EP0260275A1 - Optically active compounds - Google Patents

Abstract

Optically active compounds of the formula I can be used as components of chiral titled smectic liquid crystal phases: R1-C*HX-Q-A4-Z1-A2-(Z2-A3)n-X'-Q'-C*HY'-R5 (I) wherein R1-C*HX-Q- and -X'-Q'-C*HY-R5 are identical optically active radicals selected from the group -O-C*HCH3-COO-n-alkyl, -O-C*HCH3-CH2-O-n-alkyl, -OCO-C*HC1-CHCH3-CH3, -OCO-C*HCl-C*HCH3-C2H5, -OCO-C*HCl-CH2-CHCH3-CH3, -OCO-C*HCl-C(CH3)3, -COO-C*HCH3-COO-n-alkyl, -O-CO-C*HCH3-o-n-alkyl, -OCH2-C*HCH3-O-n-alkyl, -COO-C*HCH3CH2-O-n-allyl, -OC*HCH3-CH2-COO-n-alkyl, -COO-C*HCH3-CH2-COO-n-alkyl, -OCH2-C*HCH3-COO-n-alkyl or -COO-CH2-C*HCH3-COO-n-alkyl, alkyl is of 1-12 c atoms, and -A4-Z1-A2-(Z2-A3)n- is a group of the following formulae or a mirror image thereof: <IMAGE> <IMAGE> <IMAGE> <IMAGE> <IMAGE>

Description

Optically active connections

The invention relates to optically active compounds of the formula I.

R ¹ -C * HX-QA ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -X '-Q' -C * HY '-R ⁵

wherein

R ^{1 is} an alkyl or perfluoroalkyl group, each having 1-12 C atoms, in which one or two non-adjacent CH ₂ or CF ₂ groups are also represented by O atoms and / or -CO groups and / or -CO -O groups and / or -CH = CH groups and / or -CH-halogen and / or -CHCN groups and / or -O-CO-CH-halogen and / or -O-CO-CHCN groups can be replaced ,

R ^{5 is} an alkyl group other than ^{Y '} with 1 to 15 C atoms, in which also one or two non-adjacent CH ₂ groups are represented by -O-, -CO-, -O-CO-, -CO-O- and / or -CH = CH- can be replaced,

A ² , A ³ each unsubstituted or 1,4-phenylene substituted by one or and A and two F and / or Cl atoms and / or CH ₃ groups and / or CN groups, which also includes one or two CH groups can be replaced by N, 1,4-cyclohexylene, wherein one or two non-adjacent CH ₂ groups can also be replaced by O atoms and / or S atoms, piperidine-1,4-diyl, 1,4-bicyclo- (2,2,2) -octylene-, naphthalene -2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl groups,

Z ¹ and Z ² each -CO-O-, -O-CO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -C≡C- or a single bond,

X halogen, CN or CH ₃ ,

n 0 or 1,

Q alkylene with 1 to 4 carbon atoms, including one

CH ₂ group can be replaced by -O-, -CO-, -O-CO-, -CO-O-, -CH = CH-COO-, -CH = CH-, -CHHalogen and / or -CHCN- , or a single bond,

X '-CO-O-, -O-CO-, -O-CO-O-, -CO-, -O-, -S-,

-CH = CH-, -CH = CH-COO- or a single bond,

Q 'alkylene with 1 to 5 C atoms, in which a CH ₂ group which is not linked to X' is also replaced by -O-, -CO-, -O-CO, -CO-O- or -CH = CH- can, or a single bond, and

Y 'denotes CN, halogen, methyl or methoxy, with the proviso that R ¹ and / or R ^{5 is} a branched alkyl group having 3 to 12 carbon atoms if -C * HX-Q- -CHHalogen-CO-O- and / or -X'-Q'-C * HY'- -O-CO-CH halogen means.

The compounds of the formula I, like similar compounds described in DE-OS 35 15 373, can be used as components of chiral-tapped smectic liquid-crystalline phases. Chiral-chopped smectic liquid-crystalline phases with ferroelectric properties can be produced by adding a suitable chiral dopant to base mixtures with one or more chopped smectic phases (LA Beresnev et al., Mol. Cryst. Liq. Cryst. 89, 327 (1982 HR Brand et al., J. Physique 44, (lett.), L-771 (1983), such phases can be used as dielectrics for fast switching displays based on the principle of SSFLC technology described by Clark and Lagerwall (NA Clark and ST Lagerwall, Appl. Phys. Lett. 36, 899 (1980); USP 4,367,924) on the basis of the ferroelectric properties of the chiral tufted phase. In this phase, the elongate molecules are arranged in layers, the molecules being one As the layer progresses from layer to layer, the tilt direction changes by a small angle with respect to an axis perpendicular to the layers ate a helical structure is formed. In displays that are based on the principle of SSFLC technology, the smectic layers are arranged perpendicular to the plates of the cell. The helical arrangement of the tilt directions of the molecules is suppressed by a very small distance between the plates (approx. 1-2 μm). This will make the

Longitudinal axes of the molecules are forced to line up in a plane parallel to the plates of the cell, creating two excellent tilt orientations. By applying a suitable alternating electrical field, it is possible to switch back and forth between these two states in the liquid-crystalline phase which has a spontaneous polarization. This switching process is much faster than with conventional twisted cells (TN-LCD's), which are based on nematic liquid crystals. A major disadvantage for many applications of the currently available materials with chiral-chased smectic phases (such as Sc *) is their relatively high optical anisotropy, the switching times which are not sufficiently short due to relatively high viscosity values, and that the dielectric anisotropy values are greater than zero or, if negative, has little non-zero values. Negative values of the dielectric anisotropy are required if the required planar orientation is brought about by superimposing the control field with an AC holding field with a small amplitude (JM Geary, SID conference, Orlando / Florida, April / May 1985, lecture 8.3).

It has now been found that the use of compounds of the formula I as components of chiral smutic mixtures can substantially reduce the disadvantages mentioned. The compounds of the formula I are therefore particularly suitable as components of chiral-chopped smectic liquid-crystalline phases. In particular, chemically particularly stable chiral-chopped smectic liquid-crystalline phases with favorable ferroelectric phase ranges, in particular with wide Sc * phase ranges, negative or also positive dielectric anisotropy, low optical anisotropy, favorable pitch height and high values for the spontaneous polarization and for such phases very short switching times can be produced. P is the spontaneous polarization in nC / cm ² .

With the provision of the compounds of the formula I, the range of liquid-crystalline substances which are suitable for the production of ferroelectric mixtures from various application points of view is also very broadly broadened. The compounds of formula I have a wide range of applications. Depending on the choice of the substituents, these compounds can serve as base materials from which liquid-crystalline phases are predominantly composed; However, it is also possible to add compounds of the formula I to liquid-crystalline base materials from other classes of compounds, for example to improve the dielectric and / or optical anisotropy and / or the spontaneous polarization and / or the phase range and / or the tilt angle and / or the pitch and / or the Switching times of such a phase vary. The compounds of the formula I are also suitable as intermediates for the preparation of other substances which can be used as constituents of liquid-crystalline phases.

The compounds of the formula I are colorless in the pure state and have low optical anisotropy values. Some of the compounds of the formula I show liquid-crystalline mesophases in a temperature range which is favorably located for electro-optical use, but isotropic or monotropic liquid-crystalline compounds of the formula I can also be used advantageously as components of chiral-chopped smectic phases. They are very stable chemically, thermally and against light.

The invention thus relates to the optically active compounds of the formula I and the use of the compounds of the formula I as components of liquid-crystalline phases.

The invention also relates to chiral tilted smectic liquid-crystalline phases containing at least one optically active compound of the formula I. The invention further relates to such phases containing at least one compound of the formula I and liquid crystal display elements, in particular electro-optical display elements, which contain such phases.

For the sake of simplicity, Ph in the following means a 1,4-phenylene group, in which one or two CH groups can also be replaced by N, Cy a 1,4-cyclohexylene group, in which one or two non-adjacent CH ₂ groups also have O- Atoms can be replaced and Bi a bicyclo (2,2,2) octylene group.

Above and below, R ¹ , R ⁵ , n, A ² , A3, A ⁴ , Q, X, X ', Q', Y ', Z ¹ and Z ^{2 have} the meaning given, unless expressly stated otherwise .

Accordingly, the compounds of the formula I include, in particular, compounds of the subforms Ia and Ib (with two rings)

R ¹ -C * HX-QA ⁴ -A ² --X'-Q'-C * HY'-R ⁵ Ia

R ¹ -C * HX-QA ⁴ -Z ¹ -A ² -X ^, -Q'-C * HY'-R ⁵ Ib

and Ic to If (with three rings):

R ¹ -C * HX-QA ⁴ -A ² -A ³ -X'-Q'-C * HY'-R ⁵ Ic

R ¹ -C * HX-QA ⁴ -A ² -Z ² -A ³ -X'-Q'-C * HY ^, -R ⁵ Id

R ¹ -C * HX-QA ⁴ -Z ¹ -A ² -A ³ -X ^, -Q'-C * HY ^, -R ⁵ Ie

R ¹ -C * HX-QA ⁴ -Z ¹ -A ² -Z ² -A ³ -X'-Q'-C * HY'-R ⁵ If

Among them, those of the formulas Ia, Ib, Ic, Id and Ie are particularly preferred. The preferred compounds of the formula Ia include those of the sub-formulas Ial to Ia4:

R ¹ -C * HX-Q-Ph-Ph-X ^, -Q'-C * HY'-R ⁵ Ia1

R ¹ -C * HX-Q-Cy-Ph-X ^, -Q ^, -C * HY'-R ⁵ Ia2 R ¹ -C * HX-Q-Ph-Cy-X'-Q'-C * HY ' -R ⁵ Ia3

R ¹ -C * HX-Q-Cy-Cy-X'-Q'-C * HY'-R ⁵ Ia4

Among them, those of the formulas Ia1 and Ia3 are particularly preferred.

The preferred compounds of the formula Ib include those of the sub-formulas Ibl to Ib4:

R ¹ -C * HX-Q-Ph-Z ¹ -Ph-X'-Q'-C * HY'-R ⁵ Ib1

R ¹ -C * HX-Q-Cy-Z ¹ -Ph-X'-Q ^' -C * HY'-R ⁵ Ib2

R ¹ -C * HX-Q-Ph-Z ¹ -Cy-X'-Q'-C * HY'-R ⁵ Ib3

R ¹ -C * HX-Q-Cy-Z ¹ -Cy-X'-Q'-C * HY'-R ⁵ Ib4

Among them, those of the formulas Ibl and Ib3 are particularly preferred.

The preferred compounds of formula Ic include those. of the sub-formulas Ic1 to Ic4:

R ¹ -C * HX-Q-Ph-Ph-Cy-X'-Q'-C * HY'-R ⁵ Ic1 R ¹ -C * HX-Q-Ph-Cy-Cy-X'-Q'- C * HY'-R ⁵ Ic2

R ¹ -C * HX-Q-Ph-Cy-Ph-X'-Q'-C * HY'-R ⁵ Ic3

R ¹ -C * HX-Q-Ph-Ph-Ph-X'-Q'-C * HY'-R ⁵ Ic4

The preferred compounds of the formula Id include those of the sub-formulas Idl and Id3:

R ¹ -C * HX-Q-Ph-Ph-Z ² -Cy-X'-Q'-C * HY'-R ⁵ Id1

R ¹ -C * HX-Q-Ph-Cy-Z ² -Ph-X'-Q'-C * HY ^, -R ⁵ Id2

R ¹ -C * HX-Q-Ph-Ph-Z ² -Ph-X'-Q ^, -C * HY ^, -R ⁵ Id3 The preferred compounds of the formula Ie include those of the sub-formulas Iel to Ie5:

R ¹ -Q ¹ -C * HX-Q ² -Ph-Z ¹ -Ph-Ph-X'-Q'-C * HY'-R ⁵ Ie1

R ¹ -Q ¹ -C * HX-Q ² -Ph-Z ¹ -Ph-Cy-X'-Q'-C * HY'-R ⁵ Ie2 R ¹ -Q ¹ -C * HX-Q ² -Ph -Z ¹ -Cy-Ph-X'-Q'-C * HY'-R ⁵ Ie3

R ¹ -Q ¹ -C * HX-Q ² -Ph-Z ¹ -Cy-Cy-X'-Q '-C * HY'-R ⁵ Ie4

R ¹ -Q ¹ -C * HX-Q ² -Cy-Z ¹ -Ph-Ph-X'-Q'-C * HY'-R ⁵ Ie5

Compounds of the formulas above and below are preferred in which R ¹ and R ⁵ each independently represent alkyl.

In the preferred compounds of the formulas above and below, the alkyl radicals, in which a CH ₂ group (alkoxy or oxaalkyl) can also be replaced by an O atom, can be straight-chain or branched. They preferably have 5, 6, 7-, 8, 9 or 10 carbon atoms and are therefore preferably pentyl, hexyl, heptyl, octyl, nonyl, decyl, pentoxy, hexoxy, heptoxy, octoxy, nonoxy or decoxy, and also ethyl, Propyl, butyl, undecyl, dodecyl, propoxy, ethoxy, butoxy, undecoxy, dodecoxy, 2-oxapropyl (= 2-methoxymethyl), 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxypentyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl.

A ² , A ³ and A ⁴ si.nd preferably Cy or Ph. In the compounds of the formulas above and below, Ph preferably denotes a 1,4-phenylene (Phe), a pyrimidine-2,5-diyl (pyr ), a pyridine-2,5-diyl (pyn), a pyrazine-3,6-diyl or a pyridazine-2,5-diyl group, particularly preferably Phe, Pyr or Pyn. The compounds according to the invention preferably no longer contain as a 1,4-phenylene group in which one or two CH groups are replaced by N. Cy preferably represents a 1,4-cyclohexylene group. However, particular preference is given to compounds of the formula I in which one of the groups A ² , A ³ and A ⁴ denotes a 1,4-cyclohexylene group substituted in the 1- or 4-position by CN and the nitrile group is in the axial position, ie the group A ² , A ³ or A ^{4 has} the following configuration:

Compounds of the formula I and the above partial formulas which contain a group -Ph-Ph- are particularly preferred. -Ph-Ph- is preferably -Phe-Phe-, Phe-Pyr or Phe-Pyn. The groups are particularly preferred

also unsubstituted or singly or multiply substituted by fluorine 4,4'-biphenylyl.

Z ¹ and Z ² are preferably simple formations, in the second place preferably -O-CO-, -CO-O-, -C≡C- or -CH ₂ CH ₂ -

Groups.

Particularly preferred for Z ¹ is -CO-O, -O-CO-, -C≡C- or -CH ₂ CH ₂ -, in particular the -CH ₂ CH ₂ - and the -C≡C group.

X in the compounds of the formulas above and below is halogen, CN or CH ₃ , preferably Cl or CH ₃ .

The preferred meaning of Q is alkylene with 1 to 2 carbon atoms, -O-, -O-CO- and -COO-. Compounds of the formulas above and below with branched groups R ¹ and R ⁵ may be important. Branched groups of this type usually contain no more than two chain branches. R ¹ or R is preferably a straight-chain group or a branched group with no more than one chain branch.

Preferred branched radicals are isopropyl, 2-butyl

(= 1-methylpropyl), isobutyl (= 2-methylpropyl), tert.-butyl, 2-methylbutyl, isopentyl (= 3-methylbutyl),

2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylpentyl, isopropoxy, 2-methylpropoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentoxy, 3-methylpentoxy, 2-ethylhexoxy, 1-methylhexoxy, 1-methylheptoxy, 2-oxa-3-methylbutyl, 3-oxa-4-methylpentyl.

X 'is preferably -CO-O-, -O-CO-, -CH = CH-COO- (trans) or a single bond. -CO-O-, -O-CO- or a single bond are particularly preferred.

Q 'is preferably -CH ₂ -, -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ - or a single bond, particularly preferably a single bond.

Y "is preferably CH ₃ , -CN or Cl, particularly preferably Cl or CR ₃ .

R ⁵ is preferably straight-chain or branched alkyl having 1 to 10, in particular 1 to 7,

C atoms.

Preferred compounds of the formula I are those in which X and Y 'do not simultaneously denote methyl. Preferred compounds of the formula I and Ia to Ig are those in which at least one of the radicals contained therein has one of the preferred meanings indicated.

A small group of particularly preferred meanings for the optically active radicals R ¹ (or R -C * HX-Q) and -X'-Q'-C * HY '-R ⁵ in these preferred compounds is given below:

-OC * HCH ₃ -n-alkyl, -O-CH ₂ -C * HCH ₃ -n-alkyl, -O-CH ₂ -CH ₂ - C * HCH ₃ -n-alkyl, -O-CH ₂ -CH ₂ -CH ₂ -C * HCH ₃ -n-alkyl, -C * HCH ₃ - n-alkyl, -CH ₂ -C * HCH ₃ -n-alkyl, -COO-C * CHCH ₃ -n-alkyl-, -COO-CH ₂ -C * HCH ₃ -n-alkyl, -OC * HCH ₃ -COO-n-alkyl, -O- C * HCH ₃ -CH ₂ -On-alkyl, -OCO-C ^* HCl-

CHCH ₃ -CH ₃ , -OCO-C * HCl-C * HCH ₃ -C ₂ H ₅ , -OCO-C * HCl-CH ₂ -CHCH ₃ - CH ₃ , -OCO-C * HCl-C (CH ₃ ) ₃ , -COO-C * HCH ₃ -COO-n-alkyl, -O-CO- C * HCH ₃ -On-alkyl, -OCH ₂ -C * HCH ₃ -On-alkyl, -COO-C * HCH ₃ - CH ₂ -On-alkyl, -OC * HCH ₃ -CH ₂ -COO-n-alkyl, -COO-C * HCH ₃ - CH ₂ -COO-n-alkyl, -OCH ₂ -C * HCH ₃ - COO-n-alkyl, -COO-CH ₂ - C * HCH ₃ -COO-n-alkyl.

In the preferred compounds of formula I, wherein -X'-Q'-C * HY'-R ^{5 is} an optically active radical, R ¹ -C * HX-Q may be the same or different from -X'-Q'-C * Be HY'-R ⁵ .

Preferably, -X '-Q'-C * HY'-R ⁵ and R ¹ -C * HX-Q are different and have a preferred meaning given for -X'-Q'-C * HY'-R ⁵ .

A small group of particularly preferred compounds of the formulas II to 123 is listed below: CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OOC-C * HCl- CHCH ₃ -CH ₃ I1

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) n-OOC-C * HCl- C * HCH ₃ -C ₂ H ₅ I2 CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) nOC * HCH ₃ - COO-C ₂ H ₅ I3

CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH3- CH ₂ -OC ₂ H ₅ I4

CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH ₃ -CH ₂ -COO-C ₂ H ₅ I5

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OCH ₂ - C * HCH ₃ -COO-C ₃ H ₇ I6

CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OCH ₂ - C * HCH ₃ -C ₂ H ₅ I7 C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH ₃ - C ₆ H ₁₃ ^I8

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -C * HCH ₃ -

^C 6 ^H 13 ^I9 CH ₃ -CHCH ₃ -C * HCl-COo-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -COO-C * HCH ₃ - COO-C ₂ H ₅ I10

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -COO-CH ₂ - C * HCH ₃ -COO-C ₃ H ₇ I11

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OCH ₂ -C * HCH ₃ -

OC ₂ H ₅ ^I12 CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -COO-C * HCH ₃ -

CH ₂ -COO-C ₄ H ₉ 113

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OCO-C * HCl-tC ₄ H ₉ 114

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OOC-C * HCl- iC ₄ H ₉ I15

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH ₃ - COO-C ₂ H ₅ I16

CH ₃ -CHCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OCH ₂ -C * HCH ₃ -C ₂ H ₅ I17

C ₂ H ₅ -C * HCH ₃ -C * HCl-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH ₃ -C ₆ H ₁₃ 118 C ₃ H ₇ -OOC-C * HCH ₃ -OA ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OC * HCH ₃ -COO-C ₃ H ₇ I19 C ₃ H ₇ -O-CH ₂ -C * HCH ₃ -OA ⁴ -Z ¹ -A - (Z ² -A ³ ) _n -OC * HCH ₃ - CH ₂ OC ₃ H ₇ I20

C ₂ H ₅ -OOC-C * HCH ₃ -OOC-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -COO-C * CHCH ₃ -COO-C ₂ H ₅ I21

C ₂ H ₅ -OC * HCH ₃ -COO - A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OOC-C * HCH ₃ - OC ₂ H ₅ ^I22

C ₂ H ₅ -OC * HCH ₃ -CH ₂ -OA ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -O-CH ₂ -C * HCH ₃ - OC ₂ H ₅ ^I23

Optically active compounds of the formula I are particularly preferably characterized by the formulas

R ¹ -C * HX-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -OOC-C * HY'-R ⁵ and

R ¹ -C * HX-COO-A ⁴ -Z ¹ -A ² -OOC-C * HY'-R ⁵

wherein R ¹ , R ⁵ , n, X, Y ', A ² , A ³ , A ⁴ , Z ¹ and Z ^{2 have} the meaning given in claim 1.

Particularly preferred are compounds of the above formulas in which X and Y 'are halogen, compounds of the above formulas in which A ⁴ and A ^{2 are} 1,4-phenylene, and corresponding compounds in which Z ^{1 is} a single bond.

In the compounds of the formula I and in the formulas above and below, -A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n - is preferably a group of the following formulas 1 to 16 or its mirror image:

Groups of the formulas 1, 5, 7, 9, 10, 11, 12, 13 and 14, in particular those of the formulas 5 and 7, are particularly preferred.

Those of the formulas mentioned above which contain one or more groups dio, dit, pip and / or pyr each encompass the two possible 2, 5- (dio, dit, pyr) and 1,4-position isomers (pip).

The compounds of the formula I are prepared by methods known per se, as are described in the literature (for example in the standard works such as Houben-Weyl, Methods of Organic Chemistry, Georg-Thieme-Verlag, Stuttgart), and under reaction conditions who are known and suitable for the implementations mentioned. Use can also be made of variants which are known per se and are not mentioned here in any more detail.

If desired, the starting materials can also be formed in situ in such a way that they are not isolated from the reaction mixture, but instead are immediately reacted further to give the compounds of the formula I. For example, the compounds of the formula I can be prepared by reducing a compound which otherwise corresponds to the formula I but contains one or more reducible groups and / or CC bonds instead of H atoms.

Possible reducible groups are preferably -CH = CH-, furthermore e.g. free or esterified hydroxyl groups, aromatically bound halogen atoms or carbonyl groups. Preferred starting materials for the reduction correspond to the formula I, but can be

Instead of a -CH ₂ CH ₂ group, a -CH = CH group and / or instead of a -CH ₂ group, a -CO group and / or instead of an H atom, a free or functional (e.g. in the form of their p-toluenesulfonate) contain modified OH group.

The reduction can take place, for example, by catalytic hydrogenation at temperatures between about 0 ° and about 200 ° and pressures between about 1 and 200 bar in an inert solvent, for example an alcohol such as methanol, ethanol or isopropanol, an ether such as tetrahydrofuran (THF) or dioxane , an ester such as ethyl acetate, a carboxylic acid such as acetic acid or a hydrocarbon such as cyclohexane. Suitable catalysts are suitably noble metals such as Pt or Pd, which can be used in the form of oxides (for example PtO ₂ , PdO), on a support (for example Pd on carbon, calcium carbonate or strontium carbonate) or in finely divided form.

Ketones can also by the methods of Clemmensen (with zinc, amalgamated zinc or tin and hydrochloric acid, expediently in aqueous alcoholic solution or in a heterogeneous phase with water / toluene at temperatures between about 80 and 120 °) or Wolff-Kishner (with hydrazine, expedient reduced in the presence of alkali such as KOH or NaOH in a high-boiling solvent such as diethylene glycol or triethylene glycol at temperatures between about 100 and 200 °) to the corresponding compounds of the formula I which contain alkyl groups and / or —CH ₂ CH ₂ bridges become.

Reductions with complex hydrides are also possible. For example, arylsulfonyloxy groups with LiAlH. are reductively removed, in particular p-toluenesulfonyloxymethyl groups are reduced to methyl groups, advantageously in an inert solvent such as diethyl ether or THF at temperatures between about 0 and 100 °. Double bonds can be hydrogenated (even in the presence of CN groups!) With NaBH ₄ or tributyltin hydride in methanol; for example, the corresponding cyclohexane derivatives are formed from 1-cyanocyclohexene derivatives.

Esters of the formula I can also be obtained by esterifying corresponding carboxylic acids (or their reactive derivatives) with alcohols or phenols (or their reactive derivatives).

Suitable reactive derivatives of the carboxylic acids mentioned are in particular the acid halides, especially the chlorides and bromides, and also the anhydrides, e.g. also mixed anhydrides, azides or esters, in particular alkyl esters with 1 to 4 carbon atoms in the alkyl group.

Suitable reactive derivatives of the alcohols or phenols mentioned are in particular the corresponding metal alcoholates or phenolates, preferably an alkali metal such as Na or K. The esterification is advantageously carried out in the presence of an inert solvent. Particularly suitable are ethers such as diethyl ether, di-n-butyl ether, THF, dioxane or anisole, ketones such as acetone, butanone or cyclohexanone, amides such as DMF or phosphoric acid hexamethyltriamide, hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride or tetrachlorethylene and sulfoxides such as Dimethyl sulfoxide or sulfolane. Solvents immiscible with water can at the same time advantageously be used for azeotropically distilling off the water formed during the esterification. Occasionally, an excess of an organic base, for example pyridine, quinoline or triethylamine, can also be used as a solvent for the esterification. The esterification can also be carried out in the absence of a solvent, for example by simply heating the components in the presence of sodium acetate. The reaction temperature is usually between -50 ° and + 250 °, preferably between -20 ° and + 80 °. At these temperatures, the esterification reactions are usually complete after 15 minutes to 48 hours.

In particular, the reaction conditions for the esterification largely depend on the nature of the starting materials used. A free carboxylic acid is usually reacted with a free alcohol or phenol in the presence of a strong acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. A preferred reaction mode is the reaction of an acid anhydride or, in particular, an acid chloride with an alcohol, preferably in a basic medium, the bases being in particular alkali metal hydroxides such as sodium or potassium hydroxide, alkali metal carbonates or hydrogen carbonates such as sodium carbonate, potassium carbonate or potassium hydrogen carbonate, alkali metal acetates such as sodium - or Potassium acetate, alkaline earth metal hydroxides such as calcium hydroxide or organic bases such as triethylamine, pyridine, lutidine, collidine or quinoline are important. Another preferred embodiment of the esterification is that the alcohol or the phenol is first in the

Sodium or potassium alcoholate or phenolate, e.g. by treatment with ethanolic sodium or potassium hydroxide solution, this is isolated and suspended together with sodium hydrogen carbonate or potassium carbonate with stirring in acetone or diethyl ether and this suspension is mixed with a solution of the acid chloride or anhydride in diethyl ether, acetone or DMF, advantageously at temperatures between about -25 ° and + 20 °.

Dioxane derivatives or dithiane derivatives of the formula I are expediently prepared by reacting an appropriate aldehyde (or one of its reactive derivatives) with a corresponding 1,3-diol or a corresponding 1,3-dithiol (or one of its reactive derivatives), preferably in the presence an inert solvent such as benzene or toluene and / or a catalyst, for example a strong acid such as sulfuric acid, benzene or p-toluenesulfonic acid, at temperatures between 20 ° and about 150 °, preferably between 80 ° and 120 °. Acetals are primarily suitable as reactive derivatives of the starting materials.

Some of the aldehydes and 1,3-diols or 1,3-dithiols mentioned and their reactive derivatives are known, and all of them can be prepared from compounds known from the literature without difficulty using standard organic chemistry processes. For example, the aldehydes can be obtained by oxidation of corresponding alcohols or by reduction of corresponding carboxylic acids or their derivatives, the diols by reduction of corresponding diesters and the dithiols by reaction of corresponding dihalides with NaSH. For the preparation of nitriles of the formula I, corresponding acid amides, for example those in which a CONH ₂ group is used instead of the radical X, can be dehydrated. The amides can be obtained, for example, from corresponding esters or acid halides by reaction with ammonia. Suitable water-releasing agents are, for example, inorganic acid chlorides such as SOCl ₂ , RCl ₃ , PCl ₅ , POCl ₃ , SO ₂ Cl ₂ , COCl ₂ , furthermore P ₂ O ₅ , R ₂ S ₅ , AlCl ₃ (for example as double compounds with NaCl), aromatic sulfonic acids and sulfonic acid halides. You can do it in the present or

In the absence of an inert solvent, work at temperatures between about 0 ° and 150 °; come as solvents e.g. Bases such as pyridine or triethylamine, aromatic hydrocarbons such as benzene, toluene, or xylene or amides such as DMF into consideration.

To prepare the nitriles of the formula I mentioned above, corresponding acid halides, preferably the chlorides, can also be reacted with sulfamide, advantageously in an inert solvent such as tetramethylene sulfone at temperatures between about 80 ° and 150 °, preferably at 120 °. After the usual work-up, the nitriles can be isolated directly.

Ethers of the formula I can be obtained by etherification of corresponding hydroxyl compounds, preferably corresponding phenols, the hydroxyl compound advantageously first being converted into a corresponding metal derivative, for example by. Treatment with NaH, NaNH ₂ , NaOH, KOH, Na ₂ CO ₃ or K ₂ CO _{3 is converted} into the corresponding alkali metal alcoholate or alkali metal phenolate. This can then be reacted with the corresponding alkyl halide, sulfonate or dialkyl sulfate, expediently in an inert solvent such as acetone, 1,2-dimethoxyethane, DMF or dimethyl sulfoxide or even an excess of aqueous or aqueous alcoholic NaOH or KOH at temperatures between about 20 ° and 100 °. To prepare nitriles of the formula I, corresponding chlorine or bromine compounds of the formula I can also be reacted with a cyanide, advantageously with a metal cyanide such as NaCN, KCN or Cu ₂ (CN) ₂ , for example in the presence of pyridine in an inert solvent such as DMF or N-methylpyrrolidone at temperatures between 20 ° and 200 °.

The optically active compounds of the formula I are obtained by using appropriate optically active starting materials and / or by separating the optical antipodes by means of chromatography using known methods.

The phases according to the invention contain at least one, preferably at least two, compounds of the formula I. Particularly preferred are chiral tilted smectic liquid-crystalline phases, the achiral base mixture of which, in addition to compounds of the formula I, contains at least one other component with negative or small positive dielectric anisotropy. These further components of the chiral base mixture can make up 1 to 50%, preferably 10 to 25%, of the base mixture. Compounds of the sub-formulas Va to Vp are suitable as further components with small positive or negative dielectric anisotropy:

R ⁴ and R ⁵ are each preferably straight-chain alkyl,

Alkoxy, alkanoyloxy or alkoxycarbonyl, each with 3 to 12 carbon atoms. X "is O or S, preferably O. n is

0 or 1.

Particular preference is given to the compounds of the partial forms Va, Vb, Vd and Vf, in which R ⁴ and R ⁵ each represent straight-chain alkyl or alkoxy each having 5 to 10 C atoms. The compounds of the sub-formulas Vc, Vh and Vi are suitable as additives for lowering the melting point and are normally added to the base mixtures in an amount of not more than 5%, preferably 1 to 3%. R ⁴ and R ⁵ in the compounds of the sub-formulas Vc, Vh and Vi are preferably straight-chain alkyl having 2 to 7, preferably 3 to 5, carbon atoms. Another class of compounds suitable for lowering the melting point in the phases according to the invention is that of the formula

where R ⁴ and R ⁵ di.e have the preferred meaning given for Vc, Vh and Vi.

Compounds containing the structural element M, N or O are also suitable as further components with negative dielectric anisotropy.

Preferred compounds of this type correspond to formulas VIb and VIc:

R 'and R''each preferably represent straight-chain

Alkyl or alkoxy groups, each with 2 to 10 carbon atoms. Q ¹ and Q ² each represent 1,4-phenylene, trans-1,4-cyclohexylene, 4,4'-biphenylyl, 4- (trans-4-cyclohexyl) phenyl, trans, trans-4,4'-bicyclohexyl or one of the groups Q ¹ and Q ² also a single bond.

Q ³ and Q ⁴ each represent 1,4-phenylene, 4,4'-biphenylyl or trans-1,4-cyclohexylene. One of the groups Q ³ and Q ⁴ can also mean 1,4-phenylene, in which at least one CH group has been replaced by N. R '''is an optically active residue with an asymmetric carbon atom

the structure or . Particularly preferred compounds of the formula VIc are those of the formula VIc ':

wherein A is 1,4-phenylene or trans-1,4-cyclohexylene, Z ° CH or N and n is 0 or 1.

The compounds of formula I are also suitable as components of nematic liquid crystalline phases, e.g. to avoid reverse twist.

These liquid-crystalline phases according to the invention consist of 2 to 25, preferably 3 to 15 components, including at least one compound of the formula I. The other constituents are preferably selected from the nematic or nematogenic substances, in particular the known substances, from the classes of the azoxybenzenes, benzylidene anilines, Biphenyls, terphenyls, phenyl or cyclohexyl benzoates, cyclohexane carboxylic acid phenyl or cyclohexyl esters, phenylcyclohexanes, cyclohexylbiphenyls, cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-bis-cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, phenyl- or cyclohexylpyrimidines, phenyl- or cyclohexylpyridazines as well as their N- Phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclohexylethane, optionally halogenated stilbenes, benzylphenyl ether, tolanes and substituted cinnamic acids.

The most important compounds which are possible as constituents of such liquid-crystalline phases can be characterized by the formula I '

R'-L-G-E-R '' I '

wherein L and E each a carbo- or heterocyclic ring system from the one of 1,4-disubstituted benzene and cyclohexane rings, 4,4'-disubstituted biphenyl, phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydronaphthalene, quinazoline and tetrahydroquinazoline,

-CH = CH- -N (O) = N-

-CH = CY- -CH = N (O) -

-C≡C- -CH ₂ -CH ₂ -

-CO-O- -CH ₂ -O-

-CO-S- -CH ₂ -S-

-CH = N- -COO-Phe-COO

or a single C-C bond,

Y halogen, preferably chlorine, or -CN, and R 'and R''are alkyl, alkoxy, alkanoyloxy, alkoxycarbonyl or alkoxycarbonyloxy having up to 18, preferably up to 8 carbon atoms, or one of these radicals is also CN, NC, NO ₂ , CF ₃ , F, Cl or Br.

In most of these compounds, R 'and R' 'are different from one another, one of these radicals usually being an alkyl or alkoxy group. However, other variants of the proposed substituents are also common. Many such substances or mixtures thereof are commercially available. All of these substances are obtainable by methods known from the literature.

The phases according to the invention contain about 0.1 to 99, preferably 10 to 95%, of one or more compounds of formula I. Also preferred are liquid-crystalline phases according to the invention, containing 0.1-40, preferably 0.5-30% of one or more compounds of formula I.

The phases according to the invention are prepared in a conventional manner. As a rule, the components are dissolved in one another, expediently at elevated temperature.

By means of suitable additives, the liquid crystalline

Phases according to the invention are modified so that they can be used in all previously known types of liquid crystal display elements.

Such additives are known to the person skilled in the art and are described in detail in the literature. For example, conductive salts, preferably ethyl-dimethyl-dodecyl-ammonium-4-hexyloxybenzoate, tetrabutylammonium-tetraphenylboranate or complex salts of crown ethers (see, for example, I. Haller et al., Mol. Cryst.Liq.Cryst. Volume 24, pages 249-258 (1973)) to improve the conductivity, pleochroic dyes for producing colored guest-host systems or substances for changing the dielectric anisotropy, the viscosity and / or the orientation of the nematic phases are added.

Such substances are e.g. in DE-OS 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430, 28 53 728 and 29 02 177.

The following examples are intended to illustrate the invention without limiting it. Mp. = Melting point, Kp. = Clearing point. Percentages above and below mean percentages by weight; all temperatures are given in degrees Celsius. "Conventional work-up" means: water is added, the mixture is extracted with methylene chloride, the mixture is separated off, the organic phase is dried, evaporated and the product is purified by crystallization and / or chromatography.

It also means:

K: crystalline solid state, S: smectic phase (the index indicates the phase type), N: nematic state, Ch: cholesteric phase, I: isotropic phase. The number between two symbols indicates the transition temperature in degrees Celsius.

Example 1 :

A mixture of 8 g (S, S) -3-methyl-2-chloropentanoic acid, 16 g optically active p- [5- (2,6-dimethylheptyl) pyrimidin-2-yl] phenol [obtainable by condensation of ( S) -1,1,3,3-tetraethoxy-2- (2,6-dimethylheptyl) propane with 4-hydroxyphenylamidine hydrochloride], 11.6 g N, N-dicyclohexylcarbodiimide, 0.6 g 4-N, N- Dimethylaminopyridine and 300 ml dichloromethane is stirred overnight at room temperature. After filtering off the precipitated urea derivative, the filtrate is washed with dil. Hydrochloric acid and H ₂ O and the org. Phase worked up as usual. (S, S) -3-Methyl-2-chloropentanoic acid p- [5- (2,6-dimethylheptyl) pyrimidin-2-yl] phenyl ester is obtained.

Example 2:

In the absence of moisture, at 0 ° to a mixture of 4.9 g of optically active hydroquinone-4-cyan-4- (3,7-dimethyloctyl) cyclohexane carboxylic acid ester (obtainable by esterification of 4-cyan-4- (3.7 -dimethyloctyl) - cyclohexane carboxylic acid with hydroquinone monobenzyl ether and subsequent cleavage of the benzyl group by catalytic hydrogenation), 1.87 g of optically active 2-chloro-3-methylbutyric acid and 170 mg of 4-N, N'-dimethylaminopyridine in 30 ml of dichloromethane, 3.1 g Dicyclohexylcarbodiimide in 5 ml dichloromethane was added dropwise. After stirring for 12 hours at room temperature, filtering and customary working up of the filtrate, optically active 2-chloro-3-methylbutyric acid p- (4-cyan-4- (3,7-dimethyloctyl) cyclohexylcarbonyloxy) phenyl ester is obtained. The following are produced analogously:

2-Chloro-3-methylbutyric acid p- (4-cyan-4- (2-methylbutyl) cyclohexylcarbonyloxy) phenyl ester

2-Chloro-3-methylbutyric acid p- (4-cyan-4- (2-methylbutyl) cyclohexyl) phenyl ester

2-Chloro-3-methylbutyric acid p- (4-cyan-4- (3,7-dimethyl¬octyl) cyclohexyl) phenyl ester

2-chloro-3-methylbutyric acid p- (p- (3-methylpentyl) benzoyloxy) phenyl ester 2-chloro-3-methylbutyric acid p- (trans-4- (4,8-dimethyl¬nonyl) cyclohexane carbonyloxy) -phenyl ester.

Example 3:

An excess of (S, S) -3-methyl-2-chloropentanoic acid is reacted with 4,4'-bis-hydroxybiphenyl analogously to Example 1. After customary work-up, optically active 4,4'-bis (2-chloro-3-methylpentanoyloxy) biphenyl is obtained.

The following are produced analogously:

4,4'-bis (2-chloro-3-methylbutyryloxy) biphenyl, m.p. 92 ° 4,4'-bis (2-chloro-4-methylpentanoyloxy) biphenyl, m.70 °

4,4'-bis (2-chloro-3-methylbutyryloxy) trans, trans-cyclohexylcyclohexane

4,4'-bis (2-chloro-4-methylpentanoyloxy) trans, trans-cyclohexylcyclohexane

4,4'-bis (2-chloro-3-methylpentanoyloxy) trans, trans-cyclohexylcyclohexane Example 4:

A mixture of 5.3 g of p- [p- (4-cyano-4- (2-methylbutyl) cyclohexyl) phenyl] phenol (obtainable by alkaline ether cleavage from r-1-cyano-cis-4- (4th '-propyloxybiphenyl-4-yl) -1- (2-methylbutyl) cyclohexane with potassium tert-butoxide in NMP at 180 °), 1.9 g optically active 2-chloro-3-methylbutyric acid and 170 g DMAP are suspended in 40 ml CH ₂ Cl ₂ . Then, at 0 ° 3.1 g of DCC in 5 ml of CH ₂ Cl _{2 are} added dropwise and the mixture is stirred at room temperature for 12 hours. After removal of the dicyclohexylurea and customary workup, optically active 2-chloro-3-methylbutyric acid 4 '- (4-cyan-4- (2-methylbutyl) cyclohexyl) biphenyl-4-yl ester is obtained.

Example 5:

By esterifying optically active 4- (4 '- (2-octyloxy) biphenyl-4-yl) -1-cyano-1- (2-hydroxypropyl) cyclohexane (available from 4- (4' - (2-octyloxy ) -biphenyl-4-yl) -cyclohexane carbonitrile by alkylation with optically active propylene oxide and lithium diisopropylamide as base) with optically active 2-chloro-3-methylbutyric acid gives optically active 1- [4-cis- (4 '- (2-octyloxy ) -biphenyl-4-yl) -r-1-cyancyclohexyl] -2-propyl- (2-chloro-3-methylbutyrate).

Example 6:

A solution of optically active 4- (2-octyloxy) -4'-hydroxybiphenyl in toluene is added dropwise to a solution of 2.4 g of optically active α-pentyloxypropionic acid chloride in 25 ml of pyridine and the mixture is heated under reflux for 2 hours. After the usual work-up, 4- (2-octyloxy) -4'- (α-pentyloxypropanoyloxy) biphenyl is obtained. The following are produced analogously:

4,4'-bis (α-pentyloxypropanoyloxy) biphenyl 4,4'-bis (α-butyloxypropanoyloxy) biphenyl 4,4'-bis (α-propyloxypropanoyloxy) biphenyl 4,4'-bis ( α-ethyloxypropanoyloxy) biphenyl

Example 7:

0.035 mol 4,4'-bis-hydroxybiphenyl, 0.07 mol (S) -3,7-dimethyloctanoic acid and 1 g 4-N, N'-dirnethylaminopyridine (DMAP) are dissolved in 150 ml toluene. A solution of 16.0 g of dicyclohexylcarbodiimide (DCC) in 40 ml of toluene is added dropwise, and the mixture is stirred overnight, chromatographed with toluene on silica gel, recrystallized, and optically active 4,4'-bis (3,7-dimethyloctanoyloxy) is obtained. -biphenyl, mp 72-73 °.

Example 8:

25 mmol of 4.4 '' terphenyldicarboxylic acid (obtainable by reacting dibromophenyl with CuCN in NMP and saponification of the dinitrile with KOH in diethylene glycol), 7.9 g of (S) -3,7-dimethyloctanol and 0.12 g of DMAP are in 40 ml of toluene submitted. A solution of 9.9 g of DCC in 15 ml of toluene is added dropwise with stirring at room temperature, the mixture is stirred overnight, chromatographed on silica gel using toluene, and the product is recrystallized, and 4,4'-bis (3,7-dimethyloctyloxycarbonyl) is obtained. p-terphenyl.

Example 9:

To a solution of 16.2 g (0.3 mol) of sodium methylate and 24.8 g (0.1 mol) of 1-fluoro-2,5-di- (4-hydroxyρhenyl) benzene in 150 ml of methanol are in the Boiling point 80.5 g (0.3 mol) (S) -3,7-dimethyl-1-iodoctane was added dropwise. After 5 hours the mixture is worked up as usual. After recrystallization, pure 1-fluoro-2,5-di- [4- (3,7-dimethyloctyloxy) phenyl] benzene is obtained. Example 10

According to Example 1, S, S-3-methyl-2-chloropentanoic acid in the presence of DCC with optically active 2- (p-hydroxyphenyl) -3- (3-methylpentyl) pyridine [can be prepared from 2- (pMethoxyphenyl) -3- (3-methylpenty1) pyridine esterified by basic ether cleavage with potassium tert-butoxide in NMP at 180 ° C.] and worked up as usual. (S, S) 3-Methyl-2-chloropentanoic acid p-A- (3-methylpentyl) pyridin2-yl] phenyl ester is obtained.

Example A:

A liquid-crystalline phase is produced consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine 3% 2-p-octyloxyphenyl-5-heptylpyrimidine 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine 7% 2-p- Hexyloxyphenl-5-nonylpyrimidine 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine 28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane 14% r-1-cyano- cis-4- (4'-heptylbiphenyl-4-yl) -1-hexylcyclohexane 6% r-1-cyano-cis-4- (trans-4-pentylcyclohexyl) -1- (trans4-pentylcyclohexyl) cyclohexane and 10% 2-Chloro-3-methylbutyric acid 4 '- [4-cyan-4- (3,7-dimethylheptyl) cyclohexyl] biphenyl-4-yl ester. Example B

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine 3% 2-p-octyloxyphenyl-5-heptylpyrimidine 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine 7% 2-p- Hexyloxyphenl-5-nonylpyrimidine 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine 28% r-1-cyano-cis-4- (4'-butyloxybipheny \ -4-yl) -1-octylcyclohexane

14% r-1-cyan-cis-4- (4'-heptylbiphenyl-4-yl) -1-hexylcyclohexane 6% r-1-cyan-cis-4- (trans-4-pentylcyclohexyl) -1- (trans4 -pentylcyclohexyl) cyclohexane and 10% 4,4'-bis (2-chloro-3-methylbutyryloxy) biphenyl

has a spontaneous polarization of 38 nC / cm ² at room temperature and an S * / Ch conversion at 68 °.

Example C

A liquid-crystalline phase is produced consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine 3% 2-p-octyloxyphenyl-5-heptylpyrimidine 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine 7% 2-p- Hexyloxyphenl-5-nonylpyrimidine 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine 28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane 14% r-1-cyano-cis-4- (4 * -heptylbiphenyl-4-yl) -1 -hexylcyclohexane 6% r-1-cyano-cis-4- (trans-4-pentylcyclohexyl) -1- (trans¬

4-pentylcyclohexyl) cyclohexane and 10% 3- methyl-2-chlorobutyric acid p- [5- (3-methylpentyl) pyridin-2-yl] phenyl ester.

Example D

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine, 30% r-1-cyano-cis-4- (4'-octyloxybiphenyl-4-yl) -1-octylcylohexane, 15 % r-1-cyano-cis-4- (4'-heptyloxybiphenyl-4-yl) -1-hexylcylohexane,

8% 3-methyl-2-chlorobutyric acid p- (5-nonylpyrimidin¬

2-yl) phenyl ester (optically active) and 5% 3-methyl-2-chlorobutyric acid p- [5- (3,7-dimethyloctyl) pyrimidin-2-yl] phenyl ester (optically active)

shows S ^* _C / S _A 57 °, S./Ch 61 °, Ch / I 78 ° and Pe = 13 nC / cm ² . Example E:

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 25% 2-p-nonyloxyphenyl-5-nonylpyrimidine, 30% r-1-cyano-cis-4- (4'-octyloxybiphenyl-4-yl) -1-octylcyclohexane

15% r-1-cyano-cis-4- (4'-heptylbiphenyl-4-yl) -1-hexylcyclohexane

6% 3-methyl-2-chlorobutyric acid p- (5-heptylpyridin-2-yl) phenyl ester (optically active) and 5% 2,5-bis- [p- (3-methyl-2-chlorobutyryloxy) phenyl pyridine (optically active)

shows S ^* _C / Sa 61 °, S _A / Ch 64 °, Ch / I 78 ° and P _S = 18 nC / cm ² .

Example F

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine / 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine,

7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine,

28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane 14% r-1-cyan-cis-4- (4'-heptylbiphenyl-4-yl) -1-hexylcyclohexane 6% r-1-cyan-1- (trans-4-pentylcyclohexyl) -cis-4- (trans4 -pentylcyclohexyl) -cyclohexane and 10% optically active

4,4'-bis [1- (ethoxycarbonyl) ethoxy] biphenyl

shows S _C ^* / S _A 54 °, S _A / Ch 58 °, Ch / I 78 ° and P _S = 2 nC / cm ² .

Example G

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine,

28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane 14% r-1-cyano-cis-4- (4'-heptylbiphenyl-4-yl) -1 -hexylcyclohexane 6% r-1-cyan-1- (trans-4-pentylcyclohexyl) -cis-4- (trans4-pentylcyclohexyl) -cyclohexane and 10% optically active

4,4'-bis (α-butyloxypropanoyloxy) biphenyl

shows S _C ^* / S _A 51 °, S _A / Ch 53 °, Ch / I 76 ° and P _S = 2 nC / cm ² . Example H

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine, 28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane,

14% r-1-cyan-cis-4- (4'-hexylbiphenyl-4-yl) -1-heptylcyclohexane, 6% r-1-cyan-cis-4- (trans-4-pentylcyclohexyl) -1- ( trans-4-pentylcyclohexyl) cyclohexane and 10% 4,4'-bis (2-chloro-3-methylbutyryloxy) trans; transcyclohexylcyclohexane

(optically active) shows S * / S _A 53 °, S _A / Ch 84 °, Ch / I 92 and P _S = 12 nC / cm ² .

Example I:

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine, 28% r-1-cyano-cis-4- (4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane, 14% r-1-cyano-cis-4- (4'-hexylbiphenyl-4-yl) - 1-heptylcyclohexane, 6% r-1-cyano-cis-4- (trans-4-pentylcyclohexyl) -1- (trans-4-pentylcyclohexyl) cyclohexane and 10% 4,4'-bis- (2-chloro- 4-methylpentanoyloxy) trans, transcyclohexylcyclohexane

(optically active) shows S ^* _c / S _A 58 °, S _A / Ch 82 °, Ch / I 88 ° and P _S = 14 nC / cm ² .

Example J

A liquid crystalline phase consisting of

3% 2-p-hexyloxyphenyl-5-heptylpyrimidine, 3% 2-p-heptyloxyphenyl-5-heptylpyrimidine, 3% 2-p-octyloxyphenyl-5-heptylpyrimidine, 3% 2-p-nonyloxyphenyl-5-heptylpyrimidine, 7% 2-p-hexyloxyphenyl-5-nonylpyrimidine, 23% 2-p-nonyloxyphenyl-5-nonylpyrimidine, 28% r-1-cyano-cis-4- ( _. 4'-butyloxybiphenyl-4-yl) -1-octylcyclohexane,

14% r-1-cyan-cis-4- (4'-hexylbiphenyl-4-yl) -1-heptylcyclohexane, 6% r-1-cyan-cis-4- (trans-4-pentylcyclohexyl) -1- ( trans-4-pentylcyclohexyl) cyclohexane and 10% 4,4'-bis (2-chloro-3-methylpentanoyloxy) trans, transcyclohexylcyclohexane

(optically active) shows S ^* _C / S _A 55 °, S _A / Ch 83 °, Ch / I 90 ° and P _S = 13 nC / cm ² .

INTERNATIONAL PATENT COOPERATION (PCT)

(51) International patent classification: (11) International publication number: WO 87/05 C 07 C 121/46; 121/48; 69/24; C 07 D 213/30; C 07 C 69/708; C 07 D 239/26; C 07 C 69/63; 69/76; 69/75; C 09 K 19/34; 19/30; 19/20; A3 C 09 K 19/12 (43) International

RELEASE DATE: August 27, 1987 (Aug 27

(21) International file number: PCT / DE87 / 00035 Hinter der Schule 3 a, D-6104 Seeheim-Jugenh (DE).

(22) International filing date:

January 31, 1987 (January 31, 1987) (74) Common representative: MERCK PATENT GESE SCHAFT WITH RESTRICTED LIABILITY Frankfurter Strasse 250, D-6100 Darmstadt (DE).

(31) Priority record number: P 36 04905.0 P 36 30 771.8

(81) Destination countries: AT (European patent), BE

(32) Priority dates: February 17, 1986 (February 17, 1986) European patent), CH (European patent), September 10, 1986 (September 10, 1986) (European patent), FR (European patent), (European patent), IT (European patent),

(33) Priority country: DE KR, LU (European patent), NL (European tent), SE (European patent), US.

(71) Applicant (for all destinations except US):

MERCK PATENT SOCIETY WITH BEPUBLISHED LIABILITY [DE / DE]; Frankfurter With international research report. Strasse 250, D-6100 Darmstadt (DE). Before the deadline for changes in claims expires. Publication will be repeated if

(72) Inventor; and changes arrive.

(75) Inventor / Applicant (for US only): GEELHAAR, Thomas [DE / DE]; Trajanstrasse 12, D-6500 Mainz (DE). (88) Publication date of the international Rec WÄCHTLER, Andreas [DE / DE]; Goethestrasse 34, Chenreports: January 14, 1988 (January 14, D-6103 Griesheim (DE). SCHEUBLE, Bernard [DE / JP]; Bluff 100, 100-1, Yamate-cho, Naka-ku, Yokohama-shi, Kanagawa 231 (JP) KURMEIER, Hans-Adolf [DE / DE];

(54) Title: OPTICALLY ACTIVE COMPOUNDS

(54) Description: OPTICALLY ACTIVE CONNECTIONS

(57) Abstract

Optically active compounds can be used as components of chirally tilted smectic liquid crystal phases.

(57) Summary

Optically active compounds can be used as components of chiral-chopped smectic liquid-crystalline phases.

ONLY FOR INFORMATION

Code used to identify PCT contracting states on the headers of the publications that publish international applications according to the PCT.

AT Austria FrankreichR France MR Mauritanϊen

AU Australia GA Gabon MW Malawi

BEBarbados GB United Kingdom NL Netherlands

BE Belgium Hü Hungary NO Norway

BG Bulgaria rr Italy RO Romania

BJ Benin JP Japan SD Sudan

BR Brazil KP Democratic People's Republic of Korea SE Sweden

CF Central African Republic: KR Republic of Korea SN Senegal

CG Congo LI Liechtenstein SU Soviet Union

CH Switzerland LK Sri Lanka. TD Chad

CM Cameroon LU Luxembourg TG Togo

DE Germany, Federal Republic of MC Monaco US United States

DK Denmark MG Madagascar

IT Finland ML Mali

Claims

Claims

1. Optically active compounds of the formula I.

R ¹ -C * HX-OA ⁴ -Z ¹ -A ² - (Z ² -A ³ ) _n -X'-Q'-C * HY'-R ⁵

wherein

R ^{1 is} an alkyl or perfluoroalkyl group, each having 1-12 C atoms, in which one or two non-adjacent CH ₂ or CF ₂ groups are also represented by O atoms and / or -CO groups and / or -CO -O groups and / or -CH = CH groups and / or -CH-halogen and / or -CHCN groups and / or -O-CO-CH-halogen and / or -O-CO-CHCN groups can be replaced ,

R ^{5 is} an alkyl group different from y »having 1 to 15 carbon atoms, in which also one or two non-adjacent CH ₂ groups are represented by -0-, -CO-, -O-CO-, -CO-O- and / or -CH = CH- can be replaced,

A ² , A ³ each unsubstituted or by one and A ⁴ or two F and / or Cl atoms and / or

CH ₃ groups and / or CN groups substituted 1,4-phenylene, in which one or two CH groups can also be replaced by N. 1,4-cyclohexylene, in which one or two non-adjacent CH ₂ groups can also be replaced by O atoms and / or S atoms, piperidine-1,4-diyl, 1,4-bicyclo (2,2 , 2) octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or

1,2,3,4-tetrahydronaphthalene-2,6-diyl groups,

Z ¹ and Z ² each -CO-O-, -O-CO-, -CH ₂ CH ₂ -, -OCH ₂ -, -CH ₂ O-, -C≡C- or a single bond,

X halogen, CN or CH ₃ ,

n 0 or 1,

Q alkylene with 1 to 4 carbon atoms, in which a CH ₂ group is also replaced by -O-, -CO-, -O-CO-, -CO-O-, -CH = CH-COO-, -CH = CH -, -CH halogen and / or -CHCN- can be replaced, or a single bond,

X '-CO-O-, -O-CO-, -O-CO-O-, -CO-, -O-, -S-, -CH = CH-, -CH = CH-COO- or a single bond ,

Q 'alkylene with 1 to 5 C atoms, in which a CH ₂ group which is not linked to X' is also replaced by -O-, -CO-, -O-CO, -CO-O- or -CH = CH- can, or a simple binding, and

Y 'denotes CN, halogen, methyl or methoxy, with the proviso that R ¹ and / or R ^{5 is} a branched alkyl group having 3 to 12 carbon atoms if -C ^* HX-Q- -CHHalogen-CO-O- and / or -X ^, -Q ^, -C ^* HY'- -O-CO-CH halogen means.

2. Optically active compounds of formula I according to claim 1, characterized by the formula

R ¹ -C * HX-COO-A ⁴ -Z ¹ -A ² - (Z ² -A ³ ) n-OOC-C * HY'-R ⁵

wherein R ¹ , R ⁵ , X, Y ', A ² , A ³ , ^A4 , Z ¹ , Z ² and n have the meaning given in claim 1.

3. Optically active compounds of formula I according to claim 1 characterized by the formula

R ¹ -C * HX-COO-A ⁴ -Z ¹ -A ² -OOC-C * HY'-R ⁵

wherein R ¹ , R ⁵ , X, Y ', A ² , A ⁴ and Z ^{1 have} the meaning given in claim 1.

4. Optically active compounds according to claim 3, wherein X and Y 'are halogen.

5. Optically active compounds according to claim 3, wherein A ⁴ and A ^{2 are} 1,4-phenylene.

6. Optically active compounds according to claim 4, wherein A ⁴ and A ^{2 are} 1,4-phenylene.

7. Optically active compounds according to claim 3, wherein Z ^{1 is} a single bond.

8. Optically active compounds according to claim 4, wherein Z ^{1 is} a single bond.

9. Optically active compounds according to claim 5, wherein Z ^{1 is} a single bond.

10. Optically active compounds according to claim 6, wherein Z ^{1 is} a single bond.

11. Optically active compounds according to claim 1, characterized in that the radical R ¹ -C * HX-Q- is different from the radical -X'-Q'-C ^* HY'-R ⁵ .

12. Chiral tilted smectic liquid-crystalline phase with at least two liquid-crystalline components, characterized in that it contains at least one optically active compound of the formula I according to claim 1.

13. Use of the compounds of formula I according to claim 1 as components of liquid-crystalline phases.

14. Electro-optical display element, characterized in that it is a phase after dielectric

Claim 12 contains.