Patent Description:
Liquid crystals have found widespread use since the first commercially usable liquid-crystalline compounds were found about <NUM> years ago. Known areas of application are, in particular, displays for watches and pocket calculators, and large display panels as used in railway stations, airports and sports arenas. Further areas of application are displays of portable computers and navigation systems and video applications. For the lastmentioned applications in particular, high demands are made of the response times and contrast of the images.

The spatial arrangement of the molecules in a liquid crystal has the effect that many of its properties are direction-dependent. Of particular importance for use in liquid-crystal displays are the optical, dielectric and elastomechanical anisotropies. Depending on whether the molecules are oriented with their longitudinal axes perpendicular or parallel to the two plates of a capacitor, the latter has a different capacitance; in other words, the dielectric constant ε of the liquid-crystalline medium has different values for the two orientations. Substances whose dielectric constant is larger when the longitudinal axes of the molecules are oriented perpendicular to the capacitor plates than when they are oriented parallel are known as being dielectrically positive. Most liquid crystals used in earlier displays fall into this group.

Both the polarisability of the molecule and the permanent dipole moment play a role for the dielectric anisotropy. On application of a voltage to the display, the longitudinal axis of the molecules orients itself in such a way that the larger of the dielectric constants parallel or perpendicular becomes effective. The strength of the interaction with the electric field depends on the difference between the two constants. In the case of small differences, higher switching voltages are necessary than in the case of large differences. The introduction of suitable polar groups, such as, for example, nitrile groups or fluorine, into the liquid-crystal molecules enables a broad range of working voltages to be achieved.

In the case of the liquid-crystalline molecules used in conventional liquid-crystal displays, the dipole moment oriented along the longitudinal axis of the molecules is larger than the dipole moment oriented perpendicular to the longitudinal axis of the molecules. The orientation of the larger dipole moment along the longitudinal axis of the molecule also determines the orientation of the molecule in a liquid-crystal display in the field-free state. In the most widespread TN ("twisted nematic") cells, a liquid-crystalline layer with a thickness of only from about <NUM> to <NUM> is arranged between two flat glass plates, onto each of which an electrically conductive, transparent layer of tin oxide or indium tin oxide has been vapour-deposited as electrode. A likewise transparent alignment layer, usually consisting of a polymer (for example polyimides), is located between these films and the liquid-crystalline layer. This alignment layer serves to bring the longitudinal axes of the adjacent crystalline molecules into a preferential direction through surface forces in such a way that, in the voltage-free state, they lie uniformly on the inside of the display surface with the same alignment in a flat manner or with the same small tilt angle. Two additional polarisation films which only enable linear-polarised light to enter and escape are adhesively bonded to the outside of the display in a certain arrangement.

By means of liquid crystals in which the larger dipole moment is oriented parallel to the longitudinal axis of the molecule, high-performance displays have already been developed. In most cases here, mixtures of from <NUM> to <NUM> components are used in order to achieve a sufficiently broad temperature range of the mesophase and short response times and low threshold voltages. However, difficulties are still caused by the strong viewing-angle dependence in liquid-crystal displays as are used, for example, for laptops. The best imaging quality can be achieved if the sur-face of the display is perpendicular to the viewing direction of the observer. If the display is tilted relative to the observation direction, the imaging quality drops drastically under certain circumstances. For greater comfort, attempts are being made to make the angle through which the display can be tilted from the viewing direction of an observer as large as possible. Attempts have recently been made to improve the viewing-angle dependence using liquid-crystalline compounds whose dipole moment perpendicular to the longitudinal axis of the molecules is larger than that parallel to the longitudinal axis of the molecule. In the field-free state, these molecules are oriented perpendicular to the glass surface of the display. In this way, it has been possible to achieve an improvement in the viewing-angle dependence. Displays of this type are known as VA-TFT ("vertically aligned") displays.

Also known are so-called IPS ("in-plane switching") displays, which contain an LC layer between two substrates with planar orientation, where the two electrodes are arranged on only one of the two substrates and preferably have interdigitated, comb-shaped structures. On application of a voltage to the electrodes an electric field with a significant component parallel to the LC layer is generated between them. This causes realignment of the LC molecules in the layer plane. Furthermore, so-called FFS ("fringe-field switching") displays have been reported (see, inter alia, <NPL>), which contain two electrodes on the same substrate, one of which is structured in a comb-shaped manner and the other is unstructured. A strong, so-called "fringe field" is thereby generated, i.e. a strong electric field close to the edge of the electrodes, and, throughout the cell, an electric field which has both a strong vertical component and also a strong horizontal component. FFS displays have a low viewing-angle dependence of the contrast. FFS displays usually contain an LC medium with positive dielectric anisotropy, and an alignment layer, usually of polyimide, which provides planar alignment to the molecules of the LC medium.

For the FFS display it is suggested that not only the large absolute value of Δε is important, but also the components ε(parallel) and ε(perpendicular) are significant in determining the switching behaviour. It is desirable to achieve a large value for ε(perpendicular), because this improves transmittance of the display.

In <CIT>, dibenzofuran and dibenzothiophene derivatives are proposed for the use in liquid-crystal media. However, due to their substitution pattern, the compounds described therein exhibit very strong negative dielectric anisotropy which makes them unsuitable for the application according to the present invention.

In <CIT> fluorinated dibenzothiophenes and dibenzofurans as liquid-crystalline materials are disclosed. <CIT> presents further fluorinated dibenzothiophenes for use in liquid crystals and display elements.

Development in the area of liquid-crystalline materials is far from complete. In order to improve the properties of liquid-crystalline display elements, attempts are constantly being made to develop novel compounds which enable such displays to be optimised.

An object of the present invention was to provide more diverse compounds having advantageous properties for use in liquid-crystalline media.

This object is achieved in accordance with the invention by compounds of the general formula I
<CHM>
in which.

A further object of the present invention is to provide liquid-crystalline media, in particular for use in TN, IPS or FFS displays.

This object is achieved in accordance with the invention by the provision of compounds of formula I with neutral to positive dielectric anisotropy (Δε).

The compounds of formula I are distinguished by a surprisingly large positive dielectric anisotropy (Δε) and are therefore suitable, in particular, for use in TN-TFT displays, and in IPS- and FFS displays. The compounds have a comparatively very low melting point, a very high clearing point, they exhibit very good compatibility with the conventional substances used in liquid-crystal mixtures for displays and are well soluble in such media. Even further the compounds show a very high value of ε⊥.

The compounds according to the invention preferably have a Δε in the positive region, preferably Δε > <NUM>, more preferably Δε > <NUM>.

If the group R is an alkyl radical and/or an alkoxy radical, this can be straight-chain or branched. It is preferably straight-chain, has <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> carbon atoms and accordingly is preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy, furthermore methyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octoxy, nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy or tetradecoxy.

R may each, independently of one another, be an alkenyl radical having from <NUM> to <NUM> carbon atoms, which may be straight-chain or branched. It is preferably straight-chain and has from <NUM> to <NUM> carbon atoms. Accordingly, it is preferably vinyl, prop-<NUM>- or -<NUM>-enyl, but-<NUM>-, -<NUM>- or -<NUM>-enyl, pent-<NUM>-, -<NUM>-, -<NUM>- or -<NUM>-enyl, hex-<NUM>-, -<NUM>-, -<NUM>-, -<NUM>- or -<NUM>-enyl, or hept-<NUM>-, -<NUM>-, -<NUM>-, -<NUM>-, -<NUM>- or -<NUM>-enyl.

R may each, independently of one another, be oxaalkyl, preferably straight-chain <NUM>-oxapropyl (= methoxymethyl), <NUM>-oxabutyl (= ethoxymethyl) or <NUM>-oxabutyl (= methoxyethyl), <NUM>-, <NUM>- or <NUM>-oxapentyl, <NUM>-, <NUM>-, <NUM>- or <NUM>-oxahexyl, or <NUM>-, <NUM>-, <NUM>-, <NUM>- or <NUM>-oxaheptyl.

R may each, independently of one another, be an alkyl radical having from <NUM> to <NUM> carbon atoms in which one CH<NUM> group has been replaced by -O- and one has been replaced by -CO-, where these are preferably adjacent. This thus contains an acyloxy group -CO-O- or an oxycarbonyl group -O-CO-. This is preferably straight-chain and has from <NUM> to <NUM> carbon atoms.

R may each, independently of one another, be an alkyl radical having from <NUM> to <NUM> carbon atoms in which one CH<NUM> group has been replaced by unsubstituted or substituted -CH=CH- and an adjacent CH<NUM> group has been replaced by CO or CO-O or O-CO, where this may be straight-chain or branched. It is preferably straight-chain and has from <NUM> to <NUM> carbon atoms.

R may each, independently of one another, be an alkyl radical having from <NUM> to <NUM> carbon atoms or alkenyl radical having from <NUM> to <NUM> carbon atoms, each of which is monosubstituted by -CN or -CF<NUM> and is preferably straight-chain. The substitution by -CN or -CF<NUM> is possible in any desired position.

R may each, independently of one another, be an alkyl radical in which two or more CH<NUM> groups have been replaced by -O- and/or -CO-O-, where this may be straight-chain or branched. It is preferably branched and has from <NUM> to <NUM> carbon atoms.

R may each, independently of one another, be an alkyl radical having from <NUM> to <NUM> carbon atoms or an alkenyl radical having from <NUM> to <NUM> carbon atoms, each of which is at least monosubstituted by halogen, where these radicals are preferably straight-chain and halogen is preferably -F or -Cl. In the case of polysubstitution, halogen is preferably -F. The resultant radicals also include perfluorinated radicals, such as -CF<NUM>. In the case of monosubstitution, the fluorine or chlorine substituent can be in any desired position, but is preferably in the ω-position.

The term "fluorinated alkyl radical" preferably encompasses mono- or polyfluorinated radicals. Perfluorinated radicals are included. Particular preference is given to CF<NUM>, CH<NUM>CF<NUM>, CH<NUM>CHF<NUM>, CHF<NUM>, CH<NUM>F, CHFCF<NUM> and CF<NUM>CHFCF<NUM>.

The term "fluorinated alkoxy radical" preferably encompasses mono- or polyfluorinated radicals. Perfluorinated radicals are included. Particular preference is given to OCF<NUM>.

In a preferred embodiment of the present invention the compounds of formula I are selected from the compounds of the formulae I-<NUM> to I-<NUM>:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
in which the occurring groups and parameters have the meanings given above for formula I, and independently:.

Further, the compounds of formula I are preferably selected from the compounds of the formulae I-A to I-F:
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
and more preferably from the group of formulae I-A, I-B, I-D and I-E, wherein R and X are as defined as for formula I above, and preferably X is F, CF<NUM> or OCF<NUM>, while more preferably X is CF<NUM> or OCF<NUM> for I-A to I-C.

In a preferred embodiment of the present invention, in the formula I and its sub-formulae, R denotes alkyl having <NUM> to <NUM> C atoms, in particular ethyl, propyl, buty, pentyl, cyclopropylmethyl, cyclobutyl or cyclopentyl, where n-propyl and n-pentyl are most preferred.

In a preferred embodiment of the present invention, in the formula I Z denotes a single bond.

The compounds of the general formula I are prepared by methods known per se, as described in the literature (for example in the standard works, such as Houben-Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Georg-Thieme-Verlag, Stuttgart), to be precise under reaction conditions which are known and are suitable for the said reactions. Use can be made here of variants which are known per se, but are not mentioned here in greater detail.

If desired, the starting materials can also be formed in situ by not isolating them from the reaction mixture, but instead immediately converting them further into the compounds of the general formula I.

Preferred synthetic pathways towards compounds according to the invention are shown in the schemes below and are further illustrated by means of the working examples. The syntheses can be adapted to the particular desired compounds of the general formula I by choice of suitable starting materials.

The dibenzofuran derivatives, i.e. the compounds of formula I wherein W denotes O (formula I') are preferably synthesized as shown in scheme <NUM> and are obtainable by intramolecular substitution of fluorine by nucleophilic attack of a phenolate by treatment of the phenol P with a base.

Alternatively, the analogous ring closure where the position of the OH group and the fluorine atom are interchanged, is possible as shown in scheme <NUM>.

The dibenzofuran derivatives, i.e. the compounds of formula I wherein W denotes S (formula I") are preferably synthesized as shown in scheme <NUM>.

The intermediates S (scheme <NUM>) are obtainable from the phenols P (scheme <NUM>) via the corresponding triflate according to <NPL>. Treatment of the compounds S with a strong, non-nucleophilic base, preferably potassium tert. -butanoate yields compounds I" (cf.

Another object of the present invention is thus a compound of formula P or P'
<CHM>
<CHM>
for use in a process for the synthesis of compounds of formula I,
in which the occurring groups and parameters have the meanings given above for formula I.

A further object of the present invention is a process for the synthesis of the compound of formula I from a compound of formula P or P', preferably following the synthetic pathway depicted in scheme <NUM>, scheme <NUM> or scheme <NUM> above. A process for the preparation of a compound of formula I is characterised in that a compound of formula P or P', preferably of formula P, as defined above and below, is subjected to a ring closing reaction leading to a compound of formula I as defined above and below. The ring closing reaction is a nucleophilic aromatic substitution reaction. It is preferably carried out in the presence of a base.

The reactions described should only be regarded as illustrative. The person skilled in the art can carry out corresponding variations of the syntheses described and also follow other suitable synthetic routes in order to obtain compounds of the formula I.

The compounds of the general formula I can be used in liquid-crystalline media. The present invention therefore also relates to a liquid-crystalline medium comprising two or more liquid-crystalline compounds, comprising one or more compounds of the general formula I.

The media according to the invention preferably comprise <NUM> to <NUM>%, particularly preferably <NUM> to <NUM>%, of the compounds of the formula I according to the invention.

The media preferably comprise one, two, three, four or five compounds of the formula I according to the invention.

In a preferred embodiment of the present invention the liquid-crystalline medium comprises.

In a further preferred embodiment, the medium comprises one or more compounds of formula V selected from the group of the compounds of the formulae V-<NUM> to V-<NUM>, preferably one or more of formula V-<NUM>, V-<NUM> and V-<NUM>,
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
in which the parameters have the meanings given above under formula V, and preferably.

In a further preferred embodiment the medium contains one or more compounds of the formula V-<NUM> in which at least one of the R<NUM> and R<NUM> radicals is alkenyl having <NUM> to <NUM> carbon atoms, preferably those selected from the following formulae:
<CHM>
<CHM>
<CHM>
<CHM>
in which "Alkyl" has the definition given above, and is preferably methyl or ethyl. Particular preference is given to compounds of the formula V-3d.

In a further preferred embodiment, the medium comprises one or more compounds of formula V-<NUM> selected from the group of the compounds of the formulae V-4a to V-4c,
<CHM>
<CHM>
<CHM>
in which
alkyl and alkyl* are each independently straight-chain alkyl radical having <NUM> to <NUM> carbon atoms, especially methyl, ethyl, n-propyl and pentyl.

The liquid crystalline medium preferably comprises two, three or more compounds selected from the group of compounds of formulae V-4a, V-4b and V-4c.

In a further preferred embodiment, the medium comprises one or more compounds of formula V-<NUM> selected from the group of the compounds of the formulae V-5a to V-5c, preferably V-5a:
<CHM>
<CHM>
<CHM>
in which.

The present invention also relates to electro-optical liquid-crystal display elements containing a liquid-crystalline medium according to the invention.

The media according to the invention are prepared in a manner conventional per se. In general, the components are dissolved in one another, advantageously at elevated temperature. By means of suitable additives, the liquid-crystalline phases of the present invention can be modified in such a way that they can be used in all types of liquid-crystal display elements that have been disclosed hitherto. Additives of this type are known to the person skilled in the art and are described in detail in the literature (<NPL>). For example, pleochroic dyes can be used for the preparation of coloured guesthost systems or substances can be added in order to modify the dielectric anisotropy, the viscosity and/or the alignment of the nematic phases.

For the present invention and in the following examples, the structures of the liquid-crystal compounds are indicated by means of acronyms, with the transformation into chemical formulae taking place in accordance with Tables A to C below. All radicals CnH2n+<NUM>, CmH<NUM>+<NUM> and ClH<NUM>+<NUM> or CnH2n, CmH<NUM> and ClH<NUM> are straight-chain alkyl radicals or alkylene radicals, in each case having n, m and l C atoms respectively. Preferably n, m and l are independently of each other <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. Table A shows the codes for the ring elements of the nuclei of the compound, Table B lists the bridging units, and Table C lists the meanings of the symbols for the left- and right-hand end groups of the molecules. The acronyms are composed of the codes for the ring elements with optional linking groups, followed by a first hyphen and the codes for the left-hand end group, and a second hyphen and the codes for the right-hand end group. Table D shows illustrative structures of compounds together with their respective abbreviations.

in which n and m are each integers, and the three dots ". " are placeholders for other abbreviations from this table.

In addition to the compounds of formula I, the mixtures according to the invention preferably comprise one or more compounds of the compounds shown in Table D below.

The following abbreviations are used:
(n, m, k and l are, independently of one another, each an integer, preferably <NUM> to <NUM> preferably <NUM> to <NUM>, k and l possibly may be also <NUM> and preferably are <NUM> to <NUM>, more preferably <NUM> or <NUM> and most preferably <NUM>, n preferably is <NUM>, <NUM>, <NUM>, <NUM> or <NUM>, in the combination "-nO-" it preferably is <NUM>, <NUM>, <NUM> or <NUM>, preferably <NUM> or <NUM>, m preferably is <NUM>, <NUM>, <NUM>, <NUM> or <NUM>, in the combination "-Om" it preferably is <NUM>, <NUM>, <NUM> or <NUM>, more preferably <NUM> or <NUM>. The combination "-IVm" preferably is "2V1".

Exemplary, preferred dielectrically positive compounds that can be used in combination with compounds of formula I
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

Exemplary, preferred dielectrically neutral compounds that can be used in combination with compounds of formula I
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>
<CHM>.

Table E shows chiral dopants which are optionally employed in the mixtures according to the invention.

In a preferred embodiment of the present invention, the media according to the invention comprise one or more compounds selected from the group of the compounds from Table E.

Table F shows stabilisers which can preferably be employed in the mixtures according to the invention in addition to the compounds of formula B. The parameter n here denotes an integer in the range from <NUM> to <NUM>. In particular, the phenol derivatives shown can be employed as additional stabilisers since they act as antioxidants.

In a preferred embodiment of the present invention, the media according to the invention comprise one or more compounds selected from the group of the compounds from Table F.

The invention is explained in greater detail below with reference to working examples, but without being restricted thereby.

The following examples explain the present invention without restricting it. However, they show the person skilled in the art preferred mixture concepts with compounds preferably to be employed and the respective concentrations thereof and combinations thereof with one another. In addition, the examples illustrate which properties and property combinations are accessible.

Unless explicitly noted otherwise, all temperature values indicated in the present application, such as, for example, for the melting point T(C,N), the transition from the smectic (Sm) to the nematic (N) phase T(Sm,N) and the clearing point T(N,I), are quoted in degrees Celsius (°C). denotes melting point, cl. = clearing point. The data between these symbols represent the transition temperatures.

All physical properties are and have been determined in accordance with "<NPL>, and apply for a temperature of <NUM>, and Δn is determined at <NUM> and Δε at <NUM>, unless explicitly indicated otherwise in each case.

Above and below, Δn denotes the optical anisotropy (<NUM>, <NUM>) and Δε denotes the dielectric anisotropy (<NUM>, <NUM>).

The Δε and Δn values of the compounds according to the invention are obtained by extrapolation from liquid-crystalline mixtures consisting of <NUM>% of the respective compound according to the invention and <NUM>% of the commercially available liquid-crystal mixture ZLI-<NUM> (Merck KGaA, Darmstadt). In cases of limited solubility, the compound is measured in a mixture comprising only <NUM>% of the compound.

In addition, the following symbols are used:.

A mixture of <NUM>-bromo-<NUM>,<NUM>-difluoro-phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]boronic acid (<NPL>) (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane). <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]-phenyl]-<NUM>,<NUM>-difluoro-phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>,<NUM>-difluoro-phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. Then the reaction mixture is filtered through silica gel (solvent n-heptane). The residue is purified by crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>,<NUM>-trifluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]dibenzofuran (<NUM>).

The title compound has the following phase characteristics:
Cr <NUM> N <NUM> I.

A mixture of <NUM>-bromo-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]boronic acid (<NPL>) (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane), and <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. Then the reaction mixture is filtered through silica gel (solvent n-heptane). The residue is purified by crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]-<NUM>-(trifluoromethoxy)dibenzofuran (<NUM>).

The title compound has the following phase characteristics:
Cr <NUM> SmA <NUM> N <NUM> I.

A mixture of <NUM>-bromo-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]boronic acid (<NPL>) (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB-ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane). <NUM>-[<NUM>,<NUM>-Difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. Then the reaction mixture is filtered through silica gel (solvent n-heptane). The residue is purified by crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]-<NUM>(trifluoromethyl)dibenzofuran (<NUM>).

The compound has an surprisingly high value of ε⊥.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>,<NUM>-difluoro-phenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. Then the reaction mixture is filtered through silica gel (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>,<NUM>-difluoro-phenyl] trifluoromethanesulfonate as a white solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>,<NUM>-difluoro-phenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)bis-(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. Then the reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/ethanol) to give <NUM>,<NUM>,<NUM>-trifluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]dibenzothiophene as white crystals.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. Then the reaction mixture is filtered through silica gel (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenyl] trifluoromethanesulfonate as a yellow solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)bis(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. The reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/<NUM>-propanol) to give yellow crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]-<NUM>-(trifluoromethoxy)dibenzothiophene (<NUM>). The title compound has the following phase characteristics:
Cr <NUM> Sm <NUM> SmA <NUM> N <NUM>.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. Then the reaction mixture is filtered through silica gel (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenyl] trifluoromethanesulfonate as a yellow solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)bis(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. The reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/<NUM>-propanol) to give light yellow crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohexyl]-<NUM>-(trifluoromethyl)dibenzothiophene (<NUM>).

The title compound has the following phase characteristics:
Cr <NUM> Sm (<NUM>) N <NUM>.

N-Butyllithium (<NUM>, <NUM> in hexanes) is slowly added to a solution of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]benzene (<NPL>) (<NUM>, <NUM> mol) in THF (<NUM>) at -<NUM> under argon atmosphere, and the reaction mixture is stirred for <NUM> at this temperature. Then trimethyl borate (<NUM>, <NUM> mol) is added, and the reaction mixture is stirred for an additional hour at -<NUM>. Then it is allowed to warm up to room temperature and is stirred overnight. The reaction is quenched with dist. water, and the suspension is diluted with MTB ether and treated with hydrochloric acid (<NUM>%). The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by crystallization (n-heptane) to give white crystals of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]boronic acid (<NUM>).

<CHM>
mixture of <NUM>-bromo-<NUM>,<NUM>-difluoro-phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]boronic acid (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane). <NUM>-[<NUM>,<NUM>-Difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>,<NUM>-difluoro-phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>,<NUM>-difluoro-phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. Then the reaction mixture is filtered through silica gel (solvent n-heptane). The residue is purified by crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>,<NUM>-trifluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]dibenzofuran (<NUM>).

A mixture of <NUM>-bromo-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-boronic acid (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane). <NUM>-[<NUM>,<NUM>-Difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. The residue is purified by crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]-<NUM>-(trifluoromethoxy)dibenzofuran (<NUM>).

The compound combines a low melting point, high N-I transition and a very high value for ε⊥.

A mixture of <NUM>-bromo-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NPL>) (<NUM>, <NUM> mmol), potassium carbonate (<NUM>, <NUM> mmol), tris(dibenzylideneacetone)-dipalladium(<NUM>) (<NUM>, <NUM> mmol) and CataCXium A (<NUM>, <NUM> mmol) in THF (<NUM>) and dist. water (<NUM>) is heated to reflux under nitrogen atmosphere, followed by dropwise addition of a solution of [<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]boronic acid (<NUM>, <NUM> mmol) in THF (<NUM>). The reaction mixture is heated at reflux temperature overnight. Then it is cooled to room temperature and diluted with MTB ether and dist. The aqueous phase is separated and extracted with MTB ether. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent <NUM>-chlorobutane). <NUM>-[<NUM>,<NUM>-Difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol is isolated as a yellow solid.

A mixture of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NUM>, <NUM> mmol), potassium phosphate monohydrate (<NUM>, <NUM> mmol) and DMPU (<NUM>) is stirred at <NUM> overnight. Then the reaction mixture is filtered through silica gel (solvent n-heptane). The residue is purified by crystallization (heptane) to give white crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]-<NUM>-(trifluoromethyl)dibenzofuran (<NUM>). The title compound has the following phase characteristics:
Cr <NUM> SmA <NUM> N <NUM> I.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>,<NUM>-difluorophenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. Then the reaction mixture is filtered through silica gel (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>,<NUM>-difluorophenyl] trifluoromethanesulfonate as a yellow solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>,<NUM>-difluorophenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)-bis(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. Then the reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>,<NUM>-trifluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]dibenzothiophene (<NUM>).

The title compound has the following phase characteristics:
Cr <NUM> SmA <NUM> N <NUM>.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. The reaction mixture is purified by silica gel chromatography (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenyl] trifluoromethanesulfonate as a yellow solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethoxy)phenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)bis(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. Then the reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/isopropanol) to give pale yellow crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]-<NUM>-(trifluoromethoxy)dibenzothiophene (<NUM>). The title compound has the following phase characteristics:
Cr <NUM> SmA <NUM> N <NUM>.

Trifluoromethanesulfonic anhydride (<NUM>, <NUM> mmol) is slowly added to a solution of <NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenol (<NUM>, <NUM> mmol), TEA (<NUM>, <NUM> mmol) and DMAP (<NUM>, <NUM> mmol) in dichloromethane (<NUM>) at <NUM> under nitrogen atmosphere. The solution is stirred at room temperature overnight. The reaction mixture is purified by silica gel chromatography (solvent <NUM>-chlorbutane) to give [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenyl] trifluoromethanesulfonate as a yellow solid.

This reaction is performed as a one-pot procedure. In the first step, a solution of [<NUM>-[<NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]phenyl]-<NUM>-fluoro-<NUM>-(trifluoromethyl)phenyl] trifluoromethanesulfonate (<NUM>, <NUM> mmol), <NUM>-mercapto-propionic acid <NUM>-ethylhexyl ester (<NUM>, <NUM> mmol) and DIPEA (<NUM>, <NUM> mmol) in toluene (<NUM>) is treated with tris(dibenzylideneacetone)dipalladium(<NUM>) (<NUM>, <NUM> mmol) and (oxydi-<NUM>,<NUM>-phenylene)bis(diphenylphosphine) (<NUM>, <NUM> mmol) under argon atmosphere, and the reaction mixture is heated at reflux temperature overnight. In the second step, a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added to the reaction mixture at room temperature. Then the reaction mixture is heated at reflux temperature for <NUM>, followed by addition of a second portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) and heating again at reflux temperature overnight. A third portion of a solution of potassium tert-butylate (<NUM>, <NUM> mmol) in THF (<NUM>) is added, and the reaction mixture is heated at reflux temperature for additional <NUM>. Then it is cooled to room temperature, quenched with dist. water and hydrochloric acid (<NUM> %) at <NUM> and diluted with MTB ether and THF. The aqueous phase is separated and extracted with MTB ether and THF. The combined organic phases are washed with dist. water and brine, dried (sodium sulphate) and concentrated in vacuo. The residue is purified by silica gel chromatography (solvent heptane) and crystallization (heptane/ethanol) to give white crystals of <NUM>,<NUM>-difluoro-<NUM>-[<NUM>-(<NUM>-propylcyclohexyl)cyclohex-<NUM>-enyl]-<NUM>-(trifluoromethyl)dibenzothiophene (<NUM>). The title compound has the following phase characteristics:
Cr <NUM> SmA <NUM> N <NUM>.

In analogy to the above described examples the following exemplary compounds are obtained:
In the following table the following abbreviations for the end groups are used.

The physical properties are given at a temperature of <NUM> and γ<NUM> is given in mPa·s. Phase transition temperatures are given in °C.

Liquid crystalline media using the compounds according to the invention as a component are prepared in the following. Unless indicated otherwise, percentages are % by weight. Stabilizers according to table F are optionally added to the mixtures presented below.

A nematic liquid-crystal mixture N-<NUM> having the composition and properties as indicated in the following table is used as the basis (host mixture) for preparation of several of the exemplary mixtures.

A nematic liquid-crystal medium M-<NUM> consisting of <NUM>% of the medium N-<NUM> and <NUM>% of the compound CCB-<NUM>-T of Synthesis Example <NUM> has the following properties:.

The compound CCB-<NUM>-T is well soluble in the medium N-<NUM>.

A nematic liquid-crystal medium M-<NUM> consisting of <NUM>% of the medium N-<NUM> and <NUM>% of the compound CCB-<NUM>-OT of Synthesis Example <NUM> has the following properties:.

The compound CCB-<NUM>-OT is well soluble in the medium N-<NUM>. The mixture has an advantageously high clearing point.

A nematic liquid-crystal medium M-<NUM> consisting of <NUM>% of the medium N-<NUM> and <NUM>% of the compound CCB(S)-<NUM>-OT of Synthesis Example <NUM> has the following properties:.

A nematic liquid-crystal medium M-<NUM> consisting of <NUM>% of the medium N-<NUM> and <NUM>% of the compound CLB-<NUM>-OT of Synthesis Example <NUM> has the following properties:.

A nematic liquid-crystal medium M-<NUM> consisting of <NUM>% of the medium N-<NUM> and <NUM>% of the compound CLB-<NUM>-T of Synthesis Example <NUM> has the following properties:.

A nematic liquid-crystal medium M-<NUM> consisting of the compounds indicated in the following table is prepared.

The mixture is suitable for use in an FFS display.

Claim 1:
A compound of formula I
<CHM>
in which
W denotes O or S
R denotes H, an alkyl radical having <NUM> to <NUM> C atoms, wherein one or more CH<NUM> groups in these radicals may each be replaced, independently of one another, by -C≡C- , -CF<NUM>O-, -OCF<NUM>-, -CH=CH-,
<CHM>
<CHM>
-O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which one or more H atoms may be replaced by halogen,
A<NUM> independently is trans-<NUM>,<NUM>-cyclohexylene or <NUM>,<NUM>-cyclo-hexenylene, in which one or more non-adjacent CH<NUM> groups may be replaced by -O- and in which one or more H atoms may be replaced by F,
A<NUM> independently is trans-<NUM>,<NUM>-cyclohexylene or <NUM>,<NUM>-cyclo-hexenylene, and in which one or more H atoms may be replaced by F,
Z independently denotes a single bond, -CF<NUM>O- , -OCF<NUM>-, - CH<NUM>CH<NUM>-, -CF<NUM>CF<NUM>-, -C(O)O-, -OC(O)-, -CH<NUM>O- , -OCH<NUM>-, -CF=CF-, -CH=CH- or -C≡C-, and
X denotes F, Cl, CN, NCS, fluorinated alkyl, fluorinated alkoxy, fluorinated alkenyl or fluorinated alkenyloxy each having up to <NUM> C atoms.