentrated to dryness, dried well, and 2.16 g of the target product.
(84.8%) was obtained.

[0049]

[Chemical 29]

0.40 g of the phenol obtained in iii)
(2.1 mmol), 1.59 g of acyl bromide (10.
(5 mmol) was dissolved in 20 ml of DMSO, 0.09 g (2.3 mmol) of 60% sodium hydride was added, and the mixture was stirred at 70 ° C. for 30 minutes. The reaction solution is poured into water and extracted with ether,
The ether layer was concentrated under reduced pressure, the residue was purified by silica gel column chromatography (developing solvent: chloroform), and further recrystallized from acetonitrile to obtain the desired product 0.2.
0 g (36.6%) was obtained.

¹ H-NMR (200 MHz, CDCl ₃ ) δ: 8.
60 (s, 2H), 8.30 (d, 2H), 6.95 (d, 2H), 4.05 (t, 2H), 1.95-
1.75 (m, 2H), 1.60-1.30 (m, 4H), 0.95 (t, 3H) Example 2

[0052]

[Chemical 30]

Example 1. 0.40 g (2.1 mmol) of phenol obtained in iii), 1.06 of triethylamine
g (10 mmol) was dissolved in 20 ml of THF, 0.45 g (2.1 mmol) of p-butoxybenzoic acid acid chloride was added, and the mixture was stirred at 80 ° C. for 1 hour. The reaction solution is concentrated to dryness,
The residue was purified by silica gel column chromatography (developing solvent: chloroform) and recrystallized from ethanol to obtain 0.22 g (28.6%) of the desired product.

¹ H-NMR (200 MHz, CDCl ₃ ) δ: 8.
65 (s, 2H), 8.45 (d, 2H), 8.15 (d, 2H), 7.35 (d, 2H), 7.00
(d, 2H), 4.05 (t, 2H), 1.90-1.75 (m, 2H), 1.60-1.40 (m, 2
H), 1.00 (t, 3H) Example 3

[0055]

[Chemical 31]

Example 1. iii) Phenol obtained in 0.40 g (2.1 mmol), triethylamine 1.01
g (10 mmol) was dissolved in 10 ml of dichloromethane and tran was added.
0.43 g (2.1 mmol) of acid chloride of s-4-butyl-cyclohexylcarboxylic acid was added and stirred at room temperature for 1 hour. The reaction solution was concentrated to dryness, purified by silica gel chromatography (developing solution: chloroform), and recrystallized from ethanol to give 0.41 g of the desired product (yield 54.
8%).

¹ H-NMR (200 MHz, CDCl ₃ ) δ: 8.
65 (s, 2H), 8.40 (d, 2H), 7.20 (d, 2H), 2.60-2.40 (m, 1H),
2.25-2.10 (m, 2H), 1.75-1.80 (m, 2H), 1.70-1.80 (m, 14H) Example 4

[0058]

[Chemical 32]

Example 1. 0.4 g (2.1 mmol) of phenol obtained in iii) and 1.06 g of triethylamine
(10.5 mmol) was dissolved in 0 ml of dichloromethane, 0.27 g (2.5 mmol) of acid chloride of butyric acid was added, and the mixture was stirred at room temperature for 1 hour. The reaction solution is poured into water, a small amount of 1N hydrochloric acid is added, the mixture is extracted with dichloromethane, the dichloromethane layer is concentrated under reduced pressure, the residue is purified by silica gel chromatography (developing solvent: chloroform), and recrystallized from dichloromethane to obtain the desired product. 0.25 g (45.7%) was obtained.

¹ H-NMR (200 MHz, CDCl ₃ ) δ: 8.
65 (s, 2H), 8.42 (d, 2H), 7.21 (d, 2H), 2.58 (t, 2H), 1.91-
1.72 (m, 2H), 1.07 (t, 2H)

[0061]

[Formulation Example] This compound is physically and chemically stable and exhibits a preferable liquid crystal phase (nematic phase) in a wide temperature range.
It can be used as an active ingredient of a liquid crystal composition. As a specific liquid crystal mixture to which the compound of the present invention can be added, for example, a mixture having a composition of A, B, C, D and E can be mentioned. In addition, a commercially available mixed liquid crystal ZLT-1565
(Merck Co., Ltd.) and the like are also included.

[0062]

[Chemical 33]

[0063]

[Chemical 34]

[0064]

[Test example]

[Measurement of Physical Properties] The phase transition temperature and phase of the compound were determined by visual observation using a polarizing microscope and a differential heat capacity meter (DSC). For Δn and Δε, refer to the literature [edited by Mitsuharu Okano and Shunsuke Kobayashi: Liquid Crystal-Basic Edition], Baifukan (198
5)] was measured.

[0065]

[Table 1]

[0066]

INDUSTRIAL APPLICABILITY The compound of the present invention, a 5-fluoro-2-substituted pyrimidine derivative, is a novel compound, and is provided as a component useful for preparing a liquid crystal composition used for a liquid crystal flat panel display or the like. That is, the compound of the present invention is physically and chemically stable, and preferably exhibits a stable liquid crystal phase (nematic liquid crystal phase), and many other liquid crystal compounds such as ester-based, ether-based, carbonyl-based compounds,
It has good compatibility with liquid crystal compounds such as biphenyl-based, phenylcyclohexane-based, and heterocyclic-based compounds, and can be added to a liquid crystal composition containing these to raise the NI point or improve other physical properties. . As described above, the present invention provides a compound useful as one component in constructing a liquid crystal composition used in a liquid crystal flat panel display or the like. The present invention also provides at least one compound of the present invention.
The present invention provides a practical liquid crystal composition containing a seed.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiro Yamashita 9-1, 1-7 Kasuga, Tsukuba-shi, Ibaraki 9100 Takeda Kasuga Heights (72) Inventor Hiroshi Terao 7-1-1, Omika-cho, Hitachi-shi, Ibaraki Hitachi Ltd., Hitachi Research Laboratory (72) Inventor Katsumi Kondo 7-1-1 Omika-cho, Hitachi City, Ibaraki Prefecture Hitachi Ltd. Hitachi Research Laboratory (72) Inventor Yuka Utsumi 7, Mika-cho, Hitachi City, Ibaraki Prefecture No. 1-1 Hitachi Research Laboratory, Hitachi Ltd. (72) Inventor Shuichi Ohara 7-1-1 Omikacho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd.

Claims (6)

[Claims] 1. The formula: [In the formula, R is a linear or branched carbon atom having 1 to 1 carbon atoms.
0 represents an alkyl group, Q represents a single bond, an ether bond, a thioether bond, a carboxylic acid ester bond or a thiocarboxylic acid ester bond, and m and n represent 0, 1 or 2, and X and Y each represent a single bond, a carboxylic ester bond, a thiocarboxylic ester bond, a methyleneoxy bond or an oxymethylene bond. However, when m is 0, at least one of Q and X represents a single bond, and when n is 0, at least one of X and Y represents a single bond, and both m and n are 0. Not shown. ] The compound represented by these. 2. The compound according to claim 1, wherein R is a linear alkyl group having 3 to 8 carbon atoms, and m and n are 0 or 1. 3. A compound represented by the formula (I) is represented by: The compound according to claim 1, which is 4. Formula (1): [In the formula, each symbol has the same meaning as in claim 1. ] The compound represented by the formula [In the formula, each symbol has the same meaning as in claim 1. ] The compound of formula (2) [In the formula, each symbol has the same meaning as in claim 1. A compound represented by the formula: [In the formula, each symbol has the same meaning as in claim 1. ] By reacting a compound represented by [In the formula, each symbol has the same meaning as in claim 1. ] The compound represented by the formula [In the formula, each symbol has the same meaning as in claim 1. ] And a compound of the formula: Has the same meaning as. ] By reacting a compound represented by the formula: [In the formula, X ′ has the same meaning as described above, and other symbols have the same meaning as in claim 1. ] The method of manufacturing the compound represented by these. 5. The formula: [In the formula, each symbol has the same meaning as in claim 1. ] The compound or its active derivative represented by these, and a formula R-OH [In formula, R shows the same meaning as Claim 1. ] The compound represented by the formula or an active derivative thereof is reacted with [In the formula, each symbol has the same meaning as in claim 1. ] The manufacturing method of the compound represented by these. 6. A liquid crystal composition comprising the compound according to claim 1.