Acetalization method, method for manufacturing liquid crystal compound, and compound

Abstract

To provide a method for efficiently synthesizing NF liquid crystal groups and NF liquid crystal materials exhibiting novel and excellent properties.SOLUTION: There is provided a method for promoting an acetalization reaction by reacting at least one aldehyde compound with at least one dihydric alcohol compound, preferably in the presence of at least one dehydrating agent, wherein the acetalization reaction is promoted by providing an at least partially heterogeneous reaction system with mechanical energy to directly absorb the energy. The method for producing the liquid crystal compound includes the acetalization method.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an acetalization method, a method for producing a liquid crystal compound including the acetalization method, and the compound. [Background technology]

[0002] In recent years, three types of N F Although the liquid crystal molecules DIO, RM734, and UUQU-4-N all have different molecular structures, F These molecular species exhibit a unique large dielectric constant, polarization density, and nonlinear optical properties (Non-Patent Documents 1 to 4). These molecular species have different phase series and undergo a N F The N phase appears and then appears at room temperature. F The common feature is that both molecular species undergo a transition from the thermodynamically metastable N F Indicates the phase. In recent years, the inventors trans DIO / cis In the diastereomeric mixture of DIO and UUQU-4-N, F It has been revealed that the anisotropic growth of cybotactic clusters in the phases affects the phase sequence, and that the presence of clusters rather than differences in molecular structure is the key to the N F These results reveal that it contributes to phase expression. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Mandle, RJ, Cowling, SJ & Goodby, JW Rational design of rod-like liquid crystals exhibiting two nematic phases. Chem. Eur. J. 23, 14554-14562 (2017). [Non-Patent Document 2] Mandle, RJ, Cowling, SJ & Goodby, JW A nematic to nematic transformation exhibiting by a rod-like liquid crystal. Phys. Chem. Chem. Phys. 19, 11429-11435 (2017). [Non-Patent Document 3] Nishikawa, H. et al. A fluid liquid-crystal material with highly polar order. Adv. Mater. 29, 1702354 (2017). [Non-Patent Document 4] Li, J. et al. Development of ferro- electric nematic fluids with giant-ε dielectricity and nonlinear optical properties, Sci. Adv. 7, eabf5047 (2021). Summary of the Invention [Problem to be solved by the invention]

[0004] However, N F In order to apply liquid crystal materials, it is necessary to develop a stable N F Phase must be expressed, N F It is an issue to clarify the cause of the thermodynamic instability of the phase. F It is necessary to develop a group of liquid crystals and investigate them from various angles. F The purpose of the present invention is to provide a method for efficiently synthesizing liquid crystals. F The object is to provide a liquid crystal material. [Means for solving the problem]

[0005] As a result of intensive research to solve the above problems, the inventors of the present application have developed a method for reducing the amount of organic solvent used, directly contacting the reaction raw materials, and using mechanochemical synthesis, which has been attracting attention in recent years as an efficient reaction method with a small environmental impact, to achieve a high-performance organic solvent synthesis method using N F The present inventors have found that by incorporating this compound into the synthesis of liquid crystals, various DIO, RM and UUQU species as well as novel compounds can be efficiently obtained, thereby completing the present invention. Furthermore, the inventors have found that the newly obtained compound exhibits excellent physical properties, which has led to the completion of the present invention.

[0006] That is, the present invention provides the following.

[0007] <1> A method for reacting at least one aldehyde compound with at least one dihydric alcohol compound to cause an acetalization reaction, comprising the steps of: The acetalization method according to claim 1, wherein the acetalization reaction is carried out by providing mechanical energy to an at least partially heterogeneous reaction system and allowing the reaction system to directly absorb the energy. <2> The acetalization reaction is carried out in the presence of at least one dehydrating agent. <1> The acetalization method according to claim 1. <3> The at least one aldehyde compound is represented by the following formula (II), and the at least one dihydric alcohol is represented by the following formula (III): <1> or <2> 2. The acetalization method according to claim 1 ; Esterification reactions; Formula (II) [ka] In formula (II), "Ar" represents a carbon-based or hetero-based aromatic ring, and Ar may be fused with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with another organic group; Formula (III) [ka] In formula (III), "R" represents a substituent. <4> A method for producing a liquid crystal compound having a partial structure represented by the following formula (I), A method for producing a liquid crystal compound, comprising a step of reacting at least one aldehyde compound with at least one dihydric alcohol compound to cause an acetalization reaction to proceed, wherein in the step, the acetalization reaction is caused to proceed by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy; Formula (I) [ka] In formula (I), "Ar" represents a carbon-based or hetero-based aromatic ring, which may be condensed with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with other organic groups; * represents the position where the partial structure represented by formula (I) is bonded to another atom; and the arrow indicates the long axis direction of the liquid crystal. <5> The acetalization reaction is carried out in the presence of at least one dehydrating agent. <4> A method for producing the liquid crystal compound according to claim 1. <6> The method further comprises at least one step selected from the group of reaction steps below, the at least one step being characterized in that the reaction proceeds by providing mechanical energy to at least a part of a heterogeneous reaction system and directly absorbing the energy. <4> or <5> The method according to Reaction process group Esterification reactions between monoalcohols and monocarboxylic acids; etherification reactions between mono- or polyhydric alcohols and alkyl halides; oxidation reactions that convert aldehyde groups to carboxyl groups; and cross-coupling reactions. <7> A compound represented by the following formula: [ka] In the formula, "R" represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, each "X" independently represents a hydrogen atom or a fluorine atom, and "Z" represents a nitro group, a fluorine atom or a cyano group. <8> <7> The present invention relates to a method for producing a compound represented by any one of formulas (4) and (5) described in the above, which comprises at least one step selected from the group of reaction steps below, and which is characterized in that the at least one step proceeds by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy. Reaction process group Esterification reactions between monoalcohols and monocarboxylic acids; etherification reactions between mono- or polyhydric alcohols and alkyl halides; oxidation reactions that convert aldehyde groups to carboxyl groups; and cross-coupling reactions. <9> <7> 2. A device having at least a layer comprising at least one of the compounds according to claim 1. <10> In the layer, the compound exhibits a ferroelectric liquid crystal phase, at least temporarily. <9> The device described in. <11> The ferroelectric liquid crystal phase is at least one of a ferroelectric nematic phase and a ferroelectric smectic phase. <10> The device described in. <12> Fixed in a given liquid crystal phase <7> A film comprising at least one of the compounds described in 1. Effect of the Invention

[0008] The acetalization method of the present invention is more convenient than conventional methods because the reaction proceeds in a very short time, the amount of solvent used can be reduced, the method is environmentally friendly and clean, and the method can be performed at low cost. Furthermore, the acetalization method of the present invention does not require the use of a large-scale apparatus such as a Dean-Stark apparatus. Furthermore, the method for producing a liquid crystal compound of the present invention also allows the reaction to proceed in a very short time, reduces the amount of solvent used, is environmentally friendly, and is also low cost. F Liquid crystal groups can be efficiently synthesized, and thus N F Elucidation of the cause of thermodynamic instability of the phase and N F Applications of liquid crystal materials are expected. Furthermore, according to the present invention, it is possible to provide a liquid crystal compound having excellent physical properties that can be used for various applications, and a device, a film, and the like using said compound. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 shows the results of DFT calculations estimating the dipole moments of the compounds BIOTN1 and BIOTN2 obtained in Example 4. [Diagram 2] 1 shows DSC curves of compounds BIOTN1 and BIOTN2 obtained in Example 4. [Diagram 3] 1A is a schematic diagram showing how the jar of the ball mill of the embodiment is heated with a heat gun, and FIG. 1B is a calibration curve showing the correlation between the adjusted temperature of the heat gun (external temperature Tex of the jar) and the internal temperature Tin of the jar when the jar of the ball mill of the embodiment is heated with the heat gun. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below.

[0011] [Acetalization method] The acetalization method of the present invention is a method in which at least one aldehyde compound and at least one dihydric alcohol compound are reacted, preferably in the presence of at least one dehydrating agent, to cause an acetalization reaction to proceed, and is characterized in that the acetalization reaction proceeds by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy.

[0012] Aldehyde Compounds In the acetalization method of the present invention, the aldehyde compound is not particularly limited as long as it is a compound having at least one aldehyde group (-C(=O)H) in one molecule, but an aldehyde compound represented by the following formula (II) is preferred.

[0013] [ka]

[0014] In formula (II), "Ar" represents a carbon-based or hetero-based aromatic ring. Ar in formula (II) may be condensed with one or more other carbon-based and / or hetero-based aromatic rings. In addition, when the ring-constituting atoms of Ar in formula (II) have hydrogen atoms, one or more hydrogen atoms may be substituted with other organic groups.

[0015] Examples of the carbon-based aromatic ring represented by Ar include, but are not limited to, the following carbon-based aromatic rings: [ka] In the above formula, "Y" is at least one group selected from a single bond, a saturated or unsaturated divalent hydrocarbon group, ether (-O-), carbonyl (-C(=O)-), ester (-C(=O)O-), sulfide (-S-), amino (-N(R')-) and amide (-C(=O)N(R')-), or a combination of these groups, and "R'" in the amino group and amide group is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0016] Examples of the heteroaromatic ring represented by Ar include, but are not limited to, the following heteroaromatic rings: [ka]

[0017] Examples of other organic groups that may substitute for the hydrogen atom bonded to the ring-constituting atom of Ar include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, and hexyl groups; halogen-substituted alkyl groups, such as trifluoromethyl groups, in which some or all of the hydrogen atoms of the alkyl groups are substituted with halogen atoms; alkoxy groups having 1 to 6 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy groups; halogeno groups, such as fluoro, chloro, bromo, and iodo; nitro; and cyano. Examples of other organic groups that may substitute for the hydrogen atom bonded to the ring-constituting atom of Ar include fluoro groups.

[0018] Examples of aldehyde compounds include, but are not limited to, benzaldehyde, 3,5-difluorobenzaldehyde.

[0019] Dihydric alcohol compounds In the acetalization method of the present invention, the dihydric alcohol compound is not particularly limited as long as it is a compound having at least two hydroxyl groups (-OH) in one molecule, but a dihydric alcohol compound represented by the following formula (III) is preferred.

[0020] [ka]

[0021] In formula (III), "R" represents a substituent.

[0022] In formula (III), examples of the substituent represented by R include a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. In formula (III), examples of the substituent represented by R include a hydrogen atom and an alkyl group having 1 to 7 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and further preferably an alkyl group having 1 to 3 carbon atoms.

[0023] In the acetalization method of the present invention, the dihydric alcohol compound is preferably used in an amount of 1.0 to 3.0 equivalents, more preferably 1.2 to 2.5 equivalents, and even more preferably 1.5 to 2.2 equivalents, relative to 1 equivalent of the aldehyde compound.

[0024] Dehydrating agents In the acetalization method of the present invention, the dehydrating agent is used to remove water produced by the acetalization reaction, and any known dehydrating agent capable of adsorbing low molecular weight compounds such as water can be used. Examples of the dehydrating agent include magnesium sulfate, sodium sulfate, molecular sieves, and silica gel, and among these, magnesium sulfate is preferred.

[0025] In the acetalization method of the present invention, the amount of dehydrating agent may be appropriately determined depending on the amount of water generated in the acetalization reaction and the type of dehydrating agent. For example, when magnesium sulfate is used as the dehydrating agent, it is preferably used in an amount of 1 to 5 equivalents, and more preferably about 3 equivalents, per equivalent of the aldehyde compound.

[0026] catalyst In the acetalization method of the present invention, a known catalyst that is usually used in acetalization reactions may be used. Examples of the catalyst include acid catalysts such as p-toluenesulfonic acid (TsOH), methanesulfonic acid, and sulfuric acid. In addition, examples of the catalyst include Lewis acid catalysts such as zirconium chloride (IV).

[0027] In the acetalization method of the present invention, when a catalyst is used, the amount of the catalyst is preferably 0.5 to 1.5 equivalents, more preferably 0.7 to 1.2 equivalents, and even more preferably 0.8 to 1.1 equivalents, relative to 1 equivalent of the aldehyde compound.

[0028] Reaction method The acetalization method of the present invention is characterized in that mechanical energy is provided to an at least partially heterogeneous reaction system and the acetalization reaction is allowed to proceed by directly absorbing the energy. The mechanical energy provided to the reaction system is energy generated by mechanical operations such as mixing, grinding, compression, impact, etc., and examples of the apparatus used in the acetalization method of the present invention that utilizes such mechanical energy include various apparatuses used in mechanochemical synthesis such as mixers, grinders, compressors, etc. More specifically, examples of the apparatus used in the acetalization method of the present invention include ball mills, bead mills, jet mills, vibration mills, extruders, etc.

[0029] The acetalization method of the present invention will now be described in more detail, taking mechanochemical synthesis using a ball mill as an example. The material of the jar and ball is not particularly limited, but examples thereof include zirconia, hardened steel, stainless steel, tungsten carbide, agate, alumina, silicon nitride, etc. In the present invention, from the viewpoint of suppressing contamination caused by the material of the jar and ball, the material of the jar and ball is preferably one having high density and hardness, and for example, a jar and ball made of zirconia can be suitably used. The volume of the jar is not particularly limited, and commercially available jars of various volumes can be selected according to the amount of reactant. For example, jars of 1 to 1000 mL can be used. The filling rate of the reactants relative to the volume (internal volume) of the jar is not particularly limited and may be appropriately selected depending on the volume of the jar and the size of the ball, and may be, for example, 10 to 70%, preferably 20 to 60%, and more preferably 30 to 50%. The vibration frequency of the jar is not particularly limited, but can be, for example, 3 to 50 Hz. The size of the ball is not particularly limited and can be appropriately selected depending on the volume of the jar to be used, for example, balls with a diameter of 0.5 to 20 mm can be used for a jar having a volume in the above range. In addition, one ball or two or more balls may be used for one jar.

[0030] The acetalization method of the present invention may be carried out at room temperature (1 to 30°C) without heating, or may be carried out with heating. The heating method can be appropriately selected depending on the apparatus used for the reaction. For example, when a ball mill is used, a method of heating a jar containing the reactants with a heat gun can be mentioned. In this case, as shown in the examples described later, the adjusted temperature of the heat gun (jar external temperature T ex ) and the internal temperature of the jar T in A calibration curve showing the correlation between the temperature and the desired temperature T inside the jar is prepared in advance. in Adjust the temperature of the heat gun so that the temperature (external temperature of the jar T ex ) is preferably set.

[0031] In the acetalization method of the present invention, the term "at least partially heterogeneous reaction system" means that the reaction system is not a homogeneous liquid phase as a whole, and refers to either the entire reaction system being in a solid phase or a part or the entire amount of the reactants (i.e., the aldehyde compound and the dihydric alcohol compound) being present in the reaction system without being dissolved in the liquid phase.

[0032] Depending on the type and characteristics of the reactants, the presence or absence of a catalyst, and the type of the catalyst, in the acetalization method of the present invention, a liquid assisted grinding (hereinafter referred to as LAG) method may be used to make the reaction system "at least partially heterogeneous". That is, a very small amount of solvent may be added to the reaction system. The solvent added here is preferably one having a vapor pressure of 15 kPa (room temperature) or less, since a solvent with a high vapor pressure may leak out of the system during the reaction. Examples of such solvents include ethyl acetate (EA), 1,4-dioxane (DIOX), 2-methyltetrahydrofuran (2Me-THF), trimethyl orthoformate, and triethyl orthoformate. Such a solvent added in a very small amount to the reaction system may be referred to as an "additive" in this specification. In the acetalization method of the present invention, when an additive is added, the amount of the additive is in a range such that the parameter η (mg / μL), defined as the ratio of the additive to the total amount of solid components contained in the reaction system, is 0<η≦1. Note that reaction systems can be classified according to the value of η as follows: η=0 (solid-phase reaction), 0<η≦1 (LAG method), 1<η≦10 (slurry method), and 10<η (typical solution reaction), and in this specification, an "at least partially heterogeneous reaction system" is a reaction system that at least satisfies η≦10.

[0033] According to the acetalization method of the present invention, a compound having an acetal group represented by the following formula can be produced in a shorter time than in conventional acetalization methods. [ka] In the above formula, * represents the position at which the acetal group represented by the above formula is bonded to another atom.

[0034] In addition, in the acetalization method of the present invention, when an aldehyde compound represented by the above formula (II) is used as the aldehyde compound and a dihydric alcohol compound represented by the above formula (III) is used as the dihydric alcohol, a compound having a partial structure represented by the following formula (I) can be produced. Formula (I) [ka] In formula (I), "Ar" represents a carbon-based or hetero-based aromatic ring, and Ar may be condensed with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with another organic group; * represents the position at which the partial structure represented by formula (I) is bonded to another atom. The compound having the partial structure represented by formula (I) is preferably a liquid crystal compound whose major axis direction is the direction of the arrow in formula (I).

[0035] [Method of manufacturing liquid crystal compound] The method for producing a liquid crystal compound having a partial structure represented by formula (I) of the present invention includes a step of reacting at least one aldehyde compound with at least one dihydric alcohol compound, preferably in the presence of at least one dehydrating agent, to proceed with an acetalization reaction, and is characterized in that in the step, the acetalization reaction proceeds by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy.

[0036] Formula (I) [ka]

[0037] In formula (I), "Ar" represents a carbon-based or hetero-based aromatic ring, which may be condensed with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with other organic groups; * represents the position where the partial structure represented by formula (I) is bonded to another atom; and the arrow indicates the long axis direction of the liquid crystal.

[0038] Examples of the carbon-based or hetero-based aromatic ring represented by "Ar" in formula (I) include the same as those exemplified in formula (II) above.

[0039] The aldehyde compound used in the method for producing a liquid crystal compound of the present invention is preferably an aldehyde compound represented by the above formula (II), and the dihydric alcohol compound used in the method for producing a liquid crystal compound of the present invention is preferably a dihydric alcohol compound represented by the above formula (III).

[0040] The method for producing a liquid crystal compound of the present invention may include, in addition to the step of proceeding with the acetalization reaction, at least one step selected from the group of reaction steps below, and the at least one step proceeds by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy. Reaction process group Esterification reactions between monoalcohols and monocarboxylic acids; etherification reactions between mono- or polyhydric alcohols and alkyl halides; oxidation reactions that convert aldehyde groups to carboxyl groups; and cross-coupling reactions.

[0041] Depending on the types of aldehyde compound and dihydric alcohol compound used in the step of proceeding with the acetalization reaction, or by appropriately combining the step of proceeding with the acetalization reaction with at least one step selected from the group of reaction steps described above and other known reaction steps, various liquid crystal compounds having a partial structure represented by formula (I) can be produced. Each reaction in the group of reaction steps can be carried out in accordance with a known solution reaction, except that the reaction is carried out by providing mechanical energy to at least a part of a heterogeneous reaction system and directly absorbing the energy. An example of each reaction is shown below.

[0042] [1] Esterification reaction of monoalcohol with monocarboxylic acid An example of the esterification reaction between a monoalcohol and a monocarboxylic acid is shown in the following formula. [ka] The monocarboxylic acid is preferably an aromatic carboxylic acid as shown in the above formula, and "Ar" can be exemplified by various carbon-based or hetero-based aromatic rings exemplified in the aldehyde compound in the above acetalization method. R 1 The monoalcohol represented by -OH may be an aliphatic monoalcohol or an aromatic monoalcohol. 1 Examples of the aromatic monoalcohol include various alcohols in which R is a linear or branched alkyl group having 1 to 14 carbon atoms, an alicyclic alkyl group having 3 to 6 carbon atoms, or a group having an oxetane ring. 1 Examples of the alcohol include various alcohols having various carbon-based or hetero-based aromatic rings, which are represented by "Ar", as exemplified in the aldehyde compound of the above acetalization method. The conditions of the esterification reaction represented by the above formula can be referred to, for example, ACS Sustainable Chem. Eng. 8, 15703-15715 (2020). More specifically, in addition to monocarboxylic acids and monoalcohols, condensing agents such as {{[(1-cyano-2-ethoxy-2-oxoethylidene)amino]oxy}-4-morpholinomethylene}dimethylammonium hexafluorophosphate (COMU) and chloro-N,N,N',N'-tetramethylformamidinium hexafluorophosphate (TCFH) and K2HPO4 are placed in a jar for mechanochemical synthesis (mechanoesterification). At this time, the amount of additives such as ethyl acetate is preferably an amount such that η = 0.1 to 1.0 μL / mg, more preferably an amount such that η = 0.19 to 0.8 μL / mg. The esterification reaction represented by the above formula can be carried out at room temperature.

[0043] [2] Etherification reaction of mono- or polyhydric alcohol with alkyl halide An example of the etherification reaction between a mono- or polyhydric alcohol and an alkyl halide is shown in the following formula. [ka] The mono- or polyhydric alcohol is preferably an aromatic alcohol as shown in the above formula, where "Ar" can be exemplified by various carbon-based or hetero-based aromatic rings exemplified in the aldehyde compound in the above acetalization method, and n is an integer of 1 to 6. In the above formula, the alkyl halide is R 2 -Br (bromide), but other alkyl halides are also acceptable. 2 is, for example, an alkyl group having 1 to 6 carbon atoms. In the case of a monoalcohol in the above formula where n=1, for example, the etherification reaction represented by the above formula can be carried out by using 1 to 3 equivalents of an alkyl halide, 1 to 3 equivalents, preferably 3 equivalents, of K2CO3, and 5 to 20 mol% of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst, with the addition of N,N-dimethylformamide (DMF) (η=0.2 to 0.8 μL / mg) relative to 1 equivalent of the monoalcohol. The etherification reaction represented by the above formula may be carried out at room temperature or under heating (up to 80° C.).

[0044] [3] Oxidation reaction that converts aldehyde groups to carboxyl groups An example of an oxidation reaction for converting an aldehyde group to a carboxyl group is shown in the following formula. [ka] The compound having an aldehyde group is preferably an aromatic aldehyde as shown in the above formula, and "Ar" can be exemplified by various carbon-based or hetero-based aromatic rings exemplified in the aldehyde compound in the above acetalization method. The conditions for the oxidation reaction represented by the above formula can be found in, for example, Org. Lett. 5, 1031-1034 (2003) (solution reaction). For mechanochemical synthesis, for example, 1.5 to 3 equivalents, preferably 2 equivalents, of oxone per equivalent of a compound having an aldehyde group is used, and N,N-dimethylformamide (DMF) is added (η=1.0 μL / mg). The oxidation reaction represented by the above formula can be carried out at room temperature.

[0045] [4] Cross-coupling reaction An example of the cross-coupling reaction is the Suzuki-Miyaura coupling (SMC) reaction shown in the following formula. [ka] Another example of the cross-coupling reaction is the Miyaura-Ishiyama coupling (MIC) reaction shown in the following formula. [ka] Furthermore, another example of the cross-coupling reaction is the Sonogashira-Hagiwara coupling (SHC) reaction shown in the following scheme. [ka] In the above formula, "Ar 1 " and "Ar 2 " can independently be exemplified by various carbon-based or hetero-based aromatic rings exemplified in the aldehyde compound in the above acetalization method. In the above formula, "X" is a halogen atom.

[0046] The conditions for each coupling reaction can be determined by reference to known conditions for solution reactions. In the SMC reaction, in addition to the aromatic borane acid shown in the above formula, its pinacol ester may be used as the organic boron compound, Pd(dppf)2Cl2 or the like may be used as the palladium catalyst, and K2CO3 or Cs2CO3 or the like may be used as the base. The SMC reaction may be carried out at room temperature or under heating (up to 110°C). In the MIC reaction, in addition to bis(pinacolato)diboron (B2pin2) shown in the above formula, pinacolborane (H-Bpin) or diboronic acid (B2(HO)4) may be used as the boron source, Pd(dppf)2Cl2 or the like may be used as the palladium catalyst, and potassium acetate (KOAc) or the like may be used as the base. The MIC reaction may be performed at room temperature or under heating (up to 80°C). In the SHC reaction, a catalyst such as Pd(PPh)3Cl2:CuI=3:1 (molar ratio) can be used, and an amine such as diisopropylamine (DIPA) can be used as a base. The SHC reaction can be carried out at room temperature or under heating (up to 80°C).

[0047] After each reaction, the product may be purified by a conventional method, for example, recrystallization, reprecipitation, column chromatography, etc., but is not limited to these.

[0048] The above cross-coupling reaction may be carried out with reference to the conditions, examples, etc. disclosed in WO 2020 / 085396.

[0049] [Compound] The compound of the present invention is represented by any one of the following formulas (1) to (5). [ka] In the formula, "R" represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, each "X" independently represents a hydrogen atom or a fluorine atom, "Y" represents a fluorine atom, a nitro group or a cyano group, and "Z" represents a nitro group, a fluorine atom or a cyano group. "R" is more preferably an alkyl group having 1 to 18 carbon atoms, further preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 1 to 8 carbon atoms.

[0050] The compound represented by any one of formulas (1) to (5) of the present invention can be produced by combining various known methods, or by utilizing the method of the present invention. Specifically, the latter can be produced by appropriately combining, for example, the acetalization method of the present invention, at least one step selected from the group of reaction steps, and other known reaction steps. Among the steps of the method for producing the compound represented by any one of formulas (1) to (5), in particular, the acetalization method of the present invention and at least one step selected from the group of reaction steps are carried out by providing mechanical energy to at least a part of a heterogeneous reaction system and directly absorbing the energy, which allows the compound to be produced in a very short time compared to the conventional method, and furthermore, the amount of solvent used can be reduced compared to the conventional method, which is environmentally friendly, clean, and low cost, making it preferable.

[0051] An example of the method for producing the compound represented by formula (1) is shown in Example 1 below. That is, in step 1, the acetalization method of the present invention is carried out using an aldehyde compound and a dihydric alcohol compound to obtain a 1,3-dioxane derivative. In step 2, the 1,3-dioxane derivative obtained in step 1 is converted to a carboxylic acid by a known reaction to obtain a carboxylic acid derivative. Meanwhile, in step 3, a phenol derivative is obtained from a halogen compound having a phenolic hydroxyl group and an organoboron compound by the above [4] SMC reaction. Finally, a compound represented by formula (1) can be produced from the carboxylic acid derivative obtained in step 2 and the phenol derivative obtained in step 3 by the above [1] esterification reaction. Among the above-mentioned examples of the production method, steps 1, 3, and 4 can be mechanochemical synthesis, which is carried out by providing mechanical energy to a heterogeneous reaction system and directly absorbing the energy, and compared to the case where all steps are solution reactions, the reaction proceeds in a very short time, the amount of solvent used can be reduced, the environmental load is low, clean, and low cost can be achieved.

[0052] An example of the method for producing the compound represented by formula (2) is shown in Example 2 below. That is, in step 1, an ether compound is obtained by the above [2] etherification reaction using a monoalcohol having a phenolic hydroxyl group and an alkyl halide. In step 2, the carboxylic acid ester structure of the ether compound obtained in step 1 is converted to a carboxylic acid by a known reaction to obtain a carboxylic acid derivative. In step 3, an aldehyde derivative is obtained from the aldehyde group-containing phenol derivative obtained in step 2 by the above [1] esterification reaction. In step 4, the aldehyde group of the aldehyde derivative obtained in step 3 is converted to a carboxy group by the above [3] oxidation reaction. Finally, a compound represented by formula (2) can be produced from the carboxylic acid derivative and phenol derivative obtained in step 4 by the above [1] esterification reaction. Among the above-mentioned examples of the production method, steps 1 to 5 can be mechanochemical synthesis, which is carried out by providing mechanical energy to a heterogeneous reaction system and directly absorbing the energy, and compared to the case where all steps are solution reactions, the reaction proceeds in a very short time, the amount of solvent used can be reduced, the environmental load is low, clean, and low cost can be realized.

[0053] An example of the method for producing the compound represented by formula (3) is shown in Example 3 below. That is, in step 1, iodination of a benzene derivative is performed by a known reaction, or an iodine-substituted benzene derivative is prepared. In step 2, a biphenyl derivative is obtained from the iodine-substituted benzene derivative and an organoboron compound obtained in step 1 by the above-mentioned [4] SMC reaction. In step 3, the biphenyl derivative obtained in step 2 is converted to a carboxylic acid by a known method to obtain a carboxylic acid derivative. In step 4, a compound represented by formula (3) can be produced from the carboxylic acid derivative and phenol derivative obtained in step 3 by the above-mentioned [1] esterification reaction. Among the above-mentioned examples of the production method, steps 2 and 4 can be mechanochemical synthesis, which is carried out by providing mechanical energy to a heterogeneous reaction system and directly absorbing the energy, and compared to the case where all steps are solution reactions, the reaction proceeds in a very short time, the amount of solvent used can be reduced, the environmental load is low, clean, and low cost can be realized.

[0054] An example of a method for producing the compound represented by formula (4) is shown in Example 4 below. That is, in step 1, an acetylene derivative is obtained from an aromatic halogen compound and an aromatic acetylene compound by the above-mentioned [4] SHC reaction. In step 2, an aromatic compound is obtained from an aromatic halogen compound and bis(pinacolato)diboron by the above-mentioned [4] MIC reaction. In step 3, a biphenyl derivative having an acetylene group is obtained from the acetylene derivative obtained in step 1 and the aromatic compound obtained in step 2 by the above-mentioned [4] SMC reaction. In step 4, a reaction of removing the protecting group of the biphenyl derivative obtained in step 3 is performed by a known method. On the other hand, in step 5, an aromatic compound having an oxetane ring is obtained from a monoalcohol having an oxetane ring and an aromatic monocarboxylic acid by the above-mentioned [1] esterification reaction. In step 6, a reaction is performed to induce an orthobicycloester group from the aromatic compound having an oxetane ring obtained in step 5, and in step 7, the compound obtained in step 6 is iodized by a known method to obtain an iodine compound having an orthobicycloester group. In step 8, the compound represented by formula (4) can be produced by the above-mentioned [4] SMC reaction from the biphenyl derivative having an acetylene group obtained in step 4 and the iodine compound having an orthobicycloester group obtained in step 7. Among the above-mentioned examples of the production method, steps 1, 2, 4, 5 and 8 can be mechanochemical synthesis in which mechanical energy is provided to a heterogeneous reaction system and the energy is directly absorbed to proceed, and compared with the case where all steps are solution reactions, the reaction proceeds in a very short time, the amount of solvent used can be reduced, the environmental load is low, and the process is clean and low cost. Another example of the method for producing the compound represented by formula (4) is shown in Example 5 below. That is, steps 1 to 4 are the same as steps 1 to 4 of Example 4 to obtain a biphenyl derivative having an acetylene group. tAn aromatic compound having a BuO group is iodized by a known method, and in step 6, an SHC reaction is carried out using this and a biphenyl derivative having an acetylene group obtained in steps 1 to 4. Then, in step 7, t The compound represented by formula (4) can be produced by carrying out a deprotection reaction of the BuO group, an esterification reaction with a compound having an oxetane ring in step 8, and an orthoesterification reaction to induce an orthobicycloester group in step 9, each by a known method. Among the above-mentioned examples of the production method, steps 1, 2, 3, and 6 can be carried out by mechanochemical synthesis, in which mechanical energy is provided to a heterogeneous reaction system and the energy is directly absorbed, and the reaction proceeds in a very short time compared to when all steps are solution reactions, and the amount of solvent used can be reduced, making it environmentally clean and realizing low cost.

[0055] As an example of a method for producing the compound represented by formula (5), a method of combining Examples 1 and 4 described below can be mentioned. That is, in step 1, the acetalization method of the present invention is carried out using an aldehyde compound and a dihydric alcohol compound in the same manner as in step 1 of the compound represented by formula (1), to obtain a 1,3-dioxane derivative. In step 2, the compound obtained in step 1 is iodized by a known method in the same manner as in step 7 of the compound represented by formula (4), to obtain an iodine compound having a 1,3-dioxane structure. Meanwhile, in steps 3 to 6, a biphenyl derivative having an acetylene group is obtained in the same manner as in steps 1 to 4 of the compound represented by formula (4). In step 7, the compound represented by formula (5) can be produced by the above [4] SMC reaction from the iodine compound having a 1,3-dioxane structure obtained in step 2 and the biphenyl derivative having an acetylene group obtained in step 6 in the same manner as in step 8 of the compound represented by formula (4).

[0056] The present invention also relates to a device having at least a layer containing at least one of the compounds of the present invention. The device of the present invention is not particularly limited in terms of its driving principle and function as long as it uses the compound of the present invention. Since one example of the compound of the present invention exhibits a ferroelectric liquid crystal phase, the device may be one that utilizes this liquid crystal phase as a function. In this embodiment, the compound exhibits a ferroelectric liquid crystal phase temporarily or permanently in the layer. Examples of the ferroelectric liquid crystal phase include a ferroelectric nematic phase and a ferroelectric smectic phase. There is no particular limitation on the method of driving the device of the present invention, and the device can be driven by supplying physical energy such as electricity, voltage, temperature change, magnetic field, etc. In addition, the predetermined function of the device having a layer containing the compound of the present invention exhibiting a predetermined liquid crystal phase is, for example, an image display function, but is not limited thereto. The present invention also relates to a film comprising at least one of the compounds of the present invention fixed in a predetermined liquid crystal phase, examples of which include ferroelectric liquid crystal phases, examples of which include ferroelectric nematic phases and ferroelectric smectic phases. Examples of the compound represented by the formula (4) include compounds that exhibit a ferroelectric nematic phase and a ferroelectric smectic phase in a predetermined temperature range at 0°C to 300°C. Examples of the compound represented by the formula (4) include compounds that exhibit a ferroelectric nematic phase and a ferroelectric smectic phase in a predetermined temperature range at 0°C to 300°C, and transition to a ferroelectric heliconical nematic phase between the ferroelectric nematic phase and the ferroelectric smectic phase. In such a compound, it is preferable that R in the formula (4) is a hydrocarbon group containing a medium linear structure of C4 to 6 in the long axis direction of the molecule. For example, 4BOE, 5BOE, 6BOE, etc. in the examples described later are exemplified. EXAMPLES

[0057] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0058] Unless otherwise stated, the mechanochemical synthesis in the following examples was carried out under the following conditions: The compound and zirconia ball (12 mm diameter × 1) were packed into an FTS zirconia jar (15 mL or 30 mL), which was then attached to a Retsch ball mill (MM400) and vibrated at a frequency of 30 Hz to perform mechanochemical synthesis.

[0059] For syntheses that required heating, the synthesis was carried out while heating from the normal direction of the jar with a temperature-controlled heat gun. A schematic diagram showing the heating with a heat gun is shown in Figure 3a. The distance between the heating jar and the nozzle of the heat gun was 1 cm (10 mm). Then, before carrying out the mechanochemical synthesis, the temperature of the heat gun was first adjusted (jar external temperature T ex ) and the internal temperature of the jar T in Based on this calibration curve, the internal temperature of the jar, T in The temperature outside the jar T is adjusted to the desired temperature. ex A mechanochemical synthesis involving heating was carried out.

[0060] [Example 1] Mechanochemical synthesis of DIO species The DIO species was synthesized according to the scheme shown in the following steps 1 to 4. In the scheme below, the solid arrows indicate reaction steps by mechanochemical synthesis, and the dashed arrows indicate solution reaction steps (the same applies below).

[0061] [ka]

[0062] Process 1 3,5-Difluorobenzaldehyde (1 equivalent) was used as the starting material, 2-propyl-1,3-propanediol (1.7 equivalents), TsOH (0.9 equivalents) as an acid catalyst, and magnesium sulfate (MgSO4, 3.0 equivalents) as a dehydrating agent were placed in a jar. inMechanochemical synthesis was carried out at 110°C. The reaction was completed in just 5 minutes. After the reaction, the mixture was dissolved in dichloromethane, washed with distilled water, dried and the solvent was removed to obtain the target product (yield 94%).

[0063] Process 2 In step 2, as shown in the above formula, a reaction (solution reaction) was carried out to convert the 1,3-dioxane derivative, which was the product of step 1, into a carboxylic acid. The reaction time for step 2 was about 1.5 hours.

[0064] Process 3 Starting from 4-bromo-3-fluorophenol (1 equivalent), 3,4,5-trifluorobenzeneboronic acid (1.5 equivalents), K2CO3 (3 equivalents), Pd(dppf)2Cl2 (3 mol%) and BHT (10 mol%) were placed in a jar, and 1,4-dioxane (DIOX) was added (η = 0.5 μL / mg) to obtain T in Mechanochemical synthesis was carried out at 80°C. The reaction was completed in 10 minutes. The reaction product was subjected to short column chromatography to remove residual Pd, and the target product was obtained by further column chromatography (yield 80%).

[0065] Process 4 In step 4, mechanoesterification of the carboxylic acid obtained in step 2 and the phenol derivative obtained in step 3 was carried out according to the method of Dalidovich et al. (ACS Sustainable Chem. Eng. 8, 15703-15715 (2020)). That is, the carboxylic acid obtained in step 2, the phenol derivative obtained in step 3, and {{[(1-cyano-2-ethoxy-2-oxoethylidene)amino]oxy}-4-morpholinomethylene}dimethylammonium hexafluorophosphate (COMU) and K2HPO4 as condensing agents were placed in a jar, and ethyl acetate (EA) was added (η = 0.19 to 0.8 μL / mg) to perform mechanochemical synthesis. The reaction was completed in 20 minutes, and the target product (compound 2d) was obtained.

[0066] Step 1 was carried out under the above-mentioned conditions (condition 1-1 in Table 1 below) as well as under conditions 1-2 to 1-4 shown in Table 1 below. By changing the type and concentration of the acid catalyst, the diastereomeric ratio of the 1,3-dioxane derivative, which was the product of step 1, was changed. In addition, under conditions 1-C1 and 1-C2 in which a dehydrating agent was not used, the reaction of step 1 did not proceed.

[0067] [Table 1]

[0068] Moreover, step 3 was carried out under the above-mentioned conditions (condition 3-1 in the following Table 2) as well as under conditions 3-2 to 3-3 shown in the following Table 2. When 3,4,5-trifluorobenzene pinacol boronic acid was used as the organoboron compound, the reaction time was shortened by making water coexist in the reaction system.

[0069] [Table 2]

[0070] Furthermore, using compounds having the substituents shown in Table 3, various DIO species were synthesized in the same manner according to steps 1 to 4.

[0071] [Table 3]

[0072] As described above, by steps 1 to 4 including the acetalization method of the present invention, various compounds (DIO species) having a structure represented by formula (1) could be produced in a synthesis time of about 2.5 hours (excluding purification time). Of the synthesis time, the total time required for mechanochemical synthesis in step 3 / 4 was only 0.5 hours, which is shorter than the conventional method, and it was found that it is possible to produce various DIO species by a highly convenient method without using a large-scale apparatus such as a Dean-Stark apparatus.

[0073] [Example 2] Mechanochemical synthesis of RM species The RM species was synthesized according to the scheme shown in steps 1 to 5 below. [ka]

[0074] Process 1 Starting from methyl 4-methoxysalicylate (1 equivalent), R 2 Br(3 equivalents, R 2 (Table 4 below), K2CO3 (3 equivalents), and tetrabutylammonium bromide (TBAB, 20 mol%) as a phase transfer catalyst were placed in a jar, and N,N-dimethylformamide (DMF) was added (η = 0.2 μL / mg) to obtain T in Mechanoether synthesis was carried out at 80°C. The reaction was completed in just 5 minutes, and a paste-like mixture was obtained. After the reaction, the mixture was separated by column chromatography to obtain the target product. Moreover, when step 1 was carried out in the same manner except that heating was not performed, the reaction time was 90 minutes. The yield of the reaction in step 1 was 90% or more regardless of the reaction temperature.

[0075] Process 2 The product of step 1 was placed in a jar as starting material, NaOH (2 equivalents) and HO (5 equivalents), and DIOX was added (η=10 μL / mg). in The reaction was carried out at 100°C. 10 minutes after the start of the reaction, a large amount of sodium salt precipitated in the jar, and the reaction was completed. The reactants were transferred to a separate container with water, and 1M HCl was added to adjust the pH to <4 to obtain the desired carboxylic acid (yield 90%).

[0076] Process 3 The carboxylic acid (1.1 equivalents) obtained in step 2, aldehyde group-containing phenol derivative (1 equivalent), COMU (1.1 equivalents) and K2HPO4 (3 equivalents) were placed in a jar, and EA was added (η is shown in Table 4 below) to synthesize mechanoester. After the reaction was completed, the mixture was thoroughly washed with distilled water, dried, and the solvent was distilled off, and the target product was separated by column chromatography (yield 90%).

[0077] Process 4 The aldehyde derivative (1 equivalent) obtained in step 3 and oxone (2 equivalents) were placed in a jar as starting materials, and DMF was added (η = 1.0 μL / mg) to carry out the mechano-oxidation reaction. The ball mill was stopped once 30 minutes after the start of the reaction, and after cooling, the reaction was carried out for an additional 30 minutes. After the reaction, distilled water was added, and the precipitate was filtered off, dissolved in diethyl ether, dried, and the solvent was distilled off to obtain a carboxylic acid (yield 95%).

[0078] Process 5 In step 5, mechanocondensation reaction was carried out according to step 3 above. That is, the carboxylic acid (1.1 equivalents) obtained in step 4, the phenol derivative (1 equivalent), COMU (1.1 equivalents), and K2HPO4 (3 equivalents) were placed in a jar, and EA was added to synthesize mechanoester. After the reaction was completed, the mixture was thoroughly washed with distilled water, dried, and the solvent was removed, and the target product was separated by column chromatography (yield 90%).

[0079] R 1 and R 2 The conditions and reaction time in step 3 are shown in the table below. [Table 4] Through steps 1 to 5 above, various compounds (RM species) having the structure represented by formula (2) could be obtained in a synthesis time of only about 1.9 hours (excluding purification time) at the shortest. Compared to liquid crystal synthesis by normal solution reaction, the synthesis of RM species can be calculated to take about 1 / 20 to 1 / 30 of the time.

[0080] [Example 3] Mechanochemical synthesis of UUZU species The UUZU species was synthesized according to the scheme shown in steps 1 to 4 below. [ka]

[0081] Process 1 In step 1, as shown in the above formula, iodination (solution reaction) of a benzene derivative was carried out. The reaction time in step 1 was 1.5 hours.

[0082] Process 2 In step 2, as shown in the above formula, iodobenzene (1 equivalent), which is the product of step 1, is used as the starting material, and 3,5-difluorophenylboronic acid (1.2 equivalents), Cs2CO3 (3 equivalents), and Pd(dppf)2Cl2 (3 mol%) are placed in a jar, and DIOX is added (η = 0.5 μL / mg) to obtain T in Mechanochemical synthesis was carried out at 110°C. The reaction was completed in 10 minutes. After post-treatment of the reactants, the product was separated by column chromatography to obtain the target product (95%).

[0083] Process 3 In step 3, as shown in the above formula, a reaction (solution reaction) was carried out to convert the product of step 2 into a carboxylic acid. The reaction time for step 3 was 3 hours.

[0084] Process 4 In step 4, similarly to step 4 in Example 1, mechanochemical synthesis was carried out from the carboxylic acid derivative and the phenol derivative obtained in step 3. The reaction was completed in 20 minutes, and the target product (compound 6a) was obtained in 88% yield.

[0085] Step 2 was carried out under the above conditions (condition 2-1 in Table 5 below) as well as conditions 2-2 to 2-4 shown in Table 5 below. [Table 5] *1 Although the reaction time was shorter than in condition 2-1, 1 1 H NMR measurement confirmed peaks at chemical shifts of 6.7 ppm and 7.05 ppm due to by-products, and the isolated yield was reduced to 88%. *2 1 The conversion rate was confirmed by 1 H NMR measurement, and was found to be 47% 1 hour after the start of the reaction. *3 1The conversion rate was confirmed by 1 H NMR measurement, and was found to be 92% 30 minutes after the start of the reaction and 100% after 1 hour. In step 2 of the synthesis of UUZU species, it was found that using Cs2CO3 as a base gave the desired product very rapidly and in high yield.

[0086] Furthermore, using compounds having the substituents shown in Table 6, various UUZU species were synthesized in a similar manner by steps 1 to 4. [Table 6]

[0087] Through steps 1 to 4, various compounds (UUZU species) having the structure represented by formula (3) were obtained in a synthesis time of about 5 hours (excluding purification time). Of the synthesis time, the total time required for mechanochemical synthesis in step 2 / 4 was only 0.5 hours.

[0088] [Example 4] New N F Mechanosynthesis of compounds New N F The compound was synthesized according to the scheme shown in steps 1 to 8 below. [ka]

[0089] Process 1 2-Bromo-1,3-difluoro-5-iodobenzene (1 equivalent) was used as the starting material, and triisopropylsilylacetylene (1.2 equivalents), Pd(PPh3)2Cl2 (3 mol%), CuI (1 mol%) and DIPA (1.5 equivalents) were placed in a jar and subjected to a mechano-SHC reaction without heating. In step 1, the molar ratio of Pd(PPh3)2Cl2 / CuI was 3 / 1 to suppress homocoupling, and the vibration frequency was set to 25 Hz. The reaction was completed in 5 minutes. The reactants were separated by column chromatography to obtain the desired product (yield 95%).

[0090] Process 2 4-Bromo-2,6-difluorobenzonitrile (1 equivalent) was used as the starting material, and B2pin2 (1.2 equivalents), Pd(dppf)2Cl2 (3 mol%), and KOAc (3 equivalents) were placed in a jar, and DIOX was added (η = 0.4 μL / mg) to obtain T in The mechano-MIC reaction was carried out at 80°C. The reaction was completed in 20 minutes, and the reactants were separated by column chromatography (stationary phase: SiO2, mobile phase: hexane → dichloromethane) to obtain the target product (yield 80%).

[0091] Process 3 The compound obtained in step 1 (1 equivalent) and the compound obtained in step 2 (1.2 equivalents) were placed in a jar, and Cs2CO3 (3 equivalents) and Pd(dppf)2Cl2 (3 mol%) were further placed in the jar, and DIOX was added (η = 0.5 μL / mg). in The mechano-SMC reaction was carried out at 110°C and was completed in 20 minutes. When 3 equivalents of water was added under the same conditions as above, the reaction was completed in only 5 minutes without side reactions. After post-treatment of the reactants, the product was separated by column chromatography to obtain the target product (83%).

[0092] Process 4 In step 4, as shown in the above formula, the protecting group of the compound obtained in step 3 was removed (solution method) to obtain the target alkyne derivative (yield 67%).

[0093] Process 5 Starting from 3,5-difluorobenzoic acid (1 equivalent), 3-methyl-3-oxetanemethanol (1.1 equivalents), COMU (1.1 equivalents), K2HPO4 (3 equivalents) and BHT (10 mol%) were placed in a jar, and EA was added (η = 0.19 μL / mg) to carry out the mechanoester reaction without heating. After working up the reaction product, the target product was obtained by column chromatography (stationary phase: SiO2, mobile phase: dichloromethane) (yield 89%).

[0094] Process 6 In step 6, as shown in the above formula, an orthobicycloester group was introduced by a solution reaction into the compound obtained in step 5. The reaction time in step 6 was 1.5 hours.

[0095] Process 7 In step 7, as shown in the above formula, the compound obtained in step 6 was iodized (solution reaction). The reaction time in step 7 was 1.5 hours.

[0096] Process 8 Finally, step 8 was carried out in which the compound obtained in step 4 (mesogen unit) and the compound obtained in step 7 (counter unit) were linked together. A mesogenic unit (1 equivalent), a counter unit (1 equivalent), Pd(PPh3)2Cl2 (3 mol%), CuI (1 mol%) and DIPA (1.5 equivalents) were placed in a jar, and DIOX was added (η = 0.5 μL / mg) to obtain a T in The mechano-SMC reaction was carried out at 80°C. The reaction was completed in 20 minutes (yield 80%). The crude product was extracted with dichloromethane, washed with water and dried, separated by column chromatography (stationary phase: neutral Al2O3, mobile phase: hexane / dichloromethane = 4 / 6 → dichloromethane), and purified by recrystallization to obtain the target product BIOTN1 (yield 50%).

[0097] The target product BIOTN2 was obtained in the same manner as above, except that in step 5, 3-ethyl-3-oxetanemethanol was used instead of 3-methyl-3-oxetanemethanol. Through the above steps 1 to 8, a novel N having a structure represented by formula (4) was obtained in about 5 hours of synthesis (the total time required for mechanochemical synthesis in step 5 / 8 of the steps was 1.5 hours). F The compounds BIOTN1 (BIOTN1 is a compound represented by the above formula (4) in which Z is a nitro group, X is a fluorine atom, and R is a methyl group) and BIOTN2 (BIOTN2 is a compound represented by the above formula (4) in which Z is a nitro group, X is a fluorine atom, and R is an ethyl group) could be obtained.

[0098] DFT calculation New N F DFT calculations were performed to estimate the dipole moments of compounds BIOTN1 and BIOTN2. First, the structure was optimized using the molecular mechanics method MM2, and then calculations were performed using Gaussian 16 under the conditions of DFT[6-311G+(d,p)], opt=tight, empirical dispersion=gd3bj, int=ultrafine. The calculation took about 43 hours. The results are shown in Figure 1.

[0099] DSC measurement New N F The DSC curves of compounds BIOTN1 and BIOTN2 are shown in FIG. BIOTN1 is transformed from the crystalline phase to N at 222°C. F On cooling, it crystallized at 199 °C, and when heated to 222 °C, it again changed to N F Therefore, the N phase indicated by BIOTN1 F The phase is said to be thermodynamically stable. When heated to 291°C, N F The phase disappeared and transitioned to the isotropic phase. When the isotropic phase was subsequently cooled, N F Liquid crystal droplets appeared. As the liquid crystal cooled, F Although the phase region expanded, it is believed that some of the compounds decomposed because uniform domain formation did not occur.

[0100] [Example 5] Synthesis example of compound nBOE (n = 1 to 8) The nBOE compounds were synthesized according to the scheme shown in the following steps 1 to 9. In the following description, "MC" means a mechanochemical reaction step, and a reaction step without the notation of "MC" means a solution reaction step. [ka] Each step will now be described in detail.

[0101] Step 1: MC-Sonogashira coupling reaction Compound 2 ((4-bromo-3,5-difluorophenyl)ethynyl)triisopropylsilane) was obtained in the same manner as in Step 1 of Example 4. [ka]

[0102] Step 2 MC-Suzuki coupling reaction Next, compounds 4a, 4b and 4c were each synthesized in the same manner as in step 2 of Example 4 or according to a conventional method. [ka]

[0103] Step 3: MC-Miyaura coupling reaction Next, compounds 5a, 5b and 5c were each synthesized in the same manner as in step 3 of Example 4, or according to a conventional method. [ka]

[0104] Step 4: Deprotection of TIPS group with TBAF Next, compounds 6a, 6b and 6c were each synthesized in the same manner as in step 4 of Example 4, or according to a conventional method. [ka]

[0105] Step 5: Iodination reaction Next, compound 8 (tert-butyl 3,5-difluoro-4-iodobenzoate) was synthesized by the following method. LDA (lithium diisopropylamide) was prepared by adding 27.6 mL of n-BuLi (43 mmol, 1.56 M) in hexane to a THF solution (200 mL) of diisopropylamine (6.0 mL, 43 mmol) while maintaining the temperature at -78°C. The mixed solution was stirred while maintaining the temperature at 0°C, and then cooled to -78°C again. To the LDA solution, a THF (10 mL) solution of tert-butyl 3,5-difluorobenzoate (7.7 g, 35.8 mmol) was added, and the mixture was stirred for 30 minutes. Iodine (10 g, 39.4 mmol) was then added to the mixture. After stirring for 5 minutes, the reaction solution was warmed to 0°C and stirred for 1.5 hours. The mixture was poured into ice water and extracted with a mixture of EtOAc and hexane (1:1). The organic layer was dried over Na2SO4. The resulting solution was passed through a short pad of silica gel and further washed with a mixture of hexane and CH2Cl2 (hexane / CH2Cl2 = 1:1). The resulting solution was concentrated and dried under reduced pressure to obtain a brown solid (9.8 g, 28.7 mmol, 80.2%). The NMR of the product is as follows. [ka]

[0106] Step 6: MC-Sonogashira coupling reaction Next, compounds 9a, 9b and 9c were each synthesized by a conventionally known method. [ka]

[0107] Process 7 t Deprotection of BuO group Next, compounds 10a, 10b and 10c were synthesized in the following manner. To a solution of 9a (1.57 g, 3.22 mmol) in CH2Cl2 (18 mL) was added TFA (6 mL) in air at 0°C. After stirring for 1 h, the resulting solution was allowed to warm to room temperature and stirred for an additional 3.5 h. The reaction was quenched by adding water and extracted with CH2Cl2. The organic layer was dried over Na2SO4 and concentrated in vacuo to give 10a as a light brown solid (1.34 g, 3.11 mmol, 96.6%). Compounds 10b and 10c were also synthesized in the same manner, except that compound 9a was replaced with the same molar amount of compound 9b or compound 9c, respectively. [ka]

[0108] Step 8 Esterification reaction Next, compounds 11a, 11b and 11c were synthesized in the following manner. To a solution of compound 10a (620 mg, 1.44 mmol) in CHCl (17 mL), 3-methyl-3-oxetanemethanol (266 mg, 1.68 mmol), EDAC-HCl (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 322 mg, 1.68 mmol) and DMAP (4-dimethylaminopyridine, 51.3 mg, 0.42 mmol) were added in air while maintaining the temperature at 0°C. After stirring for 0.5 h, the solution was allowed to warm to room temperature and stirred for an additional 2 h. The reaction was quenched by adding water and extracted with CHCl. ​​The organic layer was dried over NaSO and concentrated. The crude product was purified by silica gel chromatography (eluent: hexane / CH2Cl2 mixture, 1:4 to 0:100) to obtain compound 11a as a white solid (360 mg, 0.64 mmol, 99%). Compounds 11b-j were synthesized in the same manner except that compound 10a was replaced with the same moles of compound 10b or compound 10c, and 3-alkyl-3-oxetanemethanol having the R shown below was used. [ka] [ka]

[0109] Step 9 Orthoesterification reaction Compounds nBOE (12a-12h), 4BOE-F (12i) and 4BOE-NO2 (12j) were synthesized by the following method. To a solution of 11a (663 mg, 1.19 mmol) in CH2Cl2 (6 mL), BF3-OEt2 (14.7 mL, 0.12 mmol) was added in air while maintaining the temperature at 0°C. After stirring for 1.5 h, the mixture was allowed to warm to room temperature and stirred for an additional 1.5 h to proceed with the reaction. The reaction was quenched by adding Et3N (828 mL, 5.94 mmol) and water, and extracted with CH2Cl2. The organic layer was dried over Na2SO4 and then concentrated. The residue was purified by neutral alumina column chromatography on silica gel (eluent was hexane / CHCl3 1:4 to 1:1) to obtain 12a (512 mg, 0.92 mmol, 77%) as a white solid. Other compounds were synthesized in the same manner. The structures and identification data of the obtained compounds are shown in the following table. [ka] [ka] [ka] [Explanation of symbols]

[0110] 1 Heat gun 2 Heat gun nozzle 3 Jar L Distance between the jar and the nozzle of the heat gun

Claims

1. A method for reacting at least one aldehyde compound with at least one dihydric alcohol compound to cause an acetalization reaction, comprising the steps of: The acetalization method according to claim 1, wherein the acetalization reaction is carried out by providing mechanical energy to an at least partially heterogeneous reaction system and allowing the reaction system to directly absorb the energy.

2. 2. The acetalization process according to claim 1, wherein the acetalization reaction is carried out in the presence of at least one dehydrating agent.

3. The acetalization method according to claim 1, wherein the at least one aldehyde compound is represented by the following formula (II) and the at least one dihydric alcohol is represented by the following formula (III): Esterification reaction; Formula (II) 【Chemistry 1】 In formula (II), "Ar" represents a carbon-based or hetero-based aromatic ring, and Ar may be fused with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with another organic group; Formula (III) 【Chemistry 2】 In formula (III), "R" represents a substituent.

4. A method for producing a liquid crystal compound having a partial structure represented by the following formula (I), A method for producing a liquid crystal compound, comprising a step of reacting at least one aldehyde compound with at least one dihydric alcohol compound to cause an acetalization reaction to proceed, the step being characterized in that the acetalization reaction is caused to proceed by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy; Formula (I) 【Chemistry 3】 In formula (I), "Ar" represents a carbon-based or hetero-based aromatic ring, and may be condensed with one or more other carbon-based and / or hetero-based aromatic rings, and when a ring-constituting atom has a hydrogen atom, one or more hydrogen atoms may be substituted with another organic group; * represents the position where the partial structure represented by formula (I) is bonded to another atom; and the arrow indicates the long axis direction of the liquid crystal.

5. The method for producing a liquid crystal compound according to claim 4, wherein the acetalization reaction is carried out in the presence of at least one dehydrating agent.

6. The method according to claim 4, further comprising at least one step selected from the group of the following reaction steps, wherein the at least one step is carried out by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy. Reaction process group Esterification reactions between monoalcohols and monocarboxylic acids; etherification reactions between mono- or polyhydric alcohols and alkyl halides; oxidation reactions that convert aldehyde groups to carboxyl groups; and cross-coupling reactions.

7. A compound represented by the following formula: 【Chemistry 4】 In the formula, "R" represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, each "X" independently represents a hydrogen atom or a fluorine atom, and "Z" represents a nitro group, a fluorine atom, or a cyano group.

8. A method for producing a compound represented by either formula (4) or (5) according to claim 7, comprising at least one step selected from the group of reaction steps below, the at least one step being characterized in that the at least one step is carried out by providing mechanical energy to an at least partially heterogeneous reaction system and directly absorbing the energy. Reaction process group Esterification reactions between monoalcohols and monocarboxylic acids; etherification reactions between mono- or polyhydric alcohols and alkyl halides; oxidation reactions that convert aldehyde groups to carboxyl groups; and cross-coupling reactions.

9. A device having at least a layer comprising at least one compound according to claim 7.

10. 10. The device of claim 9, wherein in said layer said compound exhibits, at least temporarily, a ferroelectric liquid crystal phase.

11. 11. The device of claim 10, wherein the ferroelectric liquid crystal phase is at least one of a ferroelectric nematic phase and a ferroelectric smectic phase.

12. A film comprising at least one compound according to claim 7 fixed in a given liquid crystal phase.

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