DE3837663A1 - Urethane derivatives - Google Patents

Abstract

Urethane derivatives of the formula I R<1>-Q<1>-(A<1>-Z<1>)n-A<2>-Q<2>-R<2> in which R<1> and R<2> in each case independently of one another are an alkyl or alkenyl radical having up to 18 C atoms, in which one or more CH2 groups can be replaced by a radical selected from the group -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O- and -C IDENTICAL C-, 2 hetero atoms not being adjacent, and which is unsubstituted or substituted by -CN or by at least one halogen, one of the radicals R<1> and R<2> is also H, or one of the radicals R<1>-Q<1>- and Q<2>-R<2> is also F, Cl, CN, OCF3 or CF3, Q<1> and Q<2> in each case independently of one another are -CO-O-, -O-CO- or a single bond, A<1> and A<2> in each case independently of one another are a) a 1,4-phenylene radical, in which one or two CH groups can be replaced by N, b) a 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups can be replaced by -O- or -S-, c) a 1,4-cyclohexenylene, a 1,4-bicyclo[2.2.2]octylene or a piperidine-1,4-diyl radical, where the radicals a) and b) can be monosubstituted or polysubstituted by halogen atoms, cyano and/or methyl groups, Z<1> in each case independently of one another is -CO-O-, -O-CO-, -CH2-CH2-, -OCH2-, -CH2O- or a single bond, and n is 1, 2 or 3, with the proviso that at least one group A<1>-Z<1> or A<2>-Q<2> is a radical of the formula <IMAGE> and/or at least one group Q<1>-A<1> or Z<1>-A<2> is a radical of the formula <IMAGE> are suitable... Original abstract incomplete.

Description

The invention relates to urethane derivatives of the formula I

R¹-Q¹- (A¹-Z¹) _n -A²-Q²-R² (I)

wherein
R¹ and R² each independently an unsubstituted or with -CN or with at least one halogen substituted alkyl or alkenyl radical having up to 18C atoms, in which one or more CH₂ groups can be replaced by a radical selected from the group - O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O- and -C≡C-, where 2 heteroatoms are not adjacent, one of the radicals R¹ and R² also H, or one of the radicals R¹-Q¹- and Q²-R² also F, Cl, CN, OCF₃ or CF₃,
Q¹ and Q² each independently of one another -CO-O-, -O-CO- or a single bond,
A¹ and A² are each independently

• a) a 1,4-phenylene radical, wherein one or two CH groups can be replaced by N,
• b) a 1,4-cyclohexylene radical, wherein one or two non-adjacent CH₂ groups by -O- or -S- can be replaced,
• c) a 1,4-cyclohexenylene, a 1,4-bicyclo- [2,2,2] octylene or a piperidine-1,4- diyl residue,

where the radicals a) and b) can be substituted one or more times by halogen atoms, cyano and / or methyl groups,
Z¹ each independently of one another -CO-O-, -O-CO-, -CH₂-CH₂-, -OCH₂-, -CH₂O- or a single bond, and
n is 1, 2 or 3,
with the proviso that at least one group A¹-Z¹ or A²-Q² is a radical of the formula

and or at least one group Q¹-A¹ or Z¹-A² is a radical of the formula

means.

For the sake of simplicity, the following mean:
Phe a 1,4-phenylene group, Cy a 1,4-cyclohexylene group, Dio a 1,3-dioxane-2,5-diyl group, Dit a 1,3-dithiane-2,5-diyl group, Pip a piperidine-1 , 4-diyl group, BCO a 1,4-bicyclo [2.2.2] octylene group, Pyd a pyridine-2,5-diyl group and Pyr a pyrimidine-2,5-diyl group, which groups may be unsubstituted or substituted. In the following, ure means a radical of the formula

The compounds of formula I can be used as components liquid crystalline phases are used, in particular for displays based on the principle of twisted Cell (TN displays), the guest-host effect, the effect the deformation of erected phases or the effect based on dynamic dispersion.

Furthermore, the compounds of formula I as Kompo chiral tilted phases with ferroelectric Properties are used, especially for dis plays based on the SSFLC principle.

Similar liquid crystalline piperidine derivatives are be already known from DE-OS 32 20 155 and DD-OS 2 25 427. However, these are not urethane derivatives, i.e. H. they do not have a carboxyl group, which di is directly linked to the piperidine nitrogen.

The known piperidine derivatives generally have Disadvantages such as B. poor solubility in mixtures gene, high viscosity and chemical, especially thermal cal, instability. In addition, these connections have a low dielectric anisotropy. It therefore exists a need for high dielectric ani compounds sotropy, which allow mixtures for various to improve electro-optical applications.

The invention was based, new stable task to find liquid crystalline or mesogenic compounds the as components of liquid crystalline phases are suitable.

It has now been found that the compounds of Formula I excellent as both nematic components as well as smectic liquid crystal phases.

With the provision of the compounds of formula I the range of liquid is also very general crystalline substances that can be found among different application aspects for manufacturing liquid crystalline mixtures are suitable, ver broadens.

The compounds of formula I have a wide range Scope of application. Depending on the selection of the Substituents can use these compounds as base mates rialien serve from which liquid crystalline phases to the majority are composed; but it can also compounds of formula I liquid crystalline Ba sismaterials from other classes of compounds added be, for example, the dielectric and / or optical anisotropy or other parameters of a sol to optimize the dielectric. The connections of the Formula I are also suitable as intermediates for Manufacture of other substances that prove to be inventory Let parts of liquid crystalline phases be used.

The compounds of formula I are colored in the pure state and form liquid crystalline mesophases in one for the electro-optical use of conveniently located tempera door area.  

The invention thus relates to the compounds of Formula I and the use of the compounds of For mel I as components of liquid crystalline phases.

The invention also relates to liquid crystalline Phases containing at least one compound of the formula I and liquid crystal display elements, ins special electro-optical display elements, such Phases included.

Above and below R¹, R², A¹, A², Q¹, Q² and Z¹ the meaning given, unless expressly something else is noted.

The compounds of formula I accordingly include Compounds of subforms Ia to In:

R¹-Q¹-A¹-A²-Q²-R² (Ia)

R¹-Q¹-A¹-Z¹-A²-Q²-R² (Ib)

R¹-Q¹-A¹-A¹-A²-Q²-R² (Ic)

R¹-Q¹-A¹-Z¹-A¹-A²-Q²-R² (Id)

R¹-Q¹-A¹-A¹-Z¹-A²-Q²-R² (Ie)

R¹-Q¹-A¹-Z¹-A¹-Z¹-A²-Q²-R² (If)

R¹-Q¹-A¹-A¹-A¹-A²-Q²-R² (Ig)

R¹-Q¹-A¹-Z¹-A¹-A¹-A²-Q²-R² (Ih)

R¹-Q¹-A¹-A¹-Z¹-A¹-A²-Q²-R² (Ii)

R¹-Q¹-A¹-A¹-A¹-Z¹-A²-Q²-R² (Ij)

R¹-Q¹-A¹-Z¹-A¹-Z¹-A¹-A²-Q²-R² (Ik)

R¹-Q¹-A¹-Z¹-A¹-A¹-Z¹-A²-Q²-R² (Il)

R¹-Q¹-A¹-A¹-Z¹-A¹-Z¹-A²-Q²-R² (Im)

R¹-Q¹-A¹-Z¹-A¹-Z¹-A¹-Z¹-A²-Q²-R² (In)

These include those of the sub-formulas Ia, Ib, Ic, Id and Ie preferred.

In the compounds of the formulas above and below R¹ and R² are preferably alkyl, furthermore alkoxy.  

Preference is also given to compounds before and after standing formulas in which one of the radicals R¹-Q¹, R²-Q², CN, F or Cl means.

A¹ and A² are preferably Pip, Cyc, Phe, Dio or Pyr; preferably does not contain the compound of formula I. more than one of the residues Dio, Dit, Pip, BCO, Pyn or Pyr.

At least one of the groups as required A¹-Z¹ or A²-Q² they are a radical of the formula

or at least one of the groups Q¹-A¹ or Z¹-A¹ is a radical of the formula O-CO-N-, contain the Compounds of formula I at least one ure group.

n is preferably 0, 1 or 2, particularly preferably 1.

The groups Z 1, which can be the same and different, are preferred single bonds, secondly be preferably -CO-O-, -O-CO-, or -CH₂CH₂ group. Especially preferred compounds of formula I, wherein all Groups Z¹ and Z² are single bonds or a group Z¹ or Z² means -CO-O-, -O-CO- or -CH₂-CH₂-.

The groups Q¹ and Q², which are the same and different can, are preferably single bonds in the second line preferably -CO-O- or -O-CO-, particularly preferred are compounds of formula I, wherein Q¹-A¹ and A²-Q² mean an ure group.  

R¹ and R² have in the formulas above and below preferably 2-10 C atoms, in particular 3-7 C atoms. In R¹ and R² one or two CH₂ groups can he sets. Preferably only one CH₂ group is replaced by -O-, -CO-, -C≡C- or -S-, in particular by -O-, -CO- or -C≡C-.

In the formulas above and below, R 1 and R² is preferably alkyl, alkoxy or another oxaalkyl group, also alkyl groups in which one or more rere CH₂ groups selected by a grouping the group -O-, -O-CO-, -C≡C-, -CH = CH-, -CH-halogen- and -CHCN- or a combination of two Neten groupings can be replaced, two Hete roatoms are not directly linked.

One of R¹-Q¹ and R²-Q² preferably also means Halogen or CN. Halogen means F, Cl or Br, preferably wise F. If none of R¹ and R² is halogen or CN means R¹ and R² together preferably have 4-16 carbon atoms, especially 4-10 carbon atoms.

If R¹-Q¹ and R²-Q² alkyl radicals, in which also a ("Alkoxy" or "oxaalkyl") or two ("alkoxylakoxy" or "Dioxaalkyl") not adjacent CH₂ groups by O atoms can be replaced, so they can straight chain or branched. They are preferably straight-chain, have 2, 3, 4, 5, 6 or 7 carbon atoms and be are preferably ethyl, propyl, butyl, pentyl, Hexyl, heptyl, ethoxy, propoxy, butoxy, pentyloxy, Hexyloxy or heptyloxy, furthermore methyl, octyl, nonyl, Decyl, undecyl, dodecyl, tridecyl, tetradecyl, penta decyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyl oxy, dodecyloxy, tridecyloxy or tetradecyloxy.  

Oxaalkyl preferably means straight-chain 2-oxypropyl (= Methoxymethyl), 2- (= ethoxymethyl) or 3-oxabutyl (= 2-methoxyethyl), 2-, 3- or 4-oxypentyl, 2-, 3-, 4- or 5-oxahexyl, 2-, 3-, 4-, 5- or 6-oxyheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-oxanonyl, 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxydecyl, 1,3-dioxabutyl (= methoxymethoxy), 1,3-, 1,4-, 2,4-dioxa pentyl, 1,3-, 1,4-, 1,5-, 2,4-, 2,5- or 3,5-dioxahexyl, 1,3-, 1,4-, 1,5-, 1,6-, 2,4-, 2,5-, 2,6-, 3,5-, 3,6- or 4,6-dioxaheptyl.

If R¹-Q¹ and R²-Q² represent an alkyl radical in which a CH₂ group is replaced by -S-, this can ge be wheel-chained and branched. This is preferably Straight chain and means 2-thiapropyl, 2 or 3-thiabutyl, 2-, 3- or 4-thiapentyl, 2-, 3-, 4- or 5-thiahexyl, 2-, 3-, 4-, 5- or 6-thiaheptyl, 2-, 3-, 4-, 5-, 6- or 7-thiaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or 8-thianonyl or 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-thiadecyl.

Alkyl radicals R¹-Q¹ or R²-Q², in are particularly preferred those of the group A¹ and / or A² adjacent CH₂ group is replaced by -S- and thus preferably means Me thylthio, ethylthio, propylthio, butylthio, pentylthio, Hexylthio, Heptylthio, Octylthio, Nonylthio or Decylthio.

If R¹-Q¹ and R²-Q² represent an alkenyl radical, can this can be straight-chain or branched. Preferably it is straight-chain and has 2 to 10 carbon atoms. He means that for 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, Dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or Dec-9-enyl.  

If R¹-Q¹ and R²-Q² are alkoxycarbonyl, alkanoyl oxy- or alkoxycarbonylalkyl radical mean in which Q¹ or Q² mean -O-CO- or -CO-O- or in one CH₂ group is replaced by -O-CO- or -CO-O-, so it can be straight or branched. Preferential it is wise straight-chain and has 2 to 11 carbon atoms. He means 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, butoxy carbonyl, pentyloxycarbonyl, hexyloxycarbonyl, heptyloxy carbonyl, octyloxycarbonyl, nonyloxycarbonyl, decyloxy carbonyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, Propoxycarbonylmethyl, butoxycarbonylmethyl, 2- (methoxy carbonyl) ethyl, 2- (ethoxycarbonyl) ethyl, 2- (propoxy carbonyl) ethyl, 3- (methoxycarbonyl) propyl, 3- (ethoxy carbonyl) propyl, 4- (methoxycarbonyl) butyl.

If R¹-Q¹ and R²-Q² represent an unsaturated radical, in which Q¹ or Q² is -O-CO- or -CO-O- or in which a CH₂ group by -CO-, -O-CO- or -O-CO- er is set, the carbonyl group is preferably Conjugated double bond. This is preferably (Meth) acryloyloxyalkyl radical straight-chain and has 4 to 13 carbon atoms. Accordingly, it means especially acryloyloxy methyl, 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxy hexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloyl oxymethyl, 23-methacryloyloxyethyl, 3-methacryloyloxy propyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-meth acryloyloxyoctyl, 9-methacryloyloxynonyl.  

Compounds of the formula I which are used for polymerization reactions suitable wing groups R¹-Q¹ and / or R²-Q², are suitable for the preparation of liquid crystalline polymers.

Compounds of formula I with branched wing groups R¹-Q¹ and / or R²-Q² can occasionally because of a bes seren solubility in the usual liquid crystalline Base materials may be important, but especially as chiral dopants if they are optically active. Smectic compounds of this type are suitable as a com components for ferroelectric materials.

Branched groups of this type usually do not contain more than a chain branch. Preferred branched R¹-Q¹ and / or R²-Q² are isopropyl, 2-butyl (= 1- Methylpropyl), isobutyl (= 2-methylpropyl), 2-methylbutyl, Isopentyl (= 3-methylbutyl), 2-methylpentyl, 3-methylpen tyl, 2-ethylhexyl, 2-propylpentyl, isopropoxy, 2-methyl propoxy, 2-methylbutoxy, 3-methylbutoxy, 2-methylpentyloxy, 3-methylpentyloxy, 2-ethylhexyloxy, 1-methylhexyloxy, 1-methylheptyloxy, 2-oxa-3-methylbutyl, 3-oxa-4-methyl pentyl, 4-methylhexyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methyloctyloxy, 6-methyloctanoyloxy, 5-methylheptyloxy carbonyl, 2-methylbutyryloxy, 3-methylvaleryloxy, 4-methylhexanoyloxy, 2-chloropropionyloxy, 2-chloro-3- methylbutyryloxy, 2-chloro-4-methylvaleryloxy, 2-chloro 3-methylvaleryloxy, 2-methyl-3-oxapentyl, 2-methyl-3- oxahexyl, 2-fluoro-3-methylvaleryloxy, 2-fluoromethylbutoxy.

If R¹-Q¹ and R²-Q² are one with more than one halogen substituted alkyl or alkoxy radical is halo gene preferably fluorine. This fluorinated alkyl or Alkoxy radical thus preferably means perfluoroalkyl or Perfluoroalkoxy and has 1 to 7 carbon atoms, especially tri fluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluor butyl, undecafluoropentyl, tridecafluorhexyl or penta  decafluorheptyl or trifluoromethoxy, pentafluoroethoxy, Heptafluoropropoxy, nonafluorobutoxy, undecafluoropentyloxy, Tridecafluorohexyloxy or pentadecafluoroheptyloxy.

If R¹-Q¹ and R²-Q² represent an alkyl radical in which two or more CH₂ groups by -O- and / or -CO-O- er sets, it can be straight-chain or branched. It is preferably branched and has 3 to 12 carbon atoms. Accordingly, it means especially bis-carboxy-methyl, 2,2- Bis-carboxy-ethyl, 3,3-bis-carboxy-propyl, 4,4-bis-car boxy-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 (methoxycar bonyl) methyl, 2,2-bis (methoxycarbonyl) ethyl, 3,3-bis (methoxycarbonyl) propyl, 4,4-bis (methoxycarbonyl) butyl, 5,5-bis (methoxycarbonyl) pentyl, 6,6-bis (methoxycarbo nyl) 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 (ethoxy carbonyl) pentyl.

Compounds of the formula I which are used for polycondensation have suitable wing groups R¹-Q¹ and / or R²-Q², are suitable for the representation of liquid crystalline polycon densate.

Formula I includes both the racemates of these compounds as well as the optical antipodes and their mixtures.

Among the compounds of the formulas I and Ia to In those in which at least one of the residues contained therein one of the preferred specified Has meanings.

Of the dinuclear compounds of the formula Ia and Ib those of the sub-formulas I1 to I6 are particularly preferred:

R¹-Phe-Ure-R² (I1)

R¹-Cy-Ure-R² (I2)

R¹-BCO-Ure-R² (I3)

R¹-Pyr-Ure-R² (I4)

R¹-Pyd-Ure-R² (I5)

R¹-Phe-CH₂CH₂-ure-R² (I6)

R¹-Cy-CH₂CH₂-ure-R² (I7)

R¹-ure-CH₂CH₂-ure-R² (I8)

Of the trinuclear compounds Ic to If are those of the sub-formulas I9 to I23 are particularly preferred:

R¹-Phe-Phe-Ure-R² (I9)

R¹-Phe-Cy-Ure-R² (I10)

R¹-Cy-Cy-Ure-R² (I11)

R¹-Cy-Phe-Ure-R² (I12)

R¹-Pyr-Phe-Ure-R² (I13)

R¹-Phe-Ure-Phe-R² (I14)

R¹-Cy-Ure-Phe-R² (I15)

R¹-Cy-Ure-Cy-R² (I16)

R¹-Pyr-Ure-Cy-R² (I17)

R¹-Pyr-Ure-Phe-R² (I18)

R¹-Ure-Phe-Ure-R² (I19)

R¹-Phe-CH₂CH₂-ure-Phe-R² (I20)

R¹-Cy-CH₂CH₂-ure-Phe-R² (I21)

R¹-Cy-CH₂CH₂-ure-Cy-R² (I22)

R¹-Ure-CH₂CH₂-Ure-Phe-R² (I23)

From the tetranuclear compounds of the formula Ig to In those of the sub-formulas I24 to I28 are special prefers:

R¹-A¹-A¹-A¹-ure-R² (I24)

R¹-A¹-A¹-CHE₂CH₂-ure-R² (I25)

R¹-A¹-Ure-A²-R² (I26)

R¹-A¹-Z¹-A¹-A¹-ure-R² (I27)

R¹-A¹-Z¹-A¹-ure-R² (I28)

In the aforementioned compounds of the formulas I1 to I5, I9 to I17, I24 and I25 to I28 mean both Ure a group of the formula

as well as a group of the formula

In contrast, ure in the compounds of the formula I6-I7 means I20-I22 and I25 preferably a group of formula

Particularly preferred compounds of formula I are in the following groups I to IX listed.

Alkyl preferably means straight-chain methyl, ethyl, Propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl or Decyl, particularly preferably one with the urea Group linked wing group methyl.

Alkoxy preferably means straight-chain methoxy, Ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyl oxy, octyloxy, nonyloxy or decyloxy.

Halogen preferably means chlorine or fluorine, in particular special fluorine. In the following, the group -Pip- CO-O is a group of the formula

a group of the formula

PheF means a 1,4-phenylene substituted with fluorine group

• I. Alkyl-Phe-Pip-CO-O-alkyl
  Alkoxy-Phe-Pip-CO-O-alkyl
  Alkyl-Phe-O-CO-Pip-alkyl
  Alkoxy-Phe-O-CO-Pip alkyl
  Alkyl-Cy-O-CO-Pip-alkyl
  Alkyl-PheF-O-CO-Pip-alkyl
  Halogen-PheF-O-CO-Pip alkyl
  Nitrile-PheF-O-CO-Pip alkyl
  Alkyl-pyr-o-co-pip-alkyl
  Alkyl-Phe-O-CO-Pip alkoxy
  Alkoxy-Phe-O-CO-Pip alkoxy
  Alkyl-Cy-O-CO-Pip-Alkoxy
• II. Alkyl-Cy-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkoxy-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Phe-CH₂O-Pip-CO-O-alkyl
  Alkyl-Cy-CH₂O-Pip-CO-O-alkyl
  Alkyl-Cy-OCH₂-Pip-CO-O-alkyl
  Alkyl-Phe-OCH₂-Pip-CO-O-alkyl
  Alkoxy-Phe-OCH₂-Pip-CO-O-alkyl
  Alkyl-Pyr-CH₂CH₂-Pip-CO-O-alkyl
  Halogen-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Halogen-PheF-CH₂CH₂-Pip-CO-O-alkyl
  Nitrile-PheF-CH₂CH₂-Pip-CO-O-alkyl
• III. Alkyl-Phe-Phe-Pip-CO-O-alkyl
  Alkyl-Cy-Phe-Pip-CO-O-alkyl
  Alkyl-cy-cy-pip-CO-O-alkyl
  Alkyl-Phe-Cy-Pip-CO-O-alkyl
  Alkoxy-Phe-Cy-Pip-CO-O-alkyl
  Alkyl-Phe-Phe-O-CO-Pip-alkyl
  Alkoxy-Phe-Phe-O-CO-Pip alkyl
  Alkyl-Phe-Phe-O-CO-Pip alkoxy
  Alkyl-Cy-Phe-O-CO-Pip alkoxy
  Alkyl-Cy-Phe-O-CO-Pip-Alkyl
  Alkyl-Phe-Cy-O-CO-Pip alkoxy
  Alkyl-Phe-PheF-O-CO-Pip alkoxy
  Alkyl-PheF-Phe-O-CO-Pip alkoxy
  Alkoxy-Phe-Cy-O-CO-Pip alkyl
  Alkyl-Phe-Cy-O-CO-Pip-alkyl
  Alkyl-Cy-Cy-O-CO-Pip-Alkyl
  Alkyl-pyr-phe-o-co-pip-alkyl
  Nitrile-Phe-Phe-O-CO-Pip alkyl
  Halogen-Phe-Phe-O-CO-Pip alkyl
  Alkyl-PheF-Phe-O-CO-Pip-alkyl
  Alkyl-Phe-Pip-CO-O-Phe-alkyl
  Alkyl-Phe-Pip-CO-O-Phe-CN
  Alkyl-Phe-Pip-CO-O-PheF-CN
  Alkyl-Phe-Pip-CO-O-PheF halogen
  Alkoxy-Phe-Pip-CO-O-Phe-alkyl
  Alkoxy-Phe-Pip-CO-O-Phe-alkoxy
  Alkyl-Phe-Pip-CO-O-Phe-alkoxy
  Alkyl-cy-pip-CO-O-Phe-alkoxy
  Alkyl-Cy-Pip-CO-O-Phe-alkyl
• V. Alkyl-Phe-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Cy-Cy-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Phe-PheF-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-PheF-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkoxy-PheF-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkoxy-Phe-Phe-CH₂CH₂-Pip-CO-O-alkyl
  Alkoxy-Phe-PheF-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Phe-CH₂CH₂-Cy-Pip-CO-O-alkyl
  Alkyl-Phe-CH₂CH₂-Phe-Pip-CO-O-alkyl
  Alkyl-PheF-CH₂CH₂-Phe-Pip-CO-O-alkyl
• IV. Alkyl-Phe-CH₂CH₂-Cy-O-CO-Pip-alkyl
  Alkyl-Phe-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Alkyl-PheF-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Alkoxy-PheF-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Nitrile-PheF-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Nitrile-Phe-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Alkyl-Phe-CH₂CH₂-Cy-O-CO-Pip-Alkoxy
  Alkyl-Phe-CH₂CH₂-Phe-O-CO-Pip-Alkoxy
  Nitrile-Phe-CH₂CH₂-Phe-O-CO-Pip-Alkoxy
  Alkoxy-Phe-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Alkyl-Cy-CH₂CH₂-Phe-O-CO-Pip-alkyl
  Alkyl-Cy-CH₂CH₂-Cy-O-CO-Pip-alkyl
• VII. Alkyl-Phe-O-CO-Pip-CH₂CH₂-Pip-CO-O-Alkyl
  Alkoxy-Phe-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
  Alkoxy-PheF-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
  Nitrile-PheF-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-PheF-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
  Alkyl-Cy-O-CO-Pip-CH₂CH₂-Pip-CO-O-alkyl
• VIII. Alkyl-Pip-CO-O-Phe-O-CO-Pip-Alkyl
  Alkyl-Pip-CO-O-Cy-O-CO-Pip-Alkyl
  Alkyl-pip-CO-O-PheF-O-CO-pip-alkyl
  Alkoxy-Pip-CO-O-Phe-O-CO-Pip-Alkyl
  Alkoxy-Pip-CO-O-Phe-O-CO-Pip-Alkoxy
  Alkoxy-Pip-CO-O-Cy-O-CO-Pip-Alkoxy
• IX. Alkyl-Phe-Phe-Phe-Pip-CO-O-alkyl
  Alkoxy-Phe-Phe-Phe-Pip-CO-O-alkyl
  Alkyl-Phe-Phe-Pip-CO-O-Phe-alkyl
  Alkyl-Phe-Phe-Pip-CO-O-Phe-nitrile
  Alkyl-Phe-Phe-Pip-CO-O-PheF nitrile
  Alkyl-Phe-Phe-Pip-CO-O-PheF alkoxy
  Alkyl-Phe-Phe-Pip-CO-O-PheF alkyl
  Alkyl-Phe-Phe-Pip-CO-O-Cy-alkyl
  Alkyl-Phe-Pip-CO-O-Phe-Cy-alkyl
  Alkyl-Phe-Pip-CO-O-Phe-Phe-alkyl
  Alkyl-Phe-Pip-CO-O-Phe-Phe-nitrile
  Alkyl-Phe-Pip-CO-O-Phe-Phe-alkoxy
  Alkyl-Phe-Pip-CO-O-PheF-Phe-alkoxy
  Alkyl-Phe-Pip-CO-O-PheF-PheF-alkoxy
  Alkyl-Phe-Pip-CO-O-PheF-PheF-Nitrile
  Alkyl-pip-CO-O-Phe-Phe-Phe-alkyl
  Alkyl-pip-CO-O-Phe-Phe-Phe-nitrile
  Alkyl-pip-CO-O-Phe-Phe-Cy-alkyl
  Alkyl-pip-CO-O-PheF-Phe-Cy-alkyl
  Alkyl-pip-CO-O-Phe-PheF-Cy-alkyl
  Alkoxy-Pip-CO-O-PhePhe-Phe-alkyl
  Alkoxy-Pip-CO-O-PhePhe-Nitrile
  Alkoxy-Pip-CO-O-PhePhe-Phe-CyAlkyl

The compounds of formula I are known per se methods as described in the literature (e.g. in standard works such as Houben-Weyl, methods of organization African chemistry, Georg-Thieme-Verlag, Stuttgart) ben, and under reaction conditions that for the implementations mentioned are known and suitable. There at you can also from well-known, not closer here make use of the variants mentioned.

If desired, the starting materials can also be in situ are formed such that they can be removed from the reaction mix not isolated, but immediately to the Reacts compounds of formula I.

The compounds of the formula I are based on the 4- substituted piperidinecarbamic acids by esterification or from the 4-substituted piperidine carbamide esters accessible by transesterification.

These in turn are made of 4-substituted piperidines obtainable by carboxylation.  

Suitable carboxylation reagents are e.g. B. chlorine formates, phosgene or diphosgene.

Furthermore, the compounds of formula I produce by using 4-substituted piperidines of Formula II

wherein R¹, Q¹, A¹ and Z have the meaning given, and m is 0, 1, 2 or 3 with chloroformates of the formula III

wherein A¹, A², Z¹, Q² and R² have the meaning given, o is 0, 1 or 2 and p is 0 or 1, the sum of m, p and o being 1, 2 or 3.

The 4-substituted piperidines of formula II are e.g. B. from the corresponding pyridines by reduction produced.

Furthermore, the 4-substituted piperidines of the formula II starting from 4-oxopiperidine derivatives, their nitrogen atom with a suitable protecting group is provided.

Suitable protecting groups are e.g. B. trialkylsilyl, Benzyl, trityl or diphenylmethyl groups.  

These protected 4-oxopiperidine derivatives can with Grignard or Wittig reagents are condensed, and is obtained after hydrogenation of the double bond and Ab cleavage of the protecting group the 4-substituted Piperi dine of formula II.

The 4-substituted piperidines of the formula II, in which the group Z¹ linked to the piperidine radical in the 4-position is CH₂O or CO-O- or in the case m = 0, R¹-Q¹ is alkoxy, are also based on 4-oxopiperidine derivatives accessible by reduction of the carbonyl group and subsequent esterification or etherification.

The chloroformates of formula III are from the ent speaking alcohols

R²-Q²- (A²) _p - (Z¹-A¹) _o -OH

with Phos gene or diphosgene produced.

The compounds of the formulas I and II can be prepared by using a compound that is otherwise of the formula I or II corresponds, but instead of H atoms one or ent several reducible groups and / or C-C bonds holds, reduces.

Carbonyl are preferred as reducible groups groups into consideration, especially keto groups e.g. B. free or esterified hydroxyl groups or aromatic bonded halogen atoms. Preferred starting materials for the Reduction correspond to Formula I, but can be in place a cyclohexane ring a cyclohexene ring or cyclo hexanone ring and / or in place of a -CH₂CH₂ group -CH = CH group and / or instead of a -CH₂ group -CO group and / or a free one instead of an H atom or one functional (e.g. in the form of its p-toluenesulfo nats) contain modified OH group.  

The reduction can e.g. B. done by catalytic Hydrogenation at temperatures between about 0 ° and about 200 ° and pressures between about 1 and 200 bar in an inert solvent, e.g. B. an alcohol like Methanol, ethanol or isopropanol, an ether such as Tetrahydrofuran (THF) or dioxane, an ester such as Ethyl acetate, a carboxylic acid such as acetic acid or a hydrocarbon such as cyclohexane. As a cat gates are suitable precious metals such as Pt or Pd, in the form of oxides (e.g. PtO₂, PdO), on one Carrier (e.g. Pd on coal, calcium carbonate or stron tium carbonate) or used in finely divided form can be.

Ketones can also be prepared using Clemmensen's methods (with Zinc, amalgamated zinc or tin and hydrochloric acid moderately in aqueous-alcoholic solution or in heterogeneous Rabbit with water / toluene at temperatures between about 80 and 120 °) or Wolff-Kishner (with Hydrazi, purpose moderately in the presence of alkali such as KOH or NaOH in one high-boiling solvents such as diethylene glycol or Triethylene glycol at temperatures between about 100 and 200 °) to the corresponding compounds of formula I, which contain alkyl groups and / or -CH₂CH₂ bridges, be reduced.

Reductions with complex hydrides are also possible Lich. For example, arylsulfonyloxy groups with LiAlH₄ be removed reductively, especially p-toluene who reduced sulfonyloxymethyl groups to methyl groups the, conveniently in an inert solvent such as Di ethyl ether or THF at temperatures between about 0 and 100 °. Double bonds can (even in the presence of CN groups) with NaBH₄ or tributyltin hydride in Methanol are hydrogenated.  

Esters of the formula I can also correspond by esterification carbonic acids (or their reactive derivatives) with alcohols or phenols (or their reactive Derivatives) can be obtained.

As reactive derivatives of the carboxylic acids mentioned the acid halides are particularly suitable the chlorides and bromides, furthermore the anhydrides, e.g. B. also mixed anhydrides, azides or esters, in particular Alkyl esters with 1-4 C atoms in the alkyl group.

As reactive derivatives of the alcohols mentioned or Phenols come in particular the corresponding metal alcoholates or phenolates, preferably an alkali metals such as Na or K, into consideration.

The esterification is advantageous in the presence of an inert Solvent carried out. Are particularly suitable Ethers such as diethyl ether, di-n-butyl ether, THF, dioxane or Anisole, ketones such as acetone, butanone or cyclohexanone, amides such as DMF or phosphoric acid hexamethyl triamide, hydro substances such as benzene, toluene or xylene, halogenated hydrocarbons substances such as carbon tetrachloride or tetrachlorethylene and Sulfoxides such as dimethyl sulfoxide or sulfolane. With water Immiscible solvents can be advantageous at the same time adheres to the azeotropic distillation of the esterification formed water can be used. Occasionally, too an excess of an organic base, e.g. B. pyridine, chino lin or triethylamine as a solvent for the esterification be applied. The esterification can also be absent a solvent, e.g. B. by simply heating the Components carried out in the presence of sodium acetate will. The reaction temperature is usually between -50 ° and + 250 °, preferably between -20 ° and + 80 °. At these temperatures the esterification reactions are usually ended after 15 minutes to 48 hours.  

In particular, the reaction conditions for the Ver esterification largely depends on the nature of the starting material used fabrics off. So a free carboxylic acid with a free one Alcohol or phenol usually in the presence of a strong one Acid, for example a mineral acid such as hydrochloric acid or Sulfuric acid, implemented. A preferred mode of reaction is the implementation of an acid anhydride or in particular an acid chloride with an alcohol, preferably in a basic environment, with Alka lime metal hydroxides such as sodium or potassium hydroxide, alkali metal carbonates or hydrogen carbonates such as sodium carbonate, Sodium bicarbonate, potassium carbonate or potassium hydro gene carbonate, alkali metal acetates such as sodium or potassium acetate, alkaline earth metal hydroxides such as calcium hydroxide or organic bases such as triethylamine, pyridine, lutidine, colli din or quinoline are important. Another before preferred embodiment of the esterification is that the alcohol or phenol is first added to the sodium or transferred to potassium alcoholate or phenolate, e.g. B. by Treatment with ethanolic sodium or potassium hydroxide solution, this isolated and together with sodium bicarbonate or Potassium carbonate with stirring in acetone or diethyl ether suspended and this suspension with a solution of Acid chloride or anhydride in diethyl ether, acetone or DMF added, expedient at temperatures between about -25 ° and + 20 °.

For the preparation of nitriles of the formula I (in which R 1 and / or R²CN and / or wherein A¹ and / or A³ through at least one CN group is substituted) can ent speaking acid amides, e.g. B. those in place the radical X is a CONH₂ group, dehydrated will. The amides are e.g. B. from corresponding esters or acid halides by reaction with ammonia true. The following are suitable as water-releasing agents for example inorganic acid chlorides such as SOCl₂, PCl₃,  PCl₅, POCl₃, SO₂Cl₂, COCl₂, furthermore P₂O₅, P₂S₅, AlCl₃ (e.g. as a double compound with NaCl), aromatic sulfonic acids and sulfonic acid halides. You can do it in the present or absence of an inert solvent at Tempe ratures work between about 0 ° and 150 °; as a solution means come z. B. bases such as pyridine or triethylamine, aromatic hydrocarbons such as benzene, toluene or Xylene or amides such as DMF can be considered.

For the preparation of the aforementioned nitriles from For mel I you can also corresponding acid halides, before preferably the chlorides, react with sulfamide, appropriately in an inert solvent such as tetramethylene sulfone at temperatures between about 80 ° and 150 °, preferably wise at 120 °. After the usual work-up you can isolate the nitriles directly.

Ethers of formula I (wherein R¹ and / or R² is an alkoxy means group and / or wherein Z¹ and / or Z² is a -OCH₂- or is a -CH₂O group) are ent by etherification speaking hydroxy compounds, preferably correspond of phenols, available, the hydroxy compound purpose moderately first in a corresponding metal derivative, e.g. B. by treatment with NaH, NaNH₂, NaOH, KOH, Na₂CO₃ or K₂CO₃ in the corresponding alkali metal alcoholate or Alkali metal phenolate is transferred. This can then with the corresponding alkyl halide, sulfonate or Dialkyl sulfate are implemented, advantageously in one inert solvents such as acetone, 1,2-dimethoxyethane, DMF or dimethyl sulfoxide or an excess aqueous or aqueous-alcoholic NaOH or KOH Temperatures between about 20 ° and 100 °.  

For the preparation of nitriles of the formula I (in which R 1 and / or R² signifies CN and / or wherein A¹ and / or A² represent at least one CN group is also substituted) corresponding chlorine or bromine compounds of the formula I. (wherein R¹ and / or R² are Cl or Br and / or wherein A¹ and / or A² by at least one Cl or Br atom is substituted) with a cyanide, expediently with a metal cyanide such as NaCN, KCN or Cu₂ (CN) ₂, e.g. B. in the presence of pyridine in an inert Solvents such as DMF or N-methylpyrrolidone at Tempe temperatures between 20 ° and 200 °.

Compounds of the formula I, in which R¹ and / or R² F, Cl, Br or CN can also mean from the corresponding Diazonium salts by exchanging the diazonium group against a fluorine, chlorine or bromine atom or against one CN group, e.g. B. according to the methods of Schiemann or Sandmeyer.

The diazonium salts are e.g. B. producible by nitriding of compounds corresponding to formula I, however Place the residues R¹ and / or R² one (or two) water contain atom (s), reduction to the corresponding Amines and diazotization, for example with NaNO₂ or KNO₂ in aqueous solution at temperatures between about -10² and + 10 °.

You can replace the diazonium group with fluorine diazotize in anhydrous hydrofluoric acid and then heat, or add to the with tetrafluoroboric acid Diazonium tetrafluoroborates, which are then thermally be decomposed.  

An exchange for Cl, Br or CN is successful by reaction of the aqueous diaonium salt solution with Cu₂Cl₂, Cu₂Br₂ or Cu₂ (CN) ₂ according to the method of Sandmeyer.

The representation of the alkyne compounds (R¹ and / or R² Alkyl group, in which one or more CH₂ groups by -C≡C- are replaced z. B. by implementing the ent speaking halogen compound with an acetylide in one basic solvents with transition metal catalysis; Palladium catalysts can preferably be used here are, in particular a mixture of bis (triphenylphos phin) palladium (II) chloride and copper iodide in piperidine as a solvent.

The liquid-crystalline phases according to the invention consist from 2 to 25, preferably 3 to 15 components, including at least one compound of formula I. The other Be components are preferably selected from the nema tables or nematogenic substances, especially be known substances from the classes of azoxybenzenes, Benzylidenanilines, biphenyls, terphenyls, phenyl or Cyclohexylbenzoate, cyclohexane-carboxylic acid phenyl or -cyclohexyl esters, phenylcyclohexanes, cyclohexylbiphenyls, Cyclohexylcyclohexanes, cyclohexylnaphthalenes, 1,4-bis cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, phenyl or cyclohexylpyrimidines, phenyl- or cyclohexyldioxanes, Phenyl- or cyclohexyldithiane, 1,2-bis-phenylethane, 1,2-bis-cyclohexylethane, 1-phenyl-2-cyclohexylethane, optionally halogenated stilbenes, benzylphenyl ether, Tolanes and substituted cinnamic acids.  

The main as components of such liquid crystalline phases in question compounds can be characterized by Formula 2,

R′-L-G-E-R ′ ′ (2)

where L and E each have a carbocyclic or heterocyclic ring system from that of 1,4-disubstituted benzene and Cyclohexane rings, 4,4′-disubstituted biphenyl, Phenylcyclohexane and cyclohexylcyclohexane systems, 2,5-disubstituted pyrimidine and 1,3-dioxane rings, 2,6-disubstituted naphthalene, di- and tetrahydro naphthalene, quinazoline and tetrahydroquinazoline group,

or a C-C single bond, Y halogen, preferably Chlorine, or -CN, and R 'and R' 'alkyl, alkoxy, alkanoyl oxy or alkoxycarbonyloxy with up to 18, preferably up to 8 carbon atoms, or one of these residues also mean CN, NC, NO₂, CF₃, F, Cl or Br.

Most of these compounds are R ′ and R ′ ′ different from one another, one of these residues mostly is an alkyl or alkoxy group. But others too Variants of the proposed substituents are common Lich. Many such substances or mixtures thereof are commercially available. All of these substances are can be produced by methods known from the literature.  

The liquid-crystalline phases according to the invention contain about 0.1 to 99%, preferably 10 to 95%, one or several compounds of formula I. Also preferred are liquid crystalline phases, the 0.1-50, in particular whose 0.5-30% of one or more compounds of Formula I included. Isotropic compounds of For mel I can be used in the phases according to the invention will.

The preparation of the liquid-crystalline according to the invention Phases take place in the usual way. Usually the components are dissolved into one another, expediently at elevated temperature.

By means of suitable additives, the liquid crystalline Phases are modified according to the invention so that they are known in all types of Liquid crystal display elements are used can.

Such additives are known to the expert and in the Literature described in detail. For example, you can Conductive salts, preferably ethyl-dimethyl-dodecyl-ammonium 4-hexyloxybenzoate, tetrabutylammonium tetraphenylboranate or complex salts of crown ethers (cf. e.g. I. Haller et al., Mol. Cryst. Liq. Cryst. Volume 24, pages 249-258 (1973)) to improve conductivity, dichroic Dyes for the production of colored guest-host systems or substances for changing the dielectric Anisotropy, viscosity and / or orientation the nematic phases are added. Such Substances are e.g. B. in DE-OS 22 09 127, 22 40 864, 23 21 632, 23 38 281, 24 50 088, 26 37 430, 28 53 728 and 29 02 177.  

The following examples are intended to illustrate the invention, without limiting it. F = melting point, K = clearing point. Percentages above and below mean percentages by weight percent; all temperatures are in degrees Celsius give.

It also means: Cr: crystalline, solid state, S: smectic phase (the index denotes the phase type), N: nematic phase, Ch: cholesteric phase. The number between two symbols gives the um conversion temperature in degrees Celsius. "Usual on work "means adding water if necessary, Extraction with methylene chloride, ether or toluene, Separating the phases, drying the organic phase, Purification of the residue by distillation and / or Crystallization and / or chromatography.

Example 1 Preparation of 4,4′-ethylene piperdinedicarbamic acid dialkyl esters

To a solution of 7.3 g of 4,4'-ethylene piperidine, 30 ml of ice water and 10 g of ice are added dropwise with stirring, 7.7 g of chlorine methyl formate and 10 ml NaOH (10 mol / l) so that the reaction temperature does not exceed 15 ° C. Man allows to react for 2 hours and filters the contents of the flask from. The residue is washed several times with small portions cold water. The still wet 4,4'-ethylene piperidine Dimethyl dicarbamic acid is recrystallized from ethanol lized. F 131 ° C.  

The following are produced analogously:

4,4'-ethylene piperidine dicarbamic acid diethyl ester
4,4'-Ethylene piperidine dicarbamic acid dipropyl ester
4,4'-ethylene piperidine dicarbamic acid dibutyl ester
4,4'-ethylene piperidine dicarbamic acid dipentyl ester
4,4'-ethylenepiperidine dicarbamic acid dihexyl ester
4,4'-ethylenepiperidine dicarbamic acid diheptyl ester
4,4'-ethylenepiperidine dicarbamic acid dioctyl ester

Example 2 2a) 4-Alkylpiperidinecarbamic acid methyl ester

45.85 g of NaOH biscuits are dissolved in 50 ml of H₂O and mixed with 87.2 g of methylpiperidine. 92.3 g chlorine methyl formate is added dropwise so that the Temperature does not exceed 15 ° C. Then leaves react for 4 hours at room temperature and place the reaction mixture in the refrigerator overnight closet. The oily product is separated off and by means of Kugelrohr distillation gives 4-methylpiperidinecarb amic acid methyl ester. Kp 100 ° C / 15 torr.

2b) 4-Alkylpiperidinecarbamic acid ester cyclohexyl ester

10 g trans, trans-4-propylbicyclohexyl-4'-ol and 15.5 g 4-Methylpiperidincarbamidsäuremethylester are under Submitted nitrogen and mixed with 0.2 g of sodium. The reaction is stirred at 112 ° C. for 8 hours, 16 Stand for hours and then cook for 8 hours Reflux. Ball tube distillation is not used set carbamic acid methyl ester, the The residue is column chromatographed (silica gel / Petroleum ether / THF) separated. The 4-methyl thus obtained piperidinecarbamic acid 4- (4-propylcyclohexyl) cyclohexyl ester is recrystallized from ethanol, mp 52 ° C.  

The following are produced analogously:

4-Ethylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Propylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Butylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Pentylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Hexylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Heptylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Octylpiperidinecarbamic acid trans, trans-4'-propyl bicyclohexyl-4-ester
4-Ethylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Propylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Butylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Pentylpiperidinecarbamic acid-trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Hexylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-heptylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Octylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Nonylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
4-Methylpiperidinecarbamic acid trans, trans-4'-pentyl bicyclohexyl-4-ester
Trans-4-propylcyclohexyl 4-ethylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-propylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-butylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-pentylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-hexylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-heptylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-octylpiperidinecarbamic acid
Trans-4-propylcyclohexyl 4-methylpiperidinecarbamic acid

Example 3 3a) Aryl chloroformate

To a solution of 200 ml dry diethyl ether and 6.3 g of 3-fluoro-4-hydroxybenzonitrile (chilled with ice-cream salt mixture) are initially 10.2 g under nitrogen Diphosgene and then 4.1 g of pyridine were added dropwise. The mixture is stirred for 5 hours at 0 ° C, and then allowed to slowly come to room temperature. The reaction mixture remains Stand for 72 hours at room temperature. Emerging Phos gene is introduced into methanolic KOH solution. The precipitated pyridine hydrochloride is filtered off and the solvent was distilled off. The chloroformic acid [(3-fluoro-4-cyano) phenyl] ester remains as a residue back and becomes the synthesis of the carbamic acid ester used uncleaned.  

3b) 4-alkylpiperidinecarbamic acid aryl ester

In a solution of 8 g triethylamine and 6 g 4-methyl piperidine in 150 ml of benzene is added dropwise with vigorous Stir slowly at 5-10 ° C 9.4 g chloroformic acid - [(3- fluor-4-cyano) phenyl] ester dissolved in 50 ml of benzene. The mixture is left to react for an hour in an ice bath. That out fallen triethylamine chlorohydrate is from the benzoli filtered off solution and the benzene below normal pressure distilled off. The remaining 4-methyl pipe 3-fluoro-4-cyanophenyl ridincarbamic acid using flash chromatography with silica gel / toluene cleans. The oil obtained crystallizes slowly, F. 48-49 ° C.

The following are produced analogously:

3-fluoro-4-cyano-phenyl 4-ethylpiperidinecarbamic acid
4-Propylpiperidinecarbamic acid 3-fluoro-4-cyano-phenyl ester, mp 52 ° C
3-fluoro-4-cyano-phenyl 4-butylpiperidinecarbamic acid
3-fluoro-4-cyano-phenyl 4-pentylpiperidinecarbamic acid
3-fluoro-4-cyano-phenyl 4-hexylpiperidinecarbamic acid
3-fluoro-4-cyano-phenyl 4-heptylpiperidinecarbamic acid
3-fluoro-4-cyano-phenyl 4-octylpiperidinecarbamic acid
4-cyanophenyl 4-methylpiperidinecarbamic acid
4-cyanophenyl 4-ethylpiperidinecarbamic acid
4-cyanophenyl 4-propylpiperidinecarbamic acid
4-cyanophenyl 4-butylpiperidinecarbamic acid
4-cyanophenyl 4-pentylpiperidinecarbamic acid
4-cyanophenyl 4-hexylpiperidinecarbamic acid
4-cyanophenyl 4-heptylpiperidinecarbamic acid
4-cyanophenyl 4-octylpiperidinecarbamic acid
4-pentylphenyl 4-methylpiperidinecarbamic acid
4-pentylphenyl 4-ethylpiperidinecarbamate
4-pentylphenyl 4-propylpiperidinecarbamic acid
4-pentylphenyl 4-butylpiperidinecarbamic acid
4-pentylphenyl 4-pentylphenyl carbamate
4-pentylphenyl 4-hexylpiperidinecarbamic acid
4-pentylphenyl 4-heptylpiperidinecarbamic acid
4-pentylphenyl 4-octylpiperidinecarbamic acid
4-methylphenyl 4-methylphenyl carbamate
4-methylphenyl 4-ethylpiperidinecarbamate
4-methylphenyl 4-propylpiperidinecarbamate,
F. 56 ° C
4-Butylpiperidinecarbamic acid 4-methylphenyl ester
4-methylphenyl 4-pentylpiperidinecarbamic acid
4-octylpiperidinecarbamic acid 4-methylphenyl ester
4-propylphenyl 4-methylpiperidinecarbamate
4-propylphenyl 4-ethylpiperidinecarbamate
4-propylphenyl 4-propylpiperidinecarbamate
4-propylphenyl 4-butylpiperidinecarbamate
4-propylphenyl 4-pentylpiperidinecarbamic acid
4-propylphenyl 4-hexylpiperidinecarbamic acid
4-propylphenyl 4-heptylpiperidinecarbamate
4'-methylpiperidinecarbamic acid 4'-propylbiphenyl-4-ylester
4'-Ethylpiperidinecarbamic acid, 4'-propylbiphenyl-4-ylester
4-Propylpiperidinecarbamic acid 4'-propylbiphenyl-4-ylester
4'-Butylpiperidinecarbamic acid, 4'-propylbiphenyl-4-ylester
4-Pentylpiperidinecarbamic acid 4'-propylbiphenyl-4-ylester
4'-Propylbiphenyl-4-ylester 4-hexylpiperidinecarbamic acid
4'-Heptylpiperidinecarbamic acid 4'-propylbiphenyl-4-ylester
4- (Trans-4-pentylcyclohexyl) phenyl 4-methylpiperidinecarbamic acid
4- (Trans-4-pentylcyclohexyl) phenyl 4-ethylpiperidinecarbamic acid
4- (Trans-4-pentylcyclohexyl) phenyl 4-propylpiperidinecarbamic acid
4- (Trans-4-pentylcyclohexyl) phenyl 4-butylpiperidinecarbamic acid
4- (trans-4-pentylcyclohexyl) phenyl 4-pentylpiperidinecarbamic acid
4- (Trans-4-pentylcyclohexyl) phenyl 4-hexylpiperidinecarbamic acid
4- (trans-4-pentylcyclohexyl) phenyl 4-heptylpiperidinecarbamic acid

With 4- (p-alkylphenyl) piperidine (made by Kon densification of p-alkylphenyl magnesium bromide with 1-benzyl 4-oxo-piperidine (after J. P. Schaefer, H. J. Bloomfield, Org. React., 1967, 15, 1), dehydration, hydrogenation and subsequent reductive cleavage of the benzyl group) and 3a) are obtained analogously:

4- (p-Methylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-ethylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-Propylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-Butylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-Pentylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-Hexylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-heptylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester
4- (p-Octylphenyl) piperidinecarbamic acid 3-fluoro-4-cyano phenyl ester

Example 4

A mixture consists of the following compounds:

49 wt% 4-trans- (4-propylcyclohexyl) phenyl butyrate
23 wt% trans-4-cyclohexyl-4-trans- (4-butylcyclohexyl) benzoate
18 wt% trans-4-cyclohexyl-4-trans- (4-ethylcyclo hexyl) benzoate
10% by weight 3-fluoro-4-cyanophenyl 4-methylpiperidinecarbamic acid.

A commercial TNC cell filled with this mixture, consisting of two on the inside with transpa annually electrodes provided glass plates at a distance of 9.5 µm, has a twist angle of 90 ° and one Tilt angle between 0 and 3 °. Crossed between two ten polarizers can be reached by applying a chip voltage of 3.0 V 10% of the saturation contrast.  

For comparison: an appropriate mix that takes place of the carbamic acid ester the same proportion of the known contains 4-trans- (4-propylcyclohexyl) benzonitrile, shows this contrast at 3.5 V.

Claims (6)

1. Urethane derivatives of formula I, R¹-Q¹- (A¹-Z¹) _n -A²-Q²-R² (I) wherein
R¹ and R² each independently an un substituted or with -CN or with at least one halogen substituted alkyl or alkenyl radical having up to 18 carbon atoms, in which one or more CH₂ groups can be replaced by a radical selected from the group -O-, -S-, -CO-, -O-CO-, -CO-O-, -O-CO-O- and -C≡C-, where 2 heteroatoms are not adjacent, one of the radicals R¹ and R² also H, or one of the radicals R¹-Q¹- and Q²-R² also F, Cl, CN, OCF₃ or CF₃,
Q¹ and Q² each independently of one another -CO-O-, -O-CO- or a single bond,
A¹ and A² are each independently

• a) a 1,4-phenylene radical, in which one or two CH groups can be replaced by N,
• b) a 1,4-cyclohexylene radical, in which one or two non-adjacent CH₂ groups can be replaced by -O- or -S-,
• c) a 1,4-cyclohexenylene, a 1,4-bi cyclo [2,2,2] octylene or a piperidine-1,4-diyl radical,

where the residues a) and b) can be substituted one or more times by halogen atoms, cyano and / or methyl groups,
Z¹ each independently of one another -CO-O-, -O-CO-, -CH₂-CH₂-, -OCH₂-, -CH₂O- or a single bond, and
n is 1, 2 or 3,
with the proviso that at least one group A¹-Z¹ or A²-Q² is a radical of the formula and / or at least one group Q¹-A¹ or Z¹-A² represents a radical of the formula means. 2. Use of the compounds of formula I as a compo nenten liquid-crystalline phases.   3. Liquid crystalline phase with at least two liquid crystalline components, characterized thereby records that at least one component Ver bond of formula I. 4. liquid crystal display element, characterized in that it is a liquid crystalline phase according to claim 3 contains. 5. Electro-optical display element according to claim 4, characterized in that it is a dielectric a liquid-crystalline phase according to claim 3 contains.