# US 5,344,585 A · Use of 4-fluoropyrimidine derivatives as component for ferroelectric liquid crystal mixtures

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- Number: US 5,344,585 A
- Document ID: US5344585A
- Status: Granted
- Kind: A
- Application number: 07/758,633
- Filed: 1991-09-12
- Granted: 1994-09-06
- Earliest claimed: 1990-09-14
- Assignees: Hoechst Aktiengesellschaft
- Inventors: Rainer Wingen; Gerhard Illian
- Web page: https://patentgrep.com/patent/US5344585A

## CPC

- C09K 19/42: Mixtures of liquid crystal compounds covered by two or more of the preceding groups C09K19/06 - C09K19/40
- C07D 239/34: One oxygen atom
- C07D 405/12: linked by a chain containing hetero atoms as chain links
- C07F 7/0812: {comprising a heterocyclic ring}
- C09K 19/3458: {Uncondensed pyrimidines}
- C09K 19/3466: {Pyrimidine with at least another heterocycle in the chain}
- C09K 19/406: {containing silicon}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)

## Abstract

The use of a fluoropyrimidine derivative of the general formula (I) as component in a ferroelectric liquid crystal mixture comprising 2 to 20 components, ##STR1## in which the symbols have the following meaning: R.sup.1 and R.sup.2 independently of one another are, for example, straight-chain or branched alkyl having 1 to 16 carbon atoms, a and b are, for example, both equal to 0 or 1, ##STR2## for example, phenylene or cyclohexylene, and --M.sup.1 -- is, for example, --CO--O--, --O--CO--, --CH.sub.2 --O-- or --O--CH.sub.2, leads to improved switching characteristics in electrooptical display devices.

## Claims

### Claim 1

A ferroelectric liquid crystal mixture comprising 2 to 20 components and comprising at least one 4-fluoropyrimidine of the formula (I): ##STR19## in which the symbols have the following meaning: R.sup.1 and R.sup.2 independently of one another are straight-chain or branched alkyl having 1 to 16 carbon atoms, it being possible for one or two non-adjacent --CH.sub.2 -- groups to be replaced by --O--, --S--, --CO--, --CO--O--, --O--CO--, --CH.dbd.CH--, --OC(O)O--, --C.dbd.C--, ##STR20## or --Si(CH.sub.3).sub.2 --, or are one of the following groups: ##STR21## ##STR22## R.sup.3 and R.sup.4 independently of one another are H or alkyl having 1 to 16 carbon atoms or alkenyl having 2 to 16 carbon atoms, or R.sup.3 and R.sup.4 together are --(CH.sub.2).sub.4 -- or --(CH.sub.2).sub.5 --,
--M.sup.1 -- is --CO--O, --O--CO--, --CH.sub.2 --O--, --O--CH.sub.2 --, --C.dbd.C--, --CH.dbd.CH--, --CH.sub.2 --CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2 --, --CH.sub.2 CH.sub.2 CH.sub.2 O--
--M.sup.2 -- is CH.sub.2 --O--, --O--CH.sub.2, ##STR23## or a single bond a and b independently of one another are zero or one, on condition that a is zero if b is zero, and ##STR24## independently of one another are 1,4-phenylene, 1,4-cyclohexylene, 2,5-pyridinediyl or (1,3,4)thiadiazol-2,5-diyl.

### Claim 2 (depends on 1)

A mixture as claimed in claim 1, wherein the symbols in formula (I) have the following meaning:
R.sup.1 and R.sup.2 independently of one another are alkyl having 1 to 16 carbon atoms, it being possible for the --CH.sub.2 -- group to be replaced by --O--, --CO--O--, --O--CO--, ##STR25## or --Si(CH.sub.3).sub.2 --, or are ##STR26## --M.sup.1 -- is --CO--O, O--CH--, CH.sub.2 O or --OCH.sub.2 -- --M.sup.2 -- is --CO--O-- or --CH.sub.2 O-- ##STR27## independently of one another are 1,4-phenylene or 1,4-cyclohexylene, R.sup.3 and R.sup.4 are both H or C.sub.1 -C.sub.5 -alkyl, or R.sup.3 and R.sup.4 together are --(CH.sub.2).sub.5 --, and
a, b independently of one another are zero or one, on condition that a is zero if b is zero.

### Claim 3 (depends on 1)

A mixture as claimed in claim 1, wherein the symbols in formula (I) have the following meaning:
R.sup.1 and R.sup.2 independently of one another are alkyl having 5 to 12 carbon atoms, it being possible for one --CH.sub.2 -- group to be replaced by --O-- and for a further --CH.sub.2 -- group to be replaced by ##STR28## or are ##STR29## --M.sup.1 -- is --CO--O-- or --O--CO--, ##STR30## is 1,4-phenylene, ##STR31## is 1,4-cyclohexylene and R.sup.3 and R.sup.4 are both H or C.sub.1 -C.sub.5 -alkyl, or R.sup.3 and R.sup.4 together are --(CH.sub.2).sub.5 --, and
a=b and is zero or one.

### Claim 4 (depends on 1)

A mixture as claimed in claim 1, wherein, in formula (I), the groups R.sup.1 and R.sup.2 independently of one another are alkyl having 5 to 12 carbon atoms, it being possible for one --CH.sub.2 -- group to be replaced by --CO--O--, --O--CO-- or --O-- and the terminal --CH.sub.2 -- group being replaced by ##STR32##

### Claim 5 (depends on 1)

A ferroelectric liquid crystal switching and display element comprising support plates, electrodes, at least one orientation layer, and a ferroelectric liquid crystal medium, which element contains a ferroelectric liquid crystal mixture as claimed in claim 1 as liquid crystal medium.

### Claim 6 (depends on 5)

A ferroelectric liquid crystal switching and display element as claimed in claim 5, further comprising an antireflex, passivation, compensation or barrier layer.

### Claim 7 (depends on 1)

A mixture as claimed in claim 1, wherein the compound of the formula (I) is 4-fluoro-5-octyl-oxy-2-(4-octyloxyphenyl) pyrimidine.