DE4215277B4 - Benzene derivatives and their use for a liquid crystalline medium - Google Patents

Abstract

worin
R H, einen unsubstituierten, einen einfach durch CN oder CF₃ oder einen mindestens einfach durch Halogen substituierten Alkyl- oder Alkenylrest mit 1 bis 15 C-Atomen, wobei in diesen Resten auch eine oder mehrere CH₂-Gruppen jeweils unabhängig von einander durch -O-, -S-,

-CO-, -CO-O-, -O-CO- oder -O-CO-O- so ersetzt sein können, daß O-Atome nicht direkt miteinander verknüpft sind,
L¹ und L² jeweils unabhängig voneinander H oder F,
A¹ und A² jeweils unabhängig voneinander einen
(a) trans-1,4-Cyclohexylenrest, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen durch -O- und/oder -S- ersetzt sein können,
(b) 1,4-Phenylenrest, worin auch eine oder zwei CH-Gruppen durch N ersetzt sein können,
(c) Rest aus der Gruppe 1,4-Cyclohexenylen, 1,4-Bicyclo(2,2,2)-octylen, Piperidin-1,4-diyl, Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl und 1,2,3,4-Tetrahydronaphthalin-2,6-diyl,
wobei die Reste (a) und (b) durch ein oder zwei Fluor substituiert sein können,
Z¹ und Z² jeweils unabhängig voneinander -CO-O-,...Benzene derivatives of the formula I,

wherein
RH, an unsubstituted, an alkyl or alkenyl radical having 1 to 15 carbon atoms, which is monosubstituted by CN or CF ₃ or at least monosubstituted by halogen, where one or more CH ₂ groups are each independently of one another by -O , -S-,

-CO-, -CO-O-, -O-CO- or -O-CO-O- may be replaced so that O atoms are not directly linked to one another,
L ¹ and L ^{2 are} each independently H or F,
A ¹ and A ² each independently
(a) trans-1,4-cyclohexylene radical, in which also one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-,
(b) 1,4-phenylene radical, in which also one or two CH groups may be replaced by N,
(c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo (2,2,2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6- diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl,
where the radicals (a) and (b) can be substituted by one or two fluorine,
Z ¹ and Z ^{2 are} each independently of one another -CO-O -, ...

Description

worin
R H, einen unsubstituierten, einen einfach durch CN oder CF₃ oder einen mindestens einfach durch Halogen substituierten Alkyl- oder Alkenylrest mit 1 bis 15 C-Atomen, wobei in diesen Resten auch eine oder mehrere CH₂-Gruppen jeweils unabhängig voneinander durch -O-, -S-,

-CO-, -CO-O-, -O-CO- oder -O-CO-O- so ersetzt sein können, daß O-Atome nicht direkt miteinander verknüpft sind,
L¹ und L² jeweils unabhängig voneinander H oder F
A¹ und A² jeweils unabhängig voneinander einen

• (a) trans-1,4-Cyclohexylenrest, worin auch eine oder mehrere nicht benachbarte CH₂-Gruppen durch -O- und/oder -S- ersetzt sein können,
• (b) 1,4-Phenylenrest, worin auch eine oder zwei CH-Gruppen durch N ersetzt sein können,
• (c) Rest aus der Gruppe 1,4-Cyclohexenylen, 1,4-Bicyclo(2,2,2)-octylen, Piperidin-1,4-diyl, Naphthalin-2,6-diyl, Decahydronaphthalin-2,6-diyl und 1,2,3,4-Tetrahydronaphthalin-2,6-diyl,

wobei die Reste (a) und (b) durch ein oder zwei Fluor substituiert sein können,
Z¹ und Z² jeweils unabhängig voneinander -CO-O-, -O-CO-, -CH₂O-, -OCH₂-, -CH₂CH₂-, -CH=CH-, -C≡C- oder eine Einfachbindung, einer der Reste Z¹ und Z² auch -(CH₂)₄- oder -CH=CH-CH₂CH₂-,
m 0, 1 oder 2, und
X H, F, Cl oder C_xH_(2x+1–y)F_y,
wobei 0 ≤ y ≤ 2x + 1 ist,
bedeutet.The invention relates to novel benzene derivatives of the formula I,

wherein
R is an unsubstituted, an alkyl or alkenyl radical having 1 to 15 C atoms which is monosubstituted by CN or CF ₃ or at least monosubstituted by halogen, where one or more CH ₂ groups in these radicals are each independently of one another denoted by -O- , -S-,

-CO-, -CO-O-, -O-CO- or -O-CO-O- may be replaced so that O atoms are not directly linked to one another,
L ¹ and L ^{2 are} each independently H or F
A ¹ and A ² each independently

• (a) trans-1,4-cyclohexylene radical, in which also one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-,
• (b) 1,4-phenylene radical, in which also one or two CH groups may be replaced by N,
• (c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo (2,2,2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6- diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl,

where the radicals (a) and (b) can be substituted by one or two fluorine,
Z ¹ and Z ^{2 are} each independently -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ CH ₂ -, -CH = CH-, -C≡C- or a single bond, one of Z ¹ and Z ² also - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ -,
m 0, 1 or 2, and
XH, F, Cl or C _x H _{(2x + 1-y)} F _y ,
where 0 ≤ y ≤ 2x + 1,
means.

The The invention further relates to the use of these compounds as components of liquid crystalline Media. The compounds of the formula I can be used as components of liquid-crystalline Media are used, especially for displays based on the principle the twisted cell, the guest-host effect, the effect of deforming upright phases or the effect based on dynamic dispersion.

Of the Invention was based on the object new stable liquid crystalline or to find mesogenic compounds which are components of liquid-crystalline Media are suitable and in particular at the same time a comparatively low viscosity possess and a relatively high dielectric anisotropy.

It has now been found that compounds of the formula I as components of liquid-crystalline Media excellent are suitable. In particular she over comparatively low viscosities. Leave with their help Stable liquid crystalline Media with a broad mesophase range and advantageous values for the optical and dielectric anisotropy. These media also have a very good low temperature behavior.

beschrieben, die jedoch bei tieferen Temperaturen zu smektischen Phasen tendieren.In WO 88/08441 compounds having a terminal OCF ₂ CF ₂ H group such. B.

described, but tend to smectic phases at lower temperatures.

in the With regard to the most diverse fields of application of such compounds with high Δε, however, it was desirable, have further compounds with high nematogeneity available on the specific applications precisely tailored Have properties.

With the provision of compounds of formula I is also quite generally the range of liquid-crystalline substances, which differ from various application aspects Production of liquid-crystalline mixtures are suitable, considerably widened.

The Compounds of the formula I have a wide range of applications. Dependent on from the choice of substituents, these compounds can be considered as Base materials serve, from which liquid-crystalline media for the predominant Part are composed; it can but also compounds of the formula I liquid-crystalline base materials be added from other classes of compounds, for example, the dielectric and / or optical anisotropy of such a dielectric to influence and / or its threshold voltage and / or its viscosity to optimize.

The Compounds of the formula I are colorless in the pure state and form liquid crystalline Mesophases in a for the electro-optical use favorable located temperature range. Chemical, thermal and against light they are stable.

object The invention thus relates to the compounds of the formula I and the Use of these compounds as components of liquid-crystalline Media. Possible Applications are also liquid crystalline Media containing at least one compound of the formula I and liquid crystal display elements, in particular electroopic display elements, such media contain.

Cyc einen 1,4-Cyclohexylrest Y O-CH₂-CF₂-CF₂-X, For the sake of simplicity, A ³ in the following mean a radical of the formula

Cyc is a 1,4-cyclohexyl radical Y is O-CH ₂ -CF ₂ -CF ₂ -X,

Che a 1,4-cyclohexenylene, Dio a 1,3-dioxane-2,5-diyl, Dit a 1,3-dithian-2,5-diyl, Phe a 1,4-phenylene, Pyd a Pyridine-2,5-diyl, Pyr is a pyrimidine-2,5-diyl and Bi is a bicyclo (2,2,2) -octylene, where Cyc and / or Phe are unsubstituted or mono- or disubstituted by F or CN can be substituted.

A ² and A ² are preferably selected from the group Cyc, Che, Phe, Pyr, Pyd and Dio, wherein preferably only one of the radicals A ¹ and A ² present in the molecule is Che, Phe, Pyr, Pyd or Dio.

The compounds of the formula I accordingly comprise compounds having two rings of the subformulae Ia and Ib: RA ² -A ³ -Y Ia RA ² -Z ² -A ³ -Y Ib Compounds with three rings of subformulae Ic to If: RA ¹ -A ² -A ³ -Y Ic RA ¹ -Z ¹ -A ² -Z ² -A ³ -Y Id RA ¹ -Z ¹ -A ² -A ³ -Y Ie RA ¹ -A ² -Z ² -A ³ -YIf and compounds with four rings of the subformulae Ig to Im: RA ¹ -A ¹ -A ² -A ³ -Y Ig RA ¹ -Z ¹ -A ¹ -A ² -A ³ -Y Ih RA ¹ -A ¹ -Z ¹ -A ² -A ³ -Y Ii RA ¹ -A ¹ -A ² -Z ¹ -A ³ -Y Ij RA ¹ -Z ¹ -A ¹ -Z ¹ -A ² -A ³ -Y Ik RA ¹ -A ¹ -Z ¹ -A ² -Z ² -A ³ -Y II RA ¹ -Z ¹ -A ¹ -Z ¹ -A ² -Z ² -A ³ -Y Im

among them are particularly those of the subformulae Ia, Ib, Ic, Id, Ie, If, Ii and Il are preferred.

The preferred compounds of sub-formula Ia include those of sub-formulas Iaa to Iah: R-Phe-A ³ -Y Iaa R-Phe-A ³ -Y Iab R-Dio-A ³ -Y Iac R-Pyr-A ³ -Y I ad R-Pyd-A ³ -Y Iae R-Cyc-A ³ -Y Iaf R-Cyc-A ³ -Y tag R-Che-A ³ -Y Iah

among them those of the formulas Iaa, Iab, Iac, Iad, Iaf and Iag are especially prefers.

The preferred compounds of sub-formula Ib include those of sub-formulas Iba and Ibb: R-Cyc-CH ₂ CH ₂ -A ³ -Y Iba R-Cyc-COO-A ³ -Y Ibb

The preferred compounds of sub-formula Ic include those of sub-formulas Ica to Ico: R-Phe-Phe-A ³ -Y Ica R-Phe-Phe-A ³ -Y Icb R-Phe-Dio-A ³ -Y Icc R-CyC-CyC-A ³ -Y Icd R-Phe-Cyc-A ³ -Y Ice R-Cyc-Cyc-A ³ -Y Icf R-Pyd-Phe-A ³ -Y Icg R-Pyr-Phe-A ³ -Y i R-Phe-Pyr-A ³ -Y Ici R-Cyc-Pyr-A ³ -Y Icj R-Cyc-Phe-A ³ -Y Ick R-Cyc-Phe-A ³ -Y I Cl R-Dio-Phe-A ³ -Y Icm R-Che-Phe-A ³ -Y Icn R-Phe-Che-A ³ -Y Ico

among them those of the formulas Ica, Icc, Icd, Ice, Ici and Icj are especially prefers.

The preferred compounds of the partial formula Id include those of the partial formulas Ida to Idm: R-Phe-Z ¹ -Phe-Z ¹ -A ³ -Y Ida R-Phe-Z ¹ -Phe-Z ¹ -A ³ -Y Idb R-Phe-Z ¹ -Dio-Z ¹ -A ³ -Y Idc R-Cyc-Z ¹ -Cyc-Z ¹ -A ³ -Y Idd R-CycZ ¹ -Cyc-Z ¹ -A ³ -Y Ide R-Pyd-Z ¹ -Phe-Z ¹ -A ³ -Y Idf R-Phe-Z ¹ -Pyd-Z ¹ -A ³ -Y Idg R-Pyr-Z ¹ -Phe-Z ¹ -A ³ -Y Idh R-Phe-Z ¹ -Pyr-Z ¹ -A ³ -Y Idi R-Phe-Z ¹ -Cyc-Z ¹ -A ³ -Y Idj R-Cyc-Z ¹ -Phe-Z ¹ -A ³ -Y Idk R-Cyc-Z ¹ -Phe-Z ¹ -A ³ -Y Idl R-Dio-Z ¹ -Phe-Z ¹ -A ³ -Y Idm

The preferred compounds of sub-formula Ie include those of sub-formulas Iea to Iel: R-Pyr-Z ¹ -Phe-A ³ -Y Iea R-Dio-Z ¹ -Phe-A ³ -Y Ieb R-Phe-Z ¹ -Phe-A ³ -Y Iec R-Cyc-Z ¹ -Phe-A ³ -Y IED R-Cyc-Z ¹ -Phe-A ³ -Y Iee R-Phe-Z ¹ -Cyc-A ³ -Y Ief R-Cyc-Z ¹ -cyc-A ³ -Y Ieg R-Cyc-Z ¹ -cyc-A ³ -Y Ieh R-Phe-Z ¹ -Dio-A ³ -Y Iei R-Pyd-Z ¹ -Phe-A ³ -Y Ij R-Phe-Z ¹ -pyr-A ³ -Y Iek R-Cyc-Z ¹ -pyr-A ³ -Y Iel

The preferred compounds of the partial formula If include those of the partial formulas Ifa to Ifr: R-Pyr-Phe-Z ¹ -A ³ -Y-Ifa R-Pyr-Phe-OCH ₂ -A ³ -Y Ifb R-Phe-Phe-Z ¹ -A ³ -Y Ifc R-Phe-Phe-OOC-A ³ -Y Ifd R-Phe-Phe-Z ¹ -A ³ -Y Ife R-Cyc-Cyc-Z ¹ -A ³ -Y Iff R-Cyc-Cyc-Z ¹ -A ³ -Y Ifg R-Cyc-Cyc-CH ₂ CH ₂ -A ³ -Y-Ifh R-Pyd-Phe-Z ¹ -A ³ -Y Ifi R-dio-Phe-Z ¹ -A ³ -Y Ifj R-Phe-Cyc-Z ¹ -A ³ -Y-Ifk R-Phe-Cyc-Z ¹ -A ³ -Y Ifl R-Phe-Pyd-Z ¹ -A ³ -Y-Ifm R-Che-Phe-Z ¹ -A ³ -Y Ifn R-Phe-Che-Z ¹ -A ³ -Y Ifo R-Cyc-Phe-Z ¹ -A ³ -Y Ifp R-Cyc-Phe-OOC-A ³ -Y Ifq R-Cyc-Phe-Z ¹ -A ³ -Y Ifr

In the compounds of the formulas above and below, Y is preferably O-CH ₂ -C ₂ F ₅ or O-CH ₂ -CF ₂ -CF ₂ H.

R is preferably alkyl, furthermore alkoxy. A ¹ and / or A ^{2 are} preferably Phe, Cyc, Che, Pyr or Dio. The compounds of the formula I preferably contain no more than one of the radicals Bi, Pyd, Pyr, Dio or Dit.

Preference is also given to compounds of the formula I and of all subformulae in which A ¹ and / or A ^{2 is} monosubstituted or disubstituted by F or simply by CN-substituted 1,4-phenylene. In particular, these are 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene and 3,5-difluoro-1,4-phenylene, as well as 2-cyano-1,4-phenylene and 3-cyano-1 , 4-phenylene. In a particularly preferred embodiment, A ^{2 is} 3,5-difluoro-1,4-phenylene and m is 1 or 2.

Z ¹ and Z ^{2 are} preferably a single bond, -CO-O-, -O-CO- and -CH ₂ CH ₂ -, secondarily preferably -CH ₂ O- and -OCH ₂ -.

If one of the radicals Z ¹ and Z ^{2 is} - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ -, the other radical Z ¹ or Z ² (if present) is preferably the single bond.

worin Z² -(CH₂)₄- oder -CH=CH-CH₂CH₂- bedeutet und R, A¹, A², m, L, Q, X die bei Formel I angegebene Bedeutung haben. Auch die bevorzugten Bedeutungen für R, A¹, A², m, L² und X entsprechen denen für die Verbindungen der Formel I.Preferred compounds of this type correspond to the partial formula I '

wherein Z ² - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ - and R, A ¹ , A ² , m, L, Q, X have the meaning given in formula I. The preferred meanings for R, A ¹ , A ² , m, L ² and X correspond to those for the compounds of the formula I.

m is preferably 1 or 0, particularly preferably 0.

If R represents an alkyl radical and / or an alkoxy radical, this may straight-chain or branched. Preferably, it is straight-chain, has 2, 3, 4, 5, 6 or 7 carbon atoms and therefore preferably Ethyl, propyl, butyl, pentyl, hexyl, heptyl, ethoxy, propoxy, butoxy, Pentoxy, hexoxy or heptoxy, furthermore methyl, octyl, nonyl, decyl, Undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octoxy, Nonoxy, decoxy, undecoxy, dodecoxy, tridecoxy or tetradecoxy.

oxaalkyl preferably denotes straight-chain 2-oxapropyl (= methoxymethyl), 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxapentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxo-octyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl.

If R is an alkyl radical in which a CH ₂ group is replaced by -CH = CH-, this may be straight-chain or branched. It is preferably straight-chain and has 2 to 10 C atoms. It therefore means especially vinyl, prop-1, or prop-2-enyl, but-1, 2- or but-3-enyl, pent-1, 2-, 3- or pent-4-enyl, hex 1-, 2-, 3-, 4- or hex-5-enyl, hept-1, 2-, 3-, 4-, 5- or hept-6-enyl, Oct-1, 2-, 3-, 4-, 5-, 6- or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, 7- or non-8-enyl, decyl, 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or dec-9-enyl.

If R is an alkyl radical in which one CH ₂ group has been replaced by -O- and one by -CO-, these are preferably adjacent. Thus, these include an acyloxy group -CO-O- or an oxycarbonyl group -O-CO-. Preferably, these are straight-chain and have 2 to 6 carbon atoms.

she therefore especially acetyloxy, propionyloxy, butyryloxy, Pentanoyloxy, hexanoyloxy, acetyloxymethyl, propionyloxymethyl, Butyryloxymethyl, pentanoyloxymethyl, 2-acetyloxyethyl, 2-propionyloxyethyl, 2-butyryloxyethyl, 3-acetyloxypropyl, 3-propionyloxypropyl, 4-acetyloxybutyl, 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 R is an alkyl radical in which a CH ₂ group is replaced by unsubstituted or substituted -CH = CH- and an adjacent CH ₂ group by CO or CO-O or O-CO-, this may be straight-chain or branched , Preferably, it is straight-chain and has 4 to 13 carbon atoms. It therefore particularly denotes acryloyloxymethyl, 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloyloxymethyl, 2-metha cryloyloxyethyl, 3-methacryloyloxypropyl, 4-methacryloyloxy-butyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl, 9-methacryloyloxynonyl.

If R is a monosubstituted by CN or CF ₃ alkyl or alkenyl radical, this radical is preferably straight-chain and the substitution by CN or CF ₃ in ω-position.

If R is an alkyl or at least monosubstituted by halogen Alkenyl means, this radical is preferably straight-chain and halogen is preferably F or Cl. With multiple substitution Halogen is preferably F. The resulting radicals also include perfluorinated radicals. For single substitution, the fluoro or chlorine substituent in any position, preferably however in the ω position.

links the formula I, the over for polymerization reactions suitable wing groups R have, are suitable for the preparation of liquid-crystalline Polymers.

links of the formula I with branched wing groups R can occasionally because of a better solubility in the usual liquid crystalline Base materials of importance, but especially as a chiral Dopants when they are optically active. Smectic compounds These types are suitable as components for ferroelectric materials.

Compounds of the formula I with S _A phases are suitable, for example, for thermally addressed displays.

branched Groups of this kind usually contain no 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-ethylhexoxy, 1-methylhexoxy, 1-methylheptoxy.

If R is an alkyl radical in which two or more CH ₂ groups have been replaced by -O- and / or -CO-O-, this may be straight-chain or branched. Preferably, it is branched and has 3 to 12 carbon atoms. It therefore particularly denotes bis-carboxy-methyl, 2,2-bis-carboxy-ethyl, 3,3-bis-carboxy-propyl, 4,4-bis-carboxy-butyl, 5,5-bis-carboxy-pentyl, 6,6-bis-carboxy-hexyl, 7,7-bis-carboxy-heptyl, 8,8-bis-carboxy-octyl, 9,9-bis-carboxy-nonyl, 10,10-bis-carboxy-decyl, Bis (methoxycarbonyl) methyl, 2,2-bis (methoxycarbonyl) ethyl, 3,3-bis (methoxycarbonyl) propyl, 4,4-bis (methoxycarbonyl) butyl, 5,5-bis (methoxy-carbonyl) -pentyl, 6,6-bis (methoxycarbonyl) -hexyl, 7,7-bis- (methoxycarbonyl) -heptyl, 8,8-bis- (methoxycarbonyl) -octyl, bis- (ethoxycarbonyl) - methyl, 2,2-bis (ethoxycarbonyl) ethyl, 3,3-bis (ethoxycarbonyl) propyl, 4,4-bis (ethoxycarbonyl) butyl, 5,5-bis (ethoxycarbonyl) hexyl.

links the formula I, the over for polycondensations suitable wing groups R are suitable to represent liquid crystalline Polycondensates.

formula I included both the racemates of these compounds and the optical antipodes as well as their mixtures.

Under these compounds of the formula I and the sub-formulas are those preferred in which at least one of the radicals contained therein has one of the preferred meanings given.

In the compounds of the formula I, those stereoisomers are preferred, in which the rings cyc and piperidine are trans-1,4-disubstituted. Those of the above formulas containing one or more Groups Pyd, Pyr and / or Dio contain, each enclosing the two 2,5-position isomers.

Preferred smaller groups of compounds are those of the subformulae I1 to I12:

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

Some very particularly preferred smaller groups of compounds are those of sub-formulas 1A to 1I:

The Compounds of the formula I are prepared by methods known per se as described in the literature (e.g., in the standard works as Houben-Weyl, Methods of Organic Chemistry, Georg-Thieme-Verlag, Stuttgart Bd IX, p. 867 ff.) Are described, under reaction conditions, the for the said reactions are known and suitable.

there You can also from known, not mentioned here variants Make use.

worin R, A¹, A², Z¹, Z², L² und m die angegebene Bedeutung haben, gemäß folgendem Reaktionsschema metalliert und anschließend mit einem geeigneten Elektrophil umsetzt: The compounds according to the invention can be prepared, for example, by reacting a compound of the formula II,

wherein R, A ¹ , A ² , Z ¹ , Z ² , L ² and m have the meaning indicated, metallized according to the following reaction scheme and then reacted with a suitable electrophile:

Scheme 1

From the phenol obtained, the target products are obtainable by known methods, for example by reaction of the phenol with CH ₃ SO ₂ -O-CH ₂ -CF ₂ -CF ₂ -X.

Other synthetic methods will be apparent to those skilled in the art. For example, compounds 1,3-difluoro-or mono-fluorinated analogues (L ² = H) may be in the 5-position appropriately substituted 1,3-difluorobenzene compounds or mono-fluorinated analogues (L ² = H) according to the above scheme in which are converted, and the remainder R- (A ¹ -Z ¹ ) _m -A ² -Z ² subsequently by reactions customary in liquid crystal chemistry (for example esterification, etherification or couplings, for example, according to the article E. Poetsch, Contacts (Darmstadt) 1988 (2), 5. 15 ).

Schema 3 (A = -(-A¹-Z¹-)_m-A²-/Z² = Einfachbindung)

Schema 4

Schema 5

Schema 6

The compounds of the formula II can be prepared, for example, according to the following synthesis schemes: Scheme 2 (A = - (- A ¹ -Z ¹ ) _m -A ² - / Z ² = -CH ₂ CH ₂ -)

Scheme 3 (A = - (- A ¹ -Z ¹ -) _m -A ² - / Z ² = single bond)

Scheme 4

Scheme 5

Scheme 6

The Starting materials are either known or can analogously to known Connections are made.

ester of the formula I can also by esterification of corresponding carboxylic acids (or their reactive derivatives) with alcohols or phenols (or their reactive derivatives) or by the DCC method (DCC = dicyclohexylcarbodiimide) become.

The corresponding carboxylic acids and alcohols or phenols are known or can be prepared in analogy to known Process are produced.

Schema 8

Schema 9

The synthesis of some particularly preferred compounds is described in more detail below

Scheme 8

Scheme 9

ester of the formula I can also by esterification of corresponding carboxylic acids (or their derivatives capable of acting) with alcohols or phenols (or their reactive derivatives) or by the DCC method (DCC = dicyclohexylcarbodiimide) become.

The corresponding carboxylic acids and alcohols or phenols are known or can be prepared in analogy to known Process are produced.

In a further process for the preparation of the compounds of the formula I, an aryl halide is reacted with an olefin in the presence of a tertiary amine and a palladium catalyst (see RF Heck, Acc. Chem. Res. 12 (1979) 146). Suitable aryl halides are, for example, chlorides, bromides and iodides, in particular bromides and iodides. The tertiary amines required for the success of the coupling reaction, such as triethylamine, are also suitable as solvents. As palladium catalysts, for example, its salts, in particular Pd (II) acetate, with organic phosphorus (III) compounds such as triarylphosphines are suitable. It is possible to work in the presence or absence of an inert solvent at temperatures between about 0 ° and 150 °, preferably between 20 ° and 100 °; Suitable solvents are, for example, nitriles such as acetonitriles or hydrocarbons such as benzene or toluene. The aryl halides and olefins used as starting materials are widely available commercially or can be known from the literature Processes are prepared, for example by halogenation of corresponding parent compounds or by elimination reactions of corresponding alcohols or halides.

On Stilbenderivate can be prepared in this way, for example. The Style levels can be further prepared by reacting a 4-substituted Benzaldehyde with a corresponding phosphorylide according to Wittig. you but can also produce tolans of formula I by replacing of the olefin used monosubstituted acetylene (Synthesis 627 (1980) or Tetrahedron Lett. 27, 1171 (1986)).

Farther can for the coupling of aromatic aryl halides with aryl tin compounds be implemented. These reactions are preferred with addition a catalyst such as e.g. a palladium (0) complex in inert solvents such as hydrocarbons at high temperatures, e.g. in boiling Xylene, carried out under protective gas.

couplings of alkynyl compounds with aryl halides can be prepared analogously to that of A.O. King, E. Negishi, F.J. Villani and A. Silveira in J. Org. Chem. 43, 358 (1978).

tolans of the formula I can also over the Fritsch-Buttenberg-Wiechell rearrangement (Ann., 279, 319, 1984) wherein 1,1-diaryl-2-haloethylene be rearranged to diarylacetylenes in the presence of strong bases.

tolans of the formula I can also be prepared by brominating the corresponding stilbene and subsequently subjected to dehydrohalogenation. It is possible to know, here unspecified variants apply this implementation.

Ethers of the formula I are obtainable by etherification of corresponding hydroxy compounds, preferably corresponding phenols, wherein the hydroxy compound is suitable first in a corresponding metal derivative, for example by treatment with NaH, NaNH ₂ , NaOH, KOH, Na ₂ CO ₃ or K ₂ CO ₃ in the corresponding alkali metal alcoholate or alkali metal phenolate is converted. This can then be reacted with the corresponding alkyl halide, sulfonate or dialkyl sulfate, suitably in an inert solvent such as. As acetone, 1,2-dimethoxyethane, DMF or dimethyl sulfoxide or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 ° and 100 ° C.

The Starting materials are either known or can analogously to known Connections are made.

The compounds of formula I 'with Z ² = - (CH ₂ ) ₄ - can be prepared according to the following scheme: Scheme 10

at the Pd (II) -catalyzed coupling reaction is either direct the target product I 'formed or a precursor in that completely analogous to the above methods for compounds or formula I introduced the rest -Y becomes.

The compounds of formula I 'with Z ² = -CH = CH-CH ₂ CH ₂ - can be prepared according to Wittig according to the following scheme: Scheme 11

The preferred trans isomers prepared according to the literature known isomerization become. The optionally obtained precursors with R ° = H are completely analog to the precursors of the compounds of formula I by introducing the Restes -Y converted into the compounds of formula I '.

The Aldehydes can by Heck reaction of appropriately substituted 1-bromo-3-fluorobenzene derivatives be obtained with allyl alcohol.

The liquid-crystalline media according to the invention preferably contain, in addition to one or more compounds according to the invention, as further constituents 2 to 40, in particular 4 to 30 components. With very particular preference these media contain, in addition to one or more compounds according to the invention, 7 to 25 components. These further constituents are preferably selected from nematic or nematogenic (monotropic or isotropic) substances, in particular substances from the classes of azoxybenzenes, benzylideneanilines, biphenyls, terphenyls, phenyl or cyclohexyl benzoates, cyclohexane-carboxylic acid phenyl or cyclohexyl esters, phenyl or Cyclohexyl esters of cyclohexylbenzoic acid, phenyl or cyclohexyl esters of cyclohexylcyclohexanecarboxylic acid, cyclohexyl phenyl esters of benzoic acid, of cyclohexanecarboxylic acid or of cyclohexylcyclohexanecarboxylic acid, phenylcyclohexanes, cyclohexylbiphenyls, phenylcyclohexylcyclohexanes, cyclohexylcyclohexanes, cyclohexylcyclohexylcyclohexenes, 1,4-biscyclohexylbenzenes, 4,4 'Bis-cyclohexylbiphenyls, phenyl or cyclohexylpyrimidines, phenyl or cy clohexylpyridines, phenyl- or cyclohexyl-dioxanes, phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethane, 1,2-dicyclohexylethane, 1-phenyl-2-cyclohexylethane, 1-cyclohexyl-2- (4-phenyl-cyclohexyl ) -ethanes, 1-cyclohexyl-2-biphenylylethanes, 1-phenyl-2-cyclohexyl-phenylethanes, optionally halogenated stilbenes, benzylphenyl ethers, tolans and substituted cinnamic acids. The 1,4-phenylene groups in these compounds can also be fluorinated.

The most important compounds which may be used as further constituents of media according to the invention can be characterized by the formulas 1, 2, 3, 4 and 5: R'-LE-R '' 1 R'-L-COO-E-R "2 R'-L-OOC-E-R "3 R'-L-CH ₂ CH ₂ -E-R "4 R'-LC≡E-R "5

In the formulas 1, 2, 3, 4 and 5, L and E, the same or different could be, each independently each other is a bivalent radical from the group consisting of -Phe-, -Cyc-, -Phe-Phe-, -Phe-Cyc, -Cyc-Cyc, -Pyr-, -Dio, -G-Phe- and -G-Cyc- and their Mirror images formed group, with Phe unsubstituted or fluorine-substituted 1,4-phenylene, Cyc trans-1,4-cyclohexylene or 1,4-cyclohexylene, pyr pyrimidine-2-5-diyl or pyridine-2,5-diyl, Bio 1,3-dioxane-2,5-diyl and G 2- (trans-1,4-cyclohexyl) -ethyl, pyrimidine-2,5-diyl, Pyridine-2,5-diyl or 1,3-dioxane-2,5-diyl.

Preferably one of the radicals L and E is Cyc, Phe or Pyr. E is preferred Cyc, Phe or Phe-Cyc. Preferably, the media of the invention contain one or more components selected from the compounds of Formulas 1, 2, 3, 4 and 5, wherein L and E are selected from the group Cyc, Phe and Pyr and at the same time one or more components selected from the compounds of formulas 1, 2, 3, 4 and 5, wherein one of the radicals L and E selected is selected from the group Cyc, Phe and Pyr and the other radical is selected from the group -Phe-Phe, -Phe-Cyc, -Cyc-Cyc, -G-Phe and -G-Cyc-, and optionally one or more components selected from the compounds of formulas 1, 2, 3, 4 and 5, wherein the radicals L and E selected are from the group -Phe-Cyc, -Cyc-Cyc, -G-Phe and -G-Cyc-.

R 'and R' 'are in a smaller subgroup the compounds of formulas 1, 2, 3, 4 and 5 are each independently Alkyl, alkenyl, alkoxy, alkoxyalkyl, alkenyloxy or alkanoyloxy with up to 8 carbon atoms. Below is this smaller one Subgroup group A called and the compounds are with the Partial formulas 1a, 2a, 3a, 4a and 5a. For most of these Compounds are R 'and R '' different from each other, wherein one of these radicals is usually alkyl, alkenyl, alkoxy or alkoxyalkyl is.

In a smaller subgroup of compounds of formulas 1, 2, 3, 4 and 5, other than group B, R '' is -F, -Cl, -NCS or - (O) _i CH ₃ - _{(k + 1)} F _k Cl ₁ , where i is 0 or 1 and k + 1 is 1, 2 or 3, the compounds in which R "has this meaning are designated by the subformulae 1b, 2b, 3b, 4b and 5b. Particular preference is given to those compounds of the subformulae 1b, 2b, 3b, 4b and 5b in which R "has the meaning -F, -Cl, -NCS, -CF ₃ , -OCHF ₂ or -OCF ₃ .

In R 'has the compounds of the sub-formulas 1b, 2b, 3b, 4b and 5b in the compounds sub-formulas 1a-5a given meaning and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl.

In another smaller subgroup of the compounds of the formulas 1, 2, 3, 4 and 5 are R "-CN; this subgroup is hereinafter referred to as group C and the compounds of this Subgroup corresponding to sub-formulas 1c, 2c, 3c, 4c and 5 c described. In the compounds of sub-formulas 1c, 2c, 3c, 4c and 5c has R 'the in the compounds of the sub-formulas 1a-5a meaning and is preferably alkyl, alkoxy or alkenyl.

Next the preferred compounds of groups A, B and C are also others Compounds of formulas 1, 2, 3, 4 and 5 with other variants the proposed substituents in use. All these substances are available by literature methods or in analogy thereto.

The liquid crystalline. In addition to compounds of the formula I according to the invention, media preferably contain one or more compounds which are selected from the group A and / or group B and / or group C. The mass fractions of the compounds from these groups on the liquid-crystalline media are preferred Group A: 0 to 90%, preferably 20 to 90%, in particular 30 to 90% Group B: 0 to 80%, preferably 10 to 80%, especially 10 to 65% Group C: 0 to 80%, preferably 5 to 80%, especially 5 to 50% wherein the sum of the mass fractions of the compounds of the groups A and / or B and / or C contained in the respective liquid-crystalline media is preferably 5 to 90% and in particular 10 to 90%.

The liquid crystalline Media preferably contain 1 to 40%, especially preferably 5 to 30% of compounds according to the invention. Further preferred are media containing more than 40%, in particular 45 to 90% of compounds of the invention. The media preferably contain three, four or five compounds according to the invention.

The Production of liquid crystalline Media is done in per se Wise. In general, the components are dissolved in each other, useful in increased Temperature. By suitable additives can they liquid crystalline Phases according to the invention are modified so that they are in all types of liquid crystal display elements known so far can be used. Such additives are known in the art and described in detail in the literature (H.Kalkker / R.Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980). For example, pleochroiti cal dyes for the production of colored guest host systems or substances for change dielectric anisotropy, viscosity and / or orientation be added to the nematic phases.

The following examples are intended to illustrate the invention without limiting it. Above and below, percentages are by weight. All temperatures are in degrees Celsius. Mp means melting point, bp = clearing point. Furthermore, K = crystalline state, N = nematic phase, S = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. Δn means optical anisotropy (589 nm, 20 ° C) and the viscosity (mm ² / sec) was determined at 20 ° C.

DMEU

1,3-Dimethyl-2-imidazoldinon

KOT

Kalium-tertiär-butanolat

THF

Tetrahydrofuran

pTSOH

p-Toluolsulfonsäure

"Conventional workup" means: water is optionally added, extracted with dichloromethane, diethyl ether or toluene, separated, the organic phase is dried, evaporated and the product is purified by distillation under reduced pressure or crystallization and / or chromatography. The following abbreviations are used:

DMEU

1,3-dimethyl-2-imidazoldinon

KOT

Potassium tert-butoxide

THF

tetrahydrofuran

pTSOH

p-toluenesulfonic acid

example 1

• a)
  
  0.2 mol of 2,2,3,3,3-pentafluoropropanol are dissolved in 100 ml of dichloromethane. At 0 ° C., 0.22 mol of triethylamine and then 0.22 mol of methanesulfonyl chloride are initially added under protective gas ben. After 2 h stirring at room temperature is hydrolyzed. The organic phase is separated and worked up as usual.
• b)
  
  Under protective gas, 0.075 mol of 4-bromo-2,6-difluoro-sodium phenolate in 60 ml of 1,3-dimethyl-2-imidazoldinone (DMEU) are introduced and heated. After addition of 0.108 mol of 2,2,3,3,3-pentafluoropropyl mesylate is stirred at 140 ° C for 5 h. Subsequently, the reaction mixture is poured into ice-water and extracted with ether. The organic phase is separated and worked up as usual.
• c)
  
  0.035 mol of trans, trans-4-bromo-4'-propylcyclohexyl-cyclohexane, 0.0175 mol of zinc bromide, 0.07 mol of lithium granules in 300 ml of toluene / THF (3: 1) are under protective gas for 4 h at 5 ° C under ultrasound touched. Then, 0.035 mol of 3,5-difluoro-4- (2,2,3,3,3-pentafluoropropoxy) bromobenzene and 0.5 g of PdCl ₂ dppf are added to the mixture. The mixture is stirred overnight at room temperature. After addition of 200 ml of saturated ammonium chloride solution, stirring is continued for 15 minutes. The organic phase is separated and worked up as usual. K 66 S _B (48) N 130, 5 I, Δn = + 0, 082

hergestellt:

Analogously, the following compounds of the formula

produced:

Example 2

• a)
  
  As in Example 1a), 0.25 mol of 1,1,3-trihydrotetrafluoropropanol in 125 ml of dichloromethane are reacted with 0.275 mol of triethylamine and 0.275 mol of methanesulfonyl chloride.
• b)
  
  Analogously to Example 1b), 0.1 mol of 4-bromo-2-fluoro-sodium phenolate in 80 ml of DMEU is reacted with 2,2,3,3-tetrafluoropropylmethylate.
• c)
  
  Analogously to Example 1c), 26 mmol of trans, trans-4-bromo-4'-propylcyclohexylcyclohexane, 13 mmol of zinc bromide, 52 mmol of lithium granules in 200 ml of toluene / THF (4: 1) after the ultrasound treatment with 26 mmol of 3-fluoro Reacted 4- (2,2,3,3-tetrafluropropoxy) bromobenzene. K 80 S _B 96 N 134, 7 I, Δn = +0, 086

hergestellt:

Analogously, the following compounds of the formula

produced:

Example 3

• a)
  
  Analogously to Example 1b), 0.1 mol of 4-bromo-2,6-difluoro-sodium phenolate in 80 ml of DMEU is reacted with 2,2,3,3-tetrafluoropropylmethylate.
• b)
  
  0.02 mol of p-trans-4-propylcyclohexylphenylboronic acid, 40 ml of toluene, 0.08 mol of sodium bicarbonate and 20 ml of water are introduced and stirred for 0.5 h. After addition of 2 mol% of tetrakis (triphenylphosphine) palladium (0) are further stirred at 110 ° C for 4 h. Then allowed to cool to room temperature. The organic phase is separated and worked up as usual. K 88 N 91.1 I; Δn = +0, 138

hergestellt.Analogously, the following compounds of the formula

produced.

Example 4

0.1 mol of p-trans-4-propylcyclohexyl sodium phenolate and 0.116 mol of 2,2,3,3,3-pentafluoropropylmethylate in 100 ml of DMEU are stirred for 7 days at 145.degree. The mixture is heated to 500 Added ice water and extracted with diethyl ether. The organic Phase is separated and as usual worked up. K 0 I, Δn = 0, 032

hergestellt:

Analogously, the following compounds of the formula

produced:

Example 5

0.035 mol of p-trans-4-pentylcyclohexylphenylboronic acid, 65 ml of toluene, 0.14 mol of sodium bicarbonate in 20 ml of water with 0.035 mol of 3,5-difluoro-4- (2,2,3,3,3-pentafluoropropoxy ) -bromobenzene and 2 mol% tetrakis (triphenylphosphine) palladium (0). K 51 S _C 74 N 107.4 I, Δn = 0.131

hergestellt:

Analogously, the following compounds of the formula

produced:

Example 6

Analogously to Example 1c), 0.19 mol of 4-propylcyclohexyl bromide, 0.095 mol of zinc bromide, 0.38 mol of lithium granules in 300 ml of toluene / THF (1: 1) after the ultrasound treatment with 0.038 mol of 3,5-difluoro-4- ( 2,2,3,3-tetrafluoropropoxy) bromobenzene and 3.2 g PdCl ₂ dppf reacted. K 11 I, Δn = +0.032

hergestellt:

Analogously, the following compounds of the formula

produced:

Example 7

37.1 g of I (0.1 mol) are initially charged in 150 ml of a solvent mixture of THF / toluene (1: 4 volume ratio), then 11.5 g of anhydrous zinc bromide and then 1.4 g of lithium granules are added. The mixture is sonicated under argon with stirring for 4 hrs between 0 ° C and 10 ° C to convert I to the corresponding dialkylzinc compound. The organozinc compound is mixed with 21.1 g of II (0.1 mol) and 1.5 g (2 mol%) of 1,1'-bis (diphenylphosphino) ferrocene-palladium (II) dichloride (PdCl ₂ dppf) and After removal of the ultrasonic bath and cooling for 24 h at room temperature. It is decomposed with 100 ml of saturated NH ₄ Cl solution with stirring, the organic phase separated, the aqueous phase extracted with toluene. The combined organic extracts provide after drying, concentration and chromatography on silica gel with hexane III.

mittels Malonester.) Mit II lassen sich analog I die nachfolgend aufgeführten Alkylbromide umsetzen:

(I can be produced by chain extension of

using Malonester.) With II can be analogously I implement the following alkyl bromides:

Claims (4)

Benzene derivatives of the formula I,

wherein R is H, an unsubstituted, an alkyl or alkenyl radical having 1 to 15 C atoms, which is monosubstituted by CN or CF ₃ or at least monosubstituted by halogen, where one or more CH ₂ groups in each of these radicals are also independently of one another. O-, -S-,

-CO-, -CO-O-, -O-CO- or -O-CO-O- may be replaced so that O atoms are not directly linked to each other, L ¹ and L ^{2 are} each independently H or F, A ¹ and A ^{2 are} each independently an (a) trans-1,4-cyclohexylene radical in which also one or more non-adjacent CH ₂ groups may be replaced by -O- and / or -S-, (b) 1, 4-phenylene radical, in which also one or two CH groups can be replaced by N, (c) radical from the group consisting of 1,4-cyclohexenylene, 1,4-bicyclo (2,2,2) -octylene, piperidine-1, 4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl and 1,2,3,4-tetrahydronaphthalene-2,6-diyl, where radicals (a) and (b) are substituted by one or two Z ¹ and Z ^{2 are} each independently -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -CH ₂ CH ₂ -, -CH = CH-, - C≡C- or a single bond, one of the radicals Z ¹ and Z ² also - (CH ₂ ) ₄ - or -CH = CH-CH ₂ CH ₂ -, m is 0, 1 or 2, and XH, F, Cl or C _x H _{(2x + 1-y)} F _y , where 0 ≤ y ≤ 2x + 1 means. Compounds of the formula I '

wherein R, A ¹ , A ² , Z ² , L ² , X and m have the meaning given in claim 1. Compounds of the formula I, wherein X is H or F. Use of compounds of the formula I as components liquid-crystalline Media.