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Title:
LATERALLY SUBSTITUTED CHLOROARENES, THEIR MANUFACTURE AND MIXTURES CONTAINING THEM
Document Type and Number:
WIPO Patent Application WO/1996/006061
Kind Code:
A2
Abstract:
The invention relates to a novel and simple method for manufacturing laterally substituted chloroderivatives of formula (1) and 3,6-disubstituted cyclohex-2-en-1-ones being intermediates for their manufacturing. The chloroderivatives of the present invention are useful as components of liquid crystalline mixtures used in the field of liquid crystal display technology.

Inventors:
BEZBORODOV VLADIMIR
DABROWSKI ROMAN
TROKHIMETS DIMITRI
DZIADUSZEK JERZY
SASNOVSKI GENADI
LAPINIK VALERY
Application Number:
PCT/PL1995/000017
Publication Date:
February 29, 1996
Filing Date:
August 18, 1995
Export Citation:
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Assignee:
WOJSKOWA AKAD TECH (PL)
International Classes:
C07C17/18; C07C25/18; C07C43/225; C07C45/67; C07C45/72; C07C49/657; C07C49/683; C07C49/697; C07C49/753; C09K19/30; (IPC1-7): C07C17/18; C07C25/18; C07C49/683; C07C49/697; C07C49/753; C09K19/30
Foreign References:
DE3827675A11989-03-02
Other References:
ZH. ORG. KHIM. (ZORKAE,05147492);91; VOL.27 (4); PP.830-3, NAUCHNO-ISSLED. INST. PRIKL. FIZ. PROBL. IM. SEVCHENKO;MINSK; USSR (SU) Bezborodov V S et al 'Synthesis and mesomorphic properties of 4'-cyano-3'-chloro-4-biphe nylyl esters of trans-4-alkylcyclohexanecarboxylic and 4-alkylbenzoic acids'
LIQ. CRYST. (LICRE6,02678292);91; VOL.10 (6); PP.799-802, A. N. SEVCHENKO INST. APPL. PHYS. PROBL.;MINSK; 220064; USSR (SU) Bezborodov V S et al 'Synthesis and mesomorphic properties of 4-alkyl-3,4'-disubstituted biphenyls and terphenyls'
CHEM. LETT. (CMLTAG,03667022);93; (10); PP.1663-6, UNIV. SHEFFIELD;DEP. CHEM.; SHEFFIELD; S3 7HF; UK (GB) Brettle R et al '3-Arylcyclohex-2-en-1-ones and 3,6-diarylcyclohex-2-en-1-ones. New quid crystalline compounds'
TETRAHEDRON (TETRAB,00404020);78; VOL.34 (7); PP.951-4, F. ANGELINI RES. INST.;DEP. CHEM.; ROME; ITALY Baiocchi L et al 'Aromatization of aliphatic compounds. II. On the aromatization of some alkyl substituted cyclohexenones'
CHEMICAL ABSTRACTS, vol. 108, no. 15, 11 April 1988, Columbus, Ohio, US; abstract no. 131286, YOSHIMOTO H ET AL 'Preparation of arylcyclohexanone derivatives for liquid crystal compositions' & JP,A,87 185 036 (UBE INDUSTRIES, LTD.;JAPAN) 13 August 1987
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Claims:
Claims
1. Laterally substituted chloroarenes of the general formula 1 , in which R1 and R2 are the same or different and denote YtCH^O CHj HCHj) or Y(CH2)nCH=CH(CH2)p, where Y is an H, F or Cl atom, or CN, OCF3, CF3, or COOCnH2n , n, p and k are integers from 0 to 7, m and I denote 0 or 1; s and t denote independently 0 or 1 with the condition that s+t≥1; Z, and Z2 are the same or different and denote a CH=CH, C≡C or CH2CH2 group and also a single bond when s and t is not equal to 0; A1 and A2 denote independently a single bond or one of the fragments represented by the formulae 210, where X1 f X2, X3 and X4 are independent and denote an H or F atom; B and B, denote independently a single bond or a bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH2O.
2. The method for synthesis of laterally substituted chloro arenes of general formula 1 , in which R, and R2 are the same or different and denote Y(CH2)n(O)m(CH2)k(O)r(CH2)p or Y(CH2)nCH=CH(CH2)p, where Y is an H, F, Cl atom, or CN, OCF3, CF3, or COOC^,, n, p and k are integers from 0 to 7, m and I denote 0 or 1 ; s and t denote independently 0 or 1 with the condition that s+t≥1; Z1 and 2 are the same or different and denote a CH=CH, C≡C or CH2CH2 group and also a single bond when s and t is not equal to 0; A1 and A2 denote independently a single bond or one of the fragments represented by the formulae 210, where X1 t X2, X3 and X4 are independent and denote an H or F atom; B and B1 denote independently single bond or bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH2O which consist in heating, advantageously at temperature above 50°C, the compounds of general formula 11 (scheme 1), where the symbols are the same as in the case of formula 1 , in the excess of PCI5 in hydrocarbon or chlorohydrocarbon solvent.
3. A liquid crystalline mixtures containing at least two compounds and at least one of them is a compound of the formula 1 , in which R, and R2 are the same or different and denote Y(CH2)n(O)m(CH2)k(0),(CH2)p or where Y is an H, F, Cl atom, or CN, OCF3, CF3, or COOCnH2n+1, n, p and k are integers from 0 to 7, m and I denote 0 or 1; s and t denote independently 0 or 1 with the condition that s+t≥1 ; Z1 and Z are the same or different and denote a CH=CH, C≡C or CH2CH2 group and also a single bond when s and t is not equal to 0; A, and A2 denote independently a single bond or one of the fragments repre¬ sented by the formulae 210, where X,, X2, X3 and X4 are independent and denote an H or F atom; B and B, denote independently single bond or bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH2O.
4. A liquid crystalline display composed of two plane parallel support plates, at least one of SUBSTITUTE SHEET them is transparent, on which there are electrodes, orienting layers and/or isolating layers, and/or color filters between which liquid crystalline medium is placed, characterized by the fact that the said medium is a liquid crystalline mixtures containing at least two compounds and at least one of them is a compound of the fomiula 1, in which R, and R2 are the same or different and denote Y(CH2)n(O)m(CH2)k(O)l(CH2)p or Y(CH2)nCH=CH(CH2)p, where Y is an H, F, Cl atom, or CN, OCF3, CF3, or COOC„H2n l, n, p and k are integers from 0 to 7, m and I denote 0 or 1; s and t denote independently 0 or 1 with the condition that s+t≥1 ; Z, and Z2 are the same or different and denote a CH=CH, C≡C or CH2CH2 group and also a single bond when s and t is not equal to 0; A, and A2 denote independently a single bond or one of the fragments represented by the formulae 210, where X,, X2, X3 and X4 are independent and denote an H or F atom; B and B, denote independently single bond or bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH20.
5. The intremediates for obtaining laterally substituted chloroarenes of the general formula 1 being compounds of formula 11 , where s and t denotes an integer 1 or 0 with the condition that s+t>1 , R, and R2 are the same, when s=t, and the same or different when s≠t, and denote a Y(CH2)n(O)m(CH2)k(O),(CH2)p or group, where Y denotes an H, F, or Cl atom, or a CN, OCF3, CF3, or COOC.H^, group, n, p and k are integers from the range of 0+7, m and I denote 0 or 1; Z1 and Z2 are the same or different and denote a CH=CH or C≡C group; when s+t>1 Z, denotes also a single bond or a CH2CH2 group ; A1 and A2 denote independently a single bond or one of the fragments given by formulae 210, where X,, X2, X3 and X4 denote independently an H, or F atom; and B and B, denote independently a single bond or a bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH20.
6. The method for synthesis of intermediates of the general formula 11 , where R, and R2 are the same or different and denote a terminal group: or Y(CH2)nCH=CH(CH2)p, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF3, CF3, COOCnH2n+1, n, p and k are from the range of 0+7, m and I denotes 0 or 1 ; Z, and Z2 are the same or different and denote a single bond, CH=CH, C≡C or CH2CH2 group; A1 and A2 denote independently a single bond or one of the fragments given by formulae 210, where X,, X2, X3 and X4 denote independently an H or F atom; B and B, denote independently a single bond or a bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH2O; s=0 and t=1, the process (scheme 2) consists in heating, in an organic solvent such as alcohol or ether in the presence of inorganic base or alkaline metals salts, advantageously NaOH or KOH, Na2CO3 or K2CO3, acetoacetate acid esters of formula 15, where A2 denotes a single bond or one of the fragments given by formulae 210; R2 denotes a Y(CH2)n(O)m SUBSTITUTE SHEET (CH2)k(0)r(CH2)p or Y(CH2)nCH=CH(CH2)p group, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF3, CF3, COOCnH2r ; R3 denotes an alkyl group containing from 1 to 10 carbon atoms, advantageously 2, with the compound of formula 16, where R, denotes a Y(CH2)n(0)m(CH2)k(0)r(CH2)p or Y(CH2)„CH=CH(CH2)P group, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF3, CF3, COOC.H^,; A, denotes a single bond or one of the fragments given by formulae 210; Z2 denotes a single bond or a CH=CH, C≡C or CH2CH2 group; and X denotes a piperydyl, pirolidyl, morfonylyl or dialkylamine group, containing from 1 to 15 carbon atoms, advanta¬ geously a methyl, ethyl or propyl group followed by treating the product of condensation with an aqueous solution of an acid, advantageously sulfuric acid and separating out the product from the reaction mixtures using known methods, advantageously the extraction.
7. The method for synthesis of intermediates of the general formula 11 , where R, and R2 are the same and denote a terminal group: Y(CH2)n(O)m(CH2)k(O),(CH2)p or Y(CH2)nCH=CH (CH2)p, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF3, CF3, COOCnH2n 1, n, p and k are from the range of 0+7, m and I denotes 0 or 1 ; Z and Z2 are the same or different and denote a single bond, CH=CH, C≡C or CH2CH2 group; A, and A2 denote independently a single bond or one of the fragments given by formulae 210, where X,, X2, X3 and X4 denote independently an H or F atom; B and B, denote independently a single bond or a bridge group such as CH2CH2, C≡C, CH=CH, OCH2, CH2O; s=1 and t=1 , the process (scheme 3) consists in heating, in an organic solvent such as alcohol or ether in the presence of inorganic base or alkaline metals salts, advantageously NaOH or KOH, Na2CO3 or K2C03, acetoacetate acid esters of formula 15, where A2 denotes a single bond or one of the fragments given by formulae 210; R2 denotes a YfCH^. OJn CH^OMCH;,), or Y(CH2)nCH=CH(CH2)p group, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF3, CF3, COOCnH2n+1; R3 denotes an alkyl group containing from 1 to 10 carbon atoms, advantageously 2, with the compound of formula 17, where A, denotes a single bond or one of the fragments given by formulae 210; Z, and Z2 are the same or different and denote a single bond or a CH=CH, C≡C or CH2CH2 group; and X denotes a piperydyl, pirolidyl, morfonylyl or dialkylamine group, containing from 1 to 15 carbon atoms, advantageously a methyl, ethyl or propyl group followed by treating the product of conden¬ sation with an aqueous solution of an acid, advantageously sulfuric acid and separating out the product from the reaction mixtures using known methods, advantageously the extraction. SUBSTITUTE SHEET.
Description:
Laterally substituted chloroarenes, their manufacture and mixtures containing them

This invention relates to a novel and simple method for manufacturing laterally sub¬ stituted chloroderivatives, their use as components of mixtures useful in the field of liquid crystal display technology. This invention relates also to a new method of manufacturing inter¬ mediates being 3,6-disubstituted cyclohex-2-en-1-ones.

Liquid crystal compounds containing fluorine atoms in the lateral position of the ben¬ zene ring have gain in importance as a components of a liquid crystal mixture because of their low viscosity and high chemical stability. The evidence of this give the following patent specifications: DE 4032579, DE 4030392, EP 460436, JP 92:255793, DE 4106345, DE 4027315, DE 4034508, DE 4100288, DE 4010447, DE 4110018, DE 4016130, DE 4013297, DE 4108705, DE 4012764, DE 4107120, DE 4108398, DE 4013083, DE 4012403, DE 4107389, DE 4012014, DE 4111015, DE 4037519, DE 4113053, DE 4123539, DE 4111991, DE 4104183, DE 4112024, GB 2240778, WO 92:05230, WO 91:05209, WO 92:06748, WO 91 :12233, WO 91 :15555, JP 91:203987, JP 92:54138, JP 93:58928, JP 92:91056, EP 492668, EP 502407, EP 507094.

Fluoroderivatives are characterized by low value of viscosity, low value of optical indices, and high chemical stability. For some applications, especially in the field of non-linear optics or STN displays, compounds with high values of birefringence, optical ordinary index n 0 , and perpendicular component of dielectric constant ε , and low Δε/ε x ratio are desired. Such properties can be revealed by compounds in which fluorine atom is replaced with chlorine. The known methods for the production of laterally substituted chloro- and fluoroderivatives are com¬ plicated and multistage. They have to be performed at low temperatures and using inert-atmo- sphere-lithation procedures, palladium catalyzed coupling of aryl boronic acids, or Grignard coupling.

The present invention removes these difficulties by giving a simple and effective method for preparing laterally substituted chloroderivatives and their intermediates.

This invention relates to a simple one-stage method for preparation of some 1 ,4-disub- stituted 2-chlorobenzenes by direct transformation of 3,6-disubstituted cyclohex-2-en-1-ones, and also to a new method for preparing these intermediates.

These latter compounds are interesting for preparing many other liquid crystal structures with aromatic, saturated or unsaturated rings which can be used for information displays, some of them are themselves new mesogenic compounds.

Disubstituted 3,6-diaryl- or arylalkylcyclohex-2-en-1-ones are known from JP 88:203634, 87:185036, 86:268646, 92:193844 and Brettle et al., Proceedings of the Fourth International Ferroelectric Liquid Crystals Conference, Tokyo 1993, Japan, p. 231. They are used for obtaining saturated cyclohexanones used as dopants for ferroelectric (JP 92:193844) or nematic (JP 87:185036, DE 3.510434, 86:268646) mixtures or for obtaining liquid crystalline

compounds containing laterally unsubstituted cyclohexane ring (JP 88:203634). These compounds were obtained condensing chloroethylketones with acetoacetate derivatives (JP 87:185036, Brettle et al., Chem. Lett., p. 1663 (1993)).

Derivatives of 3,6-cyclohex-2-en-1-one are known from DE 3827675A. These compounds were obtained by joining smaller molecules containing cyclohex-2-en-1-one ring, for example by coupling 4-octyloxybromobenzene with cyclohex-2-en-1-one in the presence of catalyzer which was the complex of palladium salt and triphenylphosphine.

A method for preparing two-ring cyclohex-2-en-1-ones by a Michael-type reaction using the hydrochloride of aryl β-dialkylaminoalkyl ketones and β-ketoesters or β-diketons is also known. This reaction was carried in the presence of alcoholates such as potassium tert-but- oxide, sodium ethoxide or propoxide (J.Am.Chem.Soc, 75, 1330 (1952)).

The present invention provides a method using simple and more efficient alkaline coupling agents. These agents enable also the production of a novel type of 3,6-disubstituted cyclohex-2-en-1-ones with a HC=CH bridge group directly coupled with π electron systems of cyclohex-2-en-1-one ring.

The present invention relates to the compounds of the general formula 1, in which R, and R 2 are the same or different and denote Y-(CH 2 ) n -(O) m -(CH 2 ) k -(O) l -(CH 2 ) p - or Y-(CH 2 ) n - CH=CH-(CH 2 ) P -, where Y is an H, F, Cl atom, or CN, OCF 3 , CF 3 , or COOC n H 2 , n, p and k are integers from 0 to 7, m and I denote 0 or 1 ; s and t denote independently 0 or 1 with the condition that s+t≥1 ; Z, and Z 2 are the same or different and denote a CH=CH, C≡C or CH 2 -CH 2 group and also a single bond when s and t is not equal to 0; , and A 2 denote independently a single bond or one of the fragments represented by the formulae 2-10, where X,, X 2 , X 3 and X 4 are independent and denote an H or F atom; B and B, denote independently a single bond or a bridge group such as CH 2 CH 2 , CsC, CH=CH, OCH 2 , CH 2 O.

The compounds of the present invention are produced by heating, advantageously at temperature above 50°C, the compounds of the general formula 11 (scheme 1), where the symbols are the same as in the case of formula 1 , in the excess of PCI 5 in hydrocarbon or chlorohydrocarbon solvent. Hexane, benzene, CCI 4 chlorobenzene, toluene or xylene are recommended as solvent.

The liquid crystal compounds of the present invention are useful as components of a liquid crystalline mixture. They make it possible to increase the optical anisotropy (Δn) of mixture and to adjust the value of the Δε/ε ratio. The mixtures containing the compounds according to the present invention are also the subject of the present invention.

The mixtures of the present invention contain at least two compounds and at least one of them is a compound of the formula 1.

The mixtures may be composed exclusively of compounds of formula 1 , or they may contain apart from compounds of formula 1 other known liquid crystalline compounds and other

SUBSTITUTE SHEET

substances such as solvents, optically active compounds, dichroic dyes or polymers. Compounds of formulae 1a-g are advantageous components of the mixtures of the present invention, wherein R 1 and R 2 are an alkyl or alkoxy group..

The mixture containing two- and three-ring compounds show moderate clearing points. The presence of compounds of formulae 1d-g brings about mesophase ranges of the mixtures wider than 150°C.

The invention concerns also a liquid crystalline display composed of two plane parallel support plates, at least one of them is transparent, on which there are electrodes, orienting layers and/or isolating layers, and/or color filters between which a liquid crystalline medium is placed. According to the present invention this medium is the liquid crystalline mixture of the present invention.

The invention provides also intermediates for obtaining laterally substituted chloro- arenes of the general formula 1. The intermediates are compounds of formula 11 , where s and t denotes an integer 1 or 0 with the condition that s+t;>1, R, and R 2 are the same, when s=t, and the same or different when s≠t, and denote a Y-(CH 2 ) n -(O) m -(CH 2 ) k -(O) r (CH 2 ) p - or Y-(CH 2 ) n - CH=CH-(CH 2 ) P - group, where Y denotes an H, F, or Cl atom, or a CN, OCF 3 , CF 3 , or COOC n H 2n+1 group, n, p and k are integers from the range of 0+7, m and I denote 0 or 1 ; Z, and Z 2 are the same or different and denote a CH=CH or C≡C group; when s+t>1 Z, denotes also a single bond or a CH 2 -CH 2 group ; A, and A 2 denote independently a single bond or one of the fragments given by formulae 2-10, where X,, X 2 , X 3 and X denote independently an H, or F atom; B and B 1 denote independently a single bond or a bridge group such as CH 2 CH 2 , C≡C, CH=CH, OCH 2 , CH 2 O.

The present invention provides a convenient synthetic route for the preparation of intermediates of the general formula 11, where R 1 and R 2 are the same or different and denote a terminal group: V CHd O) m -(CHMP)r(p J p - or Y-(CH 2 ) n -CH=CH-(CH 2 ) p -, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF 3 , CF 3 , COOC n H 2n+1 , n, p and k are from the range of 0+7, m and I denote 0 or 1 ; Z, and Z 2 are the same or different and denote a single bond, CH=CH, C≡C or CH 2 -CH 2 group; A, and A 2 denote independently a single bond or one of the fragments given by formulae 2-10, where X,, X 2 , X 3 and X denote independently an H or F atom; B and B 1 denote independently a single bond or a bridge group such as CH 2 CH 2 , C≡C, CH=CH, OCH 2 , CH 2 O; s and t denote independently 0 or 1 with the condition that s+t≥1.

When s=0 and t=1 , the process (scheme 2) consists in heating acetoacetate acid esters of formula 15, where A 2 denotes a single bond or one of the fragments given by formulae 2-10; R 2 denotes a Y-(CH 2 ) n -(0) m -(C 2 ) k -(0) CHJ p - or Y-(CH 2 ) n -CH---CH-(CH 2 ) p - group, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF 3 , CF 3 , COOC n H 2n+1 ; R 3 denotes an alkyl group containing from 1 to 10 carbon atoms, advantageously 2, with the

SUBSTITUTE SHEET

compound of formula 16, where R, denotes a Y-fCH j ^CH j fOHCH j ,,- or Y-(CH 2 ) n - CH=CH-(CH 2 ) P - group, where Y denotes an H, F, or Cl atom, or a terminal group such as CN, OCF 3 , CF 3 , COOC n Hj n .,; A, denotes a single bond or one of the fragments given by formulae 2-10; Z 2 denotes a single bond or a CH=CH, C≥C or CH 2 -CH 2 group; and X denotes a pipe- rydyl, pirolidyl, morfonylyl or dialkylamine group, containing from 1 to 15 carbon atoms, advantageously a methyl, ethyl or propyl group. The reaction is carried in organic solvents such as alcohols or ethers in the presence of inorganic base or alkaline metals salts, advan¬ tageously NaOH or KOH, Na 2 CO 3 or K 2 CO 3 . Very good results are obtained when inorganic base or alkaline metals salts are combined with organic base such as trialkylamine or 1 ,8-diazobicyclo[5.4.0]undec-7-ene (DBU). The addition of a small amount of tetraamonium salt sometimes results in the increased yield. Thereafter the product of condensation is treated with an aqueous solution of an acid, advantageously sulfuric acid, then it is separated out of the reaction mixtures using known methods, advantageously the extraction.

When s=1 and t=1 the process (scheme 3) consists in heating acetoacetate acid esters of formula 15, with the compound of formula 17 in the same conditions as described above (when s=0). Symbols Z 1 t A 1 ( Z 2 , and X in formula 17 have the same meaning as in formula 11 and 16.

The character of both reactions shown in scheme 2 and 3 is the same. The difference between compound 16 and compound 17 is that: compound 16 is a monofunctional compound (contains one group, which is a precursor for vinyl group) and the condensation reaction leads to the creation of a molecule with one cyclohex-2-en-1-one ring as it is shown in scheme 2; compound 17 is bifunctional compound and its use leads to the creation of a molecule contain¬ ing two cyclohex-2-en-1-one rings, as it is shown in scheme 3. The notation used in schemes 2 and 3 are the same as described above.

The formulae from 11.1 to 11.51 represent structures of compounds which can easily be produced by the described method. They were chosen for presentation because of their importance as intermediates for liquid crystalline structures, which are the subject of the invention.

Unsaturated cyclic ketones, which are the subject of the invention as intermediates, often reveal nematic and/or smectic properties. They can be used as the components of liquid crystalline mixtures, especially as dopants for ferroelectric liquid crystal mixtures, but their chemical stability is not high, especially when the cyclohexenone ring is located in such a way that a system of conjugated bonds is created. That is why the unsaturated cyclic ketones of the present invention are more important as intermediates for the synthesis of liquid crystalline compounds of higher chemical and photochemical stability being the subject of the present invention (formula 1) and others descriebed in our concurrent aplication as well as aromatic compounds of formula 12, 13 and 14 as shown in scheme 1.

SUBSTITUTE SHEET

The compound of formula 12 (scheme 1) is obtained by treating the compound of formula 11 with the Grignard reagent, then with a diluted acid to form diene, which is heated in high boiling hydrocarbons, advantageously in xylene in the presence of 10% palladium on carbon.

The compound of the formula 13 (scheme 1) is prepared by treating the compound of formula 11 with sodium borohydride in alcohols at room temperature or above, advantageously at 50° C, to obtain a diene, which is heated in the presence of Pd/C in an aromatic-hydrocarbon solvent.

The compound of the formula 14 (scheme 1) is obtained by treating the compound of formula 11 in the presence of palladium on active carbon in an aromatic-hydrocarbon solvent, advantageously in xylene, at temperature 200-220° C.

The above mentioned methods are convenient for the synthesis of laterally substituted terphenyl and quaterphenyl derivatives, the synthesis of which by other methods is a complex and multistage process (LK.M.Chen, Mol.Cryst.Liq.Cryst., 123, 185 (1985)).

3,6-Disubstituted cyclohex-2-en-1-ones are also useful for the preparation of many other classes of compounds, for example derivatives of 2,5-disubstituted cyclohexanones, which are starting materials for the synthesis of liquid crystalline derivatives of cyclohexane or cyclohexene, what was shown in scheme 4. The notation used in scheme 4 is the same as described above, except for Z^ and Z A , which denote a single bond or a CH 2 CH 2 , CH 2 O or OCH 2 group.

The present invention will be described in more detail by the following examples. However, these examples do not limit the scope of the present invention.

Example 1

Synthesis of 3,4-difluoro-3'-chloro-4 trans-4-pentylcyclohexylethyl-2)biphenyl

The mixture consisting of 0.1 mol of 3-(3,4-difluorophenyl)-6-(trans-4-pentylcyclohexylethyl- 2)cyclohex-2-one-1, 0.2 mol PCI 5 , and 100 cm 3 benzene was refluxed for 8 hours. Then it was cooled and poured into water. The layers were separated and the organic layer was washed with a solution of K 2 CO 3 until it was neutral, then it was dried over K 2 CO 3 and filtrated. Subse¬ quently, benzene was distilled off and the residue was dissolved in hexane and the obtained solution was filtrated through a silica gel layer, then the solvent was distilled off by an evapo¬ rator. The remaining oily substance was dissolved in ethanol and the solution was cooled to obtain crystals. The yield was 40% and the obtained compound had the following parameters: phase transitions Cr 13 N 45 I, refraction indices at 20°C: n 0 =1.513, n e =1.620, Δn=0.107;

SUBSTITUTE SHEET

viscosity at 40°, 30° and 20°: 48, 76 and 142 mPa-s, respectively, dielectric constants at 20°: ε,=5.4, ε x =3.8, Δε=1.6.

In an analogous manner the following compound was obtained:

2-fluoro-4-methoxy-3'-chloro-4'-(trans-4-butylcyclohexyle thyl-2)biphenyl which has the following parameters:

Cr 45.2 N 97 I

Δn=0.140, n 0 =1.517, n,=1.657

Δε=-0.25, ε =4.32, ε,=4.57

Example 2

Synthesis of 4-(trans-4-pentylcyclohexylethyl-2)-3-chloro-4'-(trans-4-pro pylcyclohexyl)biphenyl

A mixture of 2.9 g (0.005 mol) of 3-(4-(trans-4-propylcyclohexyl)phenyl)-6-(trans-4-pentyl- cyclohexylethyl-2)cyclohex-2-en-1-on, PCI 5 (1.3 g, 0.006 mol) and CCI 4 (50 cm 3 ) was heated under reflux for 6 hours. The mixture was cooled and poured onto water with ice. The organic layer was separated and washed with a solution of sodium hydroxide, then water, and dried over MgSO 4 . Carbon tetrachloride was distilled off and the crude product was purified by column chromatography (silica gel, hexane) and then recrystaliized from a hexane: ethanol (2:1) solution. The colorless crystalline solid was obtained. Yield 60.9 % (1.5g); transition temperatures: Cr 81.5 N 220.5 I; mass spectrum: 494 and 492 (M * ), 394 and 392, 327 and 325 (C 3 H 7 -C β H 10 -Ph-PhCI-CH 2 ) * , 291, 227 and 225, 205, 165.

In an analogous manner the following compounds were obtained: 4-(trans-4-butylcyclohexylethyl-2)-3-chloro-4' -(trans-4'-propyl- cyclohexylethyl-2)biphenyl Cr 63.3 N 191 I

4-(trans-4-propylcyclohexylethyl-2)-3'-chloro-4"-methoxyt eφhenyl Cr 92.6 N 232 I

4-(trans-4-pentylcyclohexyl)-3'-chloro-4"-mθthoxyteφhen yl Cr 90 N 273 I

4-(trans-4-pentylcyclohexyl)-3'-chloro-4"-ethoxyterphenyl Cr 102 N 275 I

4-(trans-4-pentylcyclohexyl)-3'-chloro-4"-fluoroteφhenyl Cr 105 N 210 I

4-pentyl-3 , "-chloro-4 , " , -methoxyquateφhenyl Cr 115 S A 141 N 298 I

SUBSTITUTE SHEET

Example 3

Mixture A of the following composition was prepared:

4-(trans-4-propylcyclohexyl)benzeneisothiocyanate 40 % wt

4-(trans-4-hexylcyclohexyl)benzeneisothiocyanate 42 % wt

4-(trans-4-octylcyclohexyl)benzeneisothiocyanate 18 % wt Mixture A was characterized by the following parameters:

T N-I 42°C

V 10 20° 1.69V

Vsc/20 0 1.95V

Δn/20° 0.1680 η/20° 12.9 mPa -s

10% wt of S^-difluoro^'-ttrans^-pentylcyclohexylethyl-ΣJ-S'-chlorobip henyl was introduced to mixture A to obtain mixture B.

10% wt of 4-(trans-4-pentylcyclohexylethyl-2)-3-chloro-4'-(trans-4-pro pylcyclohexyl)biphenyl was introduced to mixture A to obtain mixture C.

10% wt of 4-(trans-4-pentylcyclohexyl)-3'-chloro-4"-methoxyteφhenyl was introduced to mixture

A to obtain mixture D.

10% wt of 4-(trans-4-pentylcyclohexyl)-3'-chloro-4"-fluoroteφhenyl was introduced to mixture A to obtain mixture E.

10% wt of 4-pentyl-3'"-chloro-4""-methoxyquateφhenyl was introduced to mixture A to obtain mixture F.

Mixtures B, C, D, E, and F have the following parameters:

B C D E F

' /S 41.5 61.5 61 54 45 η, 20°C 15.2 15.5 16.5 17.9 15.6

Δn, 20°C 0.156 0.176 0.178 0.165 0.182

Δn ' , 20°C 0.32 0.32 0.12 0.38

Δn - estimated for the single compound

SUBSTITUTE SHEET

Example 4

Mixture G of the following composition was prepared :

4-(trans-4-propylcyclohexyl)benzeneisothiocyanate 35.0 % wt

4-(trans-4-pentylcyclohexyl)benzeneisothiocyanate 9.0 % wt

4-(trans-4-heptylcyclohexyl)benzeneisothiocyanate 16.0 % wt

4-methoxyphenyl-4-trans~pentylcyclohexanecarboxylate 10.0 % wt

4-(trans-4-ethylcyclohexyl)nonylbenzene 5.0 % wt

1-(4-(trans-4-ethylcyclohexyl)phenyl)-2-(trans-4-propylcy clohexyl)ethane 25.0 % wt

It has the following parameters: T N , 42°C η/20° 14.5mPa -s

Δn/20° 0.1408

10 % wt of 4-(trans-4-pentylcyclohexylethyl-2)-3-chloro-4'-(trans-4-pro pylcyclohexyl)biphenyl was added to mixture G to obtain mixture H which has the following parameters: T N , 72°C η/20° 17.8 mPa*s

Δn/20° 0.1445

Example 5

3-(4-ethoxystyryl)-6-pentylcyclohex-2-en-1-one

A mixture composed of hydrochloride of 2-(dimethylamino)ethyl 4-ethoxystyryl ketone (0.1 mol), ethyl 2-pentylacetoacetate (0.11 mol), sodium isopropylate (0.12 mol) i 200 ml anhydrous isopropanol was refluxed for 6 hours. Thereafter the mixture was cooled and acidified with 20% solution of H 2 SO 4 . The oily substance from the mixture was extracted with diethyl ether. The extract was washed with water, dried over anhydrous Na 2 SO 4 and filtrated. The residue obtained after the evaporation of the solvent was purified by crystallization from isopropanol, yield of 14.4 g (45 %) of 3-(4-ethoxystyryl)-6-pentylcyclohex-2-en-1-one having the following phase transition temperatures: Cr 98.5-99.3 S A 120.4-126.3 I was obtained. When KOH in the same mole ratio was used instead of sodium isopropylate the yield of the compound increased to 63%.

Using alkaline medium such as NaOH or KOH the following compounds were prepared.

SUBSTITUTE SHEET

Table 1

Example 6

3-(3,4-difluorophenyl)-6-(trans-4-pentylcyclohexylethyl-2 )cyclohex-2-en-1-one

A mixture composed of hydrochloride of β-(dimethylamino)ethyl-3,4-difluoropropiophenone (0.1 mol), ethyl 2-(trans-4-pentylcyclohexylethyl-2)acetoacetate (0.11 mol), sodium isopropylate (0.12 mol) and 150 ml of anhydrous isopropanol was refluxed for 6 hours. Thereafter the mixture was cooled and acidified with 20% solution of H 2 SO 4 . The oily substance from the mixture was extracted with diethyl ether. The extract was washed with water, dried over anhydrous Na 2 S0 4 and filtrated. The residue obtained after the evaporation of the solvent was purified by crystal¬ lization from isopropanol, where upon 20 g (52 %) 3-(3,4-difluorophenyl)-6-(trans-4-pentylcyclo- hexylethyl-2)cyclohex-2-en-1-one having the following phase transition temperatures: Cr 95.0-96.6 (N 84) I was obtained.

When 0.1 mol of KOH and 0.2 mol of DBU was used instead of sodium isopropylate the yield of the compound increased to 70%.

In an analogues way the following compounds were obtained:

3-(4-(trans-4-propylcyclohexyl)phenyl)-6-(trans-4-pentylc yclohexylethyl-2)cyclohex-2-en-1-one, Cr <20 S B 175 S A 248 l;

3-(4-(trans-4-propylcyclohexyl)phenyl)-6-(trans-4-butylcy clohexylethyl-2)cyclohex-2-en-1-one, Cr <20 S B 174 S A 243 N 252 l; 3-(4-pentylbiphenyl-4'-yl)-6-(2-cyanoethyl)cyclohex-2-en-1-o ne, Cr 92.0 N 159 I;

SUBSTITUTE SHEET

3-(4-(trans-4-propyicyclohexylethyl-2)phenyl)-6-(trans-4-but ylcyclohexylethyl-2)cyclohex-2-en-1- one, Cr <20 S θ 161 S A 222 I;

3-(4-(trans-4-butylcyclohexylethyl-2)phenyl)-6-(trans-4-b utylcyclohexylethyl-2)cyclohex-2-en-1- one, Cr 71 S B 187 S A 226 I.

Example 7

3-(4-(trans-4-propylcyclohexyl)phenyl)-6-pentylcyclohex-2 -en-1-one

A mixture composed of hydrochloride of 2-(dimethylamino)ethyl 4-(trans-4-propylcyclohexyl)- phenyl ketone (0.1 mol), ethyl 2-pentylacetoacetate (0.12 mol), potassium hydroxide (0.12 mol) and 150 ml of dioxane was refluxed for 8 hours. Thereafter the mixture was cooled, acidified with 20% solution of H 2 SO 4 . The oily substance from the mixture was extracted with diethyl ether. The extract was washed with water, dried over anhydrous Na 2 SO 4 and filtrated. The residue obtained after the evaporation of the solvent was purified by crystallization from isopro¬ panol, and.27.5 g (75 %) of 3-(4-(trans-4-propylcyclohexyl)phenyl)-6-pentylcyclohex-2-en -1-one having the following phase transition temperatures: Cr 77 S A 149 N 157 I was obtained.

The compounds shown in Table 2 were obtained in an analogues way.

Table 2

SUBSTITUTE SHEET

103-(4-butoxyphenyl)-6-methylcyclohex-2-en-1-one 71 *

11 3-(4-butoxyphenyl)-6-propylcyclohex-2-en-1-one * 67 * 97 * 12 3-(4-butoxyphenyl)-6-butylcyclohex-2-en-1-one » 67 * 96 *

13 3-(4-butoxyphenyl)-6-pentylcyclohex-2-en-1-one * 41 * 109 *

14 3-(4-pentoxyphenyl)-6-propylcyclohex-2-en-1-one * 55 * 96 *

15 3-(4-pentoxyphenyl)-6-pentylcyclohex-2-en-1-one » 53 * 110 *

16 3-(4-hexyloxyphenyl)-6-pentylcyclohex-2-en-1-one * 56 * 109 * 17 3-(4-nonyloxyphenyl)-6-pentylcyclohex-2-en-1-one * 59 * 109 * 18 3-(4-decyloxyphenyl)-6-pentylcyclohex-2-en-1-one 60 * 113 *

19 3-(4-hexyloxyphenyl)-6-butylcyclohex-2-en-1-one 75 20 3-(4-hexylphenyl)-6-pentylcyclohex-2-en-1-one r 90 21 3-(4-trifluoromethoxyphenyl)-6-pentylcyclohex-2-en-1-one 31 22 3-(biphenyl-4-yl)-6-propylcyclohex-2-en-1-one * 119 * (104) 23 3-(biphenyl-4-yl)-6-butylcyclohex-2-en-1-one I* 110 * 116' 24 3-(biphenyl-4-yl)-6-pentylcyclohex-2-en-1-one 101 * 120' 25 3-(4'-fluorobiphenyl-4-yl)-6-pentylcyclohex-2-en-1-one r 89 114 * 141

26 3-(4'-bromobiphenyl-4-yl)-6-pentylcyclohex-2-en-1-one 91 114 * 219* 27 3-(4'-methylbiphenyl-4-yl)-6-pentylcyclohex-2-en-1-one 117 * 179 * 28 3-(4'-ethylbiphenyl-4-yl)-6-pentylcyclohex-2-en-1-one 83 * 171 29 3-(4'-ethylbiphenyl-4-yl)-6-hexylcyclohex-2-en-1-one 94 * 191

30 3-(4'-pentylbiphenyl-4-yl)-6-ethylcyclohex-2-en-1-one r 93 157 31 3-(4-(4-phenylethyl-2)phenyl)-6-pentylcyclohex-2-en-1-one 66 * (54)

32 3-(4-ethoxyphenyl)-6-allilcyclohex-2-en-1-one 71 33 3-(4-(trans-4-butylcyclohexyl)phenyl)-6-(4-hexyl- 126 * 150 phenyl)cyclohexen-2-en-1-one

SUBSTITUTE SHEET

SUBSTITUTE SHEET