CN103880814A - 2-methyl-1,3-dioxepane derivative - Google Patents

Abstract

The invention discloses a 2-methyl-1,3-dioxepane derivative. The structural general formula of the compound is as shown in the formula I. The compound is stable in structure, has a wide liquid crystal state temperature range, good low-temperature intersolubility and large dielectric anisotropy delta epsilon, can be used for realizing a low threshold voltage and low rotary viscosity gamma 1 when being used in an optical device, can be used for improving the performances of a liquid crystal composition material and a display device, and has great significance in quick response of the display device. A liquid crystal composition containing the compound can be applied to preparation of liquid crystal display devices with low driving voltage, wide temperature range and quick response speed. The formula I is as shown in the specification.

Description

Dioxepane Derivatives

technical field

The invention belongs to the field of liquid crystal compound synthesis and application, and relates to a dioxepane derivative.

Background technique

Liquid crystal displays using liquid crystal compositions are widely used in displays such as instruments, computers, and televisions. For the field of liquid crystal display technology, although the market has become very large in recent years and the technology has gradually matured, people's requirements for display technology are also constantly improving. , especially in achieving fast response, reducing driving voltage, and reducing power consumption. As one of the important optoelectronic materials of liquid crystal display, liquid crystal material plays an important role in improving the performance of liquid crystal display.

Liquid crystal display elements are divided into the following modes according to the display mode: twisted nematic (TN) mode, super twisted nematic (STN) mode, in-plane mode (IPS), and vertical alignment (VA) mode. Regardless of the display mode, the liquid crystal composition needs to have the following characteristics.

(1) Chemical and physical properties are stable.

(2) Low viscosity.

(3) Have a suitable △ε.

(4) Appropriate demolition rate △n.

(5) Good compatibility with other liquid crystal compounds.

As a liquid crystal material for display, it has been greatly developed, and a large number of liquid crystal compounds have appeared. From biphenylnitrile, esters, oxygen-containing heterocycles, and pyrimidine ring liquid crystal compounds to cyclohexylbenzene, phenylacetylene, ethyl bridges, terminal alkenyl liquid crystals, and various fluorine-containing aromatic ring liquid crystal compounds Etc., continue to meet the display performance requirements of TN, STN, TFT-LCD, etc.

Any liquid crystal composition for display requires a wider liquid crystal state temperature, higher stability, more suitable viscosity, and faster response speed to electric field. But so far, no single liquid crystal monomer has been used alone in liquid crystal displays without being combined with other compounds to meet the performance requirements. If two or more kinds of liquid crystal monomers are mixed together, various properties of liquid crystals can be continuously changed. General commercial liquid crystal compositions are basically formed by mixing various monomer liquid crystals.

Contents of the invention

The object of the present invention is to provide a dioxepane derivative.

The dioxepane derivative provided by the present invention has a general structural formula as shown in formula I,

In the formula I, R ₁ and R ₂ are the same or different, and are all selected from the following groups a, b or c:

a, selected from H, Cl, F, -CN, -OCN, -OCF ₃ , -CF ₃ , -CHF ₂ , -CH ₂ F, -OCHF ₂ , -SCN, -NCS, -SF ₅ , C1-C15 At least one of alkyl, C1-C15 alkoxy, C2-C15 alkenyl and C2-C15 alkenyloxy;

b. In the group a containing -CH ₂ -, at least one -CH ₂ - is substituted by at least one of the following groups and the oxygen atoms are not directly connected: -CH=CH-, -C ≡C-, -COO-, -OOC-, cyclobutyl, -O- and -S-;

c. A group in which at least one hydrogen in the group a or b is replaced by fluorine, chlorine or deuterium;

均选自单键和下述基团中的至少一种：

are all selected from single bonds and at least one of the following groups:

Both Z ₁ and Z ₂ are selected from single bond, -CH ₂ -, -CH ₂ -CH ₂ -, -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, -CH=CH-, -C≡C -, -COO-, -OOC-, -CF ₂ O-, -OCH 2 -, -CH ₂ O-, -OCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -C _{2 F} At least one of ₄ - and -CF=CF-;

a, b and c are all integers from 0 to 3, and a+b+c≤5;

表示的基团相同或不同，

表示的基团相同或不同，

表示的基团可相同可不同。When a or b is 2 or 3,

represent the same or different groups,

represent the same or different groups,

The groups represented may be the same or different.

In the definition of _R1 and _R2 in the formula I, the C1-C15 alkyl group is specifically selected from a C2-C15 alkyl group, a C3-C15 alkyl group, a C4-C15 alkyl group, a C5-C15 Alkyl, C6-C15 Alkyl, C1-C7 Alkyl, C2-C7 Alkyl, C3-C7 Alkyl, C4-C7 Alkyl, C5-C7 Alkyl, C6-C7 Alkyl C1-C6 Alkyl, C2-C6 Alkyl, C3-C6 Alkyl, C4-C6 Alkyl, C5-C6 Alkyl, C1-C5 Alkyl, C2-C5 Alkyl , C3-C5 alkyl, C4-C5 alkyl, C1-C4 alkyl, C2-C4 alkyl, C3-C4 alkyl, C1-C3 alkyl, C1-C10 alkyl, At least one of C2-C10 alkyl, C3-C10 alkyl, C1-C10 alkyl, C1-C2 alkyl and C2-C3 alkyl;

The C1-C15 alkoxy is specifically selected from C2-C15 alkoxy, C3-C15 alkoxy, C4-C15 alkoxy, C5-C15 alkoxy, C6-C15 alkoxy C1-C7 alkoxy, C2-C7 alkoxy, C3-C7 alkoxy, C4-C7 alkoxy, C5-C7 alkoxy, C6-C7 alkoxy, C1-C6 alkoxy, C2-C6 alkoxy, C3-C6 alkoxy, C4-C6 alkoxy, C5-C6 alkoxy, C1-C5 alkoxy, C2- C5 alkoxy, C3-C5 alkoxy, C4-C5 alkoxy, C1-C4 alkoxy, C2-C4 alkoxy, C3-C4 alkoxy, C1-C3 Alkoxy, C1-C10 alkoxy, C2-C10 alkoxy, C3-C10 alkoxy, C1-C10 alkoxy, C1-C2 alkoxy and C2-C3 alkoxy at least one of the bases;

The C2-C15 alkenyl is specifically selected from C3-C15 alkenyl, C4-C15 alkenyl, C5-C15 alkenyl, C6-C15 alkenyl, C1-C6 alkenyl, C2-C6 Alkenyl, C3-C6 alkenyl, C4-C6 alkenyl, C5-C6 alkenyl, C2-C5 alkenyl, C3-C5 alkenyl, C4-C5 alkenyl, C2-C4 alkenyl At least one of C3-C4 alkenyl, C2-C10 alkenyl, C3-C10 alkenyl, C2-C8 alkenyl and C2-C3 alkenyl;

The C2-C15 alkenyloxy is specifically selected from C3-C15 alkenyloxy, C4-C15 alkenyloxy, C5-C15 alkenyloxy, C6-C15 alkenyloxy, C2-C6 alkenyloxy C3-C6 alkenyloxy, C4-C6 alkenyloxy, C5-C6 alkenyloxy, C2-C5 alkenyloxy, C3-C5 alkenyloxy, C4-C5 alkenyloxy, At least one of C2-C4 alkenyloxy, C3-C4 alkenyloxy, C2-C10 alkenyloxy, C3-C10 alkenyloxy, C2-C8 alkenyloxy and C2-C3 alkenyloxy A sort of;

Specifically, the compound shown in formula I is any one of the compounds shown in formula I-1 to formula I-7:

In the formulas I-1 to I-4, R ₁ , R ₂ , Z ₁ , The definition of is the same as that of R ₁ , R ₂ , Z ₁ , c, have the same definition;

的定义与

的定义相同。said

The definition of

have the same definition.

The compound shown in the formula I is more specifically any one of the compounds shown in the formulas I-8 to I-16:

In said formula I-8 to formula I-16, R ₁ is hydrogen or C1-C10 linear alkyl;

R ₂ is Cl, F, -OCF ₃ , -CF ₃ or -OCHF ₂ ;

L ₁ to L ₈ are all selected from any one of hydrogen and fluorine.

The compound represented by formula I provided by the present invention above can be prepared according to the following methods one to three:

method one

Method Two

method three

In addition, the above-mentioned liquid crystal mixture comprising any compound represented by the aforementioned formula I also falls within the protection scope of the present invention.

The liquid crystal mixture may also contain compounds represented by formula II to formula IV;

Of course, the liquid crystal mixture may only consist of compounds shown in formulas I to IV;

In the formulas II to IV, R ₁ , R ₂ and R ₃ are all selected from hydrogen, halogen, -CN, C1-C7 alkyl, C1-C7 alkoxy, C2-C7 alkenyl and C1 -at least one of C5 fluoroalkoxy groups;

The Z ₁ is selected from single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C-, -COO-, -OOC-, -OCH ₂ -, -CH ₂ O-, -CF At least one of ₂ O- and -OCF ₂ -;

said are selected from single bonds and any one of the following groups:

X, Y, U and V are all selected from any one of H and F;

d is an integer of 0-3.

In the formula II to formula IV, the C1-C7 alkyl is specifically selected from the C2-C7 alkyl, the C3-C7 alkyl, the C4-C7 alkyl, the C5-C7 alkyl, the C6-C7 Alkyl, C1-C6 alkyl, C2-C6 alkyl, C3-C6 alkyl, C4-C6 alkyl, C5-C6 alkyl, C1-C5 alkyl, C2-C5 alkane C3-C5 Alkyl, C4-C5 Alkyl, C1-C4 Alkyl, C2-C4 Alkyl, C3-C4 Alkyl, C1-C3 Alkyl, C1-C2 Alkyl and at least one of C2-C3 alkyl groups;

The C1-C7 alkoxy group is specifically selected from C2-C7 alkoxy group, C3-C7 alkoxy group, C4-C7 alkoxy group, C5-C7 alkoxy group, C6-C7 alkoxy group C1-C6 alkoxy group, C2-C6 alkoxy group, C3-C6 alkoxy group, C4-C6 alkoxy group, C5-C6 alkoxy group, C1-C5 alkoxy group, C2-C5 alkoxy, C3-C5 alkoxy, C4-C5 alkoxy, C1-C4 alkoxy, C2-C4 alkoxy, C3-C4 alkoxy, C1- At least one of C3 alkoxy, C1-C2 alkoxy and C2-C3 alkoxy;

The C2-C7 alkenyl is specifically selected from C3-C7 alkenyl, C4-C7 alkenyl, C5-C7 alkenyl, C6-C7 alkenyl, C2-C6 alkenyl, C3-C6 Alkenyl, C4-C6 alkenyl, C5-C6 alkenyl, C2-C5 alkenyl, C3-C5 alkenyl, C4-C5 alkenyl, C2-C4 alkenyl, C3-C4 alkenyl At least one of a group and a C2-C3 alkenyl group;

The C1-C5 fluoroalkoxy is specifically selected from C1-C4 fluoroalkoxy, C1-C3 fluoroalkoxy, C3-C5 fluoroalkoxy, C4-C5 fluoroalkoxy At least one of alkoxy, C2-C4 fluoroalkoxy, C3-C4 fluoroalkoxy and C2-C3 fluoroalkoxy;

Specifically, the liquid crystal mixture may also be composed of compounds represented by formulas I to IV in the following mass ratios:

Wherein, the mass ratio of the compounds represented by formula I to formula IV is 0-30:5-60:5-60:3-45, specifically 14:18:45:23, 14:30:11:45, 14:15:32:39, 14:20:30:36, 17:35:21:27, 9:22:32:37 or 9-17:15-35:11-45:23-45; and all The mass of the compound shown in formula I is not zero.

The above-mentioned liquid crystal composition is specifically the following liquid crystal composition a, b, c, d, e or f:

The liquid crystal mixture a includes or consists of the following components by mass:

The liquid crystal mixture a specifically includes or consists of the following components by mass:

The liquid crystal mixture b includes or consists of the following components by mass:

The liquid crystal mixture b specifically includes or consists of the following components by mass:

The liquid crystal mixture c includes or consists of the following components by mass:

The liquid crystal mixture c specifically includes or consists of the following components by mass:

The liquid crystal mixture d includes or consists of the following components by mass:

The liquid crystal mixture d specifically includes or consists of the following components by mass:

The liquid crystal mixture e includes or consists of the following components by mass:

The liquid crystal mixture e specifically includes or consists of the following components by mass:

In addition, the above-mentioned application of the compound represented by formula I or the liquid crystal mixture provided by the present invention in the preparation of liquid crystal display device materials or electro-optic display materials or electro-optical liquid crystal displays and the liquid crystal display device comprising the compound represented by formula I or the liquid crystal mixture Materials or electro-optic display materials or electro-optic liquid crystal displays also belong to the protection scope of the present invention. Wherein, the electro-optic liquid crystal displays are all TN type displays, VA type displays, IPS type displays or PDLC type displays.

The liquid crystal mixture provided by the present invention can usually be prepared by known methods, such as the method of dissolving at high temperature, etc. In addition, additives well known to those skilled in the art of the present invention can be added according to the application, such as optically active substances, Dyes, antioxidants, UV absorbers, antistatic agents, etc.

The liquid crystal compound shown in formula I provided by the invention has general physical properties necessary for the compound: stable to light and heat, wide nematic phase, good compatibility with other compounds, especially this compound has low rotational viscosity γ ₁ And the characteristics of large dielectric anisotropy (△ε>0). The synthesis of such compounds is of great significance for the development of monomeric liquid crystal compounds with low rotational viscosity _γ1 and high dielectric anisotropy Δε. The liquid crystal composition containing the compound represented by formula I has a wide temperature range of liquid crystal phase, low viscosity, suitable refractive index anisotropy and low start-up voltage, and has important application value.

Detailed ways

The following examples are used to explain the present invention, but the present invention is not limited to the following examples. The methods are conventional methods unless otherwise specified. The materials can be obtained from public commercial sources unless otherwise specified. In the following examples, GC represents gas chromatography purity, HPLC represents liquid chromatography purity, MP represents melting point, MS represents mass spectrum, 1H-NMR represents hydrogen nuclear magnetic spectrum, Δε represents dielectric anisotropy, and Δn represents optical anisotropy.

The structural correctness of the products represented by formula I obtained in the following examples were identified by gas chromatography, liquid chromatography, GC-MS mass spectrum and 1H-NMR identification. GC was measured by HP6820 gas chromatograph analyzer of Agilent Company, GC-MS analysis and determination device was MS5975C model of Agilent Company, 1H-NMR was determined by DRX-500 analysis device of Bruker.Biospin Company, and melting point was determined by WRX-1S Microthermal analyzer, set the heating rate to 3°C/min.

The physical properties of the product represented by formula I obtained in the following examples were measured in two ways: the compound itself was used as a sample for measurement and the compound was mixed with a matrix liquid crystal as a sample for measurement. The method of mixing the compound and the matrix liquid crystal as a sample to measure the physical properties of the compound is as follows: first, mix 15% of the liquid crystal compound with 85% of the matrix liquid crystal to prepare a sample, and then according to the measured value of the obtained sample, according to the following formula The extrapolation method shown to calculate the extrapolated value,

Extrapolated value=[100×(measured value of sample)-(weight percentage of matrix liquid crystal)×(measured value of matrix liquid crystal)]/weight percentage of compound, so as to obtain the physical properties of monomeric liquid crystal compound.

The composition of the matrix liquid crystal used is as follows:

The physical property determination method of the liquid crystal compound is carried out according to the standard of this industry, refer to the physical property determination method of the compound published by Aviation Industry Press in "Liquid Crystal Device Manual":

1. Determination of phase structure and transfer temperature (°C)

① Place the compound on a heating plate equipped with a polarizing microscope melting point instrument (Mettler FP-52 type), heat at a speed of 3°C/min, and use a polarizing microscope to observe the phase change, so as to determine the phase state type.

② Utilize Mettler's differential calorimetry torsion scanner DSC822e, heat up or cool down at a rate of 1°C/min, use extrapolation to find the starting point of the endothermic peak or exothermic peak accompanying the phase change of the sample, and thus Determine the transfer temperature.

The crystalline is represented by C, the smectic phase is S, the nematic phase is N, and the liquid is I.

2. Viscosity: (γ1 is measured at 20°C), using Toyo6254 comprehensive tester.

3. Optical anisotropy (refractive index anisotropy is measured at 25°C for △n), measured at 25°C with light with a wavelength of 589nm, using an Abbe refractometer to measure △n. After rubbing against the surface of the main prism (Pri3m) in one direction, the sample is dropped onto the main prism. The refractive index (n11) is the value measured when the polarization direction is parallel to the rubbing direction, the refractive index (n⊥) is the value measured when the polarization direction is perpendicular to the rubbing direction, and the value of optical anisotropy (△n) is determined by △n =n11-n⊥ to calculate.

4. Dielectric constant anisotropy (△ε, measured at 25°C) was measured by HP4284a precision LCR tester from Hewlett-Packard Company. Measure the dielectric constant ε‖ of liquid crystal molecules in the long axis direction, measure the dielectric constant (ε _⊥ ) of liquid crystal molecules in the short axis direction, and calculate the dielectric anisotropy △ε by △ε= _ε‖ -ε _⊥ .

Among the measured values, when the liquid crystal compound itself is used as the sample, the obtained value is recorded as the experimental value, and when the mixture of the liquid crystal compound and the mother liquid crystal is used as the sample, the value obtained by extrapolation is recorded as the experimental value.

Example 1, Synthesis of Compound I-17 (Synthesis Route 1)

step 1:

Add 44.4g (0.24mol) p-bromobenzaldehyde (reactant), 21.6g (0.24mol) (reactant) of 1,4-butanediol, 400ml dry toluene (solvent), 2g p-toluenesulfonic acid to a 1L three-necked flask , heated to reflux for 4 hours, separated the formed water, cooled to room temperature, washed with 100ml of water, and evaporated to dryness to obtain 55.5g of (I-17-a), with a yield of 90% and a purity of 98% by gas chromatography.

step 2

Add 25.7g (0.1mol) (I-17-a) (reactant) and 150ml tetrahydrofuran (solvent) into the reaction flask, protect it with nitrogen, cool down to -60°C, add dropwise 0.2mol n-butyllithium (reactant ) of petroleum ether (solvent) solution, the dropwise addition was completed within 1 hour, and the reaction was stirred at -50°C for 30 minutes. Then cool down to -60°C, add dropwise 13g (0.13mol) trimethyl borate (reactant) in 70ml tetrahydrofuran (solvent) solution within 1 hour, after the addition, continue to control the temperature and stir for 1 hour, then warm up to room temperature, Add 0.2mol hydrochloric acid and stir for 20 minutes, add water to wash, extract with 50ml of ethyl acetate (solvent) and separate liquids, wash the organic phase with water until neutral, and evaporate the solvent to obtain 17.8g of compound (I-17-b). 80%, liquid chromatography purity 97%.

step 3 Synthesis

Add 24.4g (0.11mol) (I-17-b) (reactant) in reaction bottle, 38.9g (0.1mol) P2 (reactant) (according to Peer.Kirschet al., Angew.Chem.Int.Ed. 2001.40.1480. Synthesis), tetrakistriphenylphosphine palladium 0.3g (catalyst), sodium carbonate 15g (catalyst), toluene 100ml (solvent), water 100ml, ethanol 100ml (solvent), heating to reflux for 4 hours, adding 100ml of water, Separation, organic phase evaporated to dryness, column chromatography, recrystallization to obtain product I-17, 34g yield 70%

The structural confirmation data of this product are as follows:

GC: 99.9%

MP: 68°C

MS: m/s%486(1.7),339(100),267(7.9),239(4.8),

1H-NMR: δ (ppm) 1.54 (m, 4H), 3.65 (m, 4H), 5.48 (s, 1H), 6.89 (m, 2H), 7.22 (d, 1H), 7.40 (m, 4H);

It can be seen from the above that the product has a correct structure and is a compound shown in formula I-17 belonging to formula I.

The liquid crystal properties of the product are as follows:

Δε: 21.3 (20°C, 589nm)

Δn: 0.119 (20°C, 1000Hz)

It can be seen from the above that the single crystal has a relatively large dielectric constant and a suitable refractive index, and can be used in mixed liquid crystals.

Example 2, Synthesis of Compound I-18 (Synthesis Route 2)

step 1

Add 0.1mol (Ⅰ-17-a), 0.12mol m-fluorophenylboronic acid (reactant), 0.13mol sodium carbonate (reactant), 80ml toluene (solvent), 60ml ethanol (solvent), 60ml water (solvent) to the reaction bottle ), under the protection of nitrogen, add 0.4g tetrakis (triphenylphosphine) palladium (catalyst), stir and heat to reflux for 3 hours. Cool down to room temperature, separate the layers, extract the aqueous phase with 50ml of toluene (solvent), and wash the organic phase with water until neutral. Evaporate the solvent to dryness, dissolve the resultant in 100ml of toluene, decolorize it through a silica gel column, elute with toluene (solvent), collect the eluent and evaporate the solvent to dryness, dissolve with 3 times of petroleum ether, freeze and recrystallize at -20°C, and filter with suction. 24.5 g of (I-18-a) were obtained as white crystals. The yield is 90%, and the gas chromatography purity is 99.5%.

step 3

Add 27.2g (0.1mol) (I-18-a) (reactant), 0.11mol potassium tert-butoxide, 80ml tetrahydrofuran (solvent) into the reaction flask, protect it with nitrogen, cool down to -90°C, and drop 0.12mol The petroleum ether (solvent) solution of n-butyllithium (reactant) was added dropwise within 1 hour, and the reaction was stirred at -90°C for 30 minutes. Still controlling the temperature to -90°C, add dropwise a solution of 0.11mol trimethyl borate (reactant) in 70ml tetrahydrofuran (solvent) within 1 hour. 100ml of water and 20ml of concentrated hydrochloric acid, stirred for 20 minutes, separated, extracted with petroleum ether (solvent) and separated, washed the organic phase with water until neutral, evaporated to dryness, heated to dissolve with 2 times petroleum ether, and then recrystallized by freezing at -20°C , and suction filtered to obtain 19 g of white crystals (I-18-b). The yield is 60%, and the liquid chromatography purity is 99.5%.

Synthesis of Step 4 Compound Ⅰ-18

Add 34.8g (0.11mol) I-18-b (reactant) and 38.9g (0.1mol) gP2 (reactant) in the reaction flask (according to Peer.Kirschet al., Angew.Chem.Int.Ed.2001.40. 1480. Synthesis), tetrakistriphenylphosphine palladium 0.3g (catalyst), sodium carbonate 15g (catalyst), toluene 100ml (solvent), water 100ml, ethanol 100ml (solvent), heated to reflux for 4 hours, added 100ml of water, and separated , the organic phase was evaporated to dryness, column chromatography, and recrystallization to obtain product I-18, 40.6g yield 70%,

The structural confirmation data of this product are as follows:

MS: m/s%333(5.3)361(8.9)433(100)580(1.4)

1H-NMR: δ (ppm) 1.54 (m, 4H), 3.65 (m, 4H), 5.48 (s, 1H), 6.89 (m, 2H), 7.02 (d, 1H), 7.22 (d, 2H), 7.40 ( m,4H),7.58(d,1H)7.83(m,1H);

As can be seen from the above, the product has a correct structure and is a compound shown in formula I-18 belonging to formula I.

The liquid crystal properties of the product are as follows:

CP: 158°C;

Δε: 20.6 (20°C, 589nm)

Δn: 0.145 (20°C, 1000Hz)

It can be seen from the above that the single crystal has a relatively large dielectric constant and a suitable refractive index, and can be used in mixed liquid crystals.

Embodiment 3, the synthesis of compound I-19

step 1

Add 25.7g (0.1mol) (I-17-a) (reactant) and 120ml tetrahydrofuran (solvent) to the reaction bottle, install the seal and stir, replace the air with nitrogen, drop the temperature to -70°C, and add 0.1mol Concentration of 2.5M butyllithium (reactant), 20 minutes after the addition, dry carbon dioxide gas (reactant), to saturation, react at this temperature for 2 hours, pour this reaction solution into 20ml concentrated Hydrochloric acid (to adjust the pH value) and 100ml of water in a beaker for hydrolysis, liquid separation, 50ml of ethyl acetate (solvent) to extract the water phase once, combine the organic phase, wash with saturated saline until neutral, dry with anhydrous sodium sulfate (drying agent), Concentrate to remove the solvent to obtain a light yellow solid, which is recrystallized once with 2 times of toluene and 1 times of ethyl acetate (solvent) to obtain 20 g of white crystals (I-19-a). The yield is 90%, and the liquid chromatography purity is 98.0%.

step 2

Add 22.2g (0.1mol) (Ⅰ-19-a), glacial acetic acid 100ml, 5%Pt/C10g to the reaction flask, hydrogenate under normal pressure for 6 hours under stirring, remove the catalyst by filtration, evaporate the solvent to dryness, add 50ml toluene for recrystallization , the yield was 50% to obtain 11.3g (Ⅰ-19-b)

step 3

Add 22.6g (0.1mol) (I-19-b), 30ml toluene (solvent) and 30ml isooctane (solvent) to the reaction flask, add 14g 1,3-propanedithiol (reactant), stir the above Heat the suspension to 50°C, add 19.2g of trifluoromethanesulfonic acid (reactant) within 30 minutes, raise the temperature to reflux after the addition, separate the generated water, and cool down to 90°C after separating the purified water. Add 100ml of methyl tert-butyl ether (solvent) within 45 minutes between 70-90°C, continue to cool down, precipitate crystals, filter under nitrogen protection, and use methyl tert-butyl ether (solvent) (25ml×4 ) and dried in vacuo to obtain 31.5 g of orange crystals (dithiane trifluoromethanesulfonate) (I-19-c). Yield 70%

step 4

Add 24.2g (0.1mol) 2,3',4',5'-tetrafluorobiphenyl-4-ol (reactant), 0.12mol triethylamine (reactant) and 130ml dichloromethane ( solvent) and cooled to -70 ° C, dropwise added the above 45g (0.1mol) (I-19-c) crystal (I-19-c) crystal (reactant) in 120ml of dichloromethane (solvent) solution, 45 minutes to complete, here After stirring at temperature for one hour, 0.4 mol of _NEt3 ·3HF (reactant) was added over 5 minutes. Then at -70°C, add 0.4mol liquid bromine (reactant) in 30ml dichloromethane (solvent) solution within one hour, then continue the reaction at -70°C for one hour, raise the temperature to 0°C, and pour the reaction solution into 160ml of 32% sodium hydroxide aqueous solution (to adjust the pH value) and 300g of ice, by adding about 45g of 32% sodium hydroxide aqueous solution dropwise to adjust the pH value of the reaction solution to 5-8. After liquid separation, the aqueous phase was extracted with 80ml of dichloromethane (solvent), and the combined organic phases were filtered with 4g of diatomaceous earth (decolorizer), washed with water, and the solvent was evaporated to dryness under reduced pressure. The obtained crude product was recrystallized from petroleum ether (solvent) after column chromatography to obtain 21.3 g of white crystal product (I-19), yield 45%, GC: 99.8%.

The structural confirmation data of this product are as follows:

MP: 56°C

MS: m/s%69(78.5)83(89.4)232(100)474(76.8)

1H-NMR: δ (ppm) 1.28 (m, 4H), 1.54 (m, 8H), 2.08 (m, 1H), 2.48 (m, 1H), 3.65 (m, 4H), 4.18 (d, 1H), 6.83 (m,2H),7.27(m,2H)7.66(m,1H);

As can be seen from the above, the product has a correct structure and is a compound shown in formula I-19 belonging to formula I.

The liquid crystal properties of the product are as follows:

Δε: 18.0 (20°C, 589nm)

Δn: 0.18 (20°C, 1000Hz)

It can be seen from the above that the single crystal has a relatively large dielectric constant and a suitable refractive index, and can be used in mixed liquid crystals.

With reference to the method of above-mentioned embodiment 1-3, only replace the substituent in the corresponding reactant according to the definition of substituent in the product, obtain each compound shown in following formula I:

Embodiment 4, liquid crystal mixture a

Mix the components according to the following parts by weight to obtain the liquid crystal mixture a provided by the invention:

The performance parameter of this liquid crystal mixture a is as follows:

CP: 97°C; △n: 0.110; △ε: 6.5; γ ₁ : 68;

It can be seen from the above that the composition has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be applied to liquid crystal displays;

According to the above composition, only two components belonging to the compound of formula I are not added, that is, the components are mixed according to the following parts by weight to obtain the liquid crystal mixture g as a control:

The performance parameter of this liquid crystal mixture g is as follows:

CP: 88°C; △n: 0.105; △ε: 4.2; γ ₁ : 65;

Compared with the liquid crystal mixture a, if the compound represented by formula I provided by the present invention is not added, the Δε of the liquid crystal mixture is significantly reduced.

Embodiment 5, liquid crystal mixture b

Mix the components according to the following parts by weight to obtain the liquid crystal mixture b provided by the invention:

The performance parameter of this liquid crystal mixture b is as follows:

CP: 85°C; △n: 0.100; △ε: 6.5; γ ₁ : 66;

It can be seen from the above that the mixture has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be suitable for liquid crystal displays.

Embodiment 6, liquid crystal mixture c

Mix the components according to the following parts by weight to obtain the liquid crystal mixture c provided by the present invention:

The performance parameter of this liquid crystal mixture c is as follows:

CP: 95°C; △n: 0.085; △ε: 6.0; γ ₁ : 75;

It can be seen from the above that the mixture has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be suitable for liquid crystal displays.

Embodiment 7, liquid crystal mixture d

Mix the components uniformly according to the following parts by weight to obtain the liquid crystal mixture d provided by the present invention:

The performance parameter of this liquid crystal mixture d is as follows:

CP: 95°C; △n: 0.100; △ε: 7.8; γ ₁ : 58;

It can be seen from the above that the mixture has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be suitable for liquid crystal displays.

Embodiment 8, liquid crystal mixture e

Mix the components uniformly according to the following parts by weight to obtain the liquid crystal mixture e provided by the present invention:

The performance parameter of this liquid crystal mixture e is as follows:

CP: 103°C; △n: 0.0105; △ε: 7.2; γ ₁ : 68;

It can be seen from the above that the mixture has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be suitable for liquid crystal displays.

Embodiment 9, liquid crystal mixture f

Mix the components according to the following parts by weight to obtain the liquid crystal mixture f provided by the invention:

The performance parameter of this liquid crystal mixture f is as follows:

CP: 90°C; △n: 0.110; △ε: 7.6; γ ₁ : 65;

It can be seen from the above that the mixture has a high clearing point, appropriate optical anisotropy, low rotational viscosity and fast response speed, and can be suitable for liquid crystal displays.

Claims (8)

1. the compound shown in formula I,

In the formula I, R ₁ and R ₂ are the same or different, and are all selected from the following groups a, b or c: a, selected from H, Cl, F, -CN, -OCN, -OCF ₃ , -CF ₃ , -CHF ₂ , -CH ₂ F, -OCHF ₂ , -SCN, -NCS, -SF ₅ , C1-C15 At least one of alkyl, C1-C15 alkoxy, C2-C15 carbon atom alkenyl and C2-C15 alkenyloxy; b. In the group a containing -CH ₂ -, at least one -CH ₂ - is substituted by at least one of the following groups and the oxygen atoms are not directly connected: -CH=CH-, -C ≡C-, -COO-, -OOC-, cyclobutyl, -O- and -S-; c. A group in which at least one hydrogen in the group a or b is replaced by fluorine, chlorine or deuterium;

are all selected from single bonds and at least one of the following groups:

Both Z ₁ and Z ₂ are selected from single bond, -CH ₂ -, -CH ₂ -CH ₂ -, -(CH ₂ ) ₃ -, -(CH ₂ ) ₄ -, -CH=CH-, -C≡C -, -COO-, -OOC-, -CF ₂ O-, -OCH 2 -, -CH ₂ O-, -OCF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF ₂ -, -C _{2 F} At least one of ₄ - and -CF=CF-; a, b and c are all integers from 0 to 3, and a+b+c≤5; When a or b is 2 or 3,

represent the same or different groups,

represent the same or different groups,

The groups represented are the same or different. 2. The compound according to claim 1, characterized in that: the compound shown in the formula I is any one of the compounds shown in the formula I-1 to the formula I-7:

In the formulas I-1 to I-4, R ₁ , R ₂ , Z ₁ ,

The definition of R ₁ , R ₂ , Z ₁ ,

have the same definition; said

The definition of

have the same definition; The compound shown in the formula I is specifically any one of the compounds shown in the formulas I-8 to I-16:

In said formula I-8 to formula I-16, R ₁ is hydrogen or C1-C10 linear alkyl; R ₂ is Cl, F, -OCF ₃ , -CF ₃ or OCHF ₂ ; L ₁ to L ₈ are all selected from any one of hydrogen and fluorine. 3. A liquid crystal mixture comprising a compound as claimed in any one of claims 1-2. 4. The liquid crystal mixture that is made up of compound shown in any one of claim 1-2 and formula II to formula IV:

In the formulas II to IV, R ₁ , R ₂ and R ₃ are all selected from hydrogen, halogen, -CN, C1-C7 alkyl, C1-C7 alkoxy, C2-C7 alkenyl and C1 -at least one of C5 fluoroalkoxy groups; The Z ₁ is selected from single bond, -CH ₂ -CH ₂ -, -CH=CH-, -C≡C-, -COO-, -OOC-, -OCH ₂ -, -CH ₂ O-, - At least one of CF ₂ O- and -OCF ₂ -; said are selected from single bonds and any one of the following groups: X, Y, U and V are all selected from any one of H and F; d is an integer of 0-3. 5. The liquid crystal mixture according to claim 4, characterized in that: the mass ratio of the compounds shown in the formulas I to IV is 0-30:5-60:5-60:3-45; and the formula The mass of the compound shown by I is not zero. 6. Use of the liquid crystal compound according to any one of claims 1-2 or the liquid crystal mixture according to any one of claims 3-5 in the preparation of liquid crystal display materials or electro-optic display materials or electro-optic liquid crystal displays. 7. A liquid crystal display material or an electro-optical display material or an electro-optical liquid crystal display comprising at least one of the liquid crystal compound according to claims 1-2 or the liquid crystal mixture according to any one of claims 3-5. 8. The application according to claim 6 or the display according to claim 7, wherein the electro-optical liquid crystal displays are all TN type displays, VA type displays, IPS type displays or PDLC type displays.