JPH1072472A - Silacyclohexane compound, liquid crystal composition and liquid crystal display element comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject new compound, having a silacyclohexane ring and a cyclohexene ring together in the molecule and useful as a liquid crystal material having a low driving voltage, a wide service temperature range and low-temperature performances, e.g. a liquid crystal material for an on- vehicle liquid crystal display. SOLUTION: This compound is represented by formula I [R is a 1-10C straight-chain alkyl, etc.; ring A is a trans-1-or a trans-4-sila-1,4-cyclohexylene having Si at the l-or the 4-position and the Si having H or a substituent group (G) of F, Cl or methyl; X is H, F, R, OR, etc. ; Y and Z are each H or F; (i) is O or 1 and X is R or OR when (i) is 0], e.g. trans-4-[4-(4- trifluoromethoxyphenyl)cyclohex-3-enyl]-1-n-penty1-1-silacyclohexane. The compound represented by formula I is obtained by reacting a compound represented by formula II (Ar is phenyl; R<2> is R) with a compound represented by formula III [M is represented by the formula MgL (L is a halogen)], providing a compound represented by formula IV, then carrying out the dehydrating reaction and further substituting the Ar with the G.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel silacyclohexane compound, a liquid crystal composition containing the same, and a liquid crystal display device containing the liquid crystal composition.

[0002]

2. Description of the Related Art A liquid crystal display device utilizes an optical anisotropy and a dielectric anisotropy of a liquid crystal material, and depending on the display mode, a TN type (twisted nematic type) and an STN type (super twisted nematic type). , SBE type (super birefringent type),
There are various types such as a DS type (dynamic scattering type), a guest-host type, a DAP type (an alignment phase deformation type) and an OMI type (optical mode interference type). The most common display devices have a twisted nematic structure based on the Schott-Helfrich effect.

The properties required of the liquid crystal material used for these liquid crystal displays slightly vary depending on the display system, but the liquid crystal temperature range is wide, and the liquid crystal is stable against moisture, air, light, heat, an electric field and the like. This is commonly required in any display method. Further, it is desired that the liquid crystal material has a low viscosity and provides a short address time, a low threshold voltage and a high contrast in the cell. At present, no single compound satisfies all of these requirements, and a liquid crystal mixture obtained by mixing several to more than ten kinds of liquid crystal compounds and latent liquid crystal compounds is actually used. Therefore, it is also important that the components are easily miscible with one another.

[0004] Among the liquid crystal compounds that can be these components, the following compounds having a cyclohexene ring in the molecular structure thereof have been known.

Embedded image

[0005]

In recent years, as the applications of liquid crystal displays have expanded, the characteristics required for liquid crystal materials have become increasingly severe and strict. In particular, it has been desired to further enhance the characteristics of conventional liquid crystal materials, such as lowering the driving voltage, widening the temperature range corresponding to the needs for vehicles, and improving low-temperature performance. From such a viewpoint, the present invention relates to a liquid crystal compound newly developed for the purpose of improving the properties of a liquid crystal material, and the feature thereof is that the compound has both a silacyclohexane ring and a cyclohexene ring in a molecular structure.

[0006]

Means for Solving the Problems The present invention provides the following general formula (1)

Embedded image [Wherein R is a linear alkyl group having 1 to 10 carbon atoms,
Represents a branched alkyl group having 3 to 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms;

Embedded image Has silicon in the 1 or 4 position, wherein the silicon is H,
Trans-1- having a substituent of F, Cl or CH ₃
Sila-1,4-cyclohexylene group or trans-4
Represents a sila-1,4-cyclohexylene group, and X is
H, CN, F, Cl, CF ₃ , CF ₂ Cl, CH (F)
Cl, OCF ₃ , OCHF ₂ , OCF ₂ Cl, OCH
(F) Cl, R, OR, (O) _p CY ₁ = CX ₁ X
₂ (p is 0 or 1, Y ₁ and X ₁ are H, F or C
1, X ₂ represents F or Cl. ) Or (O)
_{q (C n H m F 2n} -m) X 3 (q is 0 or 1, n is 2,
3 or 4, m is an arbitrary integer of 0 ≦ m ≦ 2n, and X ₃ represents H, F or Cl. Y and Z are H or F, and i is 0 or 1 (however, when i = 0, X is limited to X = R and OR)]. The present invention also provides a liquid crystal composition comprising the above silacyclohexane compound, and a liquid crystal display device comprising the liquid crystal composition.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail by showing specific examples of the silacyclohexane compound represented by the general formula (1) of the present invention. Examples of the silacyclohexane compound represented by the general formula (1) of the present invention include silacyclohexane compounds having a trans-1- or trans-4-silacyclohexane ring structure as shown below.

Embedded image

These include silacyclohexane in the molecular structure.
And a cyclohexene ring at the same time.
In the above formulas (1a) to (1f), R, R¹(X is R
Or OR = R ¹) Represents one of the following groups
You. (A) a linear alkyl group having 1 to 10 carbon atoms, that is,
Methyl, ethyl, n-propyl, n-butyl, n-pen
Tyl, n-hexyl, n-heptyl, n-octyl, n
-Nonyl or n-decyl. (B) a branched alkyl group having 3 to 8 carbon atoms, that is,
Isopropyl, sec-butyl, isobutyl, 1-methyl
Rubutyl, 2-methylbutyl, 3-methylbutyl, 1-
Methyl pentyl, 2-methyl pentyl, 3-methyl pen
Tyl, 1-ethylpentyl, 1-methylhexyl, 2-
Methylhexyl, 3-methylhexyl, 2-ethylhexyl
Syl, 3-ethylhexyl, 1-methylheptyl, 2-
Methylheptyl, or 3-methylheptyl. (C) an alkoxyalkyl group having 2 to 7 carbon atoms, that is,
Methoxymethyl, ethoxymethyl, propoxymethyl,
Butoxymethyl, pentoxymethyl, hexyloxymethyl
Methoxyethyl, ethoxyethyl, propoxyethyl
, Butoxyethyl, methoxypropyl, ethoxypro
Pill, propoxypropyl, butoxypropyl, methoxy
Cibutyl, ethoxybutyl, propoxybutyl, methoxy
Cipentyl, ethoxypentyl, or methoxyhexyl
Le. (D) an alkenyl group having 2 to 8 carbon atoms, that is, vinyl
, 1-propenyl, allyl, 1-butenyl, 3-butene
Nil, isoprenyl, 1-pentenyl, 3-pentenyl
, 4-pentenyl, dimethylallyl, 1-hexene
, 3-hexenyl, 5-hexenyl, 1-heptenyl
, 3-heptenyl, 6-heptenyl, or 7-octyl
Tenil. (E) C1-C10 mono- or difluoroalkyl
The group: fluoromethyl, 1-fluoroethyl,
1-fluoropropyl, 1-fluorobutyl, 1-fur
Oropentyl, 1-fluorohexyl, 1-fluoro
Butyl, 1-fluorooctyl, 1-fluorononyl,
1-fluorodecyl, 2-fluoroethyl, 2-fluoro
Propyl, 2-fluorobutyl, 2-fluoropent
2-fluorohexyl, 2-fluoroheptyl, 2
-Fluorooctyl, 2-fluorononyl, 2-fluoro
Rodecyl, 3-fluoropropyl, 3-fluorobutyi
3-fluoropentyl, 3-fluorohexyl, 3
-Fluoroheptyl, 3-fluorooctyl, 3-fur
Olononyl, 3-fluorodecyl, 4-fluorobutyi
4-fluoropentyl, 4-fluorohexyl, 4
-Fluoroheptyl, 4-fluorooctyl, 4-fur
Orononyl, 4-fluorodecyl, 5-fluoropentene
5-fluorohexyl, 5-fluoroheptyl, 5
-Fluorooctyl, 5-fluorononyl, 5-fluoro
Rodecyl, 6-fluorohexyl, 6-fluorohepti
6-fluorooctyl, 6-fluorononyl, 6-
Fluorodecyl, 7-fluoroheptyl, 7-fluoro
Octyl, 7-fluorononyl, 7-fluorodecyl,
8-fluorooctyl, 8-fluorononyl, 8-fur
Olodecyl, 9-fluorononyl, 9-fluorodeci
10-fluorodecyl, difluoromethyl, 1,1
-Difluoroethyl, 1,1-difluoropropyl,
1,1-difluorobutyl, 1,1-difluoropent
1,1-difluorohexyl, 1,1-difluoro
Heptyl, 1,1-difluorooctyl, 1,1-diph
Luurononyl, 1,1-difluorodecyl, 2,2-di
Fluoroethyl, 2,2-difluoropropyl, 2,2
-Difluorobutyl, 2,2-difluoropentyl,
2,2-difluorohexyl, 2,2-difluorohep
Chill, 2,2-difluorooctyl, 2,2-difluoro
Lononyl, 2,2-difluorodecyl, 3,3-diflu
Oropropyl, 3,3-difluorobutyl, 3,3-di
Fluoropentyl, 3,3-difluorohexyl, 3,
3-difluoroheptyl, 3,3-difluorooctyl
3,3-difluorononyl, 3,3-difluorode
Sil, 4,4-difluorobutyl, 4,4-difluoro
Pentyl, 4,4-difluorohexyl, 4,4-diph
Luoroheptyl, 4,4-difluorooctyl, 4,4
-Difluorononyl, 4,4-difluorodecyl, 5,
5-difluoropentyl, 5,5-difluorohexyl
5,5-difluoroheptyl, 5,5-difluoro
Octyl, 5,5-difluorononyl, 5,5-diflu
Olodecyl, 6,6-difluorohexyl, 6,6-di
Fluoroheptyl, 6,6-difluorooctyl, 6,
6-difluorononyl, 6,6-difluorodecyl,
7,7-difluoroheptyl, 7,7-difluorooctyl
Chill, 7,7-difluorononyl, 7,7-difluoro
Decyl, 8,8-difluorooctyl, 8,8-diflu
Orononyl, 8,8-difluorodecyl, 9,9-diph
Luurononyl, 9,9-difluorodecyl, 10,10
-Difluorodecyl.

In the above equations (1a) to (1f), G is
H, F, Cl, or CH_ThreeRepresents With the above equation (1e)
In (1f), X is H, CN, F, Cl, C
F_Three, CF _TwoCl, CH (F) Cl, OCF_Three, OCH
F_Two, OCF_TwoCl, OCH (F) Cl, R, OR,
(O)_pCY₁= CX₁X_Two(P is 0 or 1, Y₁You
And X ₁Is H, F or Cl, X_TwoRepresents F or Cl
You. ) Or (O)_q(C_nH_mF_2n-m) X_Three(Q is
0 or 1, n is 2, 3 or 4, m is 0 ≦ m ≦ 2n
Any integer, X_ThreeRepresents H, F or Cl. )
You. In the general formula (1), when i = 0, X is R or
Or OR. For example, in the above equations (1a) to (1d)
Is the case. In the above equations (1e) and (1f), Y, Z
Represents H or F independently of each other.

In the silacyclohexane compound represented by the general formula (1), a partial skeleton structure

Embedded image Specific examples include the following. In the following example, j is 1 ≦ j ≦ 10, lowercase L is 1 ≦ (lowercase L) ≦ 10, and k and h are integers represented by 2 ≦ k + h ≦ 7.

Embedded image

Embedded image

Embedded image

Among the silacyclohexane compounds represented by the general formula (1) described above, the following are preferred. Silacyclohexane compound (1) of the present invention
As the ring structure of (1a), (1c),
(1e). .

The silacyclohexane compound (1) of the present invention
In the above, R is preferably any one of the following groups. The same applies to R ¹ in formulas (1a) to (1f). (F) a linear alkyl group having 2 to 7 carbon atoms, that is, ethyl, n-propyl, n-butyl, n-pentyl, n-
Hexyl, or n-heptyl. (G) Among the branched alkyl groups having 3 to 8 carbon atoms, isopropyl, sec-butyl, isobutyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-methylpentyl, 2-methylpentyl, or 2 -Ethylhexyl. (H) an alkoxyalkyl group having 2 to 6 carbon atoms, that is, methoxymethyl, ethoxymethyl, propoxymethyl,
Pentoxymethyl, methoxyethyl, ethoxyethyl,
Methoxypropyl, or methoxypentyl. (I) Among alkenyl groups having 2 to 8 carbon atoms, vinyl, 1
-Propenyl, 3-butenyl, 1-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 5-hexenyl, 6-heptenyl, or 7-octenyl. (J) Among mono- or difluoroalkyl groups having 2 to 7 carbon atoms, 2-fluoroethyl, 2-fluoropropyl,
2-fluorobutyl, 2-fluoropentyl, 2-fluorohexyl, 2-fluoroheptyl, 4-fluorobutyl, 4-fluoropentyl, 4-fluorohexyl,
4-fluoroheptyl, 5-fluoropentyl, 5-fluorohexyl, 5-fluoroheptyl, 6-fluorohexyl, 6-fluoroheptyl, 7-fluoroheptyl, 2,2-difluoroethyl, 2,2-difluoropropyl, 2 , 2-Difluorobutyl, 2,2-difluoropentyl, 2,2-difluorohexyl, 2,2-difluoroheptyl, 4,4-difluorobutyl, 4,4
-Difluoropentyl, 4,4-difluorohexyl,
4,4-difluoroheptyl, 5,5-difluoropentyl, 5,5-difluorohexyl, 5,5-difluoroheptyl, 6,6-difluorohexyl, 6,6-difluoroheptyl, or 7,7-difluoroheptyl.

The silacyclohexane compound (1) of the present invention
In, for example, in the case of the equations (1a) to (1f),
For G, preferably, H, F or CH _3,.

The silacyclohexane compound (1) of the present invention
In the partial skeleton

Embedded image Is preferably as follows.

Embedded image

Embedded image

[0015] Of the above,

Embedded image Indicates that Δε is close to zero,

Embedded image Indicates that Δε has a negative value.

Next, a method for producing the silacyclohexane compound represented by the general formula (1) of the present invention will be described. [I] Ring skeleton forming reaction [I] —Ring skeleton forming reaction of compounds represented by formulas (1a), (1c) and (1e) represented by formulas (1a), (1c) and (1e) The ring skeleton forming reaction of the compound will be described in detail below.

Embedded image In the above formula, Ar is a phenyl or tolyl group, M is M
gL (L is halogen, preferably Cl, Br, I), Z
represents nL or Li. R ² represents R or Ar.
"*" Indicates a step of introducing a substituent onto silicon, and the term [I
I] will be described later. R, R ¹ , G, X, Y, and Z are the same as defined above.

The silacyclohexylcyclohexanone compound used as a starting material here is obtained, for example, according to the method described in Japanese Patent Application No. 6-154219.
This compound is reacted with an alkyl metal reagent R ¹ M to obtain a cyclohexanol compound, which is then dehydrated to obtain a cyclohexene compound. This is called [II]
By introducing various substituents onto silicon according to the method described in the above, a compound of the general formula (1a), which is the target product, is obtained. Further, a cyclohexanol compound is obtained by reacting a silacyclohexylcyclohexanone compound with a phenyl metal compound, and then a cyclohexene compound is obtained by dehydration, and then various substituents are introduced on silicon according to the method described in [II]. By the general formula (1)
The compound of e) is obtained. Further, this compound is reacted with R ¹ OH under acidic conditions to obtain a ketal compound, and then de-R ¹ OH is removed with a base to obtain an enol ether compound. By introducing various substituents into the above, a compound of the general formula (1c), which is the target product, is obtained.

[I]-general formulas (1b), (1d),
Ring skeleton forming reaction of compound represented by (1f) The ring skeleton forming reaction of the compound represented by formulas (1b), (1d) and (1f) will be described in detail below.

Embedded image In the above formula, the phenylcyclohexenyl metal reagent (i
), An alkylcyclohexenyl metal reagent (ii) and an alkoxycyclohexenyl metal reagent (iii) are obtained as follows.

Embedded image In the above formula, Ar is a phenyl or tolyl group, M is M
gL (L is halogen, preferably Cl, Br, I), Z
represents nL or Li. “*” Indicates a step of introducing a substituent onto silicon, which will be described later in section [II]. G ¹ represents halogen, G ² represents halogen or Ar. R, R ¹ ,
G, X, Y, and Z are the same as defined above.

The silacyclohexanone compound used as a starting material is described in, for example, Japanese Patent Application No. 6-78125.
Obtained according to the method described in

A cyclohexanol compound is obtained by reacting cyclohexanedione monoethylene ketal with a phenyl metal reagent and then dehydrated to obtain a silacyclohexenephenyl compound, which is then treated with an acidic aqueous solution to obtain a phenylcyclohexenone compound. This compound and NaBH
₄ or a metal hydride such as LiAlH ₄ to obtain a cyclohexanol compound, and then to react with a brominating agent such as N-bromosuccinimide or Br ₂ to obtain a cyclohexyl bromide compound. Reaction with zinc gives phenylcyclohexenyl metal reagent (i). Similarly, an alkylcyclohexenyl metal reagent (ii) is obtained from cyclohexanedione monoethylene ketal and an alkyl metal reagent. Furthermore, cyclohexanedione monoethylene ketal is reacted with R ¹ OH under acidic conditions to obtain a ketal compound, and then de-R ¹ OH is removed with a base to obtain an enol ether compound, followed by the same steps as those described above. An alkoxycyclohexenyl metal reagent (iii) is obtained. On the other hand, a diarylsilacyclohexanone and a phosphorus ylide prepared from an alkyltriphenylphosphonium halide are reacted to form a silacyclohexylidene compound,
Next, after hydrogenation in the presence of a hydrogenation catalyst, a halosilacyclohexane compound is obtained by a desilylation reaction using an electrophile. This is reacted with an alkylcyclohexenyl metal reagent (ii), and then various substituents are introduced onto silicon according to the method described in the item [II] to obtain a target compound of the general formula (1b). Similarly, from the reaction with the phenylcyclohexenyl metal reagent (i), the compound represented by the general formula (1f)
A compound of an alkoxycyclohexenyl metal reagent (iii
) Gives a compound of general formula (1d).

[II] Method for Introducing Various Substituents on Silicon General Formula

Embedded image In out represented by silacyclohexane compound, R ² is R
Aryl silacyclohexane compound represented by the general formula

Embedded image Is converted into chlorosilacyclohexane, fluorosilacyclohexane, hydrosilacyclohexane, and methylsilacyclohexane compounds according to the reaction formula of the partial structural formula shown below.

[0022]

Embedded image [In the above formula, Ar represents a phenyl group or a tolyl group. M
Is MgL (L is a halogen atom, preferably Cl, B
r and I are represented. ), ZnL or Li. ]

The arylsilacyclohexane compound is subjected to a desilylation reaction with an electrophile to give a halosilacyclohexane, typically a chlorosilacyclohexane compound (in the general formulas (1a) to (1f), G is Cl). Can be At this time, examples of the electrophilic reagent include halogen, hydrogen halide, metal halide, sulfonic acid derivative, acid halide, and alkyl halide. In particular, iodine, chlorine, iodine monochloride, hydrogen chloride, hydrogen bromide, hydrogen iodide, mercury (II) chloride, trimethylsilyl chlorosulfonate, acetyl chloride, acetyl bromide, benzoyl chloride, tert-butyl chloride and the like are preferable. To increase the reaction rate, Lewis acids such as aluminum chloride, zinc chloride, titanium tetrachloride, and boron trifluoride may be added, or light irradiation may be performed.

The obtained chlorosilacyclohexane compound is reacted with a fluoride salt such as cesium fluoride, copper (I) fluoride, zinc fluoride, antimony fluoride, calcium fluoride, tetra-n-butylammonium fluoride and the like. Then, a fluorosilacyclohexane compound (general formula (1)
a) to (1f) when G is F).

In the obtained chlorosilacyclohexane compound, CH ₃ M (M is MgL (L is a halogen atom,
Preferably, it represents Cl, Br or I. ), ZnL or L
represents i. Is reacted with a methylsilacyclohexane compound (G is CH in general formulas (1a) to (1f)).
₃ ) is obtained.

The chlorosilacyclohexane compound or fluorosilacyclohexane compound is reduced to give a hydrosilacyclohexane compound (general formula (1a)
To (1f) when G is H). At this time, as the reducing agent, metal hydrides such as sodium hydride, calcium hydride, trialkylsilanes, borane, and dialkylaluminum, and complex hydrogens such as lithium aluminum hydride, potassium borohydride, and tributylammonium borohydride Compound (Complex)
hydride) and their substituted hydride compounds, that is, lithium trialkoxyaluminum hydride, sodium di (methoxyethoxy) aluminum hydride, lithium triethylborohydride, sodium cyanoborohydride and the like.

Further, the aforementioned general formula

Embedded image In out represented by silacyclohexane compound, R ² is A
The diarylsilacyclohexane compound represented by r is converted into a chlorosilacyclohexane, fluorosilacyclohexane, hydrosilacyclohexane, and methylsilacyclohexane compound according to the reaction formula of the partial structural formula shown below.

Embedded image

The substituent forming reactions i) to xii) in the above reaction formula will be described in detail below. (A) i) is converted into a halosilacyclohexane, typically a chlorosilacyclohexane compound ii), by a desilylation reaction with an electrophile. In addition, viii) can be obtained by repeating this desilylation reaction. At this time, as the electrophile, halogen, hydrogen halide,
Metal halides, sulfonic acid derivatives, acid halides,
Examples thereof include alkyl halides. In particular, iodine, chlorine, iodine monochloride, hydrogen chloride, hydrogen bromide, hydrogen iodide, mercury (II) chloride, trimethylsilyl chlorosulfonate, acetyl chloride, acetyl bromide, benzoyl chloride, tert-butyl chloride and the like are preferable. To increase the reaction rate, Lewis acids such as aluminum chloride, zinc chloride, titanium tetrachloride, and boron trifluoride may be added, or light irradiation may be performed. (B) ii) reacting with an organometallic reagent that is CH ₃ M (M is MgL (L represents a halogen atom, preferably Cl, Br, I), ZnL or Li) or RM; Obtain iii) or iv). (C) From iv) in the same manner as from i) to ii)
v) (a compound in which G is Cl in the general formulas (1a) to (1f)) is obtained. (D) reduction of v) to give vi) (general formulas (1a) to
(Compound in which G is H in (1f)). At this time, as the reducing agent, metal hydrides such as sodium hydride, calcium hydride, trialkylsilanes, borane, and dialkylaluminum, and complex hydrogens such as lithium aluminum hydride, potassium borohydride, and tributylammonium borohydride Compound (Complex hy
and its substituent hydride compounds, that is, lithium triethylborohydride, sodium di (methoxyethoxy) aluminum hydride, lithium triethylborohydride, sodium cyanoborohydride and the like. vi) is also ii) to i
x) can be obtained in the same way as v). (E) v) cesium fluoride, copper (I) fluoride, zinc fluoride, antimony fluoride, calcium fluoride, tetra-
Reaction with a fluoride salt such as n-butylammonium fluoride, and halogen exchange by vii) (general formula (1a)-
(Compound in which G is F in (1f)). (F) viii) to xi) or v) are obtained in the same manner as in the method for obtaining ii) to iii) and ii) to iv). Vi)
Can also be obtained from iii) in the same way as from i) to ii). (G) vix) to ix) are obtained in the same manner as in the method for obtaining vi) from v). (H) ix) is reacted with a halogen such as chlorine, bromine, iodine, iodine chloride or a halogenating agent such as copper chloride and copper iodide to obtain x). (I) From xi) in the same manner as from ii) to iv)
xii) (in the general formulas (1a) to (1f), G is CH ₃
Is obtained.

However, when R is a fluoroalkyl group, when introducing a substituent R on silicon, first, a substituent R having a silyl ether group such as a dimethyl tertiary butyl silyl ether group is introduced, and then, TBAF
(Tetrabutylammonium fluoride) and the like, after deprotection to give an alcohol,
Fluorination with a fluorinating agent such as ST (diethylaminosulfur trifluoride).

Embedded image (In the above formula, a and b are integers represented by 0 ≦ a + b ≦ 9.)

When R has two fluorine atoms on one carbon atom, when introducing a substituent R on silicon,
After introducing a substituent R having a carbonyl group protected by acetal or ketal, and then deprotecting, DAST
Difluorination with a fluorinating agent such as

Embedded image (In the above formula, a and b are integers represented by 0 ≦ a + b ≦ 9.)

[III] Formation method when X is a functional group having a CN or —CHF— unit In (1e) and (1f), X contains CN or —CH
The skeleton-forming reaction in the case where an F-unit is contained is performed according to the following method.

[III]-When X is CN A skeleton-forming reaction is carried out beforehand with a compound in which the position at which the cyano group is to be introduced is substituted by a halogen group such as Br, and then TH
A Grignard reagent is prepared in a solvent such as F (tetrahydrofuran). Next, cyanodiene (NC-CN),
Cyanogen bromide (NC-Br), cyanogen chloride (NC-Cl)
To introduce a cyano group. Alternatively, in a solvent such as DMF (dimethylformamide)
Reaction with a cyanating agent such as uCN to directly introduce a cyano group.

Embedded image The introduction of the cyano group is performed prior to or subsequent to the introduction of the substituent on silicon.

[III] -X is a fluoroalkoxy group For example, in DMEU (1,3-dimethyl-2-imidaridinone), after reacting with NaH to form a sodium salt of phenol, HyFA-Q [HyFA is A fluoroalkyl group, Q is a halogen atom (preferably Cl, B
r, I), an alkoxy group (preferably having 1 to 4 carbon atoms),
It represents a methanesulfonyloxy group, a benzenesulfonyloxy group, a p-toluenesulfonyloxy group, and a trifluoromethanesulfonyloxy group. To introduce a fluoroalkoxy group.

Embedded image The introduction of the fluoroalkoxy group is performed prior to or subsequent to the introduction of the substituent on silicon.

[III]-When X is a fluoroalkyl group: A skeleton-forming reaction is carried out beforehand with a compound in which the position at which the fluoroalkyl group is to be introduced is substituted by a halogen group such as Br, and metallization is carried out in a solvent such as THF. The reagent is used as an organometallic reagent, and is reacted with HyFA-Q in the presence of a catalyst to introduce a fluoroalkyl group. Examples of the metallizing reagent used at this time include metal lithium, metal magnesium, n-butyllithium, sec-butyllithium, t-butyllithium, lithium diisopropylamide and the like.

Embedded image (In the above formula, L represents a halogen atom.) This introduction of the fluoroalkyl group is performed before or after the introduction of the substituent onto silicon.

[III]-When X is a halogenated vinyloxy group After introducing a fluoroalkoxy group in accordance with the above item [III]-, it is dehydrofluorinated on the basis of t-BuOK or the like to form a halogenated vinyloxy group. .

Embedded image (HyFAE represents a halogenated vinyl group.) The introduction of the halogenated vinyloxy group is performed prior to or subsequent to the introduction of the substituent on silicon.

[III]-When X is a vinyl halide group After introducing a fluoroalkyl group according to the above item [III]-, the compound is dehydrofluorinated on a base such as t-BuOK to form a vinyl halide group. .

Embedded image Alternatively, it can be obtained by reacting the above Grignard reagent with HyFAE-Q in the presence of a catalyst.

Embedded image The introduction of the vinyl halide group is carried out prior to or subsequent to the introduction of the substituent on silicon.

When the compound synthesized as described above is a mixture of a trans-form and a cis-form in the conformation of the silacyclohexane ring, the compound is purified by a conventional purification means such as chromatography or recrystallization. By separating and purifying the trans form, the silacyclohexane compound of the general formula (1) of the present invention can be obtained.

The liquid crystal composition can be obtained by mixing the silacyclohexane compound of the present invention with a known compound.
The compound used for forming a liquid crystal phase by mixing with the silacyclohexane compound of the present invention can be selected from the following known compounds.

Embedded image In the above formula, (M ′) and (N ′) represent any of the following: One or more F as unsubstituted or as a substituent,
Cl-1, Br, CN, trans-1, having an alkyl group
4-cyclohexylene group trans- wherein one or two non-adjacent CH ₂ groups in the cyclohexane ring are replaced by O, S
1,4-cyclohexylene group 1,4-cyclohexenylene group One or two F or C as unsubstituted or substituted
1,4-phenylene group having l, CH ₃ or CN group 1,4-phenylene group wherein one or two CH groups in the ring are replaced by N atoms

In the above formula, Z ¹ and Z ² represent —CH ₂ CH
_{2 -, - CH = CH -} , - C≡C -, - CO 2 -, - O
_{CO -, - CH 2 O -} , - represents a single bond or - OCH _2. In the above formula, w and r are 0, 1, 2 (provided that w +
r = 1, 2, 3), and s is 0, 1, 2. In the above formula,
R ′ is hydrogen, a linear alkyl group having 1 to 10 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, a branched-chain alkyl group having 3 to 8 carbon atoms, and an alkoxy having 2 to 7 carbon atoms. It is an alkyl group or an alkenyl group having 2 to 8 carbon atoms. In the above formula, X ′ is CN, F, Cl, CF ₃ , CF ₂
Cl, CH (F) Cl, OCF ₃ , OCHF ₂ , OCF
₂ Cl, OCH (F) Cl, alkenyloxy group, fluoroalkoxy group, linear alkyl group having 1 to 10 carbon atoms, alkoxy group or alkanoyloxy group, Y ′
Represents H or F, and Z ′ represents H or F. In the above, when w and s are 2, in (M '),
When r is 2, (N ′) may contain a heterocyclic ring.

The proportion of the silacyclohexane compound represented by the general formula (1) of the present invention in the liquid crystal phase may be one or two or more of 1 to 50 mol%, preferably 5 to 30 mol%.
mol%. The liquid crystal composition has a general formula for producing a colored guest-host system.

Embedded image (In the above formula, R ″ and R ″ ′ are a substituted or unsubstituted alkyl group or dialkylamino group, and in the case of a substituted alkyl group, those substituted with a plurality of fluorine atoms or in the chain Non-adjacent —CH ₂ — is O, S, NH, S
O ₂ , O ₂ C, or

Embedded image Represents those substituted with Z ^{1 to} Z ⁹ represent hydrogen, a methyl group, a methoxy group, or a halogen group. Further, Z ¹ and Z ² , Z ⁴ and Z ⁵ , Z ⁷ and Z ⁸ can be connected to each other to form an aliphatic ring, an aromatic ring, or a nitrogen-containing aromatic ring. Y ″ represents a fluoroalkyl group, t =
0, 1, 2, u = 0, 1, 2, v = 0, 1, where u
Whenever = 0, v = 0. An azo dye represented by the general formula

Embedded image (Where X ^{1 to} X ⁵ are H, OH, halogen, CN,
Unsubstituted or substituted amino group, unsubstituted or substituted carboxylic ester, unsubstituted or substituted phenyloxy group, unsubstituted or substituted benzyl group, unsubstituted or substituted phenylthio group, unsubstituted or Represents a substituent-containing phenyl group, an unsubstituted or substituted cyclohexyloxycarbonyl group, or an unsubstituted or substituted pyridyl or pyrimidyl group. ), Or an additive for changing the dielectric anisotropy, viscosity, and orientation of the nematic phase.

The liquid crystal phase thus formed is sealed between transparent substrates having electrodes of a desired shape and used as a liquid crystal display device. This element may have various undercoats, overcoats for controlling alignment, polarizing plates, filters, reflection layers, and the like, as necessary. In addition, various kinds of devices such as a multilayer cell, a combination with another display element, a semiconductor substrate, or a light source can be used.

The driving method of the liquid crystal display element includes a dynamic scattering (DSM) method, a twisted nematic (TN) method, a super twisted nematic (STN) method, a guest host (GH) method, and a polymer dispersed liquid crystal (PDLC) method. For example, a method known in the liquid crystal display element industry can be employed.

The liquid crystal composition of the present invention used in the liquid crystal display device may further comprise a polychromatic dye for forming a colored guest-host system or a chiral doping agent for imparting a twist direction and strength. Can be contained. This additive-containing liquid crystal composition is formed by TFT or M
It is used as a liquid crystal display element by being enclosed between transparent substrates on which active elements such as IMs are formed. This element may have various undercoats, alignment control overcoats, polarizing plates, filters, reflective layers, and the like, if necessary. In addition, various kinds of devices such as a multilayer cell, a combination with another display element, a semiconductor substrate, or a light source can be used.

[0044]

The present invention will be described below in more detail with reference to specific examples. "Example 1" trans-4- (4- (4-trifluoromethoxyphenyl) cyclohex-3-enyl) -1
Production of -n-pentyl-1-silacyclohexane 28.9 g of 4-trifluoromethoxybromobenzene
(0.12 mol) to 2.92 g of magnesium (0.1
2 mol) and 100 ml of THF, and the mixture was refluxed for 3 hours to obtain a Grignard reagent. This is 4
-(4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone 34.2 g (0.10 mo
50 m of the THF solution of 1) was added dropwise. After refluxing for 2 hours, the reaction mixture was cooled to room temperature, poured into a saturated aqueous solution of ammonium chloride, and extracted with benzene. Add p to this benzene solution
-1 g of toluenesulfonic acid was added, and the generated water was separated and removed while refluxing. When no more water was distilled off, the mixture was cooled to room temperature. The reaction mixture was poured into a saturated aqueous solution of sodium bicarbonate, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography to give 4- (4-
(4-trifluoromethoxyphenyl) cyclohex-
3-enyl) -1-n-pentyl-1-phenyl-1-
Silacyclohexane was obtained. 100 ml of a dichloromethane solution of 1 mol / l iodine monochloride was added thereto, followed by stirring for 1 hour. Subsequently, 30 ml of methanol and 30 ml of triethylamine were added to this solution, followed by stirring for 1 hour.
After the reaction mixture was filtered and concentrated, it was added to 100 ml of THF.
, 5.0 g of lithium aluminum hydride and TH
F50 was added to the mixture. The reaction mixture was refluxed for 1 hour, poured into 200 ml of 10% hydrochloric acid, and extracted with ethyl acetate. After usual washing, drying and concentration, the residue was purified by silica gel chromatography, followed by recrystallization to obtain 20.5 g (yield 50%) of the desired trans isomer. IR (KBr disc) ν _max : 2918, 284
8, 2104, 1510, 1279, 1219, 116
3,887,858,802 cm ^-1 smectic-nematic transition temperature T _SN : 49 ° C Nematic-isotropic transition temperature T _NI : 107 ° C

Example 2 Trans-4- (4-
Production of (3,4-difluorophenyl) cyclohex-3-enyl) -1-n-pentyl-1-silacyclohexane Instead of 4-trifluoromethoxybromobenzene in Example 1, 3,4-difluorobromobenzene was used. Using the same procedure as in Example 1, the desired product was obtained.

Example 3 Trans-4- (4-
(3,4,5-trifluorophenyl) cyclohex-
Production of 3-enyl) -1-n-pentyl-1-silacyclohexane The same method as in Example 1 except that 3,4,5-trifluorobromobenzene was used instead of 4-trifluoromethoxybromobenzene in Example 1. The desired product was obtained by the operation.

Example 4 Trans-4- (4- (4
-Methoxyphenyl) cyclohex-3-enyl) -1
Production of -n-propyl-1-silacyclohexane 4-methoxybromobenzene was used instead of 4-trifluoromethoxybromobenzene in Example 1, and 4- (4-n
-Pentyl-4-phenyl-4-silacyclohexyl)
4- (4-n-propyl-) instead of cyclohexanone
Using 4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 5 Trans-4- (4- (4
-Fluorophenyl) cyclohex-3-enyl) -1
Production of-(4-pentenyl) -1-silacyclohexane 4-fluorobromobenzene was used in place of 4-trifluoromethoxybromobenzene in Example 1, and 4- (4-n
-Pentyl-4-phenyl-4-silacyclohexyl)
Using 4- (4- (4-pentenyl) -4-phenyl-4-silacyclohexyl) cyclohexanone instead of cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 6 Trans-4- (4- (4
-Chlorophenyl) cyclohex-3-enyl) -1-
Production of (3-methoxypropyl) -1-silacyclohexane 4-chlorobromobenzene was used instead of 4-trifluoromethoxybromobenzene in Example 1, and 4- (4-n-
Using 4- (4- (3-methoxypropyl) -4-phenyl-4-silacyclohexyl) cyclohexanone instead of pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone, in the same manner as in Example 1, I got

Example 7 Trans-4- (4- (4
-Methylphenyl) cyclohex-3-enyl) -1-
Production of (3-methylbutyl) -1-silacyclohexane Instead of 4-trifluoromethoxybromobenzene of Example 1, 4-methylbromobenzene was replaced with 4- (4-n-
Using 4- (4- (3-methylbutyl) -4-phenyl-4-silacyclohexyl) cyclohexanone instead of pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1. Obtained.

Example 8 Trans-4- (4-
Preparation of (2,3-difluoro-4-methoxyphenyl) cyclohex-3-enyl) -1-n-pentyl-1-silacyclohexane Instead of 4-trifluoromethoxybromobenzene of Example 1, 2,3- Using difluoro-4-methoxybromobenzene, the desired product was obtained in the same manner as in Example 1.

Example 9 trans-4- (4-methylcyclohex-3-enyl) -1-n-pentyl-1
-Production of silacyclohexane The target compound was obtained in the same manner as in Example 1 except that methyl chloride was used instead of 4-trifluoromethoxybromobenzene in Example 1.

Example 10 trans-4- (4-ethylcyclohex-3-enyl) -1-n-propyl-
Preparation of 1-silacyclohexane In place of 4-trifluoromethoxybromobenzene in Example 1, ethyl bromide was used instead of 4- (4-n-pentyl-
4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone was used in place of 4-phenyl-4-silacyclohexyl) cyclohexanone,
The target product was obtained in the same manner as in Example 1.

Example 11 Trans-4- (4-
(3-methoxypropyl) cyclohex-3-enyl)
Preparation of -1-n-propyl-1-silacyclohexane In place of 4-trifluoromethoxybromobenzene in Example 1, 3-methoxypropyl bromide was replaced with 4- (4-
Using 4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone instead of n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1. Obtained.

Example 12 Trans-4- (4-
(4-pentenyl) cyclohex-3-enyl) -1-
Preparation of n-propyl-1-silacyclohexane 4-pentenyl bromide was used in place of 4-trifluoromethoxybromobenzene in Example 1 and 4- (4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone Instead, 4- (4-n-propyl-4-
Using phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 13 Preparation of trans-4- (4-methylcyclohex-3-enyl) -1- (3-methoxypropyl) -1-silacyclohexane 4-trifluoromethoxybromobenzene of Example 1 In place of methyl chloride, 4- (4-n-pentyl-
4- (4- (3-methoxypropyl)-instead of 4-phenyl-4-silacyclohexyl) cyclohexanone
Using 4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 14 Trans-4- (4-n
Preparation of -propylcyclohex-3-enyl) -1- (1-propenyl) -1-silacyclohexane In place of 4-trifluoromethoxybromobenzene in Example 1, n-propylbromide was replaced with 4- (4-n 4- (4- (1-propenyl)-instead of -pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone
Using 4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 15 Trans-4- (4-n
Preparation of -propylcyclohex-3-enyl) -1- (3-methylbutyl) -1-silacyclohexane In place of 4-trifluoromethoxybromobenzene in Example 1, n-propylbromide was replaced with 4- (4-n -Pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone instead of 4- (4- (3-methylbutyl)
Using -4-phenyl-4-silacyclohexyl) cyclohexanone, the desired product was obtained in the same manner as in Example 1.

Example 16 Trans-4- (4-
(3,5-difluoro-4-difluoromethoxyphenyl) cyclohex-3-enyl) -1-n-pentyl-
Production of 1-silacyclohexane 3,5-difluoro-4- (t-butyldimethylsiloxy) -1-bromobenzene 38.8 g (0.12 mol)
l) was dropped into a mixture of 2.92 g (0.12 mol) of magnesium and 100 ml of THF, and refluxed for 3 hours to obtain a Grignard reagent. To this was added dropwise 50 ml of a THF solution of 34.2 g (0.10 mol) of 4- (4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone. After refluxing for 2 hours, the reaction mixture was cooled to room temperature, poured into a saturated aqueous solution of ammonium chloride, and extracted with benzene. 1 g of p-toluenesulfonic acid was added to this benzene solution, and the generated water was separated and removed while refluxing. When no more water was distilled off, the mixture was cooled to room temperature. The reaction mixture was poured into a saturated aqueous solution of sodium hydrogencarbonate, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography to give 4- (4- (3,5-difluoro-4- (t-butyldimethylsiloxy). ) Phenyl) cyclohex-3-enyl) -1-n-pentyl-
1-phenyl-1-silacyclohexane was obtained. 100 ml of a THF solution of 1 mol / l tetra-n-butylammonium fluoride was added thereto, and the mixture was stirred for 1 hour. The reaction mixture is poured into 100 ml of 10% hydrochloric acid,
After drying and concentration, the residue was purified by silica gel chromatography. Then, this was dissolved in 50 ml of THF,
50 ml of a 20% aqueous sodium hydroxide solution and 3.4 g of tetra-n-butylammonium hydrogen sulfate were added, and the reaction was carried out by bubbling difluorochloromethane. Pour the reaction mixture into 100 ml of 20% hydrochloric acid
After concentration, the residue was purified by silica gel chromatography to give 4- (4- (3,5-difluoro-4-difluoromethoxyphenyl) cyclohex-3-enyl) -1-.
There was obtained n-pentyl-1-phenyl-1-silacyclohexane. 100 ml of a dichloromethane solution of 1 mol / l iodine monochloride was added thereto, followed by stirring for 1 hour. Subsequently, 30 ml of methanol and 30 ml of triethylamine were added to this solution, followed by stirring for 1 hour. Filter the reaction mixture
After concentration, this was dissolved in 100 ml of THF and added to a mixture of 5.0 g of lithium aluminum hydride and 50 ml of THF. The reaction mixture was refluxed for 1 hour, poured into 200 ml of 10% hydrochloric acid, and extracted with ethyl acetate. Normal cleaning
After drying and concentration, the residue was purified by silica gel chromatography, followed by recrystallization to obtain the desired trans isomer 1
6.3 g (38% yield) were obtained.

Example 17 Trans-4- (4-
Preparation of (3-fluoro-4-difluoromethoxyphenyl) cyclohex-3-enyl) -1-n-propyl-1-silacyclohexane 3,5-difluoro-4- (t-butyldimethylsiloxy) of Example 16 Instead of -1-bromobenzene, 3
-Fluoro-4- (t-butylmethylsiloxy) -1-
The bromobenzene was prepared by using 4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone instead of 4- (4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone. 1
By the same operation as in 6, the desired product was obtained.

Example 18 Trans-4- (4-
(3,5-difluoro-4- (2,2-difluoroethoxy) phenyl) cyclohex-3-enyl) -1-n
Preparation of -propyl-1-silacyclohexane 4- (4-n-pentyl-4-phenyl- of Example 16
4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone was used in place of 4-silacyclohexyl) cyclohexanone, and 4- (4- (3,5- Difluoro-4-hydroxyphenyl) cyclohex-3-enyl) -1-
There was obtained n-propyl-1-phenyl-1-silacyclohexane. Subsequently, this was added to DMEU (1,3-dimethyl-2).
-Imidaridinone) in 50 ml and added dropwise to 50 ml of a 2 mol / l solution of sodium hydride in DMEU at room temperature. One hour later, 2,2-difluoroethyl bromide 1
7.4 g (0.12 mol) was added dropwise and stirred for 3 hours.
The reaction mixture was poured into 10% hydrochloric acid, and after ordinary washing, drying and concentration, the residue was purified by silica gel chromatography to give 4- (4- (3,5-difluoro-4- (2,2-difluoroethoxy)). Phenyl) cyclohex-3-enyl) -1-n-propyl-1-phenyl-1-silacyclohexane was obtained. To this was added 100 ml of a 1 mol / l iodine monochloride dichloromethane solution, and the mixture was stirred for 1 hour. Subsequently, 30 ml of methanol and 30 ml of triethylamine were added to this solution, followed by stirring for 1 hour. After the reaction mixture was filtered and concentrated, it was dissolved in 100 ml of THF, and 5.0 g of lithium aluminum hydride and 50 ml of THF were added.
ml of the mixture. The reaction mixture was refluxed for 1 hour, poured into 200 ml of 10% hydrochloric acid, and extracted with ethyl acetate. After ordinary washing, drying and concentration, the residue was purified by silica gel chromatography, followed by recrystallization to obtain the desired trans isomer.

Example 19 Trans-4- (4-
(3,5-difluoro-4- (2,2-difluoroethenyloxy) phenyl) cyclohex-3-enyl)-
Production of 1-n-propyl-1-silacyclohexane Using 2,2,2-trifluoroethyl bromide instead of 2,2-difluoroethyl bromide of Example 18,
In the same manner as in Example 18, 4- (4- (3,5-difluoro-4- (2,2,2-trifluoroethoxy) phenyl) cyclohex-3-enyl) -1-n-propyl-1 -Phenyl-1-silacyclohexane was obtained. Subsequently, this was dissolved in 50 ml of THF, and 2 mol / l of t-
It was added dropwise to 50 ml of a THF solution of potassium butoxide under ice-cooling. After 1 hour, the reaction mixture was poured into 10% hydrochloric acid, washed, dried and concentrated as usual. The residue was purified by silica gel chromatography to give 4- (4- (3,5-difluoro-).
4- (2,2-difluoroethenyloxy) phenyl)
(Cyclohex-3-enyl) -1-n-propyl-1-
Phenyl-1-silacyclohexane was obtained. 1m to this
ol / l dichloromethane solution of iodine monochloride 100m
was added and stirred for 1 hour. Subsequently, 30 ml of methanol and 30 ml of triethylamine were added to this solution to prepare a solution.
Stirred for hours. After filtering and concentrating the reaction mixture,
It was dissolved in 100 ml of HF and added to a mixture of 5.0 g of lithium aluminum hydride and 50 ml of THF. The reaction mixture was refluxed for 1 hour, poured into 200 ml of 10% hydrochloric acid, and extracted with ethyl acetate. After ordinary washing, drying and concentration, the residue was purified by silica gel chromatography, followed by recrystallization to obtain the desired trans isomer.

Example 20 Trans-4- (4-
(4-cyanophenyl) cyclohex-3-enyl)-
Production of 1-n-propyl-1-silacyclohexane 2-trimethylsilyl-1-bromobenzene 27.5 g
(0.12 mol) to 2.92 g of magnesium (0.1
2 mol) and 100 ml of THF, and refluxed for 3 hours to obtain a Grignard reagent. This is 4
-(4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone 31.4 g (0.10 mo
l) of a THF solution (50 ml) was added dropwise. After refluxing for 2 hours,
The reaction mixture was cooled to room temperature, poured into a saturated aqueous solution of ammonium chloride, and extracted with benzene. 1 g of p-toluenesulfonic acid was added to this benzene solution, and the generated water was separated and removed while refluxing. When no more water was distilled off, the mixture was cooled to room temperature. The reaction mixture was poured into a saturated aqueous solution of sodium hydrogen carbonate, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography to give 4- (4
-(4-trimethylsilylphenyl) cyclohex-3
-Enyl) -1-n-propyl-1-phenyl-1-silacyclohexane was obtained. To this was added 200 ml of a 1 mol / l iodine monochloride dichloromethane solution, and the mixture was stirred for 1 hour. Subsequently, 60 ml of methanol and 60 ml of triethylamine were added to the solution, and the mixture was stirred for 1 hour. After the reaction mixture was filtered and concentrated, it was dissolved in 100 ml of THF, and 5.0 g of lithium aluminum hydride and THF were added.
Added to 50 ml of the mixture. The reaction mixture was stirred at room temperature for 4 hours, poured into 200 ml of 10% hydrochloric acid and extracted with ethyl acetate. After usual washing, drying and concentration, the residue was purified by silica gel chromatography to obtain 4- (4- (4-iodophenyl) cyclohex-3-enyl) -1-n-propyl-1-silacyclohexane. . This is DMF
50 ml and 8.96 g of copper (I) cyanide (0.10 mo
l) was added and reacted at 60 ° C. for 10 hours. Subsequently, ordinary washing, drying and concentration were performed, and the residue was purified by silica gel chromatography and then recrystallized to obtain 7.8 g (yield: 24%) of the desired trans isomer.

Example 21 Trans-4- (4-
(4-trifluoromethoxyphenyl) cyclohex-
Production of 3-enyl) -1- (4-fluoropentyl) -1-silacyclohexane 28.9 g of 4-trifluoromethoxybromobenzene
(0.12 mol) to 2.92 g of magnesium (0.1
2 mol) and 100 ml of THF, and refluxed for 3 hours to obtain a Grignard reagent. This is 4
-(4,4-diphenyl-4-silacyclohexyl) cyclohexanone 34.8 g (0.10 mol) in THF
100 ml of the solution was added dropwise. After refluxing for 2 hours, the reaction mixture was cooled to room temperature, poured into a saturated aqueous solution of ammonium chloride, and extracted with benzene. 1 g of p-toluenesulfonic acid was added to this benzene solution, and the generated water was separated and removed while refluxing. When no more water was distilled off, the mixture was cooled to room temperature. The reaction mixture was poured into a saturated aqueous solution of sodium bicarbonate, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography to give 4- (4- (4-
Trifluoromethoxyphenyl) cyclohex-3-enyl) -1,1-diphenyl-1-silacyclohexane was obtained. 100 ml of a dichloromethane solution of 1 mol / l iodine monochloride was added thereto, followed by stirring for 1 hour. The reaction mixture was concentrated to give 4- (4- (4-trifluoromethoxyphenyl) cyclohex-3-enyl) -1-chloro-
A crude product of 1-phenyl-1-silacyclohexane was obtained. To this is added 50 ml of THF, followed by 4
Grignard prepared from -t-butyldimethylsiloxy-1-bromopentane in THF (1 mol / l) 20
0 ml and 1 g of copper (I) cyanide were added under ice-cooling and reacted for 5 hours. The reaction mixture was poured into a saturated aqueous solution of ammonium chloride, extracted with ethyl acetate, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography to give a residue.
-(4- (4-Trifluoromethoxyphenyl) cyclohex-3-enyl) -1- (4-t-butyldimethylsiloxypentyl) -1-phenyl-1-silacyclohexane was obtained. 100 ml of a THF solution of 1 mol / l tetra-n-butylammonium fluoride was added thereto, and the mixture was stirred for 1 hour. The reaction mixture was poured into 10% hydrochloric acid, washed, dried and concentrated as usual, and the residue was purified by silica gel chromatography. Then add dichloromethane 5
After dissolving in 0 ml, diethylaminosulfur trifluoride (48.4 g, 0.30 mol) was added at -70 ° C, and the temperature was raised to room temperature over 2 hours. The reaction mixture is poured into a saturated aqueous solution of sodium hydrogen carbonate, extracted with dichloromethane, washed, dried and concentrated in a usual manner, and the residue is purified by silica gel chromatography to give 4- (4- (4-trifluoromethoxyphenyl) cyclohex- 3-enyl) -1- (4-fluoropentyl) -1-phenyl-
1-Silacyclohexane was obtained. 100 ml of a dichloromethane solution of 1 mol / l iodine monochloride was added thereto,
Stir for 1 hour. Then add 30 ml of methanol to this solution.
And 30 ml of triethylamine, and the mixture was stirred for 1 hour. After filtering and concentrating the reaction mixture, it was added to THF 100
and added to a mixture of 5.0 g of lithium aluminum hydride and 50 ml of THF. The reaction mixture was stirred at room temperature for 4 hours, poured into 200 ml of 10% hydrochloric acid and extracted with ethyl acetate. After usual washing, drying and concentration, the residue is purified by silica gel chromatography and then recrystallized to obtain 11.1 g of the desired trans isomer (yield 26%).
I got

Example 22 Trans-4- (4-
(4-fluoropentyl) cyclohex-3-enyl)
Preparation of -1-n-propyl-l-silacyclohexane Instead of 3,5-difluoro-4- (t-butyldimethylsiloxy) -l-bromobenzene of Example 16, 4-
(T-butyldimethylsiloxy) pentyl bromide,
Instead of 4- (4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone, 4- (4-n
-Propyl-4-phenyl-4-silacyclohexyl)
Using cyclohexanone, 4
-(4- (4-hydroxypentyl) cyclohex-3
-Enyl) -1-n-propyl-1-phenyl-1-silacyclohexane was obtained. Subsequently, operations after the fluoroalkylation were performed in the same manner as in Example 21 to obtain the desired product.

Example 23 Trans-4- (4-
(3-fluoro-4-trifluoromethoxyphenyl)
(Cyclohex-3-enyl) -1-n-propyl-1-
Production of methyl-1-silacyclohexane Using 4-fluoro-4-trifluoromethoxybromobenzene in place of 4-trifluoromethoxybromobenzene in Example 21, 4- (4
-(3-Fluoro-4-trifluoromethoxyphenyl) cyclohex-3-enyl) -1,1-diphenyl-1-silacyclohexane was obtained. 1 mol / l
Was added and the mixture was refluxed for 6 hours. The reaction mixture was concentrated to give 4- (4-
(3-fluoro-4-trifluoromethoxyphenyl)
Cyclohex-3-enyl) -1,1-dichloro-1-
A crude product of silacyclohexane was obtained. To this, THF5
0 ml was added, and a THF solution (1 mol / l) of a Grignard reagent prepared from methyl chloride (80 ml) was added under ice-cooling, followed by stirring for 1 hour. Next, a Grignard reagent prepared from n-propyl bromide in a THF solution (1 m
(l / l) of 200 ml and 1 g of copper (I) cyanide were added and the mixture was further reacted for 5 hours. The reaction mixture is poured into a saturated aqueous ammonium chloride solution and extracted with ethyl acetate. After usual washing, drying and concentration, the residue is purified by silica gel chromatography and subsequently recrystallized to give the desired trans isomer 1
1.9 g (30% yield) was obtained.

Example 24 trans-4- (4-ethylcyclohex-3-enyl) -1-n-pentyl-
Production of 1-methyl-1-silacyclohexane Using ethyl bromide instead of 3-fluoro-4-trifluoromethoxybromobenzene of Example 23 and n-pentyl bromide instead of n-propyl bromide,
The desired product was obtained in the same manner as in Example 23.

Example 25 Trans-4- (4-
(4-fluorophenyl) cyclohex-3-enyl)
Production of -1-n-propyl-1-fluoro-1-silacyclohexane 21.0 g of 4-fluorobromobenzene (0.12 mol
l) was dropped into a mixture of 2.92 g (0.12 mol) of magnesium and 100 ml of THF, and refluxed for 3 hours to obtain a Grignard reagent. To this, 50 ml of a THF solution of 31.4 g (0.10 mol) of 4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone was added dropwise. After refluxing for 2 hours, the reaction mixture was cooled to room temperature, poured into a saturated aqueous solution of ammonium chloride, and extracted with benzene. 1 g of p-toluenesulfonic acid was added to this benzene solution, and the generated water was separated and removed while refluxing. When no more water was distilled off, the mixture was cooled to room temperature. The reaction mixture was poured into a saturated aqueous solution of sodium hydrogen carbonate, washed, dried and concentrated, and the residue was purified by silica gel chromatography to give 4- (4- (4-fluorophenyl) cyclohex-3-enyl) -1. -N-Propyl-1-phenyl-1-silacyclohexane was obtained.
100 ml of a dichloromethane solution of 1 mol / l iodine monochloride was added thereto, followed by stirring for 1 hour. The reaction mixture was concentrated to give 4- (4- (4-fluorophenyl) cyclohex-3-enyl) -1-n-propyl-1-chloro-1.
-A crude product of silacyclohexane was obtained. 50 ml of pentane and 30.5 g of copper (II) fluoride (0.30 mol
l) was added and reacted overnight. The reaction mixture was filtered and concentrated, and the residue was purified by silica gel chromatography, followed by recrystallization to obtain 6.7 g of the desired trans isomer (yield: 20%).

Example 26 trans-4- (4-methylcyclohex-3-enyl) -1-n-pentyl-
Preparation of 1-fluoro-1-silacyclohexane Methyl chloride was used instead of 4-fluorobromobenzene of Example 25, and 4 was used instead of 4- (4-n-propyl-4-phenyl-4-silacyclohexyl) cyclohexanone. Example 2 using-(4-n-pentyl-4-phenyl-4-silacyclohexyl) cyclohexanone
By the same operation as in 5, the desired product was obtained.

[0070]

The present invention relates to a liquid crystal compound newly developed for the purpose of improving the properties of a liquid crystal material, and its feature lies in that it has both a silacyclohexane ring and a cyclohexene ring in the molecular structure.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tsutomu Ogihara 28, Nishifukushima, Oku-ku, Nakakushiro-mura, Niigata Pref. 1 in Kushiro-mura, Nishi-Fukushima 28 Synthetic Technology Laboratory, Shin-Etsu Chemical Co., Ltd.

Claims (3)

[Claims] [Claim 1] The following general formula (1) [Wherein R is a linear alkyl group having 1 to 10 carbon atoms,
A branched alkyl group having 3 to 8 carbon atoms, an alkoxyalkyl group having 2 to 7 carbon atoms, a mono- or difluoroalkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms; ] Has silicon in the 1 or 4 position, wherein the silicon is H,
Trans-1- having a substituent of F, Cl or CH ₃
Sila-1,4-cyclohexylene group or trans-4
Represents a sila-1,4-cyclohexylene group, X represents H, CN, F, Cl, CF ₃ , CF ₂ Cl, CH
(F) Cl, OCF ₃ , OCHF ₂ , OCF ₂ Cl, O
CH (F) Cl, R, OR, (O) _p CY ₁ = CX ₁ X
₂ (p is 0 or 1, Y ₁ and X ₁ are H, F or C
1, X ₂ represents F or Cl. ) Or (O)
_{q (C n H m F 2n} -m) X 3 (q is 0 or 1, n is 2,
3 or 4, m is an arbitrary integer of 0 ≦ m ≦ 2n, and X ₃ represents H, F or Cl. Y and Z are H or F, and i is 0 or 1 (however, in the case where i = 0, X is limited to X = R or OR.)]. 2. A liquid crystal composition comprising the silacyclohexane compound according to claim 1. 3. A liquid crystal display device comprising the liquid crystal composition according to claim 2.