# Patent

## Title
Chroman compounds

## Abstract

The chroman compounds of the formula I according to the invention

R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2 

in which R1, A1, A2, A3, W1, W2, Z1, Z2, Z3, Z4, a, b and c have the meanings indicated in claim 1, have two moieties W1 and W2 derived from chroman. The compounds are suitable as components of anisotropic switching media, as used, for example, in liquid-crystal display devices.

## Background
The invention relates to compounds of the formula I

R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2  I

    in which
    W1, W2, independently of one another, denote a divalent group of the formula






    ring B denotes an unsaturated or partially saturated, six-membered ring in which one or two of the CH2 groups have been replaced by O, where no two O atoms are adjacent, and in which —CH2— may be replaced by —CHF—or —CF2— or ═CH— may be replaced by ═CF—,
    L1, L2 and L3 
    
        each, independently of one another, denote H, Cl, F, CN or CF3,
    
    
    R1, R2, independently of one another, denote H, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals may each be replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another,
    A1, A2 and A3 
    
        each, independently of one another, denote
        (a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups may be replaced by —O— and/or —S—,
        (b) a 1,4-phenylene radical, in which, in addition, one or two CH groups may be replaced by N,
        (c) 1,4-cyclohexenylene,
        (d) a radical from the group 1,3-bicyclo[1.1.1]pentylene, 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, naphthalene-2,6-diyl, tetrahydronaphthalene-2,6-diyl,
        where the radicals (a) to (d) may be substituted by one or more, in particular one or two, fluorine atoms,
    
    
    Z1, Z2, Z3 and Z4 
    
        each, independently of one another, denote —(CO)O—, —O(CO)—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —CH═CF—, —CF═CH—, —CF═CF—, —CHFCHF—, —CH2CHF—, —CHFCH2—, —C≡C—, —(CH2)4—, —CF2O—, —OCF2—, —C2F4—, —CH═CH—CH2CH2—, —CH2CH2OCF2— or a single bond, and
    
    
    a, b, c, independently of one another, denote 0 or 1, where
    a+b+c adopts the value 0, 1 or 2.


The invention furthermore relates to the use of these compounds as components of liquid-crystalline media and to liquid-crystal and electro-optical display elements which contain the liquid-crystalline media according to the invention.
The compounds of the formula I can be used as components of liquid-crystalline media, in particular for displays based on the principle of the twisted cell, the guest-host effect, the effect of deformation of aligned phases or the effect of dynamic scattering.
Documents WO 2006/040009, JP 2006199941 A and EP 14910612 disclose chroman derivatives which have only one moiety having the chroman structure.
The invention was thus based on the object of finding novel, stable compounds which are suitable as component(s) of liquid-crystalline media, in particular for TN, STN, IPS and for further active-matrix displays.
Especially in the area of compounds of very high polarity (Δε>20), which are basically advantageous for many display applications, the problem of the ever-lower solubility of the compounds is encountered. This limits the use of such compounds in practice. It is therefore also an aim to find novel, highly polar, mesogenic compounds which can at the same time be dissolved in highly polar liquid-crystal mixtures in high proportions by weight. The overall consideration of the solubility of all compounds involved crucially determines the tendency towards crystallisation at low temperatures and therefore determines the stability of the displays at temperatures at the lower end of the application range.
An object of the present invention was in addition to provide compounds which have high positive dielectric anisotropy Δε. In addition, the compounds according to the invention should be thermally and photochemically stable. Furthermore, the compounds according to the invention should be usable in liquid-crystalline mixtures in that they do not impair or even improve the liquid-crystalline phase ranges thereof. It is furthermore advantageous if the compounds according to the invention have the broadest possible nematic phase.
The compounds of the formula I are eminently suitable as components of liquid-crystal mixtures of positive dielectric anisotropy, in particular if particularly high polarity of the host mixture is important, as is the case, for example, in the production of liquid-crystal displays using blue phases (cf. WO 2004/046805 and H. Kikuchi et al. Nature Materials (2002) 1, 64-68). It has been found that the chroman derivatives according to the invention are eminently suitable as components of anisotropic electro-optical media. They can be used to obtain stable, mesogenic switching media, in particular suitable for TN-TFT, STN and IPS displays and displays based on blue phases. Owing to their properties, the compounds are particularly suitable for use in the fast-switching displays operated in the area of blue phases, particularly as constituent of polymer-stabilised media, as disclosed, for example, in document EP 1690914 A1. The compounds according to the invention are stable chemically, thermally and to (UV) light. They are colourless in the pure state. They are also distinguished by strongly positive dielectric anisotropies Δε, due to which lower threshold voltages are necessary on use in optical switching elements. A further advantage of the compounds according to the invention is the high polarity of the two substituted chroman rings.
In addition, the compounds according to the invention have a broad nematic phase range.
Through a suitable choice of the ring members and/or the terminal substituents, the physical properties of the liquid crystals according to the invention can be varied in broad ranges.
The provision of the chroman derivatives according to the invention very generally considerably broadens the range of compounds which are suitable from various applicational points of view for the preparation of liquid-crystalline mixtures.
In the mixture with suitable co-components, the compounds according to the invention form liquid-crystalline mesophases in a temperature range which is favourably located for electro-optical use. Liquid-crystalline media having broad nematic phase ranges can be prepared from the compounds according to the invention and further substances.
The chroman derivatives have a broad range of applications. Depending on the choice of substituents, these compounds can serve as base materials of which liquid-crystalline media are predominantly composed. However, it is also possible to add liquid-crystalline base materials from other classes of compound to the compounds according to the invention in order, for example, to modify the dielectric and/or optical anisotropy of a dielectric of this type and/or to optimise its working-temperature range.
The invention thus relates to the compounds of the formula I and to the use of these compounds as components of liquid-crystalline media. The invention furthermore relates to liquid-crystalline media comprising at least one compound of the formula I and to liquid-crystal display elements, in particular electro-optical display elements, which contain media of this type.
For the purposes of the present application, the numbering of the atom positions of the formula indicated for W1/2 is as follows:




The free valence of ring B is located in position 2 or 3, that of the benzo ring is arranged in position 6 or 7. The substituent L3 is localised at the remaining position 6 or 7. The ring system is preferably simultaneously connected at the mutually opposite positions 2/6 or 3/7 to the radical of the structure of the formula I, formally resulting in the substitution patterns (1) and (2):




In view of the following definitions, substitution pattern (1) is preferred.
Ring B encompasses the following ring structures and mirror images thereof, with the optional substitution by fluorine atoms not being shown:




For the purposes of the present invention, all ring elements depicted are referred to for simplification as chroman rings and the associated compounds are referred to as chroman compounds. The compounds are therefore also referred to as bischromanyl derivatives. Ring B is partially saturated if it only contains the one double bond of the benzene ring. Ring B is referred to as unsaturated if it contains two double bonds.
Ring B is preferably not substituted by fluorine atoms. It preferably has precisely one oxygen atom. In the case where ring B has a second double bond, this is preferably arranged in the β-position (allyl position) to the oxygen atom. Ring B is preferably partially saturated.
The moieties W1 and W2 preferably have, independently of one another, the following meanings with the associated names:




W1 and W2 particularly preferably adopt, independently of one another, the meaning of moiety (w10) or (w20), in particular (w10). W1 and W2 preferably adopt the same meaning. Likewise, W1 preferably adopts the meaning (w20) and W2 the meaning (w10).
The groups L1, L2 and L3 in the formula I and the sub-formulae are preferably H, Cl, F, CF3 or CN, particularly preferably H or F. At least one of the substituents L1, L2 and L3 is preferably not hydrogen. L3 preferably denotes F. L2 is preferably a hydrogen atom. L1 preferably denotes H or F.
For the group W2, L1 preferably denotes F; for the group W1, L1 preferably denotes H.
If they are not symmetrical, the ring systems indicated in groups (a) to (d) can be in both possible orientations. They are preferably arranged in such a way that the dipole of the ring is as far as possible aligned in the same direction and parallel with the same orientation to that of the chroman ring.
Z1, Z2 and Z4 preferably denote a single bond, —CH2CH2—, —CH═CH—, CH2O or —CF2O—, and in particular a single bond or —CH2CH2—.
Preferred meanings for Z3 are CH2CH2, CH2O or a single bond, particularly a single bond.
The sum of the indices a, b and c in the formula I should be 0, 1 or 2 and is preferably 0 or 1.
Preference is given to compounds of the formula I and of all sub-formulae in which A1, A2 and/or A3 denote cyclohexane-1,4-diyl, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene which is mono- or disubstituted by F or furthermore a radical from the group under point (d), as defined for formula I.
A1, A2 and A3 particularly preferably denote a divalent group selected from the formulae:




Z2, A2, b and Z3 together are preferably selected in such a way that the group —(Z2-A2)-Z3— does not denote a single bond.
R1 preferably denotes an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN or at least mono-substituted by halogen, where, in addition, one or more CH2 groups in these radicals may each be replaced, independently of one another, by —O—, —CH═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)—or —O(CO)O— in such a way that O atoms are not linked directly to one another.
R1 particularly preferably denotes alkyl, alkoxy, alkenyl or alkenyloxy having up to 7 C atoms and very particularly preferably 1-5 C alkyl or 2-5 C alkenyl.
R2 preferably denotes H, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals may each be replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another.
R2 particularly preferably denotes H, Cl, F, CN, SCN, SF5, CF3, CHF2 or OCF3, very particularly preferably F, OCF3 or CN, of these in particular CN.
If R1/2 denotes an alkyl radical and/or an alkoxy radical, this may be straight-chain or branched. It is preferably straight-chain, has 1, 2, 3, 4, 5, 6 or 7 C atoms and accordingly preferably denotes methyl, ethyl, propyl, butyl, pentyl, heptyl, hexyl, ethoxy, propoxy, butoxy, pentoxy, hexyloxy or heptyloxy, furthermore octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.
If R1/2 denotes an alkyl radical in which one CH2 group has been replaced by —CH═CH—, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. Accordingly, it denotes, in particular, vinyl, prop-1- or -2-enyl, but-1-, -2- or -3-enyl, pent-1-, -2-, -3- or -4-enyl, hex-1-, -2-, -3-, -4- or -5-enyl, hept-1-, -2-, -3-, -4-, -5- or -6-enyl, oct-1-, -2-, -3-, -4-, -5-, -6- or -7-enyl, non-1-, -2-, -3-, -4-, -5-, -6-, -7- or -8-enyl, dec-1-, -2-, -3-, -4-, -5-, -6-, -7-, -8- or -9-enyl.
If R1/2 denotes an alkyl radical in which one CH2 group has been replaced by —O— and one has been replaced by —CO—, these are preferably adjacent. These thus contain an acyloxy group —CO—O— or an oxycarbonyl group —O—CO—. These are preferably straight-chain and have 2 to 6 C atoms. Accordingly, they denote in particular acetoxy, propionyloxy, butyryloxy, pentanoyloxy, hexanoyloxy, acetoxymethyl, propionyloxymethyl, butyryloxymethyl, pentanoyloxymethyl, 2-acetoxyethyl, 2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetoxypropyl, 3-propionyloxypropyl, 4-acetoxybutyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, butoxycarbonylmethyl, 2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl, 2-(propoxycarbonyl)ethyl, 3-(methoxycarbonyl)propyl, 3-(ethoxycarbonyl)propyl, 4-(methoxycarbonyl)butyl.
If R1/2 denotes an alkyl radical in which one CH2 group has been replaced by unsubstituted or substituted —CH═CH— and an adjacent CH2 group has been replaced by CO or CO—O or O—CO, this may be straight-chain or branched. It is preferably straight-chain and has 4 to 13 C atoms. Accordingly, it denotes in particular acryloyloxymethyl, 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloyloxymethyl, 2-methacryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl, 9-methacryloyloxynonyl.
If R1/2 denotes an alkyl or alkenyl radical which is mono-substituted by CN, this radical is preferably straight-chain, and the substitution by CN is in the ω-position.
If R1/2 denotes an alkyl or alkenyl radical which is at least mono-substituted by halogen, this radical is 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. In the case of monosubstitution, the fluorine or chlorine substituent may be in any desired position, but is preferably in the ω-position.
For the purposes of the present invention, halogen denotes fluorine, chlorine, bromine or iodine, preferably Br, Cl or F, particularly preferably Cl or F, and in particular fluorine.
Compounds of the formula I which contain wing groups R1/2 which are suitable for polymerisation reactions are suitable for the preparation of mesogenic polymers, also in combination with other monomers. These polymers are suitable for the stabilisation of a mesophase which predominates under the polymerisation conditions.
Compounds of the formula I containing branched wing groups R1 may occasionally be of importance owing to still further improved solubility in the conventional liquid-crystalline base materials, but in particular as chiral dopants if they are optically active. The formula I encompasses both the racemates of these compounds and also the optical antipodes, and mixtures thereof. Smectic compounds of this type are suitable as components of ferroelectric materials.
Compounds of the formula I having SA phases are suitable, for example, for thermally addressed displays.
Branched groups of this type generally contain not more than one chain branch. Preferred branched radicals R are isopropyl, 2-butyl (=1-methylpropyl), isobutyl (=2-methylpropyl), 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-ethylhexyloxy, 1-methylhexyloxy, 1-methylheptyloxy.
In a preferred embodiment, the compounds of the formula I are characterised in that

    c denotes 1,
    Z4 denotes CF2O, and
    A3 denotes a divalent group selected from the formulae






Of the compounds of the formula I and of all sub-formulae, preference is given to those in which one or more of the radicals present therein have one of the preferred meanings indicated. Further preferred embodiments may be derived by the skilled person from the details of the example part and may be generalized for his purposes.
In the compounds of the formula I, preference is given to the stereoisomers in which the cyclohexane rings are trans-1,4-disubstituted. Those of the above-mentioned formulae which can contain a plurality of stereoisomers in each case encompass all possible stereoisomers.
Preferred smaller groups of compounds of the formula I are, in addition, those of the sub-formulae Ia to If

R1—W1—W2—R2  Ia

R1—W1—Z3—W2—R2  Ib

R1-A1-W1—W2—R2  Ic

R1—W1-A2-W2—R2  Id

R1—W1—W2-A3-R2  Ie

R1—W1—W2—Z4-A3-R2  If

The 1,4-cyclohexenylene group preferably has the following structures:




The compounds of the 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 suitable for the said reactions.
Use can also be made here of variants known per se which are not mentioned here in greater detail.
Starting from simple benzene derivatives, compounds of the formula I according to the invention can be prepared by the following methods.
The synthesis of the compounds of the formula I can be carried out, for example, using halogenated benzochromenes (compound 2), the preparation of which is described in document WO 2006/040009.




Compounds of this type can either be reacted directly (for example by transition metal-catalysed arylation of ketones, malonates, olefins, etc., Scheme 1) or modified in a suitable manner for further reaction for the synthesis of the compounds of the formula I in accordance with the following schemes using standard transformations, as are known to the person skilled in the art and described in the literature (Houben Weyl, Methoden der organischen Chemie [Methods of Organic Chemistry], Georg Thieme Verlag, Stuttgart, New York, 4th Edn. 1993).




Thus, for example, metallation of compound 2 (for X═H: using LDA, BuLi, Schlosser base; for X=Hal: using Mg, iPrMgHal, etc.) and optionally transmetallation using, for example, zinc halides, gives, inter alia, the arylmetal compounds 7 (Scheme 2), which can be converted in a versatile manner into further novel synthetic building blocks (Scheme 3).








Versatile access to synthetic building blocks for linking to the cycloaliphatic ring B is available starting from salicylaldehydes 14, which are readily accessible, for example, by the method of Duff (J. C. Duff and E. J. Bills, J. Chem. Soc. (1932) 1987; (1934) 1305; J. C. Duff, ibid. (1941) 547; (1945) 276) from phenols using hexamethylenetetramine (Scheme 4).




The condensation of the salicylaldehydes 14 with acrylonitrile analogously to L. D. Wise et al., J. Med. Chem. (1988) 31, 688-691 then gives carbonitriles (15), which can be modified in a manner familiar to the person skilled in the art in accordance with Scheme 5 and Scheme 6 to give a multiplicity of synthetic building blocks.








The following schemes show some preferred reactions of the synthetic building blocks described in Schemes 1 to 6 to give the target compounds of the formula I. Thus, directly linked bischromanyl derivatives can be obtained from the malonates 5 analogously to the synthesis of the chromans themselves (cf. WO 2006/040009) (Scheme 7).




The compounds 25 here may also contain further rings A2 (at position 7), which are accessible in an analogous manner and can be converted into the corresponding end products 27a and 27b (Schemes 8a, 8b)








The diols 24 are likewise suitable for the synthesis of dioxanes (Scheme 9). Condensation of 24 with the aldehydes 16 (cf. Scheme 5) gives the compounds 28, which can be hydrogenated to give the saturated dioxanes 29.




A possible synthetic route to compounds of the formula I containing a simple bridge Z3 between the chroman rings (i.e. without ring A2) is shown in Scheme 10. Thus, for example, the acetylene derivatives 18 can be reacted with the aryl halides 2 in a Negishi coupling to give the compounds 30a, which then, after hydrogenation, give the ethylene-bridged compounds 30b.




Structural isomers of the salicylaldehydes 14 (cf. Scheme 4), which are accessible in an analogous manner and are likewise described in WO 2006/040009, can serve for the synthesis of benzo[1,3]dioxins 33 as shown in Scheme 11, for example through acetalisation using the aldehydes 8 as starting material (cf. Scheme 3).




Scheme 12 shows the synthesis of chromans of type (w21) and (w20). Through Petasis reaction by the method of Q. Wang, M. G. Finn, Org. Lett. (2000) 2, 4063-4065, the compounds 35 can be used for the synthesis of α-substituted chroman compounds of type (w21) (chromenes), which can then be hydrogenated to give the chromans 37 (Scheme 12). The boronic acids 34 are obtained by hydroboration of the alkynes 4 (cf. Scheme 1) by processes known from the literature.








Isochromans can likewise be prepared starting from salicylaldehydes 35 (for example 41, Scheme 13). Here, the salicylaldehydes 35 are firstly reacted, for example, with trifluoromethanesulfonic anhydride to give the triflates 38, from which the stilbenes 39 can then be prepared in a Suzuki reaction with the boronic acids 34 (see above). After reduction of the aldehyde group to the alcohol 40, for example by reaction with sodium borohydride, the isochromans 41 can then be obtained by base-catalysed cyclisation by the method of R. G. F Giles et al., J. Chem. Soc. Perkin 1 (1984) 2389-2396.
An embodiment of the invention is therefore also a first process for the preparation of compounds of the formula I in which A2 is a dioxane ring and Z2 and Z3 are single bonds, which is characterised in that it includes a process step in which a compound of the formula II




in which the radicals are as defined above for formula I, is reacted with an aldehyde of the formula III





in which the radicals are as defined above for formula I, with formation of a dioxane ring. The process is preferably carried out in an organic solvent with acid catalysis. It is advantageous here continuously to remove the water formed from the reaction, for example by means of an adsorbent or by azeotropic distillation. The formula III is preferably that of compound 16 (Scheme 5).

A further embodiment of the invention is a second process for the preparation of compounds of the formula I in which b is 0 and Z3 is a single bond, which is characterised in that it includes a process step in which an oxetane compound of the formula IV




in which the radicals are as defined above for formula I, is reacted with a bromobenzene derivative of the formula V





in which the radicals are as defined above for formula I, to give a compound of the formula





and, in a further process step, is converted into compounds of the formula I or a precursor thereof by cyclisation. The cyclisation is preferably effected by a strong base. The reaction is preferably carried out in an inert solvent. A suitable strong base is, for example, potassium hydride.

Further possible synthetic routes for chroman compounds are disclosed in document WO 2006/040009 on pages 42-52 and in the examples. The last-mentioned disclosures are incorporated here by way of reference.
The liquid-crystalline media according to the invention preferably comprise 2 to 40, in particular 4 to 30, components as further constituents besides one or more compounds according to the invention. These media very particularly preferably comprise 7 to 25 components besides one or more compounds according to the invention. These further constituents are preferably selected from nematic or nematogenic (monotropic or isotropic) substances, in particular substances from the classes of the azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, phenyl or cyclohexyl esters of cyclohexanecarboxylic acid, phenyl or cyclohexyl esters of cyclohexylbenzoic acid, phenyl or cyclohexyl esters of cyclohexylcyclohexanecarboxylic acid, cyclohexylphenyl esters of benzoic acid, of cyclohexanecarboxylic acid or of cyclohexylcyclohexanecarboxylic acid, phenylcyclohexanes, cyclohexylbiphenyls, phenylcyclohexylcyclohexanes, cyclohexylcyclohexanes, cyclohexylcyclohexylcyclohexanes, 1,4-biscyclohexylbenzenes, 4,4′-biscyclohexylbiphenyls, phenyl- or cyclohexylpyrimidines, phenyl- or cyclohexylpyridines, phenyl- or cyclohexyldioxanes, phenyl- or cyclohexyl-1,3-dithianes, 1,2-diphenylethanes, 1,2-dicyclohexylethanes, 1-phenyl-2-cyclohexylethanes, 1-cyclohexyl-2-(4-phenylcyclohexyl)ethanes, 1-cyclohexyl-2-biphenylylethanes, 1-phenyl-2-cyclohexylphenylethanes, optionally halogenated stilbenes, benzyl phenyl ethers, tolans and substituted cinnamic acids. The 1,4-phenylene groups in these compounds may also be fluorinated.
The most important compounds suitable as further constituents of media according to the invention can be characterised by the formulae 1, 2, 3, 4 and 5:

R′-L-E-R′′  1

R′-L-COO-E-R′′  2

R′-L-OOC-E-R′′  3

R′-L-CH2CH2-E-R′′  4

R′-L-C≡C-E-R′′  5

In the formulae 1, 2, 3, 4 and 5, L and E, which may be identical or different, each, independently of one another, denote a divalent radical from the group formed by -Phe-, -Cyc-, -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -Pyr-, -Dio-, -G-Phe- and -G-Cyc- and their mirror images, where Phe denotes unsubstituted or fluorine-substituted 1,4-phenylene, Cyc denotes trans-1,4-cyclohexylene or 1,4-cyclohexenylene, Pyr denotes pyrimidine-2,5-diyl or pyridine-2,5-diyl, Dio denotes 1,3-dioxane-2,5-diyl and G denotes 2-(trans-1,4-cyclohexyl)ethyl.
One of the radicals L and E is preferably Cyc, Phe or Pyr. E is preferably Cyc, Phe or Phe-Cyc. The media according to the invention preferably comprise one or more components selected from the compounds of the formulae 1, 2, 3, 4 and 5 in which L and E are selected from the group consisting of Cyc, Phe and Pyr and simultaneously one or more components selected from the compounds of the formulae 1, 2, 3, 4 and 5 in which one of the radicals L and E is selected from the group consisting of Cyc, Phe and Pyr and the other radical is selected from the group consisting of -Phe-Phe-, -Phe-Cyc-, -Cyc-Cyc-, -G-Phe- and -G-Cyc-, and optionally one or more components selected from the compounds of the formulae 1, 2, 3, 4 and 5 in which the radicals L and E are selected from the group consisting of -Phe-Cyc-, -Cyc-Cyc-, -G-Phe- and -G-Cyc-.
In a smaller sub-group of the compounds of the formulae 1, 2, 3, 4 and 5, R′ and R′′ each, independently of one another, denote alkyl, alkenyl, alkoxy, alkoxyalkyl, alkenyloxy or alkanoyloxy having up to 8 carbon atoms. This smaller sub-group is called group A below, and the compounds are referred to by the sub-formulae 1a, 2a, 3a, 4a and 5a. In most of these compounds, R′ and R′′ are different from one another, one of these radicals usually being alkyl, alkenyl, alkoxy or alkoxyalkyl.
In another smaller sub-group of the compounds of the formulae 1, 2, 3, 4 and 5, which is referred to as group B, R′′ denotes —F, —Cl, —NCS or —(O)iCH3−(k+l)FkCll, where i is 0 or 1 and k+l is 1, 2 or 3; the compounds in which R′′ has this meaning are referred to by the sub-formulae 1b, 2b, 3b, 4b and 5b. Particular preference is given to compounds of the sub-formulae 1b, 2b, 3b, 4b and 5b in which R′′ has the meaning —F, —Cl, —NCS, —CF3, —OCHF2 or —OCF3.
In the compounds of the sub-formulae 1b, 2b, 3b, 4b and 5b, R′ has the meaning indicated for the compounds of the sub-formulae 1a-5a and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl.
In a further smaller sub-group of the compounds of the formulae 1, 2, 3, 4 and 5, R′′ denotes —CN. This sub-group is referred to below as group C, and the compounds of this sub-group are correspondingly described by the sub-formulae 1c, 2c, 3c, 4c and 5c. In the compounds of the sub-formulae 1c, 2c, 3c, 4c and 5c, R′ has the meaning indicated for the compounds of the sub-formulae 1a-5a and is preferably alkyl, alkoxy or alkenyl.
Besides the preferred compounds of groups A, B and C, other compounds of the formulae 1, 2, 3, 4 and 5 with other variants of the proposed substituents are also customary. All these substances are obtainable by methods which are known from the literature or analogously thereto.
Besides compounds of the formula I according to the invention, the media according to the invention preferably comprise one or more compounds selected from group A and/or group B and/or group C. The proportions by weight of the compounds from these groups in the media according to the invention are preferably
















group A:
0 to 90%, preferably 20 to 90%,




in particular 30 to 90%



group B:
0 to 80%, preferably 10 to 80%,




in particular 10 to 65%



group C:
0 to 80%, preferably 5 to 80%,




in particular 5 to 50%










where the sum of the proportions by weight of the compounds from groups A, B and C present in the media according to the invention is preferably 5 to 90% and in particular 10 to 90%.

The media according to the invention preferably comprise 1 to 40%, particularly preferably 5 to 30%, of compounds according to the invention. Preference is furthermore given to media comprising more than 40%, in particular 45 to 90%, of compounds according to the invention. The media preferably comprise two, three or four compounds 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 in accordance with the invention can be modified in such a way that they can be used in all types of liquid-crystal display element that have been disclosed to date. Additives of this type are known to the person skilled in the art and are described in detail in the literature (H. Kelker/R. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980). Polymer-stabilised media are generally subsequently subjected to polymerisation after mixing of the components. Furthermore, stabilisers, antioxidants, dyes or nanoparticles can be added.
The mixtures according to the invention are suitable for TN, STN, ECB, IPS or TN-TFT applications and in particular for applications with media in the blue phase. Particular preference is given to use in polymer-stabilised blue phases. Suitable polymeric constituents of the blue phases are mesogenic and non-mesogenic monomers, in particular mono- and diacrylates, which are polymerised in the mixture in such a way that they maintain the desired molecular structure in a broad temperature range.
The construction of the matrix display according to the invention from polarisers, electrode base plates and surface-treated electrodes corresponds to the usual design for displays of this type. The term usual design is broadly drawn here and also encompasses all derivatives and modifications of the matrix display, in particular also matrix display elements based on poly-Si TFTs.
The following examples are intended to explain the invention without limiting it. Above and below, percentage data denote percent by weight. All temperatures are indicated in degrees Celsius. M.p. denotes melting point, cl.p.=clearing point. Furthermore, C=crystalline state, N=nematic phase, S=smectic phase and I=isotropic phase. The data between these symbols represent the transition temperatures. Δn denotes optical anisotropy (589 nm, 20° C.), and the flow viscosity ν20 (mm2/sec) and the rotational viscosity γ1 [mPa·s] are each determined at 20° C.
The physical, physicochemical and electro-optical parameters are determined by generally known methods, as described, inter alia, in the brochure “Merck Liquid Crystals—Licristal®—Physical Properties of Liquid Crystals—Description of the Measurement Methods”, 1998, Merck KGaA, Darmstadt.
The dielectric anisotropy Δε of the individual substances is determined at 20° C. and 1 kHz. To this end, 5-10% by weight of the substance to be investigated are measured dissolved in the dielectrically positive mixture ZLI-4792 (Merck KGaA), and the measurement value is extrapolated to a concentration of 100%. The optical anisotropy Δn is determined at 20° C. and a wavelength of 589.3 nm, the rotational viscosity γi at 20° C., both likewise by linear extrapolation.
The following abbreviations are used above and below:

    RT room temperature
    MTB ether methyl tert-butyl ether
    THF tetrahydrofuran
    p-TsOH p-toluenesulfonic acid
    DABCO 1,4-diazabicyclo[2.2.2]octane
    Rf retention factor in chromatography
    DIBAL-H diisobutylaluminium hydride
    Pd (C) palladium on carbon (commercially available catalyst)




Example 1
6,6′-Difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7′]bichromenyl-7-carbonitrile
The synthesis of 7-bromo-6-fluoro-3-propylchroman is carried out in accordance with WO 2006/040009.
1.1. 6-Fluoro-7-iodo-3-propylchroman




10.6 g (38.8 mmol) of 7-bromo-6-fluoro-3-propylchroman are initially introduced in 100 ml of THF, and 27 ml (43.0 mmol) of a 15 percent solution of n-butyllithium in hexane are added dropwise. After 90 min, 10.0 g (39.4 mmol) of iodine, dissolved in 50 ml of THF, are added, the mixture is stirred for 1 h, and the cooling is removed. The batch is diluted with MTB ether, washed with water and with sat. sodium hydrogensulfite soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the crude product is filtered through silica gel with heptane/toluene (4:1), giving 6-fluoro-7-iodo-3-propylchroman as a colourless solid, which is sufficiently pure for further reaction.
1.2. Diethyl 2-(6-fluoro-3-propylchroman-7-yl)malonate




17.0 g (52.2 mmol) of anhydrous caesium carbonate, 700 mg (3.67 mmol) of copper(I) iodide and 700 mg (4.11 mmol) of o-phenylphenol are initially introduced under dry nitrogen, a solution of 11.4 g (33.5 mmol) of 6-fluoro-7-iodo-3-propylchroman and 16.0 g (100 mmol) of diethyl malonate in 150 ml of THF is added, and the mixture is heated under reflux overnight. MTB ether is subsequently added to the batch, which is washed with dil. hydrochloric acid and dried over sodium sulfate. The solvent is removed in vacuo, and the crude product is purified by chromatography on silica gel with heptane/ethyl acetate (4:1). The product fraction (Rf=0.55) is reacted without further purification.
1.3. 2-(6-Fluoro-3-propylchroman-7-yl)propane-1,3-diol




8.7 g (21.1 mmol) of the diethyl 2-(6-fluoro-3-propylchroman-7-yl)malonate obtained under 1.2. are initially introduced in 60 ml of toluene, and 106 ml (106 mmol) of a 1 M solution of diisobutylaluminium hydride in toluene are added dropwise at 5° C. The batch is subsequently added to ice-cold sat. ammonium chloride soln., acidified using dil. hydrochloric acid and extracted with MTB ether. The combined org. phases are dried over sodium sulfate and evaporated. Chromatography of the crude product on silica gel with MTB ether/heptane (4:1) gives 2-(6-fluoro-3-propylchroman-7-yl)propane-1,3-diol as a colourless solid.
19F-NMR (377 MHz, CDCl3)
δ=−129.0 ppm (dd, J=6.4 Hz, J=10.3 Hz, 1F, Ar—F).
1.4. 6-Fluoro-7-oxetan-3-yl-3-propylchroman




3.80 g (13.7 mmol) of 2-(6-fluoro-3-propylchroman-7-yl)propane-1,3-diol are dissolved in 70 ml of THF, and 8.7 ml (13.7 mmol) of a 15 percent solution of n-butyllithium in hexane are added at 0° C. After 30 min, 2.7 g (14.2 mmol) of p-toluenesulfonyl chloride in 30 ml of THF are added, and the mixture is stirred at RT for 1 h and re-cooled to 0° C. After addition of a further 8.7 ml (13.7 mmol) of a 15% solution of n-butyllithium in hexane, the cooling is removed, and the batch is heated under reflux for 4 h. The batch is subsequently diluted with MTB ether and washed with water. The org. phase is dried over sodium sulfate and evaporated, and the crude product is purified by chromatography on silica gel with heptane/ethyl acetate (3:2). The product fractions (Rf=0.5) are evaporated, and the product is used without further purification.
1.5. 3-(4-Bromo-2,5-difluorophenyl)-2-(6-fluoro-3-propylchroman-7-yl)propan-1-ol




4.50 g (16.6 mmol) of 1,4-dibromo-2,6-difluorobenzene are dissolved in 70 ml of ether, and 11 ml (18 mmol) of a 15 percent solution of n-butyllithium in hexane are added at −70° C. After 30 min, a solution of 3.00 g (11.0 mmol) of 6-fluoro-7-oxetan-3-yl-3-propylchroman in 30 ml of ether is added dropwise, and, after 1 h, 1.5 ml (11.9 mmol) of boron trifluoride diethyl ether complex are carefully added. The batch is left to stir for 2 h at −78° C. and overnight at RT and hydrolysed using sat. ammonium chloride soln. The org. phase is separated off and washed with water and sat. sodium chloride soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is chromatographed on silica gel, firstly with toluene and then with toluene/ethyl acetate (2:1), giving 3-(4-bromo-2,5-difluorophenyl)-2-(6-fluoro-3-propylchroman-7-yl)propan-1-ol as a colourless solid.
1.6. 7-Bromo-6,6′-difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7]bichromenyl




1.2 g (10.5 mmol) of potassium hydride (35 percent in paraffin oil) are initially introduced in 40 ml of THF, and a solution of 4.50 g (8.12 mmol) of 3-(4-bromo-2,5-difluorophenyl)-2-(6-fluoro-3-propylchroman-7-yl)propan-1-ol in 20 ml of THF is added dropwise at 30° C. The batch is subsequently stirred at 60° C. for 4 h, a little ethanol is added, and the batch is diluted with MTB ether and washed with sat. sodium chloride soln. The org. phase is dried over sodium sulfate, the solvent is removed in vacuo, and the crude product is filtered through silica gel with toluene and recrystallised from heptane/ethyl acetate, giving 7-bromo-6,6′-difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7′]-bichromenyl as colourless crystals.
19F-NMR (377 MHz, CDCl3)
δ=−119.4 ppm (dd, J=6.2 Hz, J=8.5 Hz, 1F, Ar—F), −129.6 (ddd, J=6.5 Hz, J=6.5 Hz, J=10.4 Hz, 1F, Ar—F).
1.7. 6,6′-Difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7′]-bichromenyl-7-carbonitrile




1.4 g (3.31 mmol) of 7-bromo-6,6′-difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7′]bichromenyl are dissolved in 20 ml of THF, and 3 ml (4.8 mmol) of a 15 percent solution of n-butyl-lithium in hexane are added at −50° C. The batch is left to stir for 2 h at −70° C., and a solution of 0.9 g (5.00 mmol) of p-toluenesulfonyl cyanide in 10 ml of THF is subsequently added at such a rate that the temperature does not exceed −65° C. After 30 min, the batch is allowed to thaw, diluted with ether and washed with dil. hydrochloric acid. The org. phase is dried over sodium sulfate and evaporated, and the crude product is chromatographed on silica gel with heptane/toluene (2:3), giving 6,6′-difluoro-3′-propyl-3,4,3′,4′-tetrahydro-2H,2′H-[3,7]bichromenyl-7-carbonitrile as colourless crystals of m.p. 122° C.
Phase behaviour: C 122 N (59) I
Example 2
(R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman-7-carbonitrile
2.1. 2-(6-Fluoro-3-pentylchroman-7-yl)propane-1,3-diol




The preparation is carried out analogously to the synthesis of 2-(6-fluoro-3-propylchroman-7-yl)propane-1,3-diol described under 1.3.
2.2. 6,8-Difluoro-2H-chromene-3-carbaldehyde
2.2.1. 3,5-Difluorosalicylaldehyde




260 g (2.00 mol) of 2,4-difluorophenol are dissolved in 1.6 l of trifluoroacetic acid, and 560 g (4.00 mol) of hexamethylenetetramine are added in portions. After 30 min, the batch is warmed to 75° C. and stirred overnight. 2 l of 40 percent sulfuric acid are subsequently added at RT, the mixture is left to stir for 2.5 h, 1.5 l of ice-water are added, and the mixture is stirred for a further 30 min. The deposited precipitate is separated off, washed with water and taken up in dichloromethane. The resultant solution is dried over sodium sulfate and evaporated, giving 3,5-difluorosalicylaldehyde as a beige solid.
2.2.2. 6,8-Difluoro-2H-chromene-3-carbonitrile




84 g (0.531 mol) of 3,5-difluorosalicylaldehyde are dissolved in 850 ml of acrylonitrile, 1 g (8 mmol) of p-methoxyphenol and 18 g (0.16 mol) of DABCO are added, and the mixture is heated overnight at 75° C. The batch is evaporated, the residue is taken up in dichloromethane, and the solution is filtered through silica gel, giving 6,8-difluoro-2H-chromene-3-carbonitrile, which is sufficiently pure for further reactions.
2.2.3. 6,8-Difluoro-2H-chromene-3-carbaldehyde




47.0 g (243 mmol) of 6,8-difluoro-2H-chromene-3-carbonitrile are dissolved in 300 ml of toluene, and 260 ml (260 mmol) of a 1 M solution of diisobutylaluminium hydride in toluene are added at −20° C. After 1 h, the batch is allowed to thaw, the solution is added to ice-cold dil. hydrochloric acid, and the mixture is left to stir vigorously for 2 h. The aqueous phase is separated off and extracted with MTB ether. The combined org. phases are washed with water, dried over sodium sulfate and evaporated, giving 6,8-difluoro-2H-chromene-3-carbaldehyde having a content of 99.0% (GC).
2.3. 6,8-Difluoro-3-[5-(6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]-2H-chromene




1.30 g (4.39 mmol) of 2-(6-fluoro-3-pentylchroman-7-yl)propane-1,3-diol and 900 mg (4.59 mmol) of 6,8-difluoro-2H-chromene-3-carbaldehyde are dissolved in 50 ml of dichloromethane and heated under reflux on a water separator for 5 h in the presence of 50 mg of p-toluenesulfonic acid. The solution is subsequently washed with sat. sodium hydrogencarbonate soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is recrystallised from heptane/toluene, giving 6,8-difluoro-3-[5-(6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]-2H-chromene (trans:cis=80:20) as a colourless solid.
2.4. (R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman




6,8-Difluoro-3-[5-(6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]-2H-chromene is hydrogenated to completion in THF on a palladium/active carbon catalyst. The solution is filtered and evaporated, and the residue is recrystallised from heptane, giving isomerically pure (R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman as a colourless solid.
19F-NMR (377 MHz, CDCl3)
δ=−121.8 ppm (t, J=8.6 Hz, 1F, Ar—F), −128.4 (ddd, J=6.4 Hz, J=10.4 Hz, 1F, Ar—F), −133.1 (dd, J=1.5 Hz, J=10.8 Hz, 1F, Ar—F).
2.5. (R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman-7-carbonitrile




800 mg (1.68 mmol) of (R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman are dissolved in 30 ml of THF, and 1.7 ml (2.38 mmol) of a 1.4 M solution of s-butyllithium in cyclohexane are added at −50° C. The batch is warmed at −25° C. for 5 min, left to stir at −70° C. for 2 h, and a solution of 400 mg (2.21 mmol) of p-toluenesulfonyl cyanide in 10 ml of THF is subsequently added at such a rate that the temperature does not exceed −65° C. After 1 h, the batch is allowed to thaw, diluted with ether and washed with dil. hydrochloric acid. The org. phase is dried over sodium sulfate and evaporated, and the crude product is chromatographed on silica gel with toluene, giving (R)-6,8-difluoro-3-[5-((R)-6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]chroman-7-carbonitrile as colourless crystals of m.p. 111° C.
Phase behaviour: Tg 6 C 111 N 145 I
Δε 83
Δn 0.140
Example 3
6,8-Difluoro-3-[5-(6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]-7-trifluoromethoxychroman




The synthesis described under Example 2 gives 6,8-difluoro-3-[5-(6-fluoro-3-pentylchroman-7-yl)-1,3-dioxan-2-yl]-7-trifluoromethoxychroman as a colourless solid.
Phase behaviour: Tg −22 C 88 SmA 175 N (174.8) I
19F-NMR (377 MHz, CDCl3)
δ=−59.79 ppm (t, J=7.0 Hz, 3F, —OCF3), 128.4 (dd, J=6.4 Hz, J=10.3 Hz, 1F, Ar—F), 137.2 (mc, 1F, Ar—F), 146.8 (mc, 1F, Ar—F).
Δn 0.102
Example 4
7-Cyano-6,8-difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)ethyl]-2H-chromene
4.1 6-Fluoro-3-pentylchroman-7-carbaldehyde




15.5 g (51.5 mmol) of 7-bromo-6-fluoro-3-pentylchroman are dissolved in 85 ml of THF, and 35 ml (55.7 mmol) of a 15 percent solution of n-butyllithium in n-hexane are slowly added at −70° C. After 1 h, 6.3 ml (56.7 mmol) of N-formylpiperidine in 15 ml of THF are added dropwise, and the mixture is stirred for 1 h. The batch is subsequently allowed to thaw, added to water, acidified using dil. hydrochloric acid and extracted three times with MTB ether. The combined org. phases are washed with water and sat. sodium chloride soln. and dried over sodium sulfate, the solvent is removed in vacuo, and the residue is recrystallised from heptane at −25° C., giving 6-fluoro-3-pentylchroman-7-carbaldehyde as colourless crystals (Rf=0.4; 1-chlorobutane).
4.2 (6-Fluoro-3-pentylchroman-7-yl)methanol




11.1 g (44.3 mmol) of 6-fluoro-3-pentylchroman-7-carbaldehyde are dissolved in 100 ml of ethanol, and 2.0 g (52.8 mmol) of sodium borohydride are added in portions. After 3 h, the batch is diluted with water and extracted three times with MTB ether. The combined org. phases are washed with sat. sodium chloride soln. and dried over sodium sulfate, the solvent is removed in vacuo, and the residue is filtered through silica gel with dichloromethane (Rf=0.3), giving (6-fluoro-3-pentylchroman-7-yl)methanol as a colourless solid.
4.3 7-Bromomethyl-6-fluoro-3-pentylchroman




10.2 g (38.9 mmol) of triphenylphosphine are suspended in 80 ml of acetonitrile, and 2.0 ml (39.0 mmol) of bromine are added dropwise with ice cooling. A solution of 10.0 g (38.4 mmol) of (6-fluoro-3-pentylchroman-7-yl)methanol in 20 ml of acetonitrile is subsequently added, and the mixture is stirred overnight at room temp. After addition of water, the mixture is extracted three times with n-heptane, and the combined org. phases are washed with water and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is filtered through silica gel with heptane/toluene (4:1), giving 7-bromomethyl-6-fluoro-3-pentylchroman as a colourless oil.
19F-NMR (377 MHz, CDCl3)
δ=−128.7 ppm (dd, J=6.7 Hz, J=9.7 Hz, 1F).
4.4 (6-Fluoro-3-pentylchroman-7-ylmethyl)triphenylphosphonium bromide




11.0 g (34.9 mmol) of 7-bromomethyl-6-fluoro-3-pentylchroman and 9.20 g (35.1 mmol) of triphenylphosphine are dissolved in 70 ml of acetonitrile, and the mixture is stirred overnight at room temp. The batch is subsequently cooled to 0° C., and the precipitated (6-fluoro-3-pentylchroman-7-ylmethyl)triphenylphosphonium bromide is filtered off with suction and dried in vacuo.
4.5 6,8-Difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)vinyl]-2H-chromene




10.2 g (17.7 mmol) of (6-fluoro-3-pentylchroman-7-ylmethyl)triphenylphosphonium bromide are dissolved in 50 ml of THF, and 2.0 g (17.8 mmol) of potassium tert-butoxide are added with ice cooling. After 1 h, a solution of 6,8-difluoro-2H-chromene-3-carbaldehyde in 50 ml of THF is slowly added dropwise, and the batch is left to stir overnight at room temp. The solution is subsequently added to water, acidified using dil. hydrochloric acid and extracted three times with MTB ether. The combined org. phases are washed with sat. sodium chloride soln. and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is chromatographed on silica gel with heptane/toluene (1:1) and recrystallised from heptane at −20° C., giving 6,8-difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)vinyl]-2H-chromene as yellow crystals.
19F-NMR (377 MHz, CDCl3)
δ=−120.3 ppm (dt, J=2.1 Hz, J=8.3 Hz, 1F), −128.8 (dd, J=6.5 Hz, J=10.7 Hz, 1F), −133.9 (mc, therein: d, J=10.3 Hz, 1F).
4.6 6,8-Difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)ethyl]-2H-chromene




6,8-Difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)vinyl]-2H-chromene is dissolved in THF and hydrogenated to completion on a palladium/active carbon catalyst. The catalyst is filtered off, the solution is evaporated, the residue is filtered through silica gel with toluene/heptane (3:2), and the crude product is recrystallised from n-heptane at −25° C., giving colourless crystals of m.p. 84° C.
4.7 7-Cyano-6,8-difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)ethyl]-2H-chromene




Analogously to Example 2, step 2.5., 6,8-difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)vinyl]-2H-chromene gives 7-cyano-6,8-difluoro-3-[2-(6-fluoro-3-pentylchroman-7-yl)ethyl]-2H-chromene as a colourless solid.
Phase behaviour: C 70 Sm (17) I.
Δε 53
Δn 0.119
The following compounds are prepared analogously to Examples 1-4

R1-A1-W1-A2-W2—Z4-A3-R2 

where the substituents adopt the meanings as shown in the table.








TABLE







Further example compounds
















R1
A1
W1
A2
W2
Z4
A3
R2


















1
C3H7—












F


 


2
C3H7—












CF3


 


3
C3H7—












OCF3


 


4
C3H7—












CN


 


5
C5H11—












F


 


6
C5H11—












CF3


 


7
C5H11—












OCF3


 


8
C5H11—












CN


 


9
















F


 


10
















CF3


 


11
















OCF3


 


12
















CN


 


13
C3H7—












F


 


14
C3H7—












CF3


 


15
C3H7—












OCF3


 


16
C3H7—












CN


 


17
C5H11—












F


 


18
C5H11—












CF3


 


19
C5H11—












OCF3


 


20
C5H11—












CN


 


21
















F


 


22
















CF3


 


23
















OCF3


 


24
















CN


 


25
C3H7—












F


 


26
C3H7—












CF3


 


27
C3H7—












OCF3


 


28
C3H7—












CN


 


29
C5H11—












F


 


30
C5H11—












CF3


 


31
C5H11—












OCF3


 


32
C5H11—












CN


 


33
















F


 


34
















CF3


 


35
















OCF3


 


36
















CN


 


37
C3H7—












F


 


38
C3H7—












CF3


 


39
C3H7—












OCF3


 


40
C3H7—












CN


 


41
C5H11—












F


 


42
C5H11—












CF3


 


43
C5H11—












OCF3


 


44
C5H11—












CN


 


45
















F


 


46
















CF3


 


47
















OCF3


 


48
















CN


 


49
C3H7—












F


 


50
C3H7—












CF3


 


51
C3H7—












OCF3


 


52
C3H7—












CN


 


53
C5H11—












F


 


54
C5H11—












CF3


 


55
C5H11—












OCF3


 


56
C5H11—












CN


 


57
















F


 


58
















CF3


 


59
















OCF3


 


60
















CN


 


61
C3H7—












F


 


62
C3H7—












CF3


 


63
C3H7—












OCF3


 


64
C3H7—












CN


 


65
C5H11—












F


 


66
C5H11—












CF3


 


67
C5H11—












OCF3


 


68
C5H11—












CN


 


69
















F


 


70
















CF3


 


71
















OCF3


 


72
















CN


 


73
C3H7—












F


 


74
C3H7—












CF3


 


75
C3H7—












OCF3


 


76
C3H7—












CN


 


77
C5H11—












F


 


78
C5H11—












CF3


 


79
C5H11—












OCF3


 


80
C5H11—












CN


 


81
















F


 


82
















CF3


 


83
















OCF3


 


84
















CN


 


85
C3H7—















F


 


86
C3H7—















CF3


 


87
C3H7—















OCF3


 


88
C3H7—















CN


 


89
C5H11—















F


 


90
C5H11—















CF3


 


91
C5H11—















OCF3


 


92
C5H11—















CN


 


93



















F


 


94



















CF3


 


95



















OCF3


 


96



















CN


 


97
C3H7—















F


 


98
C3H7—















CF3


 


99
C3H7—















OCF3


 


100
C3H7—















CN


 


101
C5H11—















F


 


102
C5H11—















CF3


 


103
C5H11—















OCF3


 


104
C5H11—















CN


 


105



















F


 


106



















CF3


 


107



















OCF3


 


108



















CN


 


109
C3H7—















F


 


110
C3H7—















CF3


 


111
C3H7—















OCF3


 


112
C3H7—















CN


 


113
C5H11—















F


 


114
C5H11—















CF3


 


115
C5H11—















OCF3


 


116
C5H11—















CN


 


117



















F


 


118



















CF3


 


119



















OCF3


 


120



















CN


 


121
C3H7—















F


 


122
C3H7—















CF3


 


123
C3H7—















OCF3


 


124
C3H7—















CN


 


125
C5H11—















F


 


126
C5H11—















CF3


 


127
C5H11—















OCF3


 


128
C5H11—















CN


 


129



















F


 


130



















CF3


 


131



















OCF3


 


132



















CN


 


133
C3H7—















F


 


134
C3H7—















CF3


 


135
C3H7—















OCF3


 


136
C3H7—















CN


 


137
C5H11—















F


 


138
C5H11—















CF3


 


139
C5H11—















OCF3


 


140
C5H11—















CN


 


141



















F


 


142



















CF3


 


143



















OCF3


 


144



















CN


 


145
C3H7—















F


 


146
C3H7—















CF3


 


147
C3H7—















OCF3


 


148
C3H7—















CN


 


149
C5H11—















F


 


150
C5H11—















CF3


 


151
C5H11—















OCF3


 


152
C5H11—















CN


 


153



















F


 


154



















CF3


 


155



















OCF3


 


156



















CN


 


157
C3H7—















F


 


158
C3H7—















CF3


 


159
C3H7—















OCF3


 


160
C3H7—















CN


 


161
C5H11—















F


 


162
C5H11—















CF3


 


163
C5H11—















OCF3


 


164
C5H11—















CN


 


165



















F


 


166



















CF3


 


167



















OCF3


 


168



















CN


 


169
C3H7—















F


 


170
C3H7—















CF3


 


171
C3H7—















OCF3


 


172
C3H7—















CN


 


173
C5H11—















F


 


174
C5H11—















CF3


 


175
C5H11—















OCF3


 


176
C5H11—















CN


 


177



















F


 


178



















CF3


 


179



















OCF3


 


180



















CN


 


181
C3H7—















F


 


182
C3H7—















CF3


 


183
C3H7—















OCF3


 


184
C3H7—















CN


 


185
C5H11—















F


 


186
C5H11—















CF3


 


187
C5H11—















OCF3


 


188
C5H11—















CN


 


189



















F


 


190



















CF3


 


191



















OCF3


 


192



















CN


 


193
C3H7—















F


 


194
C3H7—















CF3


 


195
C3H7—















OCF3


 


196
C3H7—















CN


 


197
C5H11—















F


 


198
C5H11—















CF3


 


199
C5H11—















OCF3


 


200
C5H11—















CN


 


201



















F


 


202



















CF3


 


203



















OCF3


 


204



















CN


 


205
C3H7—















F


 


206
C3H7—















CF3


 


207
C3H7—















OCF3


 


208
C3H7—















CN


 


209
C5H11—















F


 


210
C5H11—















CF3


 


211
C5H11—















OCF3


 


212
C5H11—















CN


 


213



















F


 


214



















CF3


 


215



















OCF3


 


216



















CN


 


217
C3H7—















F


 


218
C3H7—















CF3


 


219
C3H7—















OCF3


 


220
C3H7—















CN


 


221
C5H11—















F


 


222
C5H11—















CF3


 


223
C5H11—















OCF3


 


224
C5H11—















CN


 


225



















F


 


226



















CF3


 


227



















OCF3


 


228



















CN


 


229
C3H7—















F


 


230
C3H7—















CF3


 


231
C3H7—















OCF3


 


232
C3H7—















CN


 


233
C5H11—















F


 


234
C5H11—















CF3


 


235
C5H11—















OCF3


 


236
C5H11—















CN


 


237



















F


 


238



















CF3


 


239



















OCF3


 


240



















CN


 


241
C3H7—















F


 


242
C3H7—















CF3


 


243
C3H7—















OCF3


 


244
C3H7—















CN


 


245
C5H11—















F


 


246
C5H11—















CF3


 


247
C5H11—















OCF3


 


248
C5H11—















CN


 


249



















F


 


250



















CF3


 


251



















OCF3


 


252



















CN


 


253
C3H7—















F


 


254
C3H7—















CF3


 


255
C3H7—















OCF3


 


256
C3H7—















CN


 


257
C5H11—















F


 


258
C5H11—















CF3


 


259
C5H11—















OCF3


 


260
C5H11—















CN


 


261



















F


 


262



















CF3


 


263



















OCF3


 


264



















CN


 


265
C3H7—















F


 


266
C3H7—















CF3


 


267
C3H7—















OCF3


 


268
C3H7—















CN


 


269
C5H11—















F


 


270
C5H11—















CF3


 


271
C5H11—















OCF3


 


272
C5H11—















CN


 


273



















F


 


274



















CF3


 


275



















OCF3


 


276



















CN


 


277
C3H7—















F


 


278
C3H7—















CF3


 


279
C3H7—















OCF3


 


280
C3H7—















CN


 


281
C5H11—















F


 


282
C5H11—















CF3


 


283
C5H11—















OCF3


 


284
C5H11—















CN


 


285



















F


 


286



















CF3


 


287



















OCF3


 


288



















CN


 


289
C3H7—















F


 


290
C3H7—















CF3


 


291
C3H7—















OCF3


 


292
C3H7—















CN


 


293
C5H11—















F


 


294
C5H11—















CF3


 


295
C5H11—















OCF3


 


296
C5H11—















CN


 


297



















F


 


298



















CF3


 


299



















OCF3


 


300



















CN


 


301
C3H7—















F


 


302
C3H7—















CF3


 


303
C3H7—















OCF3


 


304
C3H7—















CN


 


305
C5H11—















F


 


306
C5H11—















CF3


 


307
C5H11—















OCF3


 


308
C5H11—















CN


 


309



















F


 


310



















CF3


 


311



















OCF3


 


312



















CN


 


313
C3H7—















F


 


314
C3H7—















CF3


 


315
C3H7—















OCF3


 


316
C3H7—















CN


 


317
C5H11—















F


 


318
C5H11—















CF3


 


319
C5H11—















OCF3


 


320
C5H11—















CN


 


321



















F


 


322



















CF3


 


323



















OCF3


 


324



















CN


 


325
C3H7—















F


 


326
C3H7—















CF3


 


327
C3H7—















OCF3


 


328
C3H7—















CN


 


329
C5H11—















F


 


330
C5H11—















CF3


 


331
C5H11—















OCF3


 


332
C5H11—















CN


 


333



















F


 


334



















CF3


 


335



















OCF3


 


336



















CN


 


337
C3H7—















F


 


338
C3H7—















CF3


 


339
C3H7—















OCF3


 


340
C3H7—















CN


 


341
C5H11—















F


 


342
C5H11—















CF3


 


343
C5H11—















OCF3


 


344
C5H11—















CN


 


345



















F


 


346



















CF3


 


347



















OCF3


 


348



















CN


 


349
C3H7—















F


 


350
C3H7—















CF3


 


351
C3H7—















OCF3


 


352
C3H7—















CN


 


353
C5H11—















F


 


354
C5H11—















CF3


 


355
C5H11—















OCF3


 


356
C5H11—















CN


 


357



















F


 


358



















CF3


 


359



















OCF3


 


360



















CN


 


361
C3H7—















F


 


362
C3H7—















CF3


 


363
C3H7—















OCF3


 


364
C3H7—















CN


 


365
C5H11—















F


 


366
C5H11—















CF3


 


367
C5H11—















OCF3


 


368
C5H11—















CN


 


369



















F


 


370



















CF3


 


371



















OCF3


 


372



















CN


 


373
C3H7—















F


 


374
C3H7—















CF3


 


375
C3H7—















OCF3


 


376
C3H7—















CN


 


377
C5H11—















F


 


378
C5H11—















CF3


 


379
C5H11—















OCF3


 


380
C5H11—















CN


 


381



















F


 


382



















CF3


 


383



















OCF3


 


384



















CN


 


385
C3H7—















F


 


386
C3H7—















CF3


 


387
C3H7—















OCF3


 


388
C3H7—















CN


 


389
C5H11—















F


 


390
C5H11—















CF3


 


391
C5H11—















OCF3


 


392
C5H11—















CN


 


393



















F


 


394



















CF3


 


395



















OCF3


 


396



















CN


 


397
C3H7—















F


 


398
C3H7—















CF3


 


399
C3H7—















OCF3


 


400
C3H7—















CN


 


401
C5H11—















F


 


402
C5H11—















CF3


 


403
C5H11—















OCF3


 


404
C5H11—















CN


 


405



















F


 


406



















CF3


 


407



















OCF3


 


408



















CN


 


409
C3H7—















F


 


410
C3H7—















CF3


 


411
C3H7—















OCF3


 


412
C3H7—















CN


 


413
C5H11—















F


 


414
C5H11—















CF3


 


415
C5H11—















OCF3


 


416
C5H11—















CN


 


417



















F


 


418



















CF3


 


419



















OCF3


 


420



















CN


 


421
C3H7—















F


 


422
C3H7—















CF3


 


423
C3H7—















OCF3


 


424
C3H7—















CN


 


425
C5H11—















F


 


426
C5H11—















CF3


 


427
C5H11—















OCF3


 


428
C5H11—















CN


 


429



















F


 


430



















CF3


 


431



















OCF3


 


432



















CN


 


433
C3H7—















F


 


434
C3H7—















CF3


 


435
C3H7—















OCF3


 


436
C3H7—















CN


 


437
C5H11—















F


 


438
C5H11—















CF3


 


439
C5H11—















OCF3


 


440
C5H11—















CN


 


441



















F


 


442



















CF3


 


443



















OCF3


 


444



















CN


 


445
C3H7—















F


 


446
C3H7—















CF3


 


447
C3H7—















OCF3


 


448
C3H7—















CN


 


449
C5H11—















F


 


450
C5H11—















CF3


 


451
C5H11—















OCF3


 


452
C5H11—















CN


 


453



















F


 


454



















CF3


 


455



















OCF3


 


456



















CN


 


457
C3H7—















F


 


458
C3H7—















CF3


 


459
C3H7—















OCF3


 


460
C3H7—















CN


 


461
C5H11—















F


 


462
C5H11—















CF3


 


463
C5H11—















OCF3


 


464
C5H11—















CN


 


465



















F


 


466



















CF3


 


467



















OCF3


 


468



















CN


 


469
C3H7—















F


 


470
C3H7—















CF3


 


471
C3H7—















OCF3


 


472
C3H7—















CN


 


473
C5H11—















F


 


474
C5H11—















CF3


 


475
C5H11—















OCF3


 


476
C5H11—















CN


 


477



















F


 


478



















CF3


 


479



















OCF3


 


480



















CN


 


481
C3H7—















F


 


482
C3H7—















CF3


 


483
C3H7—















OCF3


 


484
C3H7—















CN


 


485
C5H11—















F


 


486
C5H11—















CF3


 


487
C5H11—















OCF3


 


488
C5H11—















CN


 


489



















F


 


490



















CF3


 


491



















OCF3


 


492



















CN


 


493
C3H7—















F


 


494
C3H7—















CF3


 


495
C3H7—















OCF3


 


496
C3H7—















CN


 


497
C5H11—















F


 


498
C5H11—















CF3


 


499
C5H11—















OCF3


 


500
C5H11—















CN


 


501



















F


 


502



















CF3


 


503



















OCF3


 


504



















CN


 


505
C3H7—















F


 


506
C3H7—















CF3


 


507
C3H7—















OCF3


 


508
C3H7—















CN


 


509
C5H11—















F


 


510
C5H11—















CF3


 


511
C5H11—















OCF3


 


512
C5H11—















CN


 


513



















F


 


514



















CF3


 


515



















OCF3


 


516



















CN


 


517
C3H7—















F


 


518
C3H7—















CF3


 


519
C3H7—















OCF3


 


520
C3H7—















CN


 


521
C5H11—















F


 


522
C5H11—















CF3


 


523
C5H11—















OCF3


 


524
C5H11—















CN


 


525



















F


 


526



















CF3


 


527



















OCF3


 


528



















CN


 


529
C3H7—















F


 


530
C3H7—















CF3


 


531
C3H7—















OCF3


 


532
C3H7—















CN


 


533
C5H11—















F


 


534
C5H11—















CF3


 


535
C5H11—















OCF3


 


536
C5H11—















CN


 


537



















F


 


538



















CF3


 


539



















OCF3


 


540



















CN


 


541
C3H7—















F


 


542
C3H7—















CF3


 


543
C3H7—















OCF3


 


544
C3H7—















CN


 


545
C5H11—















F


 


546
C5H11—















CF3


 


547
C5H11—















OCF3


 


548
C5H11—















CN


 


549



















F


 


550



















CF3


 


551



















OCF3


 


552



















CN


 


553
C3H7—















F


 


554
C3H7—















CF3


 


555
C3H7—















OCF3


 


556
C3H7—















CN


 


557
C5H11—















F


 


558
C5H11—















CF3


 


559
C5H11—















OCF3


 


560
C5H11—















CN


 


561



















F


 


562



















CF3


 


563



















OCF3


 


564



















CN


 


565
C3H7—















F


 


566
C3H7—















CF3


 


567
C3H7—















OCF3


 


568
C3H7—















CN


 


569
C5H11—















F


 


570
C5H11—















CF3


 


571
C5H11—















OCF3


 


572
C5H11—















CN


 


573



















F


 


574



















CF3


 


575



















OCF3


 


576



















CN


 


577
C3H7—















F


 


578
C3H7—















CF3


 


579
C3H7—















OCF3


 


580
C3H7—















CN


 


581
C5H11—















F


 


582
C5H11—















CF3


 


583
C5H11—















OCF3


 


584
C5H11—















CN


 


585



















F


 


586



















CF3


 


587



















OCF3


 


588



















CN


 


589
C3H7—















F


 


590
C3H7—















CF3


 


591
C3H7—















OCF3


 


592
C3H7—















CN


 


593
C5H11—















F


 


594
C5H11—















CF3


 


595
C5H11—















OCF3


 


596
C5H11—















CN


 


597



















F


 


598



















CF3


 


599



















OCF3


 


600



















CN


 


601
C3H7—















F


 


602
C3H7—















CF3


 


603
C3H7—















OCF3


 


604
C3H7—















CN


 


605
C5H11—















F


 


606
C5H11—















CF3


 


607
C5H11—















OCF3


 


608
C5H11—















CN


 


609



















F


 


610



















CF3


 


611



















OCF3


 


612



















CN


 


613
C3H7—















F


 


614
C3H7—















CF3


 


615
C3H7—















OCF3


 


616
C3H7—















CN


 


617
C5H11—















F


 


618
C5H11—















CF3


 


619
C5H11—















OCF3


 


620
C5H11—















CN


 


621



















F


 


622



















CF3


 


623



















OCF3


 


624



















CN


 


625
C3H7—















F


 


626
C3H7—















CF3


 


627
C3H7—















OCF3


 


628
C3H7—















CN


 


629
C5H11—















F


 


630
C5H11—















CF3


 


631
C5H11—















OCF3


 


632
C5H11—















CN


 


633



















F


 


634



















CF3


 


635



















OCF3


 


636



















CN


 


637
C3H7—















F


 


638
C3H7—















CF3


 


639
C3H7—















OCF3


 


640
C3H7—















CN


 


641
C5H11—















F


 


642
C5H11—















CF3


 


643
C5H11—















OCF3


 


644
C5H11—















CN


 


645



















F


 


646



















CF3


 


647



















OCF3


 


648



















CN


 


649
C3H7—















F


 


650
C3H7—















CF3


 


651
C3H7—















OCF3


 


652
C3H7—















CN


 


653
C5H11—















F


 


654
C5H11—















CF3


 


655
C5H11—















OCF3


 


656
C5H11—















CN


 


657



















F


 


658



















CF3


 


659



















OCF3


 


660



















CN


 


661
C3H7—















F


 


662
C3H7—















CF3


 


663
C3H7—















OCF3


 


664
C3H7—















CN


 


665
C5H11—















F


 


666
C5H11—















CF3


 


667
C5H11—















OCF3


 


668
C5H11—















CN


 


669



















F


 


670



















CF3


 


671



















OCF3


 


672



















CN


 


673
C3H7—















F


 


674
C3H7—















CF3


 


675
C3H7—















OCF3


 


676
C3H7—















CN


 


677
C5H11—















F


 


678
C5H11—















CF3


 


679
C5H11—















OCF3


 


680
C5H11—















CN


 


681



















F


 


682



















CF3


 


683



















OCF3


 


684



















CN


 


685
C3H7—















F


 


686
C3H7—















CF3


 


687
C3H7—















OCF3


 


688
C3H7—















CN


 


689
C5H11—















F


 


690
C5H11—















CF3


 


691
C5H11—















OCF3


 


692
C5H11—















CN


 


693



















F


 


694



















CF3


 


695



















OCF3


 


696



















CN


 


697
C3H7—















F


 


698
C3H7—















CF3


 


699
C3H7—















OCF3


 


700
C3H7—















CN


 


701
C5H11—















F


 


702
C5H11—















CF3


 


703
C5H11—















OCF3


 


704
C5H11—















CN


 


705



















F


 


706



















CF3


 


707



















OCF3


 


708



















CN


 


709
C3H7—















F


 


710
C3H7—















CF3


 


711
C3H7—















OCF3


 


712
C3H7—















CN


 


713
C5H11—















F


 


714
C5H11—















CF3


 


715
C5H11—















OCF3


 


716
C5H11—















CN


 


717



















F


 


718



















CF3


 


719



















OCF3


 


720



















CN


 


721
C3H7—















F


 


722
C3H7—















CF3


 


723
C3H7—















OCF3


 


724
C3H7—















CN


 


725
C5H11—















F


 


726
C5H11—















CF3


 


727
C5H11—















OCF3


 


728
C5H11—















CN


 


729



















F


 


730



















CF3


 


731



















OCF3


 


732



















CN


 


733
C3H7—















F


 


734
C3H7—















CF3


 


735
C3H7—















OCF3


 


736
C3H7—















CN


 


737
C5H11—















F


 


738
C5H11—















CF3


 


739
C5H11—















OCF3


 


740
C5H11—















CN


 


741



















F


 


742



















CF3


 


743



















OCF3


 


744



















CN


 


745
C3H7—















F


 


746
C3H7—















CF3


 


747
C3H7—















OCF3


 


748
C3H7—















CN


 


749
C5H11—















F


 


750
C5H11—















CF3


 


751
C5H11—















OCF3


 


752
C5H11—















CN


 


753



















F


 


754



















CF3


 


755



















OCF3


 


756



















CN


 


757
C3H7—


















F


 


758
C3H7—


















CF3


 


759
C3H7—


















OCF3


 


760
C3H7—


















CN


 


761
C5H11—


















F


 


762
C5H11—


















CF3


 


763
C5H11—


















OCF3


 


764
C5H11—


















CN


 


765






















F


 


766






















CF3


 


767






















OCF3


 


768






















CN


 


769
C3H7—


















F


 


770
C3H7—


















CF3


 


771
C3H7—


















OCF3


 


772
C3H7—


















CN


 


773
C5H11—


















F


 


774
C5H11—


















CF3


 


775
C5H11—


















OCF3


 


776
C5H11—


















CN


 


777






















F


 


778






















CF3


 


779






















OCF3


 


780






















CN


 


781
C3H7—


















F 


 


782
C3H7—


















CF3


 


783
C3H7—


















OCF3


 


784
C3H7—


















CN


 


785
C5H11—


















F


 


786
C5H11—


















CF3


 


787
C5H11—


















OCF3


 


788
C5H11—


















CN


 


789






















F


 


790






















CF3


 


791






















OCF3


 


792






















CN


 


793
C3H7—


















F


 


794
C3H7—


















CF3


 


795
C3H7—


















OCF3


 


796
C3H7—


















CN


 


797
C5H11—


















F


 


798
C5H11—


















CF3


 


799
C5H11—


















OCF3


 


800
C5H11—


















CN


 


801






















F


 


802






















CF3


 


803






















OCF3


 


804






















CN


 


805
C3H7—


















F


 


806
C3H7—


















CF3


 


807
C3H7—


















OCF3


 


808
C3H7—


















CN


 


809
C5H11—


















F


 


810
C5H11—


















CF3


 


811
C5H11—


















OCF3


 


812
C5H11—


















CN


 


813






















F


 


814






















CF3


 


815






















OCF3


 


816






















CN


 


817
C3H7—


















F


 


818
C3H7—


















CF3


 


819
C3H7—


















OCF3


 


820
C3H7—


















CN


 


821
C5H11—


















F


 


822
C5H11—


















CF3


 


823
C5H11—


















OCF3


 


824
C5H11—


















CN


 


825






















F


 


826






















CF3


 


827






















OCF3


 


828






















CN


 


829
C3H7—


















F


 


830
C3H7—


















CF3


 


831
C3H7—


















OCF3


 


832
C3H7—


















CN


 


833
C5H11—


















F


 


834
C5H11—


















CF3


 


835
C5H11—


















OCF3


 


836
C5H11—


















CN


 


837






















F


 


838






















CF3


 


839






















OCF3


 


840






















CN









Further combinations of the embodiments and variants of the invention arise from the following claims.

## Claims

1. A compound of formula I


R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2  I


wherein
W1, W2, are each, independently of one another, a divalent group of the formula




ring B is an unsaturated or partially saturated, six-membered ring in which one or two of the CH2 groups are each replaced by O, where no two O atoms are adjacent, and in which —CH2— is optionally replaced by —CHF— or —CF2—, or ═CH— is optionally replaced by ═CF—,
L1, L2 and L3 
are each, independently of one another, H, Cl, F, CN or CF3,

R1, R2, are each, independently of one another, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another,
A1, A2 and A3 
are each, independently of one another,
(a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups are each optionally replaced by —O— or —S—,
(b) a 1,4-phenylene radical, in which, in addition, one or two CH groups are each optionally replaced by N,
(c) 1,4-cyclohexenylene,
(d) 1,3-bicyclo[1.1.1]pentylene, 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, naphthalene-2,6-diyl, or tetrahydronaphthalene-2,6-diyl,

where the radicals (a) to (d) are each optionally substituted by one or more fluorine atoms,
Z1, Z2, Z3 and Z4 
are each, independently of one another, —(CO)O—, —O(CO)—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —CH═CF—, —CF═CH—, —CF═CF—, —CHFCHF—, —CH2CHF—, —CHFCH2—, —C≡C—, —(CH2)4—, —CF2O—, —OCF2—, —C2F4—, —CH═CH—CH2CH2—, —CH2CH2OCF2— or a single bond, and

a, b, and c, are each, independently of one another, 0 or 1, where the sum a+b+c is 1 or 2.

2. A compound according to claim 1, wherein W1, W2, are each, independently of one another, a structural element selected from the part-structures (w10), (w11), (w20) and (w21):

3. A compound according to claim 2, wherein W1, W2, are each independently of one another, a structural element selected from the part-structures (w10) and (w20).

4. A compound according to claim 1, wherein R1 is an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups are each optionally replaced, independently of one another, by —O—, —CH═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another.

5. A compound according to claim 1, wherein R2 is Cl, F, CN, SCN, SF5, or an alkyl radical having up to 15 C atoms which is monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in the alkyl radical are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another.

6. A compound according to claim 1, wherein the sum of the indices, a+b+c, is 1.

7. A compound according to claim 1, wherein A1, A2 and A3 are each, independently of one another, a divalent group selected from the formulae:

8. A compound according to claim 1, wherein Z1, Z2, Z3 and Z4 are each, independently of one another, a single bond, —CH2CH2—, —CH═CH—, —CH2O— or —CF2O—.

9. A compound according to claim 1, wherein
c denotes 1,
Z4 denotes CF2O, and
A3 denotes a divalent group of the formula

10. A process for the preparation of a compound according to claim 1, in which A2 is a dioxane ring and Z2 and Z3 are single bonds, said process comprising:
reacting a compound of formula II





with an aldehyde of formula III




with formation of a dioxane ring.

11. A process for the preparation of a compound according to claim 1, in which b is 0 and Z3 is a single bond, said process comprising:
reacting an oxetane compound of formula IV





with a bromobenzene compound of formula V




to give a compound of formula VI



cyclizing said compound of formula VI.

12. A method of using of one or more compounds of the formula I according to claim 1 which comprises using one or more of said compounds as components in a liquid-crystalline medium.

13. A liquid-crystalline medium comprising at least two components, wherein said medium comprises at least one compound according to claim 1.

14. A liquid-crystalline medium according to claim 13, wherein said medium is polymer-stabilized in a blue phase.

15. An electro-optical display element comprising a dielectric, wherein said dielectric is a medium according to claim 13.

16. A compound according to claim 1, wherein
W1, W2, are each, independently of one another, a structural element selected from the part-structures (w10), (w11), (w20) and (w21):




R1 is an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups are each optionally replaced, independently of one another, by —O—, —CH═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another;
R2 is Cl, F, CN, SCN, SF5, or an alkyl radical having up to 15 C atoms which is monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in the alkyl radical are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another;
A1, A2 and A3 are each, independently of one another, a divalent group selected from the formulae:




Z1, Z2, Z3 and Z4 are each, independently of one another, a single bond, —CH2CH2—, —CH═CH—, —CH2O— or —CF2O—.

17. A compound of formula I


R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2  I


wherein
W1, W2, are each, independently of one another, a divalent group of the formula




ring B is an unsaturated or partially saturated, six-membered ring in which one or two of the CH2 groups are each replaced by O, where no two O atoms are adjacent, and in which —CH2— is optionally replaced by —CHF— or —CF2—, or ═CH— is optionally replaced by ═CF—,
L1, L2 and L3 
are each, independently of one another, H, Cl, F, CN or CF3,

R1, R2, are each, independently of one another, H, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another,
A1 and A2 
are each, independently of one another,
(a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups are each optionally replaced by —O— or —S—,
(b) a 1,4-phenylene radical, in which, in addition, one or two CH groups are each optionally replaced by N,
(c) 1,4-cyclohexenylene,
(d) 1,3-bicyclo[1.1.1]pentylene, 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, naphthalene-2,6-diyl, or tetrahydronaphthalene-2,6-diyl,

where the radicals (a) to (d) are each optionally substituted by one or more fluorine atoms,
A3 is a divalent group selected from




Z1, Z2, and Z3 
are each, independently of one another, —(CO)O—, —O(CO)—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —CH═CF—, —CF═CH—, —CF═CF—, —CHFCHF—, —CH2CHF—, —CHFCH2—, —C≡C—, —(CH2)4—, —CF2O—, —OCF2—, —C2F4—, —CH═CH—CH2CH2—, —CH2CH2OCF2— or a single bond,

Z4 is CF2O,
a and b are each, independently of one another, 0 or 1,
c is 1, and
the sum a+b+c is 1 or 2.

18. A compound of formula I


R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2  I


wherein
W1, W2, are each, independently of one another, a divalent group of the formula




ring B is an unsaturated or partially saturated, six-membered ring in which one or two of the CH2 groups are each replaced by O, where no two O atoms are adjacent, and in which —CH2— is optionally replaced by —CHF— or —CF2—, or ═CH— is optionally replaced by ═CF—,
L1, L2 and L3 
are each, independently of one another, H, Cl, F, CN or CF3,

R1, R2, are each, independently of one another, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another,
A1, A2 and A3 
are each, independently of one another,
(a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups are each optionally replaced by —O— or —S—,
(b) a 1,4-phenylene radical, in which, in addition, one or two CH groups are each optionally replaced by N,
(c) 1,4-cyclohexenylene,
(d) 1,3-bicyclo[1.1.1]pentylene, 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, naphthalene-2,6-diyl, or tetrahydronaphthalene-2,6-diyl,

where the radicals (a) to (d) are each optionally substituted by one or more fluorine atoms,
Z1, Z2, Z3 and Z4 
are each, independently of one another, —(CO)O—, —O(CO)—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —CH═CF—, —CF═CH—, —CF═CF—, —CHFCHF—, —CH2CHF—, —CHFCH2—, —C≡C—, —(CH2)4—, —CF2O—, —OCF2—, —C2F4—, —CH═CH—CH2CH2—, —CH2CH2OCF2— or a single bond, and

a, b, c, are each, independently of one another, 0 or 1, where the sum a+b+c is 0, 1 or 2,
wherein the group —(Z2-A2)-Z3— is not a single bond.

19. A compound of formula I


R1-(A1-Z1)a—W1—(Z2-A2)b-Z3—W2—(Z4-A3)c-R2  I


wherein
W1, W2, are each, independently of one another,
a structural element selected from the part-structures (w10), (w11), (w20) and (w21):





L1, L2 and L3 
are each, independently of one another, H, Cl, F, CN or CF3,

R1, R2, are each, independently of one another, H, Cl, F, CN, SCN, SF5, an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another,
A1, A2 and A3 
are each, independently of one another,
(a) a trans-1,4-cyclohexylene radical, in which, in addition, one or more non-adjacent CH2 groups are each optionally replaced by —O— or —S—,
(b) a 1,4-phenylene radical, in which, in addition, one or two CH groups are each optionally replaced by N,
(c) 1,4-cyclohexenylene,
(d) 1,3-bicyclo[1.1.1]pentylene, 1,4-bicyclo[2.2.2]octylene, cyclobut-1,3-diyl, spiro[3.3]heptane-2,6-diyl, naphthalene-2,6-diyl, or tetrahydronaphthalene-2,6-diyl,

where the radicals (a) to (d) are each optionally substituted by one or more fluorine atoms,
Z1, Z2, Z3 and Z4 
are each, independently of one another, —(CO)O—, —O(CO)—, —CH2O—, —OCH2—, —CH2CH2—, —CH═CH—, —CH═CF—, —CF═CH—, —CF═CF—, —CHFCHF—, —CH2CHF—, —CHFCH2—, —C≡C—, —(CH2)4—, —CF2O—, —OCF2—, —C2F4—, —CH═CH—CH2CH2—, —CH2CH2OCF2— or a single bond, and

a, b, c, are each, independently of one another, 0 or 1, where the sum a+b+c is 0, 1 or 2,
wherein at least one of L1, L2 and L3 is not H.

20. A compound according to claim 19, wherein W1, W2, are each independently of one another, a structural element selected from the part-structures (w10) and (w20).

21. A compound according to claim 19, wherein R1 is an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups are each optionally replaced, independently of one another, by —O—, —CH═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another.

22. A compound according to claim 19, wherein R2 is H, Cl, F, CN, SCN, SF5, or an alkyl radical having up to 15 C atoms which is monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in the alkyl radical are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another.

23. A compound according to claim 19, wherein
W1, W2, are each, independently of one another, a structural element selected from the part-structures (w10), (w11), (w20) and (w21):




R1 is an alkyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN, or at least monosubstituted by halogen, where, in addition, one or more CH2 groups are each optionally replaced, independently of one another, by —O—, —CH═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another;
R2 is H, Cl, F, CN, SCN, SF5, or an alkyl radical having up to 15 C atoms which is monosubstituted by CN or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in the alkyl radical are each optionally replaced, independently of one another, by —O—, —CH═CH—, —CF═CF—, —CF═CH—, —C≡C—, —S—, —CO—, —(CO)O—, —O(CO)— or —O(CO)O— in such a way that O atoms are not linked directly to one another;
A1, A2 and A3 are each, independently of one another, a divalent group selected from the formulae:




Z1, Z2, Z3 and Z4 are each, independently of one another, a single bond, —CH2CH2—, —CH═CH—, —CH2O— or —CF2O—.

24. A compound according to claim 19, wherein L1, L2, and L3 are each independently H or F.