TW201215666A - Liquid crystal compound and liquid crystal mixture - Google Patents

Abstract

A liquid crystal compound and a liquid crystal mixture are provided. The liquid crystal compound is represented by formula (I), wherein X1 and X2 are independently -F or -CF3; R is H, a C1-C15 alkyl group or a C2-C15 alkenyl group; A1 and A2 are independently 1, 4-phenylen, 1, 4-cyclohexylene or 2, 5-tetrahydropyranylene; m and n are independently 1, 2 or 3, and m+n ≤ 4.

Description

201215666 -...J1 34469twf.doc/n VI. Description of the Invention: [Technical Field] The present invention relates to a liquid crystal compound and a liquid crystal mixture, and in particular to a method having a high birefringence A low viscosity liquid crystal compound and a liquid crystal mixture. [Prior Art] • The liquid crystal display (Uquid crystal display) is an attractive device that utilizes liquid crystal photoelectric change. It has the advantages of small size, light weight, low power consumption and good display quality, so it has become a flat display in recent years. ^♦器=stream. As technology advances, the industry continues to use various methods to increase the color saturation of liquid crystal displays to meet the needs of users. For liquid crystal materials in liquid crystal displays, high optical anisotropy is required. Increasing the total structure on the main axis of the liquid crystal molecules can increase the split ratio (Δη). In addition, A has a faster liquid crystal response time' also requires a liquid crystal material having a lower viscosity (8) in units of _. SUMMARY OF THE INVENTION The present invention provides a liquid crystal compound having a high birefringence. 〇 The present invention further provides a liquid crystal mixture having a low viscosity. The present invention provides a liquid crystal compound represented by the formula (1), 34469twf.doc/n 201215666

Wherein, Xi and X2 are each independently _F or _CF3; R is H, a C1 to C15 alkyl group or a C2 to C15 alkenyl group; and Aj A2 is independently a 1,4-phenylene group, 1,4- Cyclohexyl or 2,5-tetrahydropyranylene; m and η are each independently an integer from 1 to 3, and m+n^4. According to an embodiment of the invention The liquid crystal compound, the above-mentioned ruthenium and ruthenium 2 are, for example, -F. According to the liquid crystal compound according to the embodiment of the present invention, the above-mentioned Ci to C15 alkyl group is, for example, an unsubstituted C1 to C15 alkyl group or via _ 〇_, -CO- or -COO-substituted ci to C15 alkyl. According to the liquid crystal compound of the embodiment of the invention, the above C2 to C15 alkenyl group is, for example, an unsubstituted C2 to C15 alkenyl group. Or a -C- or -C00-substituted C2 to C15 alkenyl group. According to the liquid crystal compound of the embodiment of the present invention, the above 1,4·phenylene group is, for example, unsubstituted anthracene, 4_stretched a phenylene group or a 1,4-phenylene group substituted by at least one _F. The liquid crystal compound according to the embodiment of the present invention, wherein the 1,4_cyclohexylene group is, for example, an unsubstituted anthracene, 4_extension ring Hexyl or At least one ρ-Cl substituted 1,4-cyclohexyl group. The present invention further provides a liquid crystal mixture comprising at least the above crystalline compound. Based on the above, the liquid crystal compound of the present invention has a high birefringence 201215666 L/ ΛΐυυιΟΙ 34469twf.doc/n and the comparative viscosity 'so that the liquid crystal mixture containing the liquid crystal compound has high optical anisotropy' and has a faster liquid crystal reaction speed. In addition, the liquid crystal compound of the present invention also has high thermal stability. In order to make the above features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail below with reference to the accompanying drawings. The substituted group and the substituted functional group, the single group is represented by an unsubstituted group and a substituted group, and the i'4-phenylene group is exemplified, including unsubstituted (imsUbStituted) 1,4- Phenylphenyl and substituted fluorene, phenyl, other single functional groups or single groups are all represented by this, which is well known to those skilled in the art. The present invention proposes a liquid crystal compound which can have a high birefringence and a low viscosity, thereby enabling a liquid crystal mixture containing the liquid crystal compound to have high optical anisotropy and having a relatively fast liquid crystal. Reaction speed. The liquid crystal compound of the present invention is represented by the formula (1).

Formula (I) Χι and X2 are each independently -F or -CF3, and it is preferred that both X and X2 are -F. R is hydrazine, a C1 to C15 alkyl group or a C2 to C15 alkenyl group. The alkyl group of ci to C15 is, for example, an unsubstituted C1 to C15 alkyl group or a C1 substituted by 5 201215666 i·/...v/v*w 34469twf.doc/n _0-, -CO- or -COO- C15's dazzle. The alkenyl group of C2 to C15 is, for example, an unsubstituted C2 to C15 alkenyl group or a C2 to C15 alkenyl group substituted with _〇_, <〇_ or -COO-. Αι and A! are each independently 1,4-phenylene, ι,4·cyclohexylene or 2,5-tetrahydrofuran. The 1,4-phenylene group is, for example, an unsubstituted anthracene, a 4-phenylene group or a 1,4-phenylene group which is a fluorene or a -C1 group. The 1,4_cyclohexylene group is, for example, an unsubstituted 1,4-cyclohexylene group or a 1,4-cyclohexylene group substituted with at least one _F or _匸丨. m and η are each independently an integer '1' and m+n$4. That is, the liquid crystal compound of the present invention has a structure of a tricyclic to pentacyclic ring. In the liquid crystal compound of the present invention, the melting point can be lowered by adjusting different substituents to achieve the purpose of lowering the lower limit temperature of the nemati C phase, and thus the liquid crystal incorporation having a low melting point can be adjusted. Eutectic mixture to meet the temperature range of the liquid crystal phase. Further, the liquid crystalline compound of the present invention also has the advantages of colorlessness, high heat stability and high compatibility. Furthermore, the liquid crystal compound of the present invention is mixed with other liquid crystal compounds or components to form a liquid crystal mixture. Since the liquid crystal mixture containing the liquid crystal compound has high optical anisotropy and a fast liquid crystal reaction speed, the liquid crystal mixture is applied. Used in co-plane switching (IPS) displays, MLC displays, twjsted nematic (TN) displays, (SUper_twisted nematic, STN) displays, especially for TN_thin film transistors ( Thin film transistor (TFT) display can effectively improve the display quality of the display. 201215666 uaiuujuI 34469twf.doc/n Test Example 1: Liquid crystal compound represented by formula (Μ)

Step 1 (Synthesis of Synthetic Compound lc) 350 g of 4-bromobiphenyl and 3 L of tetrahydrofuran were placed in a 5 L three-necked flask. Then, under nitrogen, the temperature was lowered to _78. Hey. Next, 625 ml of a n-butyllithium n-hexane solution (2 4 m〇1/L) was added dropwise. Then, the temperature was controlled to -78 ° C and stirred for 1 hour. Subsequently, 345 g of triisobutyl borate was added dropwise. Subsequently, the temperature was controlled to -783⁄4 and stirred for 1 hour. Then, the temperature was controlled at room temperature, and the reaction liquid was poured into a mixture of hydrochloric acid and ice to obtain 270 g of a white solid (yield: 91%).

1c Step 2 (Synthesis of Compound 2c) 100 g of compound lc, 169 g of 4-(4,-heptylcyclohexyl)bromobenzene, 2 L of f-benzene, 1 L of ethanol, 1 L of 4% hydroxide An aqueous solution of 6 g of Pd(PPh3)4 was placed in a 5 L three-necked flask. Then, it was refluxed for 6 hours under nitrogen. After the reaction was completed, the temperature was controlled to room temperature, and water of i l was added. After that, purification was carried out to obtain 154 g of a white solid (yield: 34469 twf.doc/n 201215666 L·/8 ιυυινι 75%, purity (measured by gas chromatograph) greater than 99%)

Β(〇Η)2 1c ~Pd(PPh3)4^

Step 3 (Synthesis of compound 3c) 154 g of compound 2C, 400 ml of glacial acetic acid, 35 g of angstrom, 26 g of acid-breaking acid, 90 ml of ethanol, 60 ml of water, 12 〇 (6) of ethyl acetate were added 2 L in the three-necked bottle. Then, under the continuous lion, slowly add 35 g of concentrated sulfuric acid to the flask. Then, heat and reflux for 12 hours. After the reaction was completed, the temperature was lowered to room temperature, and the three-necked flask was placed in a refrigerator for 4 hours. Thereafter, ethanol and a terpene mixed solvent were recrystallized to obtain 92 g of a white solid (yield of 46%, purity (measured by gas chromatograph) of more than 99%).

Step 4 (Synthesis of Compound 1-1) 1.2 g of difluoroalkenylphosphonium borate, 2.9 g of compound 3c, 40 ml of toluene, 20 ml of ethanol, 20 ml of water, 0.43 g of sodium hydroxide, 0.1 g of Pd(PPh3)4 was added to a 250 ml three-necked flask and returned to 201215666 ι^ΛΐυυιΟΙ 34469twf.doc/n for 6 hours under nitrogen. After the reaction was completed, the temperature was controlled to room temperature. Thereafter, 50 ml of water was added, and after purification, 2.1 g of a white solid was obtained (yield 67% purity (measured by gas chromatograph) of more than 99%, melting point of 228 ° C).

Experimental Example 2: Liquid crystal compound represented by formula (1-2)

The preparation method of the formula (1-2) is as follows: Step 1 (Synthesis of compound la), 229 g of 4-bromopropionic acid and 357 g of gasification were placed in a 2 L three-necked flask, and the mixture was heated under reflux for 3 hours. Then, remove the excess vaporized aluminum. Next, add 1.2 L of di-methane and cool to 5. Hey. Then, 32 〇〇 g of Αία ' was added and refluxed for 5 hours. Then, the obtained reactant was poured into a mixture of hydrazine and ice for hydrolysis, extraction, separation with a dream gel, and removal of the solvent to obtain 168.8 g of a pale yellow solid (yield: 8%, purity). (Measured by 201215666 i V\/ J. VX 34469twf.doc/n gas chromatograph) greater than 97%).

Aici3 C〇2H CH2C, 2 Step 2 (Synthesis of Compound 2a) Add 168.8 g of compound ia, 650 ml of ethanol to a 1 L three-necked flask. 'Control the temperature below 10 ° C and add 45 g in batches. NaBH4. Then the temperature was raised to room temperature and stirring was continued for 3 hours. After the reaction was completed, the ethanol was removed, and 450 ml of a 10% aqueous hydrochloric acid solution was added to carry out hydrolysis. Then, it was extracted with dioxane, washed with water, dried, and solvent removed to obtain 170 g of a pale yellow solid (yield: 1%, purity (measured by gas chromatograph) was greater than 97 %).

Step 3 (Synthesis of Compound 3a) 170 g of Compound 2a, 1.2 L of benzene, and 8 g of p-toluenesulfonic acid were placed in a 2-L three-necked flask and refluxed for 3 hours. After the reaction is completed, wash with water until neutral and remove stupid. Then, it was filtered with 750 ml of petroleum ether and Shiqi gum. Thereafter, petroleum ether was removed to obtain 148 g of a pale yellow oil (yield: 95%, purity (measured by gas chromatograph) was greater than 95%). 34469twf.doc/n

201215666 J w i v) 1 Step 4 (Synthesis of Compound 4a) 1.5 L of citric acid, 300 ml of 30% H 2 〇 2 was added to a 2 L of three necks, and the temperature was controlled to 35 with a water bath. 〇 to 4〇. Insufficient, compound 3a. Next, at room temperature, the reaction liquid was poured into a large water at room temperature, and a white solid was precipitated, followed by filtration. Alternatively, 3 L of a 7% aqueous solution of sulfuric acid was added to a three-necked flask, heated to boiling, and then the above white solid was added. Thereafter, it was distilled with steam to obtain 64 g of a white solid (yield: 4%, purity (measured by gas chromatography) was more than 95%).

Step 5 (Synthesis of Compound 5a) 64 g of Compound 4a, 90 mmol of ethylene glycol, 6 μM of toluene, and 3 g of p-toluenesulfonic acid were placed in a 1 L three-necked flask, and dehydrated under reflux for 3.5 hours. Then, the heating was stopped and washed with water until neutral. After the removal of toluene, the separation was carried out with 500 ml of petroleum ether and silicone, and petroleum ether was removed. Thereafter, crystallization was carried out with 150 ml of isopropyl alcohol to obtain 61 g of pale yellow 34469 twf.doc/n 201215666 λ κ a w λ w « , which is called a successor)

Step 6 (Synthesis of compound ib-1) 5.0 g of compound 5a, 6 〇g of propyl gas-based bis-phenyl acid, 8.3 g of sodium carbonate, sputum, 5 〇 ml of ethanol, 5 The water, foot, and catalyst Pd(PPh3)4 of 〇mi was added to a 5 〇〇ml three-necked flask and heated for 6 hours. Then, the temperature is lowered back to room temperature. Then, the water is used for stroke. Thereafter, the solvent was removed to give 7.2 g of a color solid (yield of 97% yield (measured by gas chromatograph) was greater than.

Step 7 (Synthesis of Compound 2b-1) 7.4 g of Compound lb-Bu 40 ml of a solution of chloroform and 5 〇 ml of 84% citric acid was placed in a 250 ml three-necked flask at 25 °C. Stir at a temperature of 〇 for 20 hours. After the reaction was completed, the reaction solution was taken up in a large amount of water and extracted with toluene. Then, the solvent was removed, and the phase stone was further subjected to 12 201215666 34469twf.d〇c/n crystallization to obtain 5.0 g of a pale yellow solid (yield 77%, purity (measured by gas chromatograph) was greater than 98%).

Step 8 (Synthesis of compound 3b-1) • A mixture of 23⁄4 chlorohydrin ether salt, 150 ml of tetrahydrofuran was added to a 5 (10) flask, and the temperature was lowered to 〇 ° C. Then, 6.6 g of potassium t-butoxide was added in portions, and the temperature was controlled to be less than 5 Torr during the addition. Next, the temperature was lowered to temperature and stirred for 1 hour. Then, the temperature was lowered to Ot, and a mixture of 5 g of the compound 2b-1 and 50 ml of tetrahydrofuran was added dropwise, and the temperature was controlled to 10 during the dropwise addition. 〇The following. Then, it was stirred at room temperature for 40 hours. Subsequently, 'saturated aqueous sodium carbonate solution was added, separation was carried out, extraction with ethyl acetate, solvent removal, separation with a ruthenium column to obtain 4.0 g of a purplish red solid (yield 74%, purity (in gas phase layer) The analyzer (measurement) is greater than 40%).

3b-1 Step 9 (Synthesis of Compound 4b-1) 4.0 g of Compound 3b-1, 50 ml of tetrahydrofuran, 5% of a 10% aqueous solution of dilute hydrochloric acid are added to a 250 ml three-necked flask, and in the chamber: θ Under 201215666 uj\ iukjivl 34469twf.doc/n Stir for 12 hours. Then, the separation was carried out with acetic acid, rubbing, and washing to neutrality. After that, the solvent was removed to obtain a mixture of seven and nine. 40%)

Color solid (yield 100%, purity (3.8 g of fumed red 1ηο/Λ in gas phase laminates • measured) greater than step 10 (synthesis of compound 1-2) 3.8 g of compound 4b_b 50 ml DMF, 19.2 g of triphenylphosphine was added to a 250 ml three-necked flask. Then, under nitrogen, add = to 60 C ' and add a mixture of 11.5 g of difluorochloroacetic acid steel and 5 μm of dmf. The reaction was controlled at 90 ° C for 6 hours, and then the reaction solution was poured into a large amount of water, extracted with benzene, the solvent was removed, and separated by a ruthenium column, and then recrystallized from ethanol. To obtain 白色.2g of a white solid (yield of 4.7%, purity (measured by gas chromatograph) greater than 99%, melting point of 80 ° C, core of 0.1736, r 1 of 95, phase transition temperature of C78S128N155I, measuring 5% of the heat loss of the material by thermogravimetric analysis is 250. 〇.

14 34469twf.doc/n 201215666 Experimental Example 3: Liquid crystal compound represented by formula (1-3)

The preparation method of the formula (1-3) is as follows: Step 1 (Synthesis of compound la)

229 g of 4-indolyl acid and 357 g of chlorinated chlorin were added to a 2 l three-necked flask and refluxed for 3 cuts. Then, remove the excess gasification. Next, add L2L's two-gas methane and cool to the well. Then, 32 〇〇 g of A1C was added and refluxed for 5 hours. Then, the obtained _ reactant was poured into hydrochloric acid and ice ship, and the solvent was transferred, extracted, and separated, and the solvent was removed to obtain a pale yellow solid with a deletion rate (yield as secret, purity (by gas chromatography). Instrumentation test is greater than 97%).

Step 2 (Synthesis of Compound 2a) I68.8 g of Compound 1a and 650 ml of ethanol were placed in a 1 L three-necked flask, the temperature was controlled below 10 ° C, and 45 g of NaBHU was added in portions. Then, the temperature was raised to room temperature and stirring was continued for 3 hours. After the reaction was completed, ethanol was removed, and hydrolysis was carried out by adding 45 ml of a 1% aqueous solution of hydrochloric acid. Then, extracted with dioxane, washed with water, dried, • s4469twf.doc/n 201215666

The private desquamate agent was used to obtain a pale yellow solid of l7G g (yield as a percent (measured by gas chromatograph) greater than 97%).

170 g of compound 2a, 1.2 L of benzene, and 8 g of p-benzoic acid were placed in a 2 L three-necked flask and refluxed for 3 hours. After the reaction is completed, take water to neutral and remove stupid. Then, take 75. After the m-ether;s ether ether and Shixi gum were treated, the oil was removed to obtain a pale yellow oil of 丨48 g (yield 95%, purity (measured by gas chromatography) Test) greater than step 3 (synthesis of compound 3a)

Step 4 (Synthesis of Compound 4a) 1.5 L of formic acid, 300 ml of 30% h202 were placed in a 2 L three-necked flask, and the temperature was controlled to 353⁄4 to 4 Torr in a water bath. Then, 148 g of the compound 3a was added. Then, it was stirred at room temperature for 12 hours. Then, the reaction liquid was poured into a large amount of water, and a white solid was precipitated, followed by filtration. Then, 3 L of 7 was added. The aqueous solution of sulfuric acid was added to a 5 L three-necked flask, heated to boiling, and then the above white solid was added. Thereafter, steaming at 34,469 twf.doc/n 201215666 AW 1 0 1 was distilled with steam to obtain 64 g of a white solid. (Yield 40%, purity (measured by gas chromatograph) greater than 95%).

Hco2h , h2o2 ~~h2so4~~1

Step 5 (Synthesis of Compound 5a) 64 g of Compound 4a, 90 ml of ethylene glycol, 600 ml of toluene, and 3 g of p-benzoic acid were placed in a 1 L three-necked flask, and dehydrated by heating under reflux for 3.5 hours. Then, the heating was stopped and washed with water until neutral. After the removal of toluene, the separation was carried out with 500 ml of petroleum ether and silicone, and petroleum ether was removed. Thereafter, crystallization was carried out with 150 ml of isopropyl alcohol to obtain 61 g of a pale yellow solid (yield: 80%, purity (measured by gas chromatograph) of more than 99%).

Step 6 (Synthesis of Compound 6a) 8 g of granules, 200 ml of tetrahydrofuran, and trace moths were placed in a 2 L three-necked flask. Then, 5 g of ethyl bromide was added under nitrogen. After the start of the reaction, a mixture of 61.2 g of the compound 5a and 300 ml of tetrahydrothymolfon 17 34469tw£d〇c/n 201215666 was added dropwise. Then, the mixture was stirred at room temperature for 2 hours, and a mixture of 146.5 g of propylcyclohexylcyclohexanone and 200 ml of tetrahydrofuran was further added. Subsequently, the mixture was stirred at room temperature for 12 hours, and the reaction solution was poured into a mixture of hydrochloric acid and ice to carry out a hydrolysis reaction. Then, extraction was carried out with toluene, and the solution was added to a 3 L three-necked flask, and then 15 g of p-toluenesulfonic acid, 5 〇 ml of ethylene glycol was added, and dehydration was carried out for 5 hours under reflux. Subsequently, it was washed with water until neutral, and recrystallized with isopropyl alcohol to obtain 68.8 g of a brownish yellow solid (yield of 75' purity (measured by gas chromatograph) was more than 98%).

6a Step 7 (Synthesis of Compound 7a) 68.8 g of Compound 6a, 50 μml of toluene, freshly ethanol, and 20 g were added to 2 L of hydrogenated dad, and hydrogen was introduced under a nitrogen pressure of 1 Mpa. 12 hours. Then, the catalyst was removed, the solvent was removed, and recrystallization was carried out with toluene and isopropyl alcohol at a rate of _24 g _ & 35%, and purity (measured by gas chromatography) of more than 99%).

34469twf.doc/n 201215666 d KA w « 01 Step 8 (Synthesis of Compound 8a) ^ f 7a'120 ml όίϊ δ4〇/ο^ψ '100 mi ; After that, pour the reaction solution into a large amount of water and use it as a stupid ==,. Time purity (measured by the desorber ==_ for driving,

Step 9 (Synthesis of compounds

A 25 8 gas oxime ether phosphate salt and 150 ml of tetrahydrofuran were added to a 5 〇〇 ml three-necked rib. Then, the temperature is lowered below 〇 ° C. Next, 6.6 g of potassium t-butoxide was added in portions (the temperature was kept below 5 during the addition. Then, the temperature was raised to room temperature and stirring was continued for one hour. Then, the temperature was below 〇 ° C. And slowly add a mixture of 5 g of compound 8a and 50 ml of tetrahydrofuran (the temperature is kept less than 10 加入 during the addition. Then, the mixture is continuously stirred for 4 hours at to / alone. After that, a saturated aqueous solution of sodium carbonate is added, And extraction with ethyl acetate. Then, the solvent was removed and purified with petroleum ether and Shiqi gum to obtain 4.5 g of a purple-red solid (yield 80% 'purity (measured by gas chromatography) ) is greater than 60%).

CHOCH 8a 9a 201215666 i4469twf.doc/n Step 10 (Synthesis of Compound 10a): 5 g of a compound 4, 9a, 5 ml of tetrahydrofuran, an aqueous solution of hydrochloric acid was added, and ml was added to the mixture for 5 hours. Then, hydrazine was carried out with ethyl acetate. After stirring 12, the solvent was removed to give 4τΓ = brain, purity (measured by gas chromatograph) greater than 60%). (yield is

CHO 10a Step 11 (Synthesis of Compound 1-3) 4.3 g of compound 1〇a, 5 〇 work 1 DMF, and 19.2 g of a three-pronged 25-neck flask were placed. Then, it was stored under nitrogen, and the private hot money was followed by slowly dropping A11.5 g of a mixture of dioxin sodium acetate and 5_DMF. Thereafter, the reaction was carried out for 6 hours by heating to 9 &>c. =, the reaction solution was poured into a large amount of water and extracted with toluene. Subsequent 'removal of solvent' and purification with stone _ with crushed gum, followed by recrystallization with ethanol to give a white solid of MG (yield (4) 297%, purity (measured by emulsion chromatography) greater than 99%, The refining point is [Hungry, Δη is 〇.10 Bu 7 1 is 128, phase transition temperature (CNI) is C140N148I, and the temperature at which the material is subjected to heat loss by thermogravimetric analysis (TGA) is 21 〇t>c).

10a : yCKXf l-3 20 201215666^ 34469twf.doc/n Experimental Example 4: Liquid crystal compound represented by formula (1-4)

The preparation method is as follows: Step 1 (Synthesis of Compound lb) 5.0 g of Compound 5a, 5.3 g of propylcyclohexylbenzeneboronic acid, 8.3 g of sodium carbonate, 100 ml of hydrazine, 5 〇ml of ethanol, 50 ml of water A sufficient amount of catalyst Pd(PPh3)4 was added to a 5 〇〇 ml three-necked flask and heated to reflux for 6 hours. Then, the temperature is lowered back to room temperature. Next, extraction is carried out with water. Thereafter, the solvent was removed to give 7.4 g of a gray solid (yield: 100%, purity (measured by gas chromatograph) was greater than 98%).

Step 2 (Synthesis of Compound 2b) 7.4 g of compound lb, 40 ml of toluene, and 50 ml of 84% citric acid solution were placed in a 250 ml three-necked flask at 25. Stir at a temperature of 〇 for 20 hours. After the reaction was completed, the reaction solution was poured into a large amount of water, and extracted with a stupid. Then, the solvent was removed and recrystallized with petroleum ether to give 5.0 g of a pale yellow solid (yield: 77%, purity (measured by gas chromatograph) was greater than 98%). 21 201215666 .........34469twf.doc/n

2b Step 3 (Synthesis of Compound 3b) Tetrahydrofuran is added to 500 ml

Place 25 g of chloroformate, 15 〇 ml - wa % in a three-necked flask and reduce the temperature. Then, add t-butanol in batches to unload the person's wealth and control the temperature to 5. (: The following. The temperature of the brain & temperature drops to room temperature, and _ i hours. Then, the temperature is lowered to 叱, and the addition of 5 g of compound 2b and 5 〇 (6) of tetrahydrofuran quotient is controlled below the thief. At room temperature, U, Ϊ,. With ί, add saturated sodium sulphate aqueous solution, separate, extract with acetonitrile, remove solvent, separate with the town tube column, 74% purity, kiss layer Analyzer ^

CH〇ch, 2b 3b Step 4 (Synthesis of compound 々b) 4.0 g of the compound %, 5 〇 (6) of the tetrazoride, and the % (nine) aqueous solution were placed in a 25 〇 ml three-necked flask and allowed to stand at room temperature for 12 hours. After the iron, the mixture is mixed..., stupid and separated, extracted with ethyl acetate. Then, 22 201215666 Washed to neutral. Thereafter, the solvent was removed to obtain 3 8 g of a purplish red solid (yield 100%, purity (measured by gas chromatograph) of more than 4%).

Step 5 (Synthesis of Compound 1-4) Φ 3.8 g of Compound 4b, 50 ml of DMF, and 19.2 g of diphenylphosphorus were placed in a 250 ml three-necked flask. Then, it was heated to 6 ° C under nitrogen and a mixed solution of 11.5 g of sodium difluorochloroacetate and 5 ml of DMF was added. Then, the temperature was controlled at 9 ° C for 6 hours. Then, the reaction liquid was poured into a large amount of water, and extracted with benzene, the solvent was removed, and the separation was carried out with a column. Thereafter, it was recrystallized from ethanol to obtain 0.2 g of a white solid (yield: 4.7%, purity (measured by gas chromatograph) of more than 99%, melting point of 8 〇ΐ, Δη of 0.1736, r 1 is 95, the transfer temperature of the two φ is C78S128N1J5I, and the temperature at which the material is subjected to heat loss by heat stress analysis is 5%.

Comparative Example 1: The liquid crystal compound represented by the formula (II) (purity (measured by a gas chromatograph) was more than 99%, and the melting point was 68. 〇 23 34469twf.doc/n

201215666 i vv/i \j ι The liquid crystal compounds in Experimental Examples 1, 2 and Comparative Example 1 were subjected to phase transfer temperature (CNI), birefringence (Δη), viscosity (γΐ), and thermogravimetric analysis (TGA). The results are shown in Table 1.

Table 1 Experimental Example 1 Experimental Example 2 Comparative Example 1 C-N-I C228X280I C88N117I C68N117I Δη 0.33 0.222 0.1926 r ι 495 172 344 TGA — 258 248

= < As shown in Table 1, since the liquid crystal compounds of Experimental Examples 1 and 2 have a \ substituent (-CHCF2), that is, a bisfluoro-terminated functional group, and thus a comparative example having only a linear substituent (-CH2CH2CH3) Compared to 1, it has a higher Δη. In addition, since the number of the cyclic structures (five 24 201215666, ring) in the liquid crystal compound of Experimental Example 1 is larger than the number of ring structures (tricyclic rings) in the liquid crystal compound of Comparative Example 1, the liquid crystal compound of Experimental Example 1 Δη is more significantly higher than Δη of the liquid crystal compound of Comparative Example 1. Further, by comparing Experimental Example 2 having the same main chain structure with Comparative Example 1, it is apparent that Experimental Example 2 having a bisfluoro-terminated functional group has a lower 71 and better thermal stability. For the liquid crystal compound of Experimental Example 1, the liquid crystal compound having a pentacyclic structure generally has a relatively high r 1 ' However, since the liquid crystal compound of Experimental Example 1 has a bisfluoro-terminated functional group', the r 1 can be lowered to 495. The present invention has been disclosed in the above embodiments, but it is not intended to limit the invention to those skilled in the art, and it is possible to make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims. [Simple description of the diagram] φ None. [Main component symbol description] None. 25

Claims (1)

201215666 34469twf.doc/n VII. Application for patents: 1. A liquid crystal compound, represented by formula (1), Wherein Χι and X2 are each independently -F or -CF3; R is hydrazine, a C1 to C15 alkyl group or a C2 to C15 alkenyl group; and 1 and Α2 are each independently 1,4_phenylene, 1,4·cyclohexylene or 2,5-extended tetrahydropyranyl; m and η are each independently an integer from 1 to 3, and m+nSA. 2. The liquid crystal compound according to claim 1, wherein Χι and X2 are both -F»3. The liquid crystal compound according to claim 1, wherein the C1 to C15 alkyl group includes Substituted ci to C15 alkyl or C- to C15 alkyl substituted with -0, -CO- or -COO-. 4. The liquid crystalline compound according to claim 1, wherein the C2 to C15 alkenyl group comprises an unsubstituted C2 to C15 alkenyl group or an O-, -CO- or -COO-substituted C2. Alkenyl to C15. 5. The liquid crystal compound according to claim 1, wherein the 1,4-phenylene group comprises an unsubstituted i,4-phenylene group or a 1,4-substituted by at least one _F or -C1. The liquid crystal compound according to claim 1, wherein the 1,4-cyclohexylene group comprises an unsubstituted ι,4-cyclohexylene group or substituted by at least one -F or -C1 1,4-cyclohexylene. 7. A liquid crystal mixture comprising at least the liquid crystal compound as described in claim 1 of the patent application. 26 201215666 34469twf.doc/n 201215666 34469twf.doc/n Formula (I) where Xi and X2 are independently -F or -CF3 ; R is H, a C1-Cl5 alkyl group or a C2-C15 alkenyl group ; Ai and A2 are independently 1,4-phenylen, 1,4-cyclohexylene Or 2,5-tetrahydropyranylene ; m and n are independently 1, 2 or 3, and m+n^4. IV. Designated representative circle: (1) The representative representative of the case: None (2) The symbol of the representative figure is simple Description: None. 5. If there is a chemical formula in this case, please disclose the chemical formula that best shows the characteristics of the invention: Formula (1)