Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D307/78—Benzo [b] furans; Hydrogenated benzo [b] furans
  • C07D307/79—Benzo [b] furans; Hydrogenated benzo [b] furans with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the hetero ring
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D307/78—Benzo [b] furans; Hydrogenated benzo [b] furans
  • C07D307/82—Benzo [b] furans; Hydrogenated benzo [b] furans with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to carbon atoms of the hetero ring
  • C07D307/83—Oxygen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
  • C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D307/78—Benzo [b] furans; Hydrogenated benzo [b] furans
  • C07D307/82—Benzo [b] furans; Hydrogenated benzo [b] furans with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to carbon atoms of the hetero ring
  • C07D307/84—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D333/00—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom
  • C07D333/50—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom condensed with carbocyclic rings or ring systems
  • C07D333/52—Benzo[b]thiophenes; Hydrogenated benzo[b]thiophenes
  • C07D333/62—Benzo[b]thiophenes; Hydrogenated benzo[b]thiophenes with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to carbon atoms of the hetero ring
  • C07D333/68—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen
  • C07D333/70—Carbon atoms having three bonds to hetero atoms with at the most one bond to halogen attached in position 2
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D405/00—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom
  • C07D405/02—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings
  • C07D405/04—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings directly linked by a ring-member-to-ring-member bond
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  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/34—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring
  • C09K19/3441—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom
  • C09K19/345—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom the heterocyclic ring being a six-membered aromatic ring containing two nitrogen atoms
  • C09K19/3458—Uncondensed pyrimidines
  • C09K19/3466—Pyrimidine with at least another heterocycle in the chain
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/34—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring
  • C09K19/3491—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having sulfur as hetero atom
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/34—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring
  • C09K19/3402—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having oxygen as hetero atom
  • C09K19/3405—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having oxygen as hetero atom the heterocyclic ring being a five-membered ring
  • C09K2019/3408—Five-membered ring with oxygen(s) in fused, bridged or spiro ring systems

Definitions

• the present invention relates to novel compounds having a fused heterocyclic ring which have the properties of liquid crystals, together with processes for their preparation and liquid crystal devices incorporating them.
• liquid crystals is well known. It refers to compounds which, as a result of their structure, will align themselves in a similar orientation, preferably at working temperatures, for example of from -40 to 200°C. These materials are useful in various devices, in particular the liquid crystal display devices or LCDs.
• Liquid crystals can exist in various phases. In essence there are three different classes of liquid crystalline material, each possessing a characteristic molecular arrangement. These classes are nematic, chiral nematic (cholesteric) and smectic.
• the molecules of nematic compounds will align themselves in a particular orientation in a bulk material.
• Smectic materials in addition to being orientated in a similar way, will align themselves closely in layers.
• a wide range of smectic phases exists, for example smectic A and smectic C.
• the molecules are aligned perpendicularly to a base or support, whilst in the latter, molecules may be inclined to the support.
• Some liquid crystal materials possess a number of liquid crystal phases on varying the temperature. Others have just one phase.
• a liquid crystal material may show the following phases on being cooled from the isotropic phase:- isotropic - nematic - smectic A - smectic C - solid. If a material is described as being smectic A then it means that the material possesses a smectic A phase over a useful working temperature range.
• Such materials are useful, in particular in display devices where their ability to align themselves and to change their alignment under the influence of voltage, is used to impact on the path of polarised light, thus giving rise to liquid crystal displays.
• These are widely used in devices such as watches, calculators, display boards or hoardings, computer screens, in particular laptop computer screens etc.
• the properties of the compounds which impact on the speed with which the compounds respond to voltage charges include molecule size, viscosity ( ⁇ n), dipole moments ( ⁇ ), conductivity etc.
• the invention provides a liquid crystal compound having a fused five and six-membered ring, at least one of said rings containing a heteroatom, and at least one of said rings carrying a substitutent.
• each ring has at least one substitutent.
• Suitable heteroatoms for use in the ring system of the invention include oxygen, sulphur, nitrogen and selenium. Where nitrogen is present, it may carry a hydrogen or a substituent group, depending upon the nature and the aromaticity of the ring system.
• the ring system may be aromatic or non-aromatic, but is preferably aromatic.
• Specific examples of the ring system of the invention include benzofurans and benzopyrans.
• the nature of the substituents on the ring will determine the particular liquid crystal properties of the compound. Large substituents will tend to increase the viscosity of the compound, thereby increasing the time taken for the molecules to adopt the appropriate orientation under the influence of a voltage. The number of free electrons which are contained within the substitutents influences optical properties of the compound. Aromatic rings will have relatively high conductivity whereas strongly electronegative groups such as cyano, will tend to reduce conductivity.
• the nature of the substitutents on the ring can therefore be selected so as to impart the desired liquid crystal properties on the final compound.
• some applications as outlined below require chiral molecules.
• the compounds of the invention suitably contain an asymmetric centre.
• Typical substituents will comprise a functional group, optionally substituted hydrocarbyl, optionally substituted alkoxy, optionally substituted heterocyclyl or carboxy or a hydrocarbyl ester or amide thereof.
• hydrocarbyl refers to any structure comprising carbon and hydrogen atoms.
• these may be alkyl, alkenyl, alkynyl, aryl such as phenyl or napthyl, arylalkyl, cycloalkyl, cycloalkenyl or cycloalkynyl.
• they will contain up to 20 and preferably up to 10 carbon atoms.
• heterocyclyl includes aromatic or non-aromatic rings, for example containing from 4 to 20, suitably from 5 to 10 ring atoms, at least one of which is a heteroatom such as oxygen, sulphur or nitrogen.
• groups include furyl, thienyl, pyrrolyl, pyrrolidinyl, imidazolyl, triazolyl, thiazolyl, tetrazolyl, oxazolyl, isoxazolyl, pyrazolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, quinolinyl, iosquinolinyl, quinoxalinyl, benzthiazolyl, benzoxazolyl, benzothienyl or benzofuryl.
• alkyl refers to straight or branched chain alkyl groups, suitably containing up to 20 and preferably up to 6 carbon atoms
• alkoxy relates to -O-alkyl groups
• alkenyl and alkynyl refer to unsaturated straight or branched chains which include for example from 2-20 carbon atoms, for example from 2 to 6 carbon atoms.
• aryl refers to aromatic groups such as phenyl or naphthyl.
• cycloalkyl refers to such groups which are cyclic and have at least 3 and suitably from 5 to 20 ring atoms. These rings may be fused together to form bicyclic, tricyclic or even larger multiple ring systems.
• hydrocarbyl groups will be may be substituted by functional groups, or by other types of hydrocarbyl group.
• cyclic groups such as aryl, heterocyclic or cycloalkyl, cycloakenyl or cycloalkynyl may be substituted by hydrocarbyl chains such as alkyl, alkenyl or alkynyl groups as well as functional groups.
• hydrocarbyl group itself an alkyl, alkenyl or alkynyl group
• it may be substituted with cyclic groups such as heterocyclic groups, aryl groups, cycloalkyl, cycloalkenyl or cycloalkynyl groups, as described above, which may themselves be further substituted by hydrocarbyl or functional groups.
• heteroatom refers to non-carbon atoms such as oxygen, nitrogen, selenium or sulphur atoms as mentioned above. Where the nitrogen atoms are present, they will generally be present as part of an amino residue so that they will be substituted for example by hydrogen or alkyl.
• amide is generally understood to refer to a group of formula C(O)NR b R° where R b and R c are hydrogen or an optionally substituted hydrocarbyl group.
• the compounds of the invention are liquid crystal compounds of general formula (I)
• each R 1 and R 3 are independently selected from cyano, halo, optionally substituted hydrocarbyl, optionally substituted alkoxy, optionally substituted heterocyclyl, a group R 13 C(O)O- where R 13 is optionally substituted hydrocarbyl or carboxy or a hydrocarbyl ester or amide thereof, provided that at least one or group R 1 or R 3 is other than cyano or halo, each R 2 and R 4 is independently selected from halo, nitro, lower alkyl optionally substituted by halo, or a group R 14 C(O)O- where R 14 is optionally substituted hydrocarbyl, n is 1 or 2, m is 0, 1, 2 or 3, p is 1 or 2 and q is 0 or 1, provided n + m does not exceed 4 and p + q does not exceed 2, and further provided the compounds are other than those described in DEI 990517 or WO 98/04544.
• each R 1 and R 3 are independently selected from cyano, halo, optionally substituted hydrocarbyl, optionally substituted alkoxy, optionally substituted heterocyclyl, or carboxy or a hydrocarbyl ester or amide thereof, provided that at least one or group R 1 or R 3 is other than cyano or halo, each R 2 and R 4 is independently selected from halo, nitro, lower alkyl optionally substituted by halo, or a group R 14 C(O)O- where R 14 is optionally substituted hydrocarbyl, n is 1 or 2, m is 0, 1, 2 or 3, p is 1 or 2 and q is 0 or 1, provided n + m does not exceed 4 and p + q does
• n is 1, and m is 0, 1 or 2, and more preferably 0 or 1 and most preferably 0.
• p is 1 and q is 0.
• Suitable lower alkyl groups for R 2 and R 4 include methyl, fluoromethyl or trifluoromethyl.
• any group R 2 or R 4 which are present are halo, especially fluoro.
• no more than two of the groups R 1 and R 2 are fluoro, and preferably no more than one of the groups R 1 and R 2 is fluoro. It has been found that ⁇ of the mixtures containing the fluorinated compounds of formula (I) are reduced compared to the mixutres which include non-fluorinated compounds of formula (I). Furthermore, the presence of fluorines at the position R 2 appears to impart more negative behaviour on the mixture.
• R 14 is suitably alkyl, cycloalkyl or aryl, preferably alkyl or aryl.
• At least one of R 1 or R 3 is cyano, in particular where low ⁇ is required.
• one of R 1 or R 3 is cyano or halo and the other is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or an ester thereof.
• R 1 or R 3 is cyano or halo and the other is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or an ester thereof.
• R 1 and R 3 when they are other than cyano or halo, are selected from optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl or optionally substituted cycloalkynyl.
• Suitable optional substituents for alkyl, alkenyl, alkynyl, groups R 1 and R 3 include functional groups as defined above, as well as aryl, cycloalkyl, heterocyclyl any of which may be substituted by alkyl, alkenyl or alkynyl as well as functional groups as defined above.
• Suitable optional substituents for aryl, heterocyclyl, cycloalkyl, cycloalkenyl or cycloalkynyl groups R 1 and R 3 include those listed above in respect of alkyl, alkyenyl and alkynyl groups, as well as alkyl, alkenyl or alkynyl, any of which may be optionally subsituted by a functional group, an aryl group, a heterocyclic group or a cycloalkyl, cycloalkenyl or cycloalkynyl group.
• R 1 and R 3 are selected from optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or a hydrocarbyl ester thereof.
• carboxy ester groups they are preferably alkyl esters or aryl esters such as phenyl esters where the phenyl group may be optionally substituted for example with alkyl, alkoxy or cyano groups.
• Suitable groups R 1 or R 3 where these are other than cyano or halo are groups of formula (i), (ii), (iii), (iv), (v), (vi), (vii) or (viii)
• R ° is an d ⁇ oalkyl group
• y and z are independently selected from 0, 1 or 2.
• At least one R 1 or R 3 group is a group of sub-formula (i) - (viii) as set out above.
• R 1 or R 3 where these are other than cyano or halo are optionally substituted cycloalkyl or optionally substituted phenyl, and particularly optionally substituted phenyl.
• Suitable substituents for the cycloalkyl or phenyl groups R 1 and R 3 include halo, alkyl especially Cs ⁇ alkyl, alkoxy such as Cs ⁇ alkoxy, cyano or phenyl which may itself be substituted by alkyl or cyano.
• Particularly suitable substituents include alkyl especially C 3 .9alkyl, alkoxy such as Cs ⁇ alkoxy, cyano or phenyl which may itself be substituted by alkyl or cyano.
• R 1 or R 3 is a group is a group of formula R 13 C(O)O- 5
• R 13 is suitably alkyl, cycloalkyl or aryl, preferably cycloalkyl.
• R 1 or R 3 can have significant effects on the properties of the compounds.
• compounds where R 1 is cyano may have a significantly different dielectric anisotropy as compared to compounds where R 3 is cyano.
• X is oxygen or sulphur and most preferably oxygen.
• substituents are arranged on the ring so as to confer an advantageous dipole on the compound.
• the substituents are suitably arranged such that the overall shape of the molecule is either bent or wedge shaped.
• substituents are suitably positioned at the 2 and 6 positions of the bicyclic ring where the group X is at position 1.
• the invention provides a compound of general formula (IA)
• R la or R lb or R 17 or R 18 is other than cyano or halo;
• R 17 is carboxy or a hydrocarbyl ester or amide thereof, R 18 is hydrogen, R 2a and R 2b are not both fluoro;
• R 1 is an optionally substituted hydrocarbyl or carboxy or a hydrocarbyl ester or amide thereof, R 2a is hydrogen, and R lb and R 2b are both fluorine, then R 17 is other than C ⁇ -8 alkyl.
• R 15 is suitably a group of formula R 13 as defined above.
• R 18 is a group of formula R 15 C(O)O-, R 15 is suitably a group R 14 as defined above.
• R 2a is hydrogen.
• at least one of R Ib , R 2b or R 18 in formula (IA) is fluoro.
• R la , R 2a , R b or R lb are fluoro, and preferably no more than one of these groups is fluoro.
• R lb or R la or R 17 or R 18 in formula (IA) is cyano or halo and at least one of the said groups on the other ring of the bicyclic ring of formula (IA) is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or a hydrocarbyl ester thereof.
• R 17 or R 18 is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or a hydrocarbyl ester thereof.
• R 17 or R 18 is halo or cyano
• at least one of R la or R lb is optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or a hydrocarbyl ester thereof
• one of R lb or R la or R 17 or R 18 in formula (IA) is cyano or halo and at least one of the said groups on the other ring of the bicyclic ring of formula (I A) is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, an optionally substituted aryl, optionally substituted heterocyclyl, carboxy or a hydrocarbyl ester thereof.
• R is a group R as defined above in relation to formula (I), one of R and R is a group R as defined in relation to formula (I) and the other is hydrogen or a group R 1 as defined in relation to formula (I);
• R 6 is hydrogen, cyano or fluoro, preferably hydrogen or fluoro
• R 9 is hydrogen, cyano or fluoro, provided that where R 5 is cyano or fluoro, at least one of R 7 or R 8 is optionally substituted alkyl, optionally subsituted cycloalkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally subsituted alkoxy, optionally substituted aryl, optionally substituted heterocyclyl, carboxy or an ester thereof; and where one of R 7 or R is cyano or fluoro and the other is hydrogen, R is optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted alkoxy, optionally
• R 5 and R 7 and/or R 8 include cyano; fluoro; alkoxy; alkenyl; alkyl, aryl or alkylaryl esters of carboxy; arylalkyl, alkenylaryl wherein the aryl ring is optionally substituted with an alkyl group, a functional group such as fluoro or alkoxy, or further aryl groups which are themselves optionally substituted with alkyl; optionally substituted pyrimidinyl wherein the optional substituents are in particular alkyl or optionally substituted cycloalkyl where the cycloalkyl ring is optionally subsituted with an alkyl group.
• R , 5' is cyano or fluoro, preferably fluoro
• one of R and R 8 is hydrogen and the other is an optionally substituted hydrocarbyl group or a heterocyclic group as described above.
• Particular examples of substituted hydrocarbyl groups for R 7 or R 8 are groups of sub-formula (i), (ii), (iii), (vi) or (viii) as defined above.
• Compounds of formula (IIA) may show advantageous properties in terms of their u.v. stability and a low susceptability to ion contamination, making them particularly suitable for use in thin film transmittor (TFT) devices.
• TFT thin film transmittor
• the compounds of the invention may be prepared by conventional methods which would be apparent to a skilled chemist.
• compounds may be prepared by adding substituents to a bicyclic ring.
• a compound of formula (I) can be prepared by reacting a compound of formula (III)
• R 1 is as defined in relation to formula (I) and Z' is a group B(OH) 2 where Z is a leaving group, or a leaving group where Z is a group B(OH) 2 ; and thereafter if desired or necessary, converting a group R 2 , R 3 or R 4 to a different such group.
• Suitable leaving groups for Z or Z' include halo such as bromo or iodo, mesylate, tosylate and triflate.
• the reaction is suitably effected in an inert organic solvent, such as 1,2-dimethoxyethane in the presence of a base such as sodium or potassium carbonate.
• the reaction is suitably effected in the presence of an inert atmosphere such as a nitrogen atmosphere.
• a catalyst such as a palladium catalyst for example tetrakis (triphenylphosphine) palladium is present.
• the reaction is suitably effected at elevated temperatures, for instance at the reflux temperature of the solvent.
• R 3 is as defined in relation to formula (I) and Z' is as defined in relation to formula (IV), and thereafter, if necessary, changing any groups R 1 , R 2 and R 4 to different such groups.
• Suitable leaving groups Z or Z' and reaction conditions will be similar to those described above in relation to the reaction between compounds of formula (HI) and (TV).
• the conversion of groups R 1 , R 2 , R 3 and R 4 to different such groups could be carried out by conventional methods as would be apparent to a skilled chemist.
• a particularly useful reaction in this context is the conversion of a carboxylic ester group such as an alkyl ester, in particular an ethyl ester, to a cyano group. This reaction may be achieved by hydrolysis of the carboxylic ester group, followed by conversion of the resultant carboxylic acid to the corresponding acid chloride and thereafter to the amide. Dehydration of the amide gives the cyano compound.
• R 3 is as defined above in relation to formula (I) and R 12 is an alkyl group such as ethyl. Thereafter, groups R 3 can be changed to different such groups on the compound of formula (III) in a similar manner to that outlined above.
• a particular preferred compound of formula (VLTI) is a compound where R 3 is a carboxylic ester group such as an alkyl ester group as this gives rise to the possibility of subsequent modification as outlined above.
• a suitable compound of formula (VITI) is diethyl bromomalonate.
• the reaction is suitably effected in an organic solvent such as butanone in the presence of a base such as potassium carbonate.
• Compounds of formula (XI) and (XII) are either known compounds or they can be prepared from known compounds by conventional methods.
• compounds of formula (I) where q is 0 and p is 1 and R 3 is a carboxy group may be prepared by introduction of a substituent R 3 group to a compound of formula (IX)
• R 2 , R 4 , X, m,n and q are as defined in relation to formula (I), and R 1 is a group R 1 as defined in relation to formula (I) or a precursor thereof; with a carboxylating agent such as Cardice in the presence of a base such as n-butyllithium and an organic solvent such as tetrahydrofuran, and thereafter acidifying the product with an acid such as glacial acetic acid.
• the carboxy group can subsequently be converted into different R 3 groups as required.
• Suitable precursor groups R 1 include groups which can be converted to the desired R 1 groups by conventional chemistry.
• a group Z or Z' as defined above.
• Compounds of formula (LX) where R 1 is a group R 1 may have liquid crystal properties in their own right and therefore these form a further aspect of the invention.
• Compounds of formula (IX) where q is 0 may be prepared by cyclisation of an acetal compound of formula (X)
• R 2 , R 4 X, n and m are as defined in relation to formula (I), and R 1 is as defined in relation to formula (IX); in the presence of polyphosphoric acid.
• the reaction is suitably effected in an organic solvent such as chlorobenzene at elevated temperature, for example at the reflux temperature of the solvent.
• R 4 is as defined in relation to formula (I) and Z" is a leaving group. Suitable leaving groups Z" are defined above in relation to the group Z.
• the reaction is suitably effected in the presence of a base such as potassium carbonate in an organic solvent such as butanone.
• Compounds of formula (IX) may be converted to compounds of formula (V) where Z is a B(OH)2 group by reaction with trimethyl borate in the presence of a base such as n-butyl lithium. Subsequent acidification with an acid such as hydrochloric acid will yield the desired product.
• the reaction is suitably effected in an organic solvent such as tetrahydrofuran and reactions of this type are exemplified hereinafter.
• R 3 is a group R 3 as defined in relation to formula (I)or a precursor thereof.
• the reaction is suitably effected in an organic solvent such as dichloromethane in the presence of a base such as N,N'-dicyclocarbodiimide (DCC) and 4-N,N- dimethylaminopyridine (DMAP).
• DCC N,N'-dicyclocarbodiimide
• DMAP 4-N,N- dimethylaminopyridine
• the reaction is suitably carried out under an inert atmosphere for example of nitrogen.
• Precursor groups R 3 may be similar to those defined above in relation to R 1 .
• Compounds of formula (XIII) may be derived from compounds of formula
• the compounds of the invention can be selected such that their liquid crystal properties, in particular the nematic/smectic properties, suit the desired application. This may be achieved by varying the substituent groups on the central ring structure as outlined above, or it may be effected by mixing the compounds with other compounds of the invention or other different liquid crystal compounds. Mixtures are suitably eutectic mixtures.
• the compounds of the present invention may be in ed with each other to form useful liquid crystal mixtures, they may also be used with liquid crystal polymers or other low molar mass non-polymer liquid crystal materials.
• the compounds of the invention can be used in a wide variety of devices, depending upon their particular properties.
• compounds with low melting points, high transition temperatures (TN-I(°C)), low viscosity and high dipole moments giving for example high values of ( ⁇ ) are required.
• Compounds of the invention include those which have such properties and other properties such as flexoelectric properties. Where the melting point is not sufficiently low, this may be reduced by mixing the compound of the invention with other liquid crystal compounds, in particular a different compound of the invention, so as to form a mixture, preferably a eutectic mixture.
• Transition temperatures may be increased by using or including in the mixture compounds of the invention which comprise at least three carbocyclic, heterocyclic or aryl ring systems, for example, compounds of formula (I) where both R 1 and R 3 comprise a carbocyclic, heterocyclic or aryl group.
• TFT trifluoroterphenyl
• compounds of the invention with TN twisted nematic values of the order of 90° are suitably selected. This is indicative of the degree of twist present in the alignment of the molecules.
• the viscosity of such compounds ( ⁇ n) is suitably low and for this reason, compounds with saturated substituent groups may be preferred.
• the compounds should have a positive ⁇ , which is a result of a longitudinal dipole moment.
• the value of the elastic constants ratio, K H /K3 3 is preferably high, whilst the conductivity is preferably low. In order to achieve these latter requirements, halo substituents such as fluoro may be preferred to cyano substituents.
• Compounds of the invention may have the properties of the so called "super- twist nematics" where the TN values are of the order of 240-270°. Such compounds generally have a high ⁇ n value, and so may contain aromatic rings. They will have a positive ⁇ and the value of K ⁇ /K33 is high to provide a sharp threshold.
• Liquid crystal devices comprising compounds of the invention of mixtures form a further aspect of the invention.
• Examples of such devices include optical and electro- optical devices, magneto-optical devices and devices providing responses to stimuli such as temperature changes and total or partial pressure changes.
• the compounds described above may also be included in a mixture, where the mixture comprises at least two compounds.
• Typical mixtures include mixtures consisting of compounds of the above- described compounds and also mixtures comprising at least one compound as described and at least one different liquid crystal compound.
• a smectic A phase compound of the invention is composed of chiral molecules, it may exhibit an electroclinic effect, i.e. a direct coupling of molecular tilt to applied field.
• a sample a tilt of the director is directly related to a tilt of the optic axis.
• the electroclinic effect results in a linear electro-optic response.
• the electro-optic effect can manifest itself as a modulation of the effective birefringence of the device.
• Electroclinic (EC) devices are useful, for example, in spatial light modulators having an output that varies linearly with applied voltage.
• a further advantage of EC devices is that they have high speed response times, much faster than twisted nematic type devices.
• One known type of ferroelectric device is bistable, in contrast the EC device is not bistable and has an output that varies linearly with applied voltage.
• the electroclinic effect is sometimes referred to as the soft-mode effect see G Andersson et al in Appl. Phys. Lett., 51, 9, (1987).
• An increase in induced tilt may result in an increase in contrast ratio.
• electroclinic devices there are a variety of electroclinic devices in which the compounds of the present invention may be incorporated.
• active black plane driving may be utilised.
• One of the walls forming the cell may be formed from a silicon substrate e.g. a wafer which possesses circuitry for driving pixels.
• the mode of operation of these devices includes either amplitude modulation or phase modulation. Similarly devices may be used in reflectance or transmissive mode.
• S A * is meant a S A phase which contains some proportion of chiral molecules, and therefore it is preferable that the compounds of the invention used in this way are chiral.
• Cholesteric or chiral nematic liquid crystals possess a twisted helical structure which is capable of responding to a temperature change through a change in the helical pitch length. Therefore as the temperature is changed, then the wavelength of the light reflected from the planar cholesteric structure will change and if the reflected light covers the visible range then distinct changes in colour occur as the temperature varies. This means that there are many possible applications including the areas of thermography and thermooptics.
• the cholesteric mesophase differs from the nematic phase in that in the cholesteric phase the director is not constant in space but undergoes a helical distortion.
• the pitch length for the helix is a measure of the distance for the director to turn through 360°
• a cholesteric material is chiral material.
• Chiral compounds of the invention may exhibit a helical mesophase and so may be used in thermographic or thermooptic applications.
• Chiral compounds of the invention may also be used in electro-optical displays as dopants, for example in twisted nematic displays where they may be used to remove reverse twist defects. They may also be used in cholesteric to nematic dyed phase change displays where they may be used to enhance contrast by preventing wave-guiding.
• thermochromic applications of cholesteric liquid crystal materials usually use thin film preparations of the materials which are then viewed against a black background. These temperature sensing devices may be placed into a number of applications involving thermometry, medical thermography, non-destructive testing, radiation sensing and for decorative purposes. Examples of these may be found in D G McDonnell in Thermotropic Liquid Crystals, Critical Reports on Applied Chemistry, Vol. 22, edited by G W Gray, 1987 pp 120-44; this reference also contains a general description of thermochromic cholesteric liquid crystals.
• thermochromic liquid crystal devices have a thin film of cholesterogen sandwiched between a transparent supporting substrate and a black absorbing layer.
• One of the fabrication methods involves producing an 'ink' with the liquid crystal by encapsulating it in a polymer and using printing technologies to apply it to the supporting substrate.
• Methods of manufacturing the inks include gelatin microencapsulation, US patent 3,585,318 and polymer dispersion, US patents 1,161,039 and 3,872,050.
• One of the ways for preparing well-aligned thin film structures of cholesteric liquid crystals involves laminating the liquid crystal between two embossed plastic sheets. This technique is described in UK patent 2,143,323.
• compounds of the present invention may be used in ferroelectric mixtures and devices.
• compounds of the invention may be used in many of the known forms of liquid crystal display devices, for example chiral smectic electro-optic devices.
• Such a device may comprise a layer of liquid crystal material contained between two spaced cell walls bearing electrode structures and surface treated to align liquid crystal material molecules.
• Ferroelectric smectic liquid crystal materials which can be produced by mixing an achiral host and a chiral dopant, use the ferroelectric properties of the tilted chiral smectic C, F, G, H, I, J and K phases.
• the chiral smectic C phase is denoted Sc* with the asterisk denoting chirality.
• the Sc phase is generally considered to be the most useful as it is the least viscous.
• Ferroelectric smectic liquid crystal materials should ideally possess the following characteristics: low viscosity, controllable spontaneous polarisation (Ps) and an Sc phase that persists over a broad temperature range which should include ambient temperature and exhibits chemical and photochemical stability. Materials which possess these characteristics offer the prospect of very fast switching liquid crystal containing devices.
• ferroelectric liquid crystal devices the molecules switch between different alignment directions depending on the polarity of an applied electric field. These devices can be arranged to exhibit bi stability where the molecules tend to remain in one of two states until switched to the other switched state.
• Such devices are termed surface stabilised ferroelectric devices, e.g. as described in US 5061047 and US 4367924 and US 4563059. This bistability allows the multiplex addressing of quite large and complex devices.
• One common multiplex display has display elements, i.e. pixels, arranged in an X, Y matrix format for the display of for example alpha numeric characters.
• the matrix format is provided by forming the electrodes on one side as a series of column electrodes, and the electrodes on the other slide as a series of row electrodes. The intersections between each column and row form addressable elements or pixels.
• Other matrix layouts are known, e.g. seven bar numeric displays.
• a common feature involves the application of a voltage, called a strobe voltage to each row or line in sequence.
• a voltage called a strobe voltage
• data voltages are applied to all column electrodes.
• the differences between the different schemes lies in the shape of the strobe and data voltage waveforms.
• the material may be switched between its two states by two strobe pulses of opposite sign, in conjunction with a data waveform.
• a blanking pulse may be used to switch the material into one of its states. Periodically the sign of the blanking and the strobe pulses may be alternated to maintain a net d.c. value.
• Blanking pulses are normally greater in amplitude and length of application than the strobe pulses so that the material switches irrespective of which of the two data waveforms is applied to any one intersection. Blanking pulses may be applied on a line by line basis ahead of the strobe, or the whole display may be blanked at one time, or a group of lines may be simultaneously blanked.
• Devices can be assessed for speed by consideration of the response time vs pulse voltage curve. This relationship may show a minimum in the switching time (tmin) at a particular applied voltage (Vmm). At voltages higher or lower than V ⁇ n the switching time is longer than t ⁇ ,. It is well understood that devices having such a minimum in their response time vs voltage curve can be multiplex driven at high duty ratio with higher contrast than other ferroelectric liquid crystal devices. It is preferred that the said minimum in the response time vs voltage curve should occur at low applied voltage and at short pulse length respectively to allow the device to be driven using a low voltage source and fast frame address refresh rate.
• Typical known materials which do not allow such a minimum when included in a ferroelectric device include the commercially available materials known as SCE13 and ZLI-3654 (both supplied by Merck UK Ltd, Poole, Dorset).
• a device which does show such a minimum may be constructed according to PCT GB 88/01004 and utilising materials such as e.g. commercially available SCE8 (Merck UK Ltd).
• Other examples of prior art materials are exemplified by PCT/GB 86/00040, PCT GB 87/00441 and UK 2232416B.
• Certain compounds of the invention may be useful in laser addressed applications in which laser beams are used to scan across the surface of the material or leave a written impression thereon.
• these materials have consisted of organic materials which are at least partially transparent in the visible region.
• the technique relies upon localised absorption of laser energy which causes localised heating and in turn alters the optical properties of the otherwise transparent material in the region of contact with the laser beam.
• a written impression of its path is left behind.
• One of the most important of these applications is in laser addressed optical storage devices, and in laser addressed projection displays in which light is directed through a cell containing the material and is projected onto a screen. Such devices have been described by Khan Appl. Phys. Lett. vol.
• Gallium arsenide lasers provide laser light at wavelengths of about 850nm, and are useful for the above applications.
• the laser wavelength may be reduced down to about 750nm.
• the storage density can be increased by using a laser of shorter wavelength.
• some compounds of the present invention may be suitable as optical storage media and may be combined with dyes for use in laser addressed systems, for example in optical recording media.
• the compounds of the present invention may also be used in pyroelectric devices for example detectors, steering arrays and vidicon cameras.
• a pyroelectric detector consists of electrode plates at least one of which may be pixellated. In operation the detector is exposed to radiation R, for example infrared radiation, which is absorbed by an electrode. This results in a rise in temperature which is transmitted to a layer of pyroelectric material by conduction, The change in temperature results in a thermal expansion and a charge is generated. This change in charge is usually small when compared with the charge output due to the change in the spontaneous polarisation, Ps with a change in temperature; this constitutes the primary pyroelectric effect. A change in charge results in a change in potential difference between the electrodes. The charge on each pixel may be read out and the resulting signal is used to modulate scanning circuits in, for example, a video monitor and for a visual image of the infra red scans.
• R for example infrared radiation
• the selective reflective properties of the materials described by the current invention may also allow for materials of the current invention to be used in inks and paints and they may therefore be useful in anti-counterfeiting operation. They may also be used in so-called security inks. Other applications include thermal control management, for example the materials may be included in a coating which may be applied to one or more windows in order to reflect infra-red radiation.
• Spatial light modulators comprises a liquid crystal cell formed by typically two glass walls and 0.1-10 ⁇ m e.g. 2.5 ⁇ m thick spacer.
• the inner faces of the walls carry thin transparent indium tin oxide electrodes connected to a variable voltage source.
• On top of the electrodes are surface alignment layers e.g. of rubbed polyimide described in detail later.
• Other alignment techniques are also suitable e.g. non-rubbing techniques such as evaporation of S1O2.
• a layer of liquid crystal material is contained between the walls and spacer.
• a linear polariser In front of the cell is a linear polariser; behind the cell is a quarter waveplate (this may be optional) and a mirror.
• An example of a linear polariser is a polarising beam splitter (not illustrated here).
• Suitable devices in which the materials of the current invention may be incorporated include beam steerers, shutters, modulators and pyroelectric and piezoelectric sensors.
• the materials of the present invention may also be useful as dopants in ferroelectric liquid crystal devices, which may be multiplexed, or they may be used in active backplane ferroelectric liquid crystal systems.
• the materials of the present invention may also be useful as host materials.
• the materials of the present invention may be included in mixtures which also contain one or more dopants.
• Trimethyl borate (16.21 g, 156 mmol) was added dropwise, keeping the temperature below -10 °C.
• the mixture was allowed to return to room temperature and hydrochloric acid (5M, 36 ml) was added whilst stirring (45 min).
• the mixture was then poured into water and ether added.
• the separated aqueous layer was washed twice with ether (2 x 200 ml), and the product was extracted from the combined ethereal phases as the sodium salt by washing with potassium hydroxide (2M, 40 ml),
• the basic solution was then washed with ether, and the product released by acidification to pH3 by adding hydrochloric acid (cone.) to the aqueous solution.
• the product was then extracted with ether (2 x 200 ml), which was washed with water and brine, dried (MgSO4), and the solvent removed in vacuo. A pale-brown solid was obtained. Yield 15.8 g (92%).
• Step 5 Preparation of 4-Propylbenzeneboronic acid l-Bromo-4-propylbenzene (11.0 g, 55 mmol) obtained in step 2, magnesium (1.5 g, 61 mmol), trimethyl borate (11.4 g, 110 mmol) were reacted using a method analogous to that described in Example 1 step 2. An off-white solid was obtained. Yield 7.5 g (83%). MS m/z 164(M + ), 147, 135, 91, 43(100%)
• Example 2 Using a method analogous to that described in Example 1 step 2, the title compound was obtained from l-bromo-4-penyltbenzene from Step 1 (15.2 g, 67 mmol), magnesium (1.9 g, 77 mmol), and trimethyl borate (13.9 g, 134 mmol). The product was obtained as a waxy white solid.
• 4-Hexylbenzeneboronic acid was obtained from the product of step 1(8.0 g, 33 mmol), magnesium (1.0 g, 40 mmol), and trimethyl borate (6.9 g, 66 mmol) using a method analogous to that describedin Example 1 step 2. A light-brown solid was obtained.
• 4-Octylbenzeneboronic acid was prepared and purified using a method analogous to that described in Example 1 step 2 using the following materials: l-Bromo-4-octylbenzene from step 1(6.0 g, 22 mmol), magnesium (0.7 g, 27 mmol), trimethyl borate (4.6 g, 44 mmol). A pale-yellow solid was obtained. Yield 4.2 g (82%). MS m/z 648(3M + -3H 2 O), (100%), 551, 452, 353, 187
• the title compound was prepared and purified in a similar manner to that described in Example 1 step using the following reagents: l-Bromo-4-nonylbenzene from step 1(5.0 g, 18 mmol), magnesium (0.5 g, 22 mmol), trimethyl borate (3.7 g, 36 mmol). A waxy white solid was obtained.
• Step 4 Preparation of 5-(4-Nonyloxyphenyl)benzofb1furan-2-carboxamide
• the product of step 3 (0.9 g, 2.4 mmol), thionyl chloride (0.9 g, 7.2 mmol), and ammonia (d 0.880, 1.4 ml) were used in a method analogous to that described in Example 1 step 6 to yield the desired compound as a white crystalline solid. Yield 0.8 g (82%), mp 201-202 °C.
• Step l Preparation of 2-(4-Pentylcvclohexyl)phenoxy)acetaldehyde dimethyl acetal
• 4-(4-pentylcyclohexyl)phenol (10.0 g, 41 mmol)
• bromoacetaldehyde dimethyl acetal 10.1 g, 60 mmol
• potassium carbonate 11.1 g, 80 mmol
• potassium iodide 0.5 g, 3 mmol
• the separated aqueous phase was saturated with salt and washed with ether 2 x 200 ml).
• the combined organic layers were washed with sodium hydroxide solution (10%), water, dried (Na 2 SO4), and the solvent removed in vacuo.
• the crude product was purified by flash chromatography [neutral alumina / petroleum fraction (bp 40-60 °C), dichloromethane 1: 1], A pale yellow liquid was obtained. Yield 10.1 g (75%), bp 195 °C at 0.01 mm Hg.
• step 1 The product of step 1 (10.1 g, 31 mmol) was added dropwise to polyphosphoric acid (13 g) in chlorobenzene (130 ml) under reflux with stirring. The mixture was refluxed overnight (glc analysis indicated a complete reaction), and allowed to cool. The solvent was removed in vacuo and sodium hydroxide solution (10%) and ether were added. The separated aqueous layer was washed with ether (2 x 200 ml) and the combined organic layers washed with water and brine, and dried (MgSO4). The solvent was removed in vacuo and the crude product purified by flash chromatography [silica gel / petroleum fraction (bp 40-60 °C)], followed by distillation. A pale-yellow liquid was obtained. Yield 4.1 g (48%), bp 165 °C at 0.01 mm Hg.
• step 3 The product of step 3 (0.2 g, 0.6 mmol), thionyl chloride (0.2 g, 1.8 mmol), ammonia
• 5-Bromobenzo[b]furan was prepared and purified in a similar manner to that described in Example 8 step 2 using the following reagents: The product of step 1 (52.6 g, 202 mmol), polyphosphoric acid (85.0 g). A colourless liquid was obtained.
• Step 4 Preparation of 5-Cvanobenzolblfuran-2-boronic acid
• Example 1 step 4 using the following reagents: l-bromo-4-propylbenzene obtained as described in Example 2 step 4 (1.0 g, 5 mmol), the product of step 4 above (1.1 g, 6 mmol), sodium carbonate (1.3 g, 13 mmol), tetrakis(triphenylphosphine)palladium(0) (0.3 g, 0.3 mmol). Colourless crystals were obtained. Yield 0.1 g (8%). Purity (hplc) 98%. Transitions (°C) K 98.0 Iso. l ⁇ L NMR CD 2 Cl 2 / ⁇ 7.93 (1H, dd), 7.79 (2H, d), 7.61 (1H, d),
• Compound 54 was prepared and purified in a similar manner to that described in Example 1 step 7 from the following reagents: Compound 44 (Example 13) (0.6 g, 1.6 mmol), thionyl chloride (1.9 g, 16 mmol). Colourless crystals were obtained. Yield 0.2 g (39%). Purity (hplc) >99.9%. Transitions (°C) K 86.5 N 87.5 Iso. X H NMR CD 2 Cl 2 / ⁇ 7.92 (1H, d), 7.79 (2H, d), 7.61 (1H, d),
• Benzonitrile-4-boronic acid was prepared and purified in a similar manner to that described in Example 9 step 4 using the following reagents:
• the separated aqueous layer was washed with ether (2 x 50 ml) and the combined organic layers were washed with sodium hydroxide solution (10%, 30 ml).
• the separated aqueous layer was washed with light petroleum (40-60 °C fraction) and acidified to pH3 with hydrochloric acid (5M). It was then washed with ether (2 x 50 ml).
• the combined organic layers were washed with water and brine, dried (MgSO4), and the solvent removed in vacuo.
• Compound 49 was prepared and purified in a similar manner to that described in Example 1 step 4 using the following reagents: l-Iodo-4-pentylbenzene from step 2(3 g, 11 mmol), 5-bromobenzo[b]furan-2-boronic acid from step 1(1.3 g, 5 mmol), sodium carbonate (1.4 g, 13.5 mmol), tetrakis(triphenylphosphine)palladium(0) (0.3 g, 0.3 mmol) The product was recrystallised from hexane. A white crystalline product was obtained. Yield 0.3 g (16%), mp 147-150 °C.
• Compound 50 was prepared in a similar manner to that described in Example 1 step 4 using the following reagents: d.
• Compound 49 (Example 22) (0.3 g, 0.9 mmol), benzonitrile-4-boronic acid (Example 19 step 1)(0.2 g, 1.0 mmol), sodium carbonate (0.2 g, 2 mmol), tetrakis(triphenylphosphine)palladium(0) (0.03 g, 0.03 mmol)
• the product was purified by flash chromatography [silica gel / hexane, propionitrile 40: 1], followed by recrystallisation (ethanol). A white solid was obtained. Yield 0.04 g (12%). Purity (hplc) 98%.
• Pentylphenyl)benzo[b]furan-2-boronic acid was prepared and purified in a similar manner to that described in Example 20 step 2 from the following reagents: 5-(4-Pentylphenyl)benzo[b]furan from step 1 (1.2 g, 5 mmol), n-butyllithium (2.5M in hexanes, 2 ml, 5 mmol), trimethyl borate (0.9 g, 9 mmol). A pale-pink solid was obtained.
• Compound 35 was prepared and purified in a similar manner to that described in Example 20 step 3 from the following reagents: Benzonitril-4-boronic acid (example 19 step 1) (0.7 g, 4 mmol), the product of step 2 above (1.1 g, 4 mmol), sodium carbonate (1.1 g, 10 mmol), tetrakis(triphenylphosphine)palladium(0) (0.2 g, 0.2 mmol). The product was recrystallised from carbon tetrachloride. Colourless, rhombic crystals were obtained.
• 5-Pentylbenzo[b]furan was prepared and purified in a similar manner to that described in Example 8 step 2 from the following reagents;
• the product of step 1 above (4.8 g, 19 mmol), polyphosphoric acid (4.6 g).
• a colourless liquid was obtained.
• step 2 The product of step 2 (2.2 g, 12 mmol), n-butyllithium (2.5M in hexanes, 5.2 ml, 13 mmol), trimethyl borate (2.59 g, 24 mmol) were reacted using a method analogous to that described in Example 20 step 2 to yield the title compound.
• the product was recrystallised from ethanol. A white crystalline product was obtained.
• Compound 51 was prepared and purified from the product of step 4 above (1.0 g, 3 mmol), the product of step 3 above (0.8 g, 4 mmol), sodium carbonate (0.9 g, 8 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.1 g, 0.1 mmol) in method analogous to that described in Example 20 step 3.
• the product was recrystallised from ethanol. Colourless, plate-like crystals were obtained. Yield 36 mg (2%). Purity (hplc) 99.5%. Transitions (°C) K 150.8 B 167.0 N 280.3 Iso.
• Step 2 Preparation of 2-Pentylbenzo[blfuran-5-boronic acid
• the title compound was prepared and purified from the product of step 1 (2.5 g, 9 mmol), magnesium (0.3 g, 11 mmol) and trimethyl borate (2.09 g, 19 mmol) in a similar manner to that described in Example 1 step 2.
• a pale-yellow solid was obtained. Yield in g (78%).
• Compound 52 was prepared and purified in a similar manner to that described in Example 1 step 4 from the product of step 3 above (1.7 g, 7 mmol), 4-cyano-4'- iodobiphenyl (Example 25 step 2) (1.7 g, 6 mmol), sodium carbonate (1.5 g, 14 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.2 g, 0.2 mmol). The reaction was carried out with exclusion of light. A white crystalline solid was obtained. Yield 0.1 g (5%).
• Benzo[b]furan-5-boronic acid was prepared and purified from 5- bromobenzo[b]furan (Example 9 step 2) (2.0 g, 10 mmol), magnesium (0.3 g, 12 mmol) and trimethyl borate (2.1 g, 20 mmol)in a similar manner to that described in Example 1 step 2.
• Trifluoromethanesulphonic anhydride (6.5 g, 23 mmol) was added dropwise to a stirred, cooled (0 °C) solution of 4-(tr ⁇ «s-n-yentylcyclohexyl)phenol (5.0 g, 20 mmol) in dry pyridine (80 ml) under dry nitrogen. The mixture was stirred at room temperature overnight. It was then poured into water and ether added. The separated aqueous layer was washed with ether (2 x 100 ml). The combined organic layers were washed with water, hydrochloric acid (10%) (twice), and brine, dried (MgSO4), and the solvent removed in vacuo. The product was purified by flash chromatography [silica gel / petroleum fraction (bp 40-60 °C), dichloromethane 7:3] A pale yellow oil was obtained. Yield 5.2 g (69%).
• Compound 54 was prepared and purified in a similar manner to that described in Example 1 step 6 using the following reagents:
• Ethyl 5-methoxybenzo[blfuran-2-carboxylate was prepared and purified from 5- methoxysalicylaldehyde (20.0 g, 131 mmol), diethyl bromomalonate (26.3 g, 110 mmol), potassium carbonate (32.5 g, 236 mmol), potassium iodide (0.9 g,
• step 3 The product of step 3 (4.8 g, 25 mmol) and thionyl chloride (14.3 g, 120 mmol) were converted to the title compound in a similar manner to that described in Example 1 step 7.
• the product was recrystallised from methanol. White needle-like crystals were obtained.
• step 4 A mixture of the product of step 4 (0.7 g, 4 mmol) and pyridinium chloride (4.6 g, 40 mmol) was refluxed (3 min). The reaction mixture was then poured into ice / water. The product was extracted into ether (2 x 200 ml), and the combined organic extracts were washed with water and brine and dried (MgSO4), and the solvent removed in vacuo. The product was recrystallised from ethanol. Colourless crystals were obtained. Yield 0.5 g (80%). Step 6
• step 5 (0.5 g, 3 mmol) and tra «s-4-pentylcyclohexylcarboxylic acid (0.6 g, 3 mmol) were dissolved in dry dichloromethane (30 ml) and (4-N,N- dimethylamino)pyridine (0.1 g, 1 mmol) was added, and the mixture stirred. N,N'- Dicyclohexylcarbodiimide (0.6 g, 3 mmol) was then added, and stirring was continued (24 h). The reaction was monitored by tic analysis. The precipitate of N,N'- dicyclohexylurea was filtered off, and the solvent removed in vacuo. The product was purified by flash chromatography [silica gel / petroleum fraction (bp 40-60 °C), dichloromethane 7:3], followed by recrystallization (ethanol). A white crystalline solid was obtained.
• Example 31 Example 31
• step 1 The product of step 1, (104.3 g, 376 mmol) and polyphosphoric acid (156.2 g)were converted to 5-bromobenzo[b]thiophene in Example 8 step 2. A white crystalline solid was obtained.
• step 2 The product of step 2 (4.6 g, 22 mmol), 4-heptylbenzeneboronic acid (Example 1 step 2) (5.7 g, 26 mmol), sodium carbonate (5.8 g, 55 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.8 g, 0.7mmol) were treated as described in Example 1 step 4 to give the title compound. A colourless was obtained, which solidified on cooling.
• Compound 100 was prepared and purified in a similar manner to that described in Example 8 step 3 using the following reagents: the product of step 3 above (2.5 g, 8 mmol) and n-butyllithium (2.5M in hexanes, 3.4 ml, 9 mmol).
• Compound 102 was prepared and purified in a similar manner to that described in Example 1 step 7 from Compound 61 (Example 31) (1.0 g, 3 mmol), thionyl chloride (3.3 g, 28 mmol). A white crystalline solid was obtained. Yield 0.4 g (43%), mp 93.2 °C.
• Compound 64 was prepared and purified in a similar manner to that described for the preparation of compound 24 using the quantities stated.
• Compound 63 in Table 1 (0.1 g, 0.3 mmol), sulphuric acid (cone.) (0.1 ml, 0.05 mmol), ethanol (5 ml).
• Phosphorus pentoxide (94.9 g, 669.0 mmol) was carefully added to a solution of l-(2,3-Difluorophenyl)heptan-l-ol (61.1 g, 267.0 mmol) from step 1 in pentane (90 ml) and the mixture was stirred overnight with exclusion of moisture.
• glc analysis revealed a complete reaction, the mixture was poured into ice/water (300 ml) and ether added (200 ml). The separated aqueous layer was washed with ether (2 x 300 ml). The combined organic layers were washed with water and brine and dried (MgSO4), and the solvent removed in vacuo. The residue was then distilled. A colourless oil was obtained.
• step 2 A mixture of the product of step 2 (30.5 g, 145 mmol) and palladium-on- charcoal (10% w/w, 1.0 g, 0.9 mmol) in ethanol (400 ml) was stirred in an atmosphere of hydrogen (glc analysis revealed a complete reaction). The mixture was then filtered through a pad of ⁇ yflo Supercef and the solvent was removed in vacuo. The product was purified by distillation.
• the compound was prepared and stored under exclusion of light. A pale-yellow liquid was obtained.
• the title compound was prepared in a similar manner to that described for the preparation of 4'-pentylbiphenylboronic acid in Example 20(2) using the quantities stated.
• the product of step 2 (1.2 g, 3.7 mmol), n-butyllithium (2.5M in hexanes, 1.6 ml, 4.0 mmol), trimethyl borate (0.8 g, 7.4 mmol).
• a white solid was obtained.
• Benzo[b]furan-5-boronic acid (Example 22(1)) (0.7 g, 4.2 mmol), 2-chloro-5- heptylpyrimidine (0.8 g, 3.7 mmol) tetrakis(triphenylphosphine)palladium(0) (0.1 g, 0.1 mmol), sodium carbonate (0.9 g, 8.8 mmol).

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