DE19755245B4 - spiro compounds - Google Patents

Abstract

Spiro compounds of the formula Iworin R, R1 independently of one another H, F, CN, CF3, CF2CF3, OCF3, OCF2H, OCF2CF3, SF5, NCS an unsubstituted, one monosubstituted by CN or CF3 or one at least monosubstituted by halogen at 1-12 C alkyl Atoms or alkenyl radical with 2-12 carbon atoms, where in these radicals one or more non-adjacent CH2 groups are each independently represented by -O-, -S-, -CO-CO-O-, -O-CO - or -O-CO-O- can be replaced, A, A1 independently of one another a) trans-cyclohexane-1,4-diyl radical, in which one or more non-adjacent CH2 groups are also replaced by -O- and / or -S - can be replaced, b) 1,4-phenylene radical, in which one or two CH groups can also be replaced by N, c) radical from the group 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, d) cyclohexene-1,4-diyl where the radicals a), b), and d) can be substituted by CN, Cl or F, Z, Z1 independently of each other -CO-O-, -O-CO-, -CH2O-, -OCH2-, -O-, -CH2CH2-, -CH = CH -, ...

Description

worin
R, R¹ unabhängig voneinander H, F, CN, CF₃, CF₂CF₃, OCF₃, OCF₂H, OCF₂CF₃, SF₅, NCS, einen unsubstituierten, einen einfach durch CN oder CF₃ oder einen mindestens einfach durch Halogen substituierten Alkylrest mit 1-12 C-Atomen oder Alkenylrest mit 2-12 C-Atomen, wobei in diesen Resten auch eine oder mehrere nicht benachbarte CH₂-Gruppen jeweils unabhängig voneinander durch -O-, -S-, -CO- -CO-O-, -O-CO- oder -O-CO-O- ersetzt sein können,
A, A¹ unabhängig voneinander einen
a) trans-Cyclohexan-1,4-diylrest, 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-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,
d) Cyclohexen-1,4-diyl
wobei die Reste a), b), und d) durch CN, Cl oder F substituiert sein können,
Z, Z¹ unabhängig voneinander -CO-O-, -O-CO-, -CH₂O-, -OCH₂-, -O-, -CH₂CH₂-, -CH=CH-, -C≡C-, -CF₂CF₂- oder eine Einfachbindung,
n, m 0 oder 1,
p 0, 1 oder 2
und
r 1, 2 oder 3 bedeutet.The invention relates to novel spiro compounds of the formula I.

wherein
R, R ^{1 are} independently H, F, CN, CF ₃ , CF ₂ CF ₃ , OCF ₃ , OCF ₂ H, OCF ₂ CF ₃ , SF ₅ , NCS, an unsubstituted one simply by CN or CF ₃ or at least one monosubstituted by halogen-substituted alkyl radical having 1-12 C atoms or alkenyl radical having 2-12 C atoms, wherein in these radicals also one or more non-adjacent CH ₂ groups each independently of one another by -O-, -S-, -CO - -CO-O-, -O-CO- or -O-CO-O- may be replaced,
A, A ¹ independently one
a) trans-cyclohexane-1,4-diyl radical, in which also one or more non-adjacent CH ₂ groups can 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-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,
d) cyclohexene-1,4-diyl
where the radicals a), b), and d) can be substituted by CN, Cl or F,
Z, Z ^{1 are} independently -CO-O-, -O-CO-, -CH ₂ O-, -OCH ₂ -, -O-, -CH ₂ CH ₂ -, -CH = CH-, -C≡C -, -CF ₂ CF ₂ - or a single bond,
n, m 0 or 1,
p 0, 1 or 2
and
r is 1, 2 or 3.

The invention further relates to the use of these compounds as components of liquid-crystalline media as well as in liquid crystal and electro-optical display elements.

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 upright phases DAP or ECB, electrically controlled birefringence or the effect of the dynamic Scattering based. The substances used hitherto for this purpose always have certain disadvantages, for example insufficient stability against the action of heat, light or electric fields, unfavorable elastic and / or dielectric properties.

Out WO 87/03 581 A1 Mesogenic dispirotetradecane are known.

It is an object of the present invention to find novel stable liquid-crystalline or mesogenic compounds which have been disclosed as components of liquid-crystalline media, in particular for TFT and STN displays.

It has now been found that the compounds of formula I are particularly suitable as Kamponenten liquid crystalline media. With their help, it is possible to obtain stable liquid-crystalline media, in particular suitable for TFT or STN displays. The new compounds are characterized above all by a high thermal stability which is advantageous for a high "holding ratio" and show at comparatively low levels Rotational viscosity favorable values of the clearing points. The compounds of the formula I have a comparatively strong positive dielectric anisotropy with simultaneously low optical anisotropy.

With the provision of compounds of the formula I, the range of liquid-crystalline substances which are suitable for the preparation of liquid-crystalline mixtures from a variety of application-technical points of view is considerably broader.

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

The compounds of the formula I are colorless in the pure state and form liquid-crystalline mesophases in a temperature range which is favorably located for the electro-optical use. Chemically, thermally and against light, they are stable.

The invention thus relates to the compounds of the formula I and the use of these compounds as components of liquid-crystalline media. The invention furthermore relates to liquid-crystalline media containing at least one compound of the formula I and to the use of the compounds of the formula I in liquid-crystal display elements.

Above and below, R, R ¹ , A, A ¹ , Z, Z ¹ , n, m, p and t have the indicated meaning, unless expressly stated otherwise. If the group A occurs several times in the compounds of formula I, it may assume the same or different meanings. The same applies to A ¹ , Z and Z ¹ as well as to all other multiply occurring groups.

For the sake of simplicity, in the following Cyc is a 1,4-cyclohexylene radical, Che is a 1,4-cyclohexenylene radical, Dio is a 1,3-dioxane-2,5-diyl radical, Dit is a 1,3-dithiane-2,5-diyl radical, Phe is a 1,4-phenylene radical, Pyd is a pyridine-2,5-diyl radical, Pyr is a pyrimidine-2,5-diyl radical and Bco is a bicyclo- (2,2,2) -octylene radical, where Cyc and / or Phe are unsubstituted or may be mono- or polysubstituted by Cl, F or CN.

in bevorzugten Ausführungsformen der Erfindung befinden sich die Reste -(Z-A)_p-R, und -(Z¹-A¹)_t-R¹ an der Gruppe W in trans-Position zueinander.W means in the following:

in preferred embodiments of the invention, the radicals - (ZA) _p -R, and - (Z ¹ -A ¹ ) _t -R ^{1 are} in trans position to each other at the group W.

Formula I comprises the preferred compounds Ia1 to Ia32 which, in addition to the group W, contain a six-membered ring: RWZ ¹ -A ¹ -R ¹ Ia1 RW-Phe-R1 Ia2 RW-CH ₂ CH ₂ -PheR ¹ Ia3 RW-CH = CH-Phe-R ¹ Ia4 RW-CF = CF-Phe-R ¹ ia5 RWC = C-Phe-R ¹ Ia6 RW-COO-Phe-R ¹ Ia7 RW-Cyc-R ¹ Ia8 RW-CH ₂ CH ₂ -Cyc-R ¹ Ia9 RW-CH = CH-Cyc-R ¹ Ia10 RW-CF = CF-Cyc-R ¹ ia11 RWC≡C-Cyc-R ¹ ia12 RW-COO-Cyc-R ¹ ia13 RW-OOC-Cyc-R ¹ Ia14 RW-Dio-R ¹ Ia15 RW-CH ₂ CH ₂ -dio-R ¹ IA16 RW-CH = CH-Dio-R ¹ Ia17 RW-CF = CF-Dio-R ¹ a18 RW-COO-Dio-R ¹ a19 RW-OOC-Dio-R ¹ a20 RW-Pyr-R ¹ a21 RW-CH ₂ OH ₂ -Pyr-R ¹ a22 RW-CH = CH-Pyr-R ¹ a23 RW-CF = CF-Pyr-R ¹ a24 RWC≡C-Pyr-R ¹ a25 RW-COO-Pyr-R ¹ a26 RW-Che-R ¹ a27 RW-CH ₂ CH ₂ -Che-R ¹ a28 RW-CH = CH-Che-R ¹ a29 RW-CF = CF-Che-R ¹ a30 RW-COO-Che-R ¹ a31 RW-OOC-Che-R ¹ a32 and likewise preferred compounds Ib1 to Ib20 which, in addition to the group W, contain two six-membered rings: RWZ ¹ -A ¹ -Z ¹ -A ¹ -R ¹ b1 RW-Phe-Phe-R ¹ Ib2 RW-Cyc-Phe-R ¹ ib3 RW-Dio-Phe-R ¹ Ib4 RW-Cyc-Cyc-R ¹ IB5 RW-Dio-Cyc-R ¹ ib6 RW-Cyc-Dio-R ¹ IB7 RW-Dio-Dio-R ¹ Ib8 RAZWZ ¹ -A ¹ -R ¹ IB9 R-Cyc-W-Phe-R ¹ Ib10 R-Dio-W-Phe-R ¹ ib11 R-Cyc-W-Cyc-R ¹ Ib12 R-Dio-W-Cyc-R ¹ Ib13 R-Dio-W-Dio-R ¹ ib14 RW-Che-Phe-R ¹ Ib15 RW-Dio-Che-R ¹ IB16 R-Phe-W-Che-R ¹ IB17 R-Che-W-Che-R ¹ IB18 R-Cyc-W-Che-R ¹ Ib19 R-Dio-W-Che-R ¹ IB20 wherein R, R ¹ , A, A ¹ , Z, Z ¹ , W, Phe, Cyc, Dio, Che and Pyr have the meaning given above.

R und R¹ bedeuten unabhängig voneinander bevorzugt geradkettiges Alkyl oder Alkoxy mit 1 bis 10 C-Atomen, Alkenyl oder Alkenyloxy mit 2 bis 10 C-Atomen, F, CN, CF₃, OCF₃, OCHF₂ oder OCF₂CF₃. p und t bedeuten unabhangig voneinander bevorzugt 0 oder 1.The cyclohexene-1,4-diyl group preferably has the following structures:

R and R ¹ independently of one another preferably denote straight-chain alkyl or alkoxy having 1 to 10 C atoms, alkenyl or alkenyloxy having 2 to 10 C atoms, F, CN, CF ₃ , OCF ₃ , OCHF ₂ or OCF ₂ CF ₃ . p and t are independently of each other preferably 0 or 1.

Compounds of the formula I in which n or m are 1 are preferred.

A and A ¹ independently of one another are preferably Phe, Cyc, Che, Pyd, Pyr or Dio, in particular Phe, Cyc or Dio. The compounds of the formula I preferably contain no more than one of the radicals Bco, Pyd, Pyr or Dit.

Preference is also given to compounds of the formula I and of all sub-formulas in which A and / or A ¹ denotes mono- or disubstituted by F or CN-substituted 1,4-phenylene.

Z und Z¹ bedeuten unabhängig voneinander bevorzugt -CH₂CH₂-, -CH=CH-, -C≡C-, -COO- oder eine Einfachbindung, insbesondere bevorzugt eine Einfachbindung, -CH₂-CH₂- oder -CH=CH-. Ganz besonders bevorzugt weisen Z und Z¹ die Bedeutung einer Einfachbindung oder -CH₂CH₂- auf.In particular, A and A ¹ independently of one another are preferred:

Z and Z ¹ independently of one another are preferably -CH ₂ CH ₂ -, -CH = CH-, -C≡C-, -COO- or a single bond, particularly preferably a single bond, -CH ₂ -CH ₂ - or -CH = CH. Most preferably, Z and Z ^{1 have} the meaning of a single bond or -CH ₂ CH ₂ -.

Compounds of formula I are preferred which are characterized in that R is straight-chain alkyl or alkoxy having 1 to 10 C atoms or alkenyl having 2 to 10 C atoms and R ^{1 is} F, CN, OCF ₃ , OCHF ₂ or OCF ₂ CF. ₃ mean.

Furthermore, compounds of the formula I are preferred in which R and R ^{1 are} independently straight-chain alkyl or alkoxy having 2 to 7 carbon atoms, while A and / or A ¹ independently of one another are Cyc and / or 2,3-difluoro-1 , 4-phenylene.

bedeutet, stellen besondere Ausführungsformen der Erfindung dar.Compounds of the formula I whose group A and / or A ¹

means represent particular embodiments of the invention.

aufweist.Particular preference is furthermore given to those compounds of the formula I which are characterized in that R is straight-chain alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, and A ^{1 is} the meaning

having.

In compounds of the formula I in which the group A and / or A ^{1 is} cyclohexane-1,4-diyl, the substituents in the 1- and 4-position are trans to each other.

worin R und R¹ die oben angegebene Bedeutung aufweisen, während L¹, L², und L³ unabhängig voneinander H oder F bedeuten.The following group of compounds of sub-formulas I1 to I92 comprises some preferred embodiments of the invention:

wherein R and R ^{1 have} the abovementioned meaning, while L ¹ , L ² , and L ³ independently of one another are H or F.

If R and / or R ¹ in the preceding and following formulas individually represent alkyl radical and / or an alkoxy radical, this may be 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, pentyloxy, hexyloxy or heptyloxy, furthermore methyl , Octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, methoxy, octyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy, tridecyloxy or tetradecyloxy.

Oxaalkyl is preferably 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 and / or R ^{1 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, Dec-1 -, 2-, 3-, 4-, 5-, 6-, 7-, 8- or dec-9-enyl. If R and / or R ^{1 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.

They therefore particularly mean 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 and / or R ^{1 is} an alkyl radical in which one CH ₂ group is replaced by unsubstituted or substituted -CH = CH- and one adjacent CH ₂ group is replaced by CO or CO-O or O-CO-, then this be straight-chain or branched. Preferably, it is straight-chain and has 4 to 13 carbon atoms. It therefore means particularly acryloyloxymethyl, 2-acryloyloxyethyl, 3-acryloyloxypropyl, 4-acryloyloxybutyl, 5-acryloyloxypentyl, 6-acryloyloxyhexyl, 7-acryloyloxyheptyl, 8-acryloyloxyoctyl, 9-acryloyloxynonyl, 10-acryloyloxydecyl, methacryloxy-oxymethyl, 2-methacryloyloxy -ethyl, 3-methacryloyloxypropyl, 4-methacryloyloxybutyl, 5-methacryloyloxypentyl, 6-methacryloyloxyhexyl, 7-methacryloyloxyheptyl, 8-methacryloyloxyoctyl, 9-methacryloyloxynonyl.

If R and / or R ¹ is monosubstituted by CN or CF ₃ is substituted alkyl or alkenyl radical, this radical is preferably straight-chain and the substitution by CN or CF ₃ in ω-position.

If R and / or R ^{1 is} an alkyl or alkenyl radical which is at least monosubstituted by halogen, this radical is preferably straight-chain and halogen is preferably F or Cl. In the case of multiple substitution, halogen is preferably F. The resulting radicals also include perfluorinated radicals. For single substitution, the fluoro or chloro substituent may be in any position, but preferably in the ω position.

Compounds of the formula I with branched wing group R and / or R ¹ may occasionally be of importance because of their better solubility in the customary liquid-crystalline base materials, but in particular as chiral dopants if they are optically active. Smectic compounds of this type are useful as components of ferroelectric materials.

Branched groups of this type usually contain no more than one chain branch. Preferred branched radicals R and / or R ¹ 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-methylpentyloxy, 3-methylpentyloxy, 2-ethylhexyloxy, 1-methylhexyloxy, 1-methylheptyloxy.

Formula I includes both the racemates of these compounds and the optical antipodes and mixtures thereof.

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

In the compounds of 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 each include the two 2,5-position isomers.

worin R² und R³ Alkyl, Alkoxy, Alkenyl oder Alkenyloxy mit 2 bis 7 C-Atomen bedeuten und R⁴ die Bedeutung F, CN oder OCF₃ aufweist.Some very particularly preferred smaller groups of compounds of the formula I are those of the partial formulas I93 to I125:

wherein R ² and R ^{3 are} alkyl, alkoxy, alkenyl or alkenyloxy having 2 to 7 carbon atoms and R ^{4 is} F, CN or OCF ₃ .

Very particularly preferred compounds of this group are those of the formulas I93, I95, I96, I97, I100, I103, I104, I108, I111 and I115.

worin
Q, Q¹ unabhängig voneinander C=O, C(OH)-(Z-A)_p-R, C(OH)-(Z¹-A¹)_t-R¹, C=CH₂ oder

r 1, 2 oder 3
und
R, R¹, Z, Z¹ A, A¹, p, t, m und n die oben angegebene Bedeutung aufweisen.Another object of the invention are the compounds of formula II, which are used as starting compounds in the preparation of the compounds of formula I:

wherein
Q, Q ¹ independently of one another are C =O, C (OH) - (ZA) _p -R, C (OH) - (Z ¹ -A ¹ ) _t -R ¹ , C =CH ₂ or

r 1, 2 or 3
and
R, R ¹ , Z, Z ¹ A, A ¹ , p, t, m and n have the abovementioned meaning.

If the group A occurs several times in the compounds of the formula II, it may assume the same or different meanings. The same applies to A ¹ , Z and Z ¹ as well as to all other repeated groups.

The preferred meanings given for the groups R, R ¹ , Z, Z ¹ A, A ¹ , p, t, m and n of the compounds of the formula I also apply to the compounds of the formula II r is 1 or 3.

The compounds of the formulas I and II are prepared by methods known per se, as described in the literature (for example in the standard works such as Houben-Weyl, Methods of Organic Chemistry, Georg Thieme Verlag, Stuttgart) under reaction conditions which are known and suitable for the reactions mentioned.

One can make use of known per se, not mentioned here variants.

If desired, the starting materials may also be formed in situ, such that they are not isolated from the reaction mixture, but immediately further reacted to the compounds of formulas I and II.

The synthesis of the compounds of formulas I and II in which A is axially fluorinated cyclohexane can be effected by the use of hydrogen fluoride under pressure or by amine-hydrogen fluoride adducts (for example, AW Grosse, CB Linn, J. Org. (1938) 26, GA Olah, M. Nojima, I. Kerekes, Synthesis, (1973) 779); G.A. Olah, X-Y. Li, Q. Wang, G.K.S.S. Prakash, Synthesis (1993) 693).

Diketones of the formula II (Q ¹ = Q ² = C = O) or their monoketals are preferably used as starting material for the preparation of liquid-crystalline compounds of the formula I. The ketones are added with an Mg, Li, Ce, Ti or Zn organic compound containing the radical R, R ¹ , (AZ) _p -R or (Z ¹ -A ¹ ) _t -R, reacted to form the corresponding tertiary alcohols which are dehydrated and then hydrogenated. In general, cis / trans isomer mixtures of the compounds of the formula I are formed, from which the individual compounds can be obtained by isomerization and / or chromatographic separation.

worin R, R¹, L¹, L² L³ und r die oben angegebene Bedeutung aufweisen.The following sub-formulas II1 to II15 represent further particularly preferred embodiments of the invention:

wherein R, R ¹ , L ¹ , L ² L ³ and r have the meaning given above.

Schema 2:

Schema 3:

Schema 4:

Schema 5:

The compounds of the invention may, for. B. be prepared according to the following reaction schemes: Scheme 1:

Scheme 2:

Scheme 3:

Scheme 4:

Scheme 5:

Schema 7:

Schema 8:

Schema 9:

Schema 10:

Schema 11:

Compound 24 is available from J. Org. Chem. 60, 7865 (1995). Scheme 6:

Scheme 7:

Scheme 8:

Scheme 9:

Scheme 10:

Scheme 11:

Alkenyls of the formula I or II are preferably obtained from the corresponding monoketones by transformation of the carbonyl group into an aldehyde according to Wittig with the ylide of a methoxymethyltriphenylphosphonium halide and subsequent hydrolysis. The repeated reaction of the aldehyde formed with this ylide leads to the corresponding aldehyde homologues. The aldehyde formed gives after further Wittig reaction with an alkylphosphonium salt, the olefin.

Esters of the formula I or II can also be obtained 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).

The corresponding carboxylic acids and alcohols or phenols are known or can be prepared analogously to known processes.

Particularly suitable as reactive derivatives of said carboxylic acids are the acid halides, especially the chlorides and bromides, and also the anhydrides, azides or esters, in particular alkyl esters having 1-4 C atoms in the alkyl group.

Suitable reactive derivatives of said alcohols or phenols are, in particular, the corresponding metal alcoholates or phenolates, preferably an alkali metal such as Na or K.

The esterification is advantageously carried out in the presence of an inert solvent. Particularly suitable are in particular 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 hexamethyltriamide, hydrocarbons such as benzene, toluene or xylene, halogenated hydrocarbons such as carbon tetrachloride or tetrachlorethylene and sulfoxides such as Dimethyl sulfoxide or sulfolane. Water-immiscible solvents can also be advantageously used to azeotropically distill off the water formed in the esterification. Occasionally, an excess of an organic base, for. As pyridine, quinoline or triethylamine, be used as a solvent for the esterification. The esterification can also in the absence of a solvent, for. B. by simply heating the components in the presence of sodium acetate, performed. The reaction temperature is usually between -50 ° and + 250 °, preferably between -20 ° and + 80 °. At these temperatures, the esterification reactions are usually completed after 15 minutes to 48 hours.

In particular, the reaction conditions for the esterification depend largely on the nature of the starting materials used. Thus, a free carboxylic acid is reacted with a free alcohol or phenol usually in the presence of a strong acid, for example a mineral acid such as hydrochloric acid or sulfuric acid. A preferred mode of reaction is the reaction of an acid anhydride or in particular an acid chloride with an alcohol, preferably in a basic medium, wherein as bases in particular alkali metal hydroxides such as sodium or potassium hydroxide, alkali metal carbonates or bicarbonates such as sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate, alkali metal acetates such as sodium or potassium acetate, alkaline earth metal hydroxides such as calcium hydroxide or organic bases such as triethylamine, pyridine, lutidine, collidine or quinoline are of importance. Another preferred embodiment of the esterification is that the alcohol or phenol is first converted into the sodium or potassium alcoholate or phenolate, z. B. by treatment with ethanolic sodium or potassium hydroxide solution, this isolated and reacted with an acid anhydride or in particular acid chloride.

Nitriles can be obtained by exchanging halogens with copper cyanide or alkali cyanide.

In a further process for the preparation of the compounds of the formula I or II in which Z and / or Z ^{1 is} -CH = CH-, an aryl halide is reacted with an olefin in the presence of a tertiary amine and a palladium catalyst (cf. Acc. Chem. Res. 12 (1979) 146). Suitable aryl halides are, for example, chlorides, bromides and iodides, in particular bromides and iodides. The necessary for the success of the coupling reaction tertiary amines, such as. As triethylamine, are also suitable as a solvent. As palladium catalysts, for example, its salts, in particular (Pd (II) acetate, with organic phosphorus (III) compounds such as, for example, triarylphosphines, can be used in the presence or absence of an inert solvent at temperatures between about 0.degree 150 ° C., preferably between 20 ° C. and 100 ° C. The solvents used may be, for example, nitriles such as acetonitrile or hydrocarbons such as benzene or toluene The aryl halides and olefins used as starting materials are commercially available or can be widely used literature methods are prepared, for example by halogenation of corresponding parent compounds or by elimination reactions of corresponding alcohols or halides.

In this way, for example stilbene derivatives can be produced. The stilbenes can be further prepared by reacting a 4-substituted benzaldehyde with a corresponding Wittig phosphorylide. However, it is also possible to prepare tolans of the formula I or II by using monosubstituted acetylene in place of the olefin (Synthesis 627 (1980) or Tetrahedron Lett. 27, 1171 (1986)).

Couplings of alkynyl compounds with aryl halides can be carried out analogously to the method described by A.D. King, E. Negishi, F.J. Villani and A. Silveira in J. Org. Chem 43, 358 (1978).

Tolans of the formula I or II can also be prepared via the Fritsch-Buttenberg-Wiechell rearrangement (Ann, 279, 319, 1984), in which 1,1-diaryl-2-haloethylenes are rearranged to diarylacetylenes in the presence of strong bases.

Tolans of formula I or II may also be prepared by brominating the appropriate stilbene and then subjecting to dehydrohalogenation. In this case, one can use known per se, not mentioned here variants of this implementation. Ethers of formula I or II are obtainable by etherification of corresponding hydroxy compounds, preferably corresponding phenols, wherein the hydroxy compound is suitably first in a corresponding metal derivative, for. B. by treatment with NaH, NaNH ₂ , NaOH, KOH, Na ₂ CO ₃ or K ₂ CO _{3 is converted} into the corresponding alkali metal or alkali metal phenolate. This can then be reacted with the entprechenden alkyl halide, sulfonate or dialkyl sulfate, suitably in an inert solvent; such as As acetone, 1,2-dimethoxythane, DMF or dimethyl sulfoxide or with an excess of aqueous or aqueous-alcoholic NaOH or KOH at temperatures between about 20 ° C and 100 ° C.

To prepare the laterally substituted fluoro or chloro compounds of the formula I or II, corresponding aniline derivatives can be added with sodium nitrite and either with tetrafluoroboric acid (for introducing an F atom) or with copper (I) chloride (for introducing a Cl atom) the diazonium salts are reacted, which are then thermally decomposed at temperatures of 100 ° -140 °.

The linking of an aromatic nucleus with a non-aromatic nucleus or two non-aromatic nuclei is preferably obtained by condensation of a lithium or organomagnesium compound with a ketone, if between the nuclei an aliphatic group Z and / or Z ¹ should be.

The organometallic compounds are prepared, for example, by metal-halogen exchange (for example according to Org. React. 6, 339-366 (1951)) between the corresponding halogen compound and a lithium organic compound, such as preferably tert-butyllithium or lithium naphthalenide, or by reaction with magnesium turnings.

The linking of two aromatic rings or an aliphatic group Z and / or Z ¹ with an aromatic ring is preferably carried out by Friedel-Crafts alkylation or acylation by reacting the corresponding aromatic compounds under Lewis acid catalysis. Suitable Lewis acids are, for. As SnCl ₄ , ZnCl ₂ or especially AlCl ₃ and TiCl ₄ .

Furthermore, the linkage of two aromatic rings by the Ullmann reaction (eg Synthesis 1974, 9) between aryl iodides with copper iodide, but preferably between an aryl-copper compound and an aryl iodide, or by the Gomberg-Bachmann reaction between an aryl diazonium salt and the corresponding aromatic compound (e.g., Org. React. 2, 224 (1944)).

Furthermore, aryl halides can be reacted with aryl tin compounds for the coupling of aromatics. These reactions are preferred with the addition of a catalyst such as. B. a palladium (O) complex in inert solvents such as hydrocarbons at high temperatures, eg. B. in boiling xylene, carried out under inert gas.

Moreover, the compounds of the formula I or II can be prepared by reducing a compound which otherwise corresponds to the formula I or the formula II but contains one or more reducible groups and / or C-C bonds instead of H atoms ,

As reducible groups are preferably carbonyl groups, in particular keto groups, also z. B. free or esterified hydroxy groups or aromatically bound halogen atoms. Preferred starting materials for the reduction are compounds corresponding to the formula I or II, but instead of a cyclohexane ring, a cyclohexene ring or cyclohexanone ring and / or instead of a -CH ₂ CH ₂ group a -CH = CH group and / or instead of -CH ₂ group is a -CO-group and / or instead of an H atom, a free or a functional (eg, in the form of its p-toluenesulfonate) modified OH group.

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

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

Furthermore, reductions with complex hydrides are possible. For example, arylsulfonyloxy groups can be removed by reduction with LiAlH ₄ , in particular p-toluenesulfonyloxymethyl groups can be reduced to methyl groups, expediently in an inert solvent such as diethyl ether or THF at temperatures between about 0 and 100 °. Double bonds can be hydrogenated with NaBH ₄ or tributyltin hydride in methanol.

The starting materials are either known or can be prepared in analogy to known compounds.

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, Cyclohexanecarboxylic 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, cyclohexanecarboxylic acid or of cyclohexylcyclohexanecarboxylic acid, phenylcyclohexanes, cyclohexylbiphenyls, phenylcyclohexylcyclohexanes, cyclohexylcyclohexanes, cyclohexylcyclohexylcyclohexenes, 1,4 Bis-cyclohexylbenzenes, 4,4'-bis-cyclohexylbiphenyls, phenyl- or cyclohexyl-pyrimidines, phenyl- or cyclohexylpyridines, phenyl- or cyclohexyl-dioxanes, phenyl- or cyclohexyl-1,3-dithiane, 1,2-diphenylethanes, 1, 2-dicyclohexylethanes, 1-phenyl-2-cyclohexylethanes, 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≡CE-R '' 5

In formulas 1, 2, 3, 4 and 5, L and E, which may be the same or different, each independently represents a bivalent radical selected 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, wherein Phe is unsubstituted or substituted by fluorine 1,4-phenylene, Cyc trans- 1,4-cyclohexylene or 1,4-cyclohexylene, Pyr pyrimidine-2-5-diyl or pyridine-2,5-diyl, Dio 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 L and E is 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 formulas 1, 2, 3, 4 and 5, in which L and E are selected from the group Cyc, Phe and Pyr and simultaneously one or more components selected from the compounds of the Formulas 1, 2, 3, 4 and 5, wherein one of the radicals L and E 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 are selected from the group -Phe-Cyc, -Cyc-Cyc, -G-Phe and -G-Cyc-.

R 'and R "in a smaller subgroup of the compounds of formulas 1, 2, 3, 4 and 5 are each independently alkyl, alkenyl, alkoxy, alkoxyalkyl, alkenyloxy or alkanoyloxy of up to 8 carbon atoms. In the following, this smaller subgroup will be called Group A and the compounds will be referred to as Partial Formulas 1a, 2a, 3a, 4a and 5a. In most of these compounds R 'and R "are different from each other, one of these radicals is usually alkyl, alkenyl, alkoxy or alkoxyalkyl.

In a smaller subgroup of the compounds of the formulas 1, 2, 3, 4 and 5 designated as group B, R '' is - F, -Cl, -NCS or - (O) ₁ CH ₃ - _{(k + 1)} F _k Cl _l , where i is 0 or 1 and k and 11, 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 the compounds of sub-formulas 1b, 2b, 3b, 4b and 5b, R 'has the meaning given for the compounds of sub-formulas 1a-5a and is preferably alkyl, alkenyl, alkoxy or alkoxyalkyl.

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

In addition to the preferred compounds of groups A, B and C, other compounds of formulas 1, 2, 3, 4 and 5 with other variants of the proposed substituents are also used. All of these substances are available by methods known from the literature or in analogy thereto.

In addition to compounds of the formula I according to the invention, the media according to the invention 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 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%, 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 inventive media is preferably 5% -90% and in particular 10% to 90%.

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

The preparation of the media according to the invention is carried out in a conventional manner. In general, the components are dissolved in each other, useful at elevated temperature. By means of suitable additives, the liquid-crystalline phases according to the invention can be modified so that they can be used in all hitherto known types of liquid-crystal display elements. Such additives are known to the person skilled in the art and are described in detail in the literature (H. Kelker / R. Hatz, Handbook of Liquid Crystals, Verlag Chemie, Weinheim, 1980). For example, pleochroic dyes can be added to produce colored guest-host systems or to modify the dielectric anisotropy, viscosity and / or orientation of 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 Clp. = Clearing point. Furthermore, K = crystalline state, N = nematic phase, Sm = smectic phase and I = isotropic phase. The data between these symbols represent the transition temperatures. Δn means optical anisotropy (589 nm 20 ° C) and Δε the dielectric anisotropy (1 kHz, 20 ° C). The viscosity (mm ² / sec) was determined at 20 ° C.

"Conventional workup" means: water is optionally added, extracted with methylene chloride, 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.

THF

Tetrahydrofuran

KOtBu

Kalium-tert.-butylat

RT

Raumtemperatur

MTB-Ether

Methyl-tert.-butylether

EE

Ethylacetat

TosMIC

Toluolsulfonylmethylisocyanid

The following abbreviations are used:

THF

tetrahydrofuran

KOtBu

Potassium tert-butoxide

RT

room temperature

MTB ether

Methyl tert-butyl ether

EE

ethyl acetate

TosMIC

toluenesulphonylmethyl

example 1

10-n-Pentyldispiro [3.2.5.2] tetradecane-2-one

a) (1RS, 5RS) -3-aza-2,4-dioxo-9-n-pentylspiro [5.5] undecane-1,5-dicarbonitrile

200 ml of ethanol are saturated at -5 ° C with dry ammonia gas. Subsequently, a mixture of 42 g of 4-n-pentylcyclohexanone and 85 g of ethyl cyanoacetate is added. The reaction vessel is sealed at 0 ° C and stored in an ice-filled Dewar. After 2-4 d, the white precipitate is filtered off and washed with cold ethanol and cold diethyl ether. The precipitate is dissolved in about 300 ml of boiling water, filtered and added in the heat with 100 ml of concentrated. Hydrochloric acid. It is allowed to cool, the resulting precipitate is filtered off, washed with water and dried at 90 ° C. Recrystallization from ethanol / water 3: 1 (v / v) gives (1RS, 5RS) -3-aza-2,4-dioxo-9-n-pentylspiro [5.5] undecane-1,5-dicarbonitrile as a white crystalline powder ,
Mp .: 157-157.5 ° C

b) 4-n-pentylcyclohexane-1,1-diacetic acid

To 55 g (1RS, 5RS) -3-AZa-2,4-dioxo-9-n-pentylspiro [5.5] undecane-1,5-dicarbonitrile are added 100 ml of conc. Sulfuric acid and stirred for 20 h at room temperature. The orange solution is then slowly added with vigorous stirring slowly with 90 ml of water and heated after the decay of vigorous evolution of heat to 150 ° C for 24 h. After cooling, it is diluted with water and the residue is filtered off. It is washed free of acid with cold water and dried. 4-n-pentylcyclohexane-1,1-diacetic acid is obtained. For further purification can be recrystallized from ethyl acetate / petroleum ether 40-60 1: 1 (v / v).
M.p .: 126-126.5 ° C

c) 1,1-bis (2-hydroxyethyl) -4-n-pentylcyclohexane

To a suspension of 8.5 g of lithium aluminum hydride in 450 ml of abs. THF are 27 g of 4-n-pentylcyclohexane-1,1-diacetic acid in 150 ml of abs. THF added dropwise at RT. The mixture is stirred for 1 h after the addition and then heated to boiling for 3 h. After cooling, excess reducing agent is hydrolyzed with water. The majority of the solvent is removed in vacuo and the residue is taken up in water. After acidification with conc. Hydrochloric acid is shaken out several times with chloroform. The combined organic extracts are washed with dil. Hydrochloric acid and water. After drying with sodium sulfate and removing the solvent i. Vak. 24.2 g (quantitative yield) of 1,1-bis (2-hydroxyethyl) -4-n-pentylcyclohexane are obtained as a viscous oil. At -40 ° C can be obtained from chloroform colorless crystals which melt at 25.5 ° C to an anisotropic liquid and at 35.5 ° C reversibly turn into an isotropic liquid.

d) 1,1-bis (2-bromoethyl) -4-n-pentylcyclohexane

To a mixture of 26.7 g of 1,1-bis (2-hydroxyethyl) -4-n-pentylcyclohexane and 75 ml of 47 percent strength. aqueous hydrobromic acid is added dropwise with cooling in ice / brine 37 ml conc. Sulfuric acid so that the internal temperature does not exceed 0 ° C. It is then heated to 95-100 ° C for 24 h. After cooling, the reaction mixture is poured onto ice and shaken several times with diethyl ether. The combined organic extracts are washed twice with water and once each with 1 M sodium bicarbonate solution and sat. Sodium chloride solution. After drying with sodium sulfate and removing the solvent i. Vak. the crude product is purified by chromatography. 1,1-bis (2-bromoethyl) -4-n-pentylcyclohexane is obtained as a solid having a melting point of 32.degree.
Bp .: 164 ° C / 0.05 Torr (decomposition)
R _f value: 0.45-0.5 (SiO ₂ , petroleum ether 40-60)

e) 9-n-pentylspiro [5.5] undecan-3-one

To a suspension of 4.5 g of sodium hydride (80 percent in mineral oil) and 250 ml of dry DMF with exclusion of moisture and Argonatamosphäre within 4 h, a solution of 18.4 g of 1,1-bis (2-bromoethyl) -4-n -pentylcyclohexane and 9.8 g of TosMIC in 200 ml of dry DMF. After completion of the addition, it is stirred for 16 h at room temp. And then carefully hydrolyze excess base with water. The solvent is largely distilled off in vacuo and the residue taken up in equal parts of chloroform and water. It is acidified with conc. Hydrochloric acid, separates the milky organic phase and shake the aqueous phase three more times with chloroform. The combined organic extracts are then concentrated to about 50 ml. After addition of the same amount of conc. Hydrochloric acid is stirred for 30 min at room temp. stirred and then diluted with water. The reaction mixture is extracted with chloroform, the organic phases are washed with water and deacidified with sat. Sodium bicarbonate solution. After drying with sodium sulfate, the solvent is removed in vacuo. The brown crude product is purified by chromatography to give a colorless viscous liquid which crystallizes after some time. Recrystallization from methanol gives 9-n-pentylspiro [5.5] undecan-3-one in the form of colorless crystals of melting point 31 ° C.
R _f value: 0.50 (SiO ₂ ; dichloromethane)

f) 9-n-pentyl-3-methylene-spiro [5.5] undecane

To a suspension of 4.5 g of methyltriphenylphosphonium bromide and 120 ml of THF abs. are added dropwise at RT 9.75 ml of n-butyllithium (1.5 molar solution in n-hexane) and stirred for 1/2 h. Subsequently, 1 g of 9-n-pentylspiro [5.5] undecan-3-one in 50 ml of THF abs. dissolved and dropped. It is stirred overnight. It hydrolyzes excess butyl lithium with 10 ml H ₂ O. The solvent is removed in vacuo and the residue taken up in ether. The aqueous phase is extracted by shaking several times with diethyl ether and the combined organic phases are washed with dil. HCl and water. After drying with Na ₂ SO ₄ , the ether is removed in vacuo and the product is purified by chromatography. 9-n-Pentyl-3-methylenespiro [5.5] undecane is obtained in the form of a colorless oil.
R _f value: 0.85 (SiO ₂ ; n-hexane)

g) 10-n-pentyl-1-dichlorodispiro [3.2.5.2] tetradecane-2-one

Dissolve 600 mg of 9-n-pentyl-3-methylenspira [5-5.] Undecane in 50 ml of diethyl ether abs. and adds 280 mg of zinc powder and 16 mg of copper acetate. Then, slowly (exothermic reaction) 0.45 g of trichloroacetyl chloride is added dropwise. It is stirred overnight at 70 ° C. After cooling, filtered from the inorganic residues and the product is purified by chromatography. 10-n-Pentyl-1-dichlorodispiro [3.2.5.2] tetradecan-2-one is obtained in the form of a colorless liquid.
R _f value: 0.68 (SiO ₂ ; n-hexane / toluene 1: 1)

h) 10-n-Pentyldisprio [3.2.5.2] tetradecan-2-one

600 mg of 10-n-pentyl-1-dichlorodispiro [3.2.5.2] tetradecan-2-one are dissolved in 5 ml of acetic acid. Add 0.45 g of zinc powder, stir. 6 h at 70 ° C and filtered after cooling from the inorganic residues. The product is purified by chromatography. This gives 10-n-Pentyldisprio [3.2.5.2] tetradecan-2-one in the form of a colorless solid which melts at 46-47 ° C.
R _f value: 0.75 (SiO ₂ ; dichloromethane)

Example 2

cis- and trans-10-n-pentyl-2- (3,4,5-trifluorophenyl) dispiro [3.2.5.2] tetradecane

To 74 mg of magnesium turnings in 10 ml of diethyl ether abs. under Arganatmosphäre and exclusion of moisture, first 1 ml of a solution of 0.35 ml of trifluorobromobenzene in 5 ml of diethyl ether abs. dropwise. After the reaction starts, the remainder of the solution is added dropwise and refluxed for 1/2 hour. Subsequently, 700 mg of 10-n-pentyldispiro [3.2.5.2] tetradecan-2-one (obtainable according to Example 1) in 10 ml of diethyl ether abs. added dropwise and heated to boiling for a further 3 h. The suspension is poured into ice-water and acidified with dil. Hydrochloric acid. The phases are separated and the aqueous phase shaken out three times with 20 ml of diethyl ether. The combined organic phases are washed with water and the solvent removed in vacuo. The residue is then taken up in 100 ml of toluene and heated with 100 mg of toluenesulfonic acid on a water for 1 h to boiling. After cooling, 50 ml of water are added, the phases are separated and the aqueous phase is extracted several times with toluene. The combined organic phases are washed with sat. NaHCO ₃ solution and water and dried with sodium sulfate. To the resulting solution is added 300 mg 10 percent. Palladium / carbon catalyst and stirred at RT and 3 bar under a hydrogen atmosphere. It is filtered by the catalyst. The product is purified by chromatography to give the cis- and the trans -10-n-pentyl-2- (3,4,5-trifluoro) phenyldispiro [3.2.5.2] tetradecane.
R _f value: 0.7 and 0.73 (SiO ₂ ; n-hexane)

Example 3

12-n-pentyl-3-dispiro [5.2.5.2] hexadecanone

a) (1RS, 5RS) -3-aza-2,4-dioxo-12-n-pentyl-dispiro [5.2.5.2] hexadecane-1,5-dicarbonitrile

120 ml of ethanol are saturated at -5 ° C with dry ammonia gas. Subsequently, a mixture of 31.6 g of 9-n-pentyl-3-spiro [5.5] undecanone (obtainable according to Example 1) and 61 g of ethyl cyanoacetate is added. The reaction vessel is sealed at 0 ° C and stored for 5-7 days in an ice-filled Dewar. The work-up is carried out analogously to Example 1a)). Recrystallization from ethanol / water 5: 1 (v / v) gives (1RS, 5RS) -3-aza-2,4-dioxo-12-n-pentyl-dispiro [5.2.5.2] hexadecane-1,5- dicarbonitrile as white crystal powder with the melting point 208 ° C.

b) 9-n-pentylspiro [5.5] undecane-3,3-diacetic acid

Saponification and decarboxylation of 13 g (1RS, 5RS) -3-aza-2,4-dioxo-12-n-pentyl-dispiro [5.2.5.2] hexadecane-1,5-dicarbonitrile in 70 ml conc. Sulfuric acid and 55 ml of water are carried out analogously to Example 1b)). A black reaction product is obtained, which is boiled in ethanol to remove insoluble charred substance, filtered hot, and then extracted several times. Ethyl acetate and ethanol / water 5: 1 (v / v) (optionally with the addition of activated carbon) is recrystallized. This gives 9-n-pentylspiro [5.5] undecane-3,3-diacetic acid as fine white crystals.
M .: K <50 S 154.5 l

c) 3,3-bis (2-hydroxyethyl) -9-n-pentylspiro [5.5] undecane

The reduction of 2 g of 9-n-pentylspiro [5.5] undecane-3,3-diacetic acid with 0.5 g of lithium aluminum hydride in 50 ml abs. THF is carried out analogously to Example 1c). This gives 1.83 g (quantitative yield) of 3,3-bis (2-hydroxyethyl) -9-n-pentylspiro [5.5] undecane.
M .: K <40 S 139 l

d) 3,3-bis (2-bromoethyl) -9-n-pentylspiro [5.5] undecane

The reaction of 1.36 g of 3,3-bis (2-hydroxyethyl) -9-n-pentylspiro [5.5] undecane with 20 ml of 47 percent strength. aqueous hydrobromic acid and 10 ml conc. Sulfuric acid is carried out analogously to Example 1 d). The crude product is purified by chromatography. 3,3-Bis (2-bromoethyl) -9-n-pentylspiro [5.5] undecane is obtained in the form of a colorless, viscous liquid which crystallizes below room temperature.
M .: 23-24 ° C
R _f value: 0.45 (SiO ₂ ; petroleum ether 40-60)

e) 12-n-pentyl-3-dispiro [5.2.5.2] hexadecanone

The cyclization of 1.3 g of 3,3-bis (2-bromoethyl) -9-n-pentylspiro [5.5] undecane with 0.6 g of TosMIC and 0.3 g of sodium hydride (80 percent in mineral oil) in a total of 30 ml dry DMF is carried out analogously to Example 1e). The crude product is worked up by chromatography. For further purification can be recrystallized from methanol. This gives 12-n-pentyl-3-dispiro [5.2.5.2] hexadecanone as colorless crystals, which melt at 87-88 ° C.
M .: 87-88 ° C
R _f value: 0.45 (SiO ₂ ; dichloromethane)

Example 4

cis and trans-12-n-pentyl-3- (3,4,5-trifluorophenyl) dispiro [5.2.5.2] hexadecane

50 mg of Mg splitter are abs in 5 ml of diethyl ether. and a solution of 0.4 g of 1-bromo-3,4,5-trifluorobenzene in 10 ml of diethyl ether abs. dropwise. The reaction solution is heated to boiling for 1/2 h. Finally, 400 mg of 12-n-pentyldispiro [5.2.5.2] hexadecan-3-one, abs in 15 ml of diethyl ether. was dissolved, slowly added dropwise and heated to boiling for a further 3 h. The suspension is poured into ice-water and acidified with dil. Hydrochloric acid. The phases are separated and the aqueous phase shaken out three times with 20 ml of diethyl ether. The combined organic phases are washed with water and the solvent is removed in vacuo. The residue is then taken up in 100 ml of toluene and 50 mg of toluenesulfonic acid on a water for 1 h heated to boiling. After cooling, 50 ml of water are added, the phases are separated and the aqueous phase is extracted several times with toluene. The combined organic phases are washed with sat. NaHCO ₃ solution and water and dried with sodium sulfate. To the toluene solution is added 150 mg 10 percent palladium / carbon catalyst and stirred at RT and 3 bar under a hydrogen atmosphere. It is filtered by the catalyst. After chromatographic workup, the cis- and trans-12-n-pentyl-3- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecane is obtained.
R _f value: 0.56 and 0.65 (SiO ₂ ; n-heptane)

Example 5

Dispiro [5.2.5.2] hexadecane-3,12-dione

a) cis, trans-1,4-cyclohexanecarbaldehyde

To 28.4 g of 1,4-cis, trans -cyclohexanedimethanol in 300 ml of dichloromethane is added 1.2 g of 2,2,6,6-tetramethylpiperidine-1-oxyl and 9.5 g of potassium bromide in 40 ml of water. Over 1 h, a solution of 396 ml of sodium hypochlorite (13% chlorine active), 15 g of sodium bicarbonate and 490 ml of water is added dropwise so that a slight reflux of the solvent is observed. It is stirred for an hour and the phases separated. The aqueous phase is shaken three times with dichloromethane. The combined organic phases are shaken with a solution of 2.65 g of potassium iodide in 150 ml of 10% HCl. The excess iodine is removed with saturated sodium thiosulfate solution. The organic phase is then washed with water and dried with sodium sulfate. The solvent is removed in vacuo and the product is purified by chromatography. This gives cis, trans-1,4-cyclohexanecarbaldehyde, which readily oxidizes in the air to the diacid.
R _f value: 0.51 (SiO ₂ , cyclohexane / EE 3: 1)

b) dispiro [5.2.5.2] hexadecane-1,10-diene-3,12-dione and Dispiro [5.2.5.2] hexadecane-1,13-diene-3,12-dione

To a solution of 12.5 g of cis, trans-1,4-cyclohexanecarbaldehyde and 15 ml of methyl vinyl ketone in 75 ml of toluene are slowly added 0.075 ml of sulfuric acid conc. added dropwise and stirred for 1/2 h at RT. The reaction solution is slowly heated to boiling for one hour on a water separator. The mixture is stirred under reflux for 6 h, allowed to cool and 50 ml of 1 M NaHCO ₃ solution are added. The phases are separated and the aqueous phase extracted three times with 20 ml of toluene. The combined organic phases are washed with sat. NaCl solution and water and dried with sodium sulfate. After removal of the solvent, the product is purified by chromatography. A mixture of dispiro [5.2.5.2] hexadecane-1,10-diene-3,12-dione and dispiro [5.2.5.2] hexadecane-1,13-diene-3,12-dione is obtained in the form of a colorless solid, which melts at 192-196 ° C.
R _f value: 0.51 (SiO ₂ , dichloromethane / EA 15: 1)

c) 3,12-dispiro [5.2.5.2] hexadecanedione

3.4 g of dispiro [5.2.5.2] hexadecanedione are dissolved in 500 ml of toluene. 700 ml of palladium / carbon catalyst are added and the mixture is stirred for 5 h at a hydrogen pressure of 3 bar at RT. Anschießend filtered from the catalyst and the solvent removed in vacuo. This gives dispiro [5.2.5.2] hexadecane-3,12-dione in the form of a colorless crystalline solid which melts at 208 ° C.

Example 6

Trispiro [4.2.2.5.2.2] 1,4-dioxa-docosan-14-one

To 80 mg of dispiro [5.2.5.2] hexadexane-3,12-dione in 50 ml of toluene are added 18 mg of ethane-1,2-diol and 1 mg of p-toluenesutfonic acid and heated for about 2 hours on a water separator. After cooling, 20 ml of 1 M sodium bicarbonate solution are added and the phases are separated. The aqueous phase is extracted by shaking several times with toluene and the combined organic phases are washed several times with water. After drying with sodium sulfate, the solvent is removed in vacuo and the residue is purified by chromatography. This gives trispiro [4.2.2.5.2.2] 1,4-dioxa-docosan-14-one in the form of a colorless solid.
R _f value: 0.51 (SiO ₂ , dichloromethane / acetone 100: 1)

Example 7

Trispiro [6.2.2.5.2.2] -1,6-dioxa-docosan-16-one

To 700 mg of 3,12-dispiro [5.2.5.2] hexadecanedione and 260 mg of 1,4-butanediol in 200 ml of toluene are added 40 mg of p-toluenesutfonic acid. The mixture is heated for 3 h on a water separator and allowed to cool. Add 100 ml of 1 M sodium bicarbonate solution and separate the phases. The aqueous phase is shaken several times with toluene and the combined organic phases are washed with water. It is dried with sodium sulfate and the solvent is removed in vacuo. The residue is purified by chromatography. Trispiro [6.2.2.5.2.2] -1,6-dioxa-docosan-16-one is obtained as a white solid which melts at 161 ° C.
R _f value: 0.46 (SiO ₂ ; cyclohexane / acetone 4: 1)

Example 8

cis and trans-12-n-pentyl-3- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecane

a) 12- (3,4,5-Triphenyl) dispiro [5.2.5.2] hexadecane-11-en-3-one

To a suspension of 62 mg Mg chips in 10 ml abs. Diethyl ether under argon, first 3 ml of a solution of 0.3 ml of 1-bromo-3,4,5-trifluorobenzene in 10 ml abs. Diethyl ether is added dropwise until the reaction occurs visible. Subsequently, the residual bromide solution is added dropwise. After complete addition, the mixture is heated to boiling for 30 min. After cooling, a solution of 700 mg of trispiro [6.2.2.5.2.2] -1,6-dioxa-docosan-16-one and 10 ml of abs is slowly added dropwise. Diethyl ether added. It is stirred for a further 2 h at reflux. After cooling, 10 ml of water are added, the phases are separated and the aqueous phase is shaken out three times with 10 ml of diethyl ether. The combined organic phases are washed with water and sat. NaCl solution and the solvent removed in vacuo. The residue is taken up in 60 ml of toluene and heated with the addition of 60 mg of p-toluenesulfonic acid for 2 h at Wasserabscheider. After renewed cooling, the toluene phase is shaken with 1 M sodium bicarbonate solution, the aqueous phase is shaken several times with toluene and the organic phases are washed with water. After drying with sodium sulfate and removal of the solvent in vacuo, the residue is purified by chromatography. This gives 12- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecane-11-en-3-one as colorless crystals which melt at 84-85 ° C.
R _f value: 0.35 (SiO ₂ ; dichloromethane)

b) cis and trans-12-n-pentyl-3- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecane

To a suspension of 24 mg Mg shavings and a crystal of iodine in 5 ml of diethyl ether abs. 2 ml of a solution of 150 mg of 1-bromopentane in 5 ml of diethyl ether abs. under argon. added dropwise until the reaction occurs. The remaining solution is then added dropwise and heated to boiling after complete addition for 30 min. After cooling, a solution of 320 mg of 12- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecan-11-en-3-one in 10 ml of diethyl ether abs. added. It is stirred for a further 2 h at reflux. After cooling, 10 ml of water are added, the phases are separated and the aqueous phase is shaken out three times with 10 ml of diethyl ether. The combined organic phases are washed with water and sat. NaCl solution, dried with sodium sulfate and the solvent removed in vacuo. The residue is taken up in 50 ml of toluene and heated with the addition of 30 mg of p-toluenesulfonic acid for 2 h on a water. After renewed cooling, the toluene phase is shaken with 1 M sodium bicarbonate solution, the aqueous phase shaken several times with toluene and the purified organic phases washed with water. After drying with sodium sulfate and removal of the solvent in vacuo, the residue is taken up in 20 ml of toluene. 30 mg of palladium / carbon catalyst are added and the suspension is stirred for 5 hours at 3 bar under a hydrogen atmosphere. It is filtered by the catalyst and the solvent removed in vacuo. The crude product is purified by chromatography. This gives the cis- and trans-12-n-pentyl-3- (3,4,5-triphenyl) dispiro [5.2.5.2] hexadecane.

Beispiele 33–56

Beispiele 57–78

Beispiele 79–102

Beispiel 103–116

The following compounds according to the invention are obtained analogously from the corresponding precursors: Examples 9-32

Examples 33-56

Examples 57-78

Examples 79-102

Example 103-116

Claims (6)

Spiro compounds of the formula I.

wherein R, R ^{1 are} independently H, F, CN, CF ₃ , CF ₂ CF ₃ , OCF ₃ , OCF ₂ H, OCF ₂ CF ₃ , SF ₅ , NCS an unsubstituted one simply by CN or CF ₃ or at least one halogen-substituted alkyl radical having 1-12 C atoms or alkenyl radical having 2-12 C atoms, where in these radicals also one or more non-adjacent CH ₂ groups are each independently of one another denoted by -O-, -S-, -CO-

-CO-O-, -O-CO- or -O-CO-O- may be replaced, A, A ¹ independently of one another a) trans-cyclohexane-1,4-diyl radical, wherein also one or more non-adjacent CH ₂ groups are replaced by -O- and / or -S-, may be replaced, b) 1,4-phenylene radical, in which one or two CH groups may be replaced by N, c) radical from the group 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, d) cyclohexene-1,4-diyl where the radicals a), b) and d) can be substituted by CN, Cl or F, Z, Z ¹ independently of one another are -CO-O-, -O-CO-, - CH ₂ O-, -OCH ₂ -, -O-, -CH ₂ CH ₂ -, -CH = CH-, -C≡C-, -CF ₂ CF ₂ -, -CF = CF- or a single bond, n , m O or 1, p, t 0, 1 or 2 where (p + t) is 0, 1 or 2. Spiro compounds according to claim 1 of the formula I, characterized in that R and R ¹ independently of one another are straight-chain alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, F, CN, CF ₃ , OCF ₃ , OCHF ₂ or OCF ₂ CF ₃ . Spiro compounds according to claim 1 or 2 of the formula I, characterized

characterized in that R is straight-chain alkyl or alkoxy having 1 to 10 carbon atoms or alkenyl or alkenyloxy having 2 to 10 carbon atoms, and A ^{1 has} the meaning. Spiro compounds according to Claims 1 to 3, of the formula I, characterized in that the radicals Z and Z ^{1 are} independently -CH ₂ CH ₂ -, -CH = CH-, -C≡C-, -COO- or a single bond. Compounds of the formula II:

wherein Q, Q ^{1 are} independently C = O, C (OH) - (ZA) _p -R, C (OH) - (Z ¹ -A ¹ ) _t -R ¹ , C = CH ₂ or

R 1, 2 or 3 and R, R ¹ , Z, Z ¹ A, A ¹ , p, t, m and n have the meaning given in claim 1. Use of compounds of the formula I according to Claims 1 to 4 as components of liquid-crystalline media.