A method for synthesizing liquid crystal compounds

Abstract

This invention provides a method for synthesizing liquid crystal compounds. This method uses dihaloalkanes and difluoromethane with leaving groups as raw materials to synthesize liquid crystal compounds while ensuring high yield and significantly reducing production costs.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and relates to a method for synthesizing liquid crystal compounds. Background Technology

[0002] Compared to traditional display devices and materials, liquid crystal display (LCD) materials have significant advantages: low driving voltage, minimal power consumption, high reliability, large display information capacity, color display, flicker-free operation, no harm to the human body, automated production process, low cost, and the ability to be manufactured into various specifications and types of LCD displays, making them portable. Due to these advantages, LCD technology has profoundly impacted the field of display imaging, promoting the development of microelectronics and optoelectronic information technology. Liquid crystal materials, with their excellent optical properties and photoelectric effects, have found widespread application in numerous display scenarios.

[0003] Liquid crystals are primarily used as dielectrics in display devices because their optical properties can be altered by applying voltage. Liquid crystal materials must possess good chemical and thermal stability, as well as good stability to electric fields and electromagnetic radiation. Furthermore, industrially usable liquid crystal phases require a mesocrystalline phase within a suitable temperature range and low viscosity.

[0004] Since liquid crystals are typically used as mixtures of multiple components, it is important that these components are easily miscible with each other. Other properties, such as response speed, dielectric anisotropy, and optical anisotropy, must meet various requirements depending on the type of liquid crystal cell and the application.

[0005] Liquid crystal compounds As a commonly used component in liquid crystal compositions, its function is to enhance the high absolute value of the negative dielectric anisotropy of the liquid crystal compound, improve the reliability of the liquid crystal composition, and reduce the viscosity of the liquid crystal composition. However, existing synthesis methods mainly rely on high-cost... Using it as a raw material significantly increases the production cost of liquid crystal assemblies, thus limiting their application. Summary of the Invention

[0006] To address the technical problems existing in the prior art, the present invention provides a method for synthesizing liquid crystal compounds, which can reduce the yield of liquid crystal compounds. It has low production costs, a simple synthesis process, and a high yield, making it suitable for industrial production.

[0007] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0008] This invention provides a method for synthesizing liquid crystal compounds, the method of which is shown in the following reaction equations:

[0009]

[0010] Wherein, X is a halogen atom, Y is any leaving group that satisfies its chemical environment, Z is O or S, and R is any one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted cycloalkyl.

[0011] As a preferred technical solution of the present invention, X is any one or a combination of at least two of F, Cl, Br or I.

[0012] And / or, Y includes

[0013] In a preferred embodiment of the present invention, R is a C1-12 alkyl group, a C1-12 alkoxy group, or a cycloalkyl group with 3-4 carbon atoms. Any one of them;

[0014] Where X1 and X2 independently represent any one of methylene, methyleneoxy, ethylene, or alkenyl groups, and ring A1 represents... Any one of them, ring A2 represents Any one of the following, where n is an integer from 1 to 6.

[0015] As a preferred embodiment of the present invention, at least one of the -CH- or -CH2- alkyl, alkoxy, or cycloalkyl groups in R is replaced by -N- or -O-.

[0016] And / or, in the R At least one of the -CH2- in it is replaced by -O-.

[0017] And / or, in the R At least one -H in the formula is replaced by -F, -Cl, -CN, -CH3 or -OCH3.

[0018] And / or, in the R At least one of -CH= in the equation is replaced by -N=.

[0019] As a preferred technical solution of the present invention, the reaction for synthesizing compound C includes: mixing compound A, compound B, a base and an organic solvent, and reacting under a protective atmosphere to obtain compound C.

[0020] As a preferred technical solution of the present invention, the temperature for the reaction of synthesizing compound C is -75 to 0°C, and the time is 1 to 10 hours.

[0021] And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, and dioxane.

[0022] And / or, the base includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, lithium hexamethyldisilamide, or potassium hexamethyldisilamide.

[0023] As a preferred technical solution of the present invention, the reaction for synthesizing compound E includes: mixing compound C, compound D, base, catalyst and organic solvent, and reacting to obtain compound E.

[0024] As a preferred technical solution of the present invention, the reaction temperature for synthesizing compound E is 50-120°C and the time is 0.5-4h.

[0025] And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, acetonitrile, or tetrahydrofuran.

[0026] And / or, the base includes any one or a combination of at least two of sodium carbonate, potassium carbonate, potassium hydroxide, sodium hydroxide, potassium tert-butoxide, or sodium tert-butoxide.

[0027] And / or, the catalyst includes potassium iodide.

[0028] As a preferred technical solution of the present invention, the reaction for synthesizing compound F includes: mixing compound E, a base and an organic solvent, and reacting under a protective atmosphere to obtain compound F.

[0029] As a preferred technical solution of the present invention, the temperature for synthesizing compound F is -75 to 20°C, and the time is 2 to 12 hours.

[0030] And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, or dioxane.

[0031] And / or, the base includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, lithium hexamethyldisilamide, or potassium hexamethyldisilamide.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] This invention provides a method for synthesizing liquid crystal compounds, which can reduce the yield of liquid crystal compounds. It has low production costs, a simple synthesis process, and a high yield, making it suitable for industrial production. Detailed Implementation

[0034] The technical solution of this application will be further described below through specific implementation methods.

[0035] This invention provides a method for synthesizing a liquid crystal compound, as shown in the following reaction equations:

[0036]

[0037] Wherein, X is a halogen atom, Y is any leaving group that satisfies its chemical environment, Z is O or S, and R is any one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted cycloalkyl.

[0038] In this invention, dihaloalkanes and difluoromethane with leaving groups are used as raw materials to synthesize... No need to use expensive At the same time, it ensured high productivity and significantly reduced production costs.

[0039] In one specific embodiment of the present invention, X is any one or a combination of at least two of F, Cl, Br or I, preferably Br.

[0040] In one specific embodiment of the present invention, Y includes

[0041] In one specific embodiment of the present invention, R is a C1-12 alkyl group, a C1-12 alkoxy group, a cycloalkyl group with 3-4 carbon atoms, or a C1-12 alkyl group. Any one of them;

[0042] Where X1 and X2 independently represent any one of methylene, methyleneoxy, ethylene, or alkenyl groups, and ring A1 represents... Any one of them, ring A2 represents Any one of the following, where n is an integer from 1 to 6. n can be 1, 2, 3, 4, 5, or 6.

[0043] In one specific embodiment of the present invention, R can be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl, and n-dodecyl, etc.

[0044] In one specific embodiment of the present invention, R can be methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, n-pentoxy, n-hexoxy, and n-dodecyloxy, etc.

[0045] In one specific embodiment of the present invention, R may be at least one -CH- or -CH2- group substituted with -N- or -O-, which is an alkyl, alkoxy, or cycloalkyl group.

[0046] In one specific embodiment of the present invention, R can be at least one of the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl, and n-dodecyl, in which at least one -CH- or -CH2- group is substituted with -N- or -O-.

[0047] In one specific embodiment of the present invention, R can be at least one of the following groups: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentooxy, hexoxy, and dodecyloxy, in which at least one -CH- or -CH2- group is substituted with -N- or -O-.

[0048] In one specific embodiment of the present invention, R can be cyclopropyl or cyclobutyl.

[0049] In one specific embodiment of the present invention, R can be At least one -CH2- group in the substance is replaced by -O-.

[0050] In one specific embodiment of the present invention, R can be A group in which at least one -H is replaced by -F, -Cl, -CN, -CH3 or -OCH3.

[0051] In one specific embodiment of the present invention, R can be At least one -CH= group in the group is replaced by -N=.

[0052] In one specific embodiment of the present invention, the reaction for synthesizing compound C includes: mixing compound A, compound B, a base and an organic solvent, and reacting under a protective atmosphere to obtain compound C.

[0053] In one specific embodiment of the present invention, compound A and compound B can be added according to the stoichiometric ratio of the chemical reaction equation, or adjusted according to the stoichiometric ratio based on the reaction situation, without specific limitations.

[0054] In one specific embodiment of the present invention, in the reaction for synthesizing compound C, the amount of alkali added can be adjusted according to the reaction conditions while maintaining the alkaline environment of the reaction, and no specific limitation is made here.

[0055] In one specific embodiment of the present invention, in the reaction for synthesizing compound C, the amount of solvent added can be adjusted according to the reaction situation when dissolving compounds A and B, and is not specifically limited here.

[0056] In one specific embodiment of the present invention, the reaction temperature for synthesizing compound C is -75 to 0°C, preferably -50 to -40°C, and the reaction time is 1 to 10 hours, preferably 3 to 5 hours. The temperature can be -75°C, -70°C, -65°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, or 0°C, etc., and the time can be 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, or 10 hours, etc., but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0057] In one specific embodiment of the present invention, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, and dioxane, preferably N,N-dimethylformamide.

[0058] In one specific embodiment of the present invention, the alkali includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, hexamethyldisilamide lithium, or hexamethyldisilamide potassium, preferably potassium tert-butoxide and / or sodium tert-butoxide.

[0059] In one specific embodiment of the present invention, after the reaction for synthesizing compound C is completed, the product is purified by means of water washing, liquid-liquid separation, evaporation and column separation to obtain pure compound C product.

[0060] In one specific embodiment of the present invention, the reaction for synthesizing compound E includes: mixing compound C, compound D, a base, a catalyst, and an organic solvent, and reacting to obtain compound E.

[0061] In one specific embodiment of the present invention, compounds C and D can be added according to the stoichiometric ratio of the chemical reaction equation, or adjusted according to the stoichiometric ratio based on the reaction conditions, without specific limitations.

[0062] In one specific embodiment of the present invention, in the reaction for synthesizing compound E, the amount of alkali added can be adjusted according to the reaction conditions while maintaining the alkaline environment of the reaction, and no specific limitation is made here.

[0063] In one specific embodiment of the present invention, in the reaction for synthesizing compound E, the amount of solvent added can be adjusted according to the reaction situation when dissolving compounds C and D, and is not specifically limited here.

[0064] In one specific embodiment of the present invention, in the reaction for synthesizing compound E, the amount of catalyst added can be adjusted according to the reaction conditions to effectively increase the reaction rate of the reaction for synthesizing compound E, and no specific limitation is made here.

[0065] In one specific embodiment of the present invention, the reaction temperature for synthesizing compound E is 50–120°C, preferably 60–80°C, and the reaction time is 0.5–4 h, preferably 1–2 h. The reaction temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, or 120°C, etc., and the reaction time can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, or 4 h, etc., but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0066] In one specific embodiment of the present invention, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, acetonitrile, or tetrahydrofuran, preferably acetonitrile.

[0067] In one specific embodiment of the present invention, the alkali includes any one or a combination of at least two of sodium carbonate, potassium carbonate, potassium hydroxide, sodium hydroxide, potassium tert-butoxide, or sodium tert-butoxide, preferably sodium carbonate and / or potassium carbonate.

[0068] In one specific embodiment of the present invention, the catalyst comprises potassium iodide.

[0069] In one specific embodiment of the present invention, after the reaction of synthesizing compound E is completed, the product is purified by means of extraction, water washing, liquid separation, evaporation and column separation to obtain pure compound E product.

[0070] In one specific embodiment of the present invention, the reaction for synthesizing compound F includes: mixing compound E, a base and an organic solvent, and reacting under a protective atmosphere to obtain compound F.

[0071] In one specific embodiment of the present invention, in the reaction for synthesizing compound F, the amount of alkali added can be adjusted according to the reaction conditions while maintaining the alkaline environment of the reaction, and no specific limitation is made here.

[0072] In one specific embodiment of the present invention, in the reaction for synthesizing compound F, the amount of solvent added can be adjusted according to the reaction situation when dissolving compound E, and is not specifically limited here.

[0073] In one specific embodiment of the present invention, the reaction temperature for synthesizing compound F is -75 to 20°C, preferably 0 to 20°C, and the reaction time is 2 to 12 hours, preferably 5 to 10 hours. The temperature can be -75°C, -70°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, 0°C, 5°C, 10°C, 15°C, or 20°C, etc., and the time can be 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours, etc., but is not limited to the listed values; other unlisted values ​​within the above ranges are also applicable.

[0074] In one specific embodiment of the present invention, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, or dioxane, preferably N,N-dimethylformamide.

[0075] In one specific embodiment of the present invention, the alkali includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, lithium hexamethyldisilamide, or potassium hexamethyldisilamide, preferably lithium hexamethyldisilamide and / or potassium hexamethyldisilamide.

[0076] In one specific embodiment of the present invention, after the reaction of synthesizing compound F is completed, the product is purified by means of antisolvent precipitation, water washing, drying, column separation and recrystallization to obtain pure compound F product.

[0077] In one specific embodiment of the present invention, the protective atmosphere includes nitrogen, helium, or argon, preferably nitrogen. Specifically, before adding the reaction raw materials, nitrogen is introduced into the reaction apparatus to replace the air therein.

[0078] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0079] Example 1

[0080] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound C are shown below:

[0081]

[0082] The reaction procedure is as follows: In a three-necked flask, 39.1 g (208.1 mmol) of compound A-1 (1,2-dibromoethane), 10 g (52.0 mmol) of compound B-1 (difluoromethylphenyl sulfone), and 150 ml of DMF were added. Under nitrogen atmosphere, the mixture was cooled to -50 °C, and 11.68 g (104.07 mmol) of potassium tert-butoxide was added in three batches, maintaining the temperature at -50 °C for 4 hours. After the reaction was completed, water was slowly added to quench the reaction. EA was added and the mixture was washed with water until neutral. The organic phase was evaporated to dryness, dissolved in n-heptane, and passed through a column. The solvent was evaporated to dryness to obtain 13 g of a yellow oily liquid.

[0083] The mass spectrometry data for compound C-1 are: 51 (40%), 77 (100%), 141 (50%), 192 (15%), 219 (45%), 297 (15%), and 299 (15%).

[0084] Example 2

[0085] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound C are shown below:

[0086]

[0087] The reaction procedure is as follows: In a three-necked flask, 45 g (208.1 mmol) of compound A-1 (1,2-dibromobutane), 10 g (52.0 mmol) of compound B-1 (difluoromethylphenyl sulfone), and 150 ml of DMF were added. Under nitrogen atmosphere, the mixture was cooled to -50 °C, and 11.68 g (104.07 mmol) of potassium tert-butoxide was added in three batches, maintaining the temperature at -50 °C for 4 hours. After the reaction was completed, water was slowly added to quench the reaction. EA was added and the mixture was washed with water until neutral. The organic phase was evaporated to dryness, dissolved in n-heptane, and passed through a column. The solvent was evaporated to dryness to obtain 15 g of a yellow oily liquid.

[0088] The mass spectrometry data of compound C-2 are: 51 (40%), 77 (100%), 141 (50%), 192 (15%), 205 (18%), 219 (26%), 233 (30%), 247 (36%), 325 (15%), and 327 (15%).

[0089] Example 3

[0090] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound C are shown below:

[0091]

[0092] The reaction procedure is as follows: In a three-necked flask, 53.7 g (208.1 mmol) of compound A-1 (1,2-dibromoheptane), 10 g (52.0 mmol) of compound B-1 (difluoromethylphenyl sulfone), and 150 ml of DMF were added. Under nitrogen atmosphere, the mixture was cooled to -50 °C, and 11.68 g (104.07 mmol) of potassium tert-butoxide was added in three batches, maintaining the temperature at -50 °C for 4 hours. After the reaction was completed, water was slowly added to quench the reaction. EA was added and the mixture was washed with water until neutral. The organic phase was evaporated to dryness, dissolved in n-heptane, and passed through a column. The solvent was evaporated to dryness to obtain 16 g of a yellow oily liquid.

[0093] The mass spectrometry data of compound C-3 are: 51 (40%), 77 (100%), 141 (50%), 192 (15%), 205 (18%), 219 (26%), 233 (30%), 247 (36%), 261 (20%), 368 (15%), and 370 (15%).

[0094] Example 4

[0095] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound E are shown below:

[0096]

[0097] The reaction procedure was as follows: 5 g (17.8 mmol) of compound D, 5.87 g (19.62 mmol) of compound C-1, 4.93 g (35.68 mmol) of potassium carbonate, 0.3 g (1.78 mmol) of potassium iodide, and 50 mL of acetonitrile were added to a 150 mL three-necked flask and reacted at 85 °C for 2 hours. After the reaction was completed, water was added to quench the reaction, followed by extraction with EA. The organic phase was washed with water until neutral, evaporated to dryness, passed through a DCM column, and evaporated to dryness to obtain 9 g of a yellow solid. 18 mL of ethanol was added and the mixture was stirred. After filtration, 8 g of a pale yellow compound E-1 was obtained.

[0098] The mass spectrometry data of compound E-1 are: 77 (12%), 91 (65%), 125 (100%), 143 (29%), 233 (78%), 252 (63%), 280 (15%), 357 (42%), and 498 (46%).

[0099] Example 5

[0100] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound E are shown below:

[0101]

[0102] The procedure was as follows: 5 g (17.8 mmol) of compound D, 6.42 g (19.62 mmol) of compound C-2, 4.93 g (35.68 mmol) of potassium carbonate, 0.3 g (1.78 mmol) of potassium iodide, and 50 mL of acetonitrile were added to a 150 mL three-necked flask and reacted at 85 °C for 2 hours. After the reaction was complete, water was added to quench the reaction, followed by extraction with EA. The organic phase was washed with water until neutral, evaporated to dryness, passed through a DCM column, and evaporated to dryness again to obtain 11 g of a yellow solid. 18 mL of ethanol was added and the mixture was stirred until a slurry was formed. After filtration, 8 g of a pale yellow compound E-2 was obtained.

[0103] The mass spectrometry data of compound E-2 are: 77 (12%), 91 (65%), 125 (100%), 143 (29%), 233 (78%), 252 (63%), 280 (15%), 293 (40%), 307 (36%), 385 (39%), and 526 (48%).

[0104] Example 6

[0105] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound E are shown below:

[0106]

[0107] The reaction procedure was as follows: 5 g (17.8 mmol) of compound D, 7.25 g (19.62 mmol) of compound C-3, 4.93 g (35.68 mmol) of potassium carbonate, 0.3 g (1.78 mmol) of potassium iodide, and 50 mL of acetonitrile were added to a 150 mL three-necked flask and reacted at 85 °C for 2 hours. After the reaction was completed, water was added to quench the reaction, followed by extraction with EA. The organic phase was washed with water until neutral, evaporated to dryness, passed through a DCM column, and evaporated to dryness to obtain 12 g of yellow solid. 18 mL of ethanol was added and the mixture was stirred. After filtration, 8.5 g of pale yellow compound E-3 was obtained.

[0108] The mass spectrometry data of compound E-3 are as follows: 77 (12%), 91 (65%), 125 (100%), 143 (29%), 233 (78%), 252 (63%), 280 (15%), 293 (40%), 307 (36%), 335 (30%), 349 (36%), 363 (40%), 377 (36%), 427 (23%), and 568 (50%).

[0109] Example 7

[0110] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound F are shown below:

[0111]

[0112] The reaction procedure is as follows: In a three-necked flask, 5 g (10.03 mmol) of E-1 and 50 mL of DMF were added. Under nitrogen atmosphere, the mixture was cooled to 0 °C, and 15 mL of commercially available LiHMDS solution (1 mol / L) was added dropwise. After the addition was complete, the mixture was allowed to warm to room temperature overnight. The reaction solution was poured into water, and a large amount of solid precipitated. The solid was filtered, and the filter cake was washed with water until neutral and then dried. The product was passed through a column chromatography line with n-heptane, the solvent was evaporated, and the product was recrystallized three times with three times the volume of ethanol to obtain 2.5 g of white solid with a GC purity of 99.9%.

[0113] The mass spectrometry data of compound F-1 are: 77 (45%), 131 (10%), 175 (15%), 223 (30%), 252 (100%), 280 (25%), 327 (5%), and 356 (50%).

[0114] Example 8

[0115] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound F are shown below:

[0116]

[0117] The reaction procedure is as follows: In a three-necked flask, 5 g (9.5 mmol) of E-2 and 50 mL of DMF were added. Under nitrogen atmosphere, the mixture was cooled to 0 °C, and 14.2 mL of commercially available LiHMDS solution (1 mol / L) was added dropwise. After the addition was complete, the mixture was allowed to warm naturally to room temperature overnight. The reaction solution was poured into water, and a large amount of solid precipitated. The solid was filtered, and the filter cake was washed with water until neutral and then dried. The product was passed through a column chromatography line with n-heptane, the solvent was evaporated, and the product was recrystallized three times with three times the volume of ethanol to obtain 2.3 g of white solid with a GC purity of 99.9%.

[0118] The mass spectrometry data of compound F-1 are: 77 (45%), 131 (10%), 175 (15%), 223 (30%), 252 (100%), 280 (25%), 327 (5%), 355 (5%), and 384 (50%).

[0119] Example 9

[0120] This embodiment provides a method for synthesizing a liquid crystal compound, wherein the reactants and reaction equations in the reaction for synthesizing compound F are shown below:

[0121]

[0122] The reaction procedure is as follows: In a three-necked flask, 5.4 g (9.5 mmol) of E-3 and 50 mL of DMF were added. Under nitrogen atmosphere, the mixture was cooled to 0 °C, and 14.2 mL of commercially available LiHMDS solution (1 mol / L) was added dropwise. After the addition was complete, the mixture was allowed to warm naturally to room temperature overnight. The reaction solution was poured into water, and a large amount of solid precipitated. The solid was filtered, and the filter cake was washed with water until neutral and then dried. The product was passed through a column chromatography line with n-heptane, the solvent was evaporated, and the product was recrystallized three times with three times the volume of ethanol to obtain 3 g of white solid with a GC purity of 99.85%.

[0123] The mass spectrometry data of compound F-1 are: 77 (45%), 131 (10%), 175 (15%), 223 (30%), 252 (100%), 280 (25%), 327 (5%), 335 (6%), 349 (8%), 363 (4%), 376 (6%), 397 (10%), and 426 (53%).

[0124] Application Example 1

[0125] This application example provides a liquid crystal composition comprising compound F-1 prepared in Example 7. The composition and mass percentage of the liquid crystal composition are shown in Table 1.

[0126] Table 1

[0127]

[0128]

[0129] Application Example 2

[0130] This application example provides a liquid crystal composition comprising compound F-2 prepared in Example 8. The composition and mass percentage of the liquid crystal composition are shown in Table 2.

[0131] Table 2

[0132]

[0133] Application Example 3

[0134] This application example provides a liquid crystal composition comprising compound F-3 prepared in Example 9. The composition and mass percentage of the liquid crystal composition are shown in Table 3.

[0135] Table 3

[0136]

[0137]

[0138] In the application example, the specific meaning of the codes in each liquid crystal molecule is shown in Table 4.

[0139] Table 4. Group structure codes of liquid crystal compounds

[0140]

[0141]

[0142] Take the following compound with the following structural formula as an example:

[0143]

[0144] If the structural formula is represented by the codes listed in Table 1, it can be expressed as: nCCGF, where n in the code represents the number of C atoms in the alkyl group at the left end. For example, if n is "3", it means that the alkyl group is -C3H7. In the code, C represents cyclohexyl, G represents 2-fluoro-1,4-phenylene, and F represents fluorine.

[0145] The abbreviated codes for the test items and the test methods in the application examples are as follows:

[0146] The abbreviated codes for the test items in the following examples are as follows:

[0147] Cp clearing point (nematic-isotropic phase transition temperature, °C);

[0148] Δn optical anisotropy (589nm, 25℃);

[0149] Δε dielectric anisotropy (1KHz, 25℃);

[0150] η flow viscosity

[0151] in,

[0152] Optical anisotropy was measured using an Abbe refractometer under a sodium lamp (589 nm) light source at 25°C.

[0153] Δε=ε ∥ -ε ⊥ , where ε ∥ ε is the dielectric constant parallel to the molecular axis. ⊥ The dielectric constant is perpendicular to the molecular axis. Test conditions: 25℃, 1KHz, test box is TN90 type, box thickness is 7μm.

[0154] η (flow viscosity): Measured by an E-type viscometer under test conditions of 25±0.5℃.

[0155] The applicant declares that the detailed process equipment and process flow of this invention are illustrated through the above embodiments, but this invention is not limited to the above detailed process equipment and process flow, that is, it does not mean that this invention must rely on the above detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, additions of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

Claims

1. A method for synthesizing a liquid crystal compound, characterized by, The synthetic method is shown in the following reaction equations: Wherein, X is a halogen atom, Y is any leaving group that satisfies its chemical environment, Z is O or S, and R is any one of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted cycloalkyl.

2. The method of synthesis of claim 1, wherein, X is any one or a combination of at least two of F, Cl, Br or I; And / or, the Y includes 3. The synthesis method according to claim 1, characterized in that, The R is a C1-12 alkyl group, a C1-12 alkoxy group, or a cycloalkyl group with 3-4 carbon atoms. Any one of them; Where X1 and X2 independently represent any one of methylene, methyleneoxy, ethylene, or alkenyl groups, and ring A1 represents... Any one of them, ring A2 represents Any one of the following, where n is an integer from 1 to 6.

4. The synthesis method according to claim 1, characterized in that, At least one of the -CH- or -CH2- in R, which is an alkyl, alkoxy, or cycloalkyl group, is substituted with -N- or -O-. And / or, in the R At least one -CH2- in it is replaced by -O-; And / or, in the R At least one -H in the formula is replaced by -F, -Cl, -CN, -CH3 or -OCH3; And / or, in the R At least one of -CH= in the equation is replaced by -N=.

5. The synthesis method according to claim 1, characterized in that, The reaction for synthesizing compound C includes: mixing compound A, compound B, a base, and an organic solvent, and reacting them under a protective atmosphere to obtain compound C.

6. The synthesis method according to claim 5, characterized in that, The reaction temperature is -75 to 0°C, and the time is 1 to 10 hours. And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, and dioxane; And / or, the base includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, lithium hexamethyldisilamide, or potassium hexamethyldisilamide.

7. The synthesis method according to claim 1, characterized in that, The reaction for synthesizing compound E includes mixing compound C, compound D, a base, a catalyst, and an organic solvent, and reacting to obtain compound E.

8. The synthesis method according to claim 7, characterized in that, The reaction is carried out at a temperature of 50–120°C for a time of 0.5–4 hours. And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, acetonitrile, or tetrahydrofuran; And / or, the base includes any one or a combination of at least two of sodium carbonate, potassium carbonate, potassium hydroxide, sodium hydroxide, potassium tert-butoxide, or sodium tert-butoxide; And / or, the catalyst includes potassium iodide.

9. The synthesis method according to claim 1, characterized in that, The reaction for synthesizing compound F includes: mixing compound E, a base, and an organic solvent, and reacting them under a protective atmosphere to obtain compound F.

10. The synthesis method according to claim 9, characterized in that, The reaction temperature is -75 to 20°C, and the time is 2 to 12 hours. And / or, the organic solvent includes any one or a combination of at least two of N,N-dimethylformamide, tetrahydrofuran, or dioxane; And / or, the base includes any one or a combination of at least two of potassium tert-butoxide, sodium tert-butoxide, n-butyllithium, lithium hexamethyldisilamide, or potassium hexamethyldisilamide.

Images