Cyanopyrimidine derivatives

Abstract

The present invention relates to compounds of formula M ##STR00001##
in which R.sup.M has the meaning indicated in claim 1, to liquid crystal mixture comprising the same, to the use of these liquid-crystal media, in particular in components for high-frequency technology, and to components of this type which contain media according to the invention, and to the production and use of these components. The components according to the invention are suitable, in particular, as phase shifters in the microwave and millimetre wave region, for microwave and millimetre wave array antennae and very particularly for so-called tunable “reflectarrays”.

Claims

1. A liquid crystal medium comprising one or more compounds of formula M ##STR00210## wherein R.sup.M denotes alkyl or alkenyl having 1 to 7 C atoms, one or more compounds of formula IA ##STR00211## wherein r denotes 0 or 1, ##STR00212## independently of one another, denote ##STR00213## wherein Y denotes S or O and wherein in the 1,4-phenylene groups, one C—H group or a plurality of CH groups, may be replaced by N, and L.sup.0 on each occurrence, independently of one another, denotes H, Br, Cl, F, —CN, —NCS, —SCN, SF.sub.5, C.sub.1-C.sub.10 alkyl, C1-C.sub.10 alkoxy, C.sub.3-C.sub.6 cycloalkyl or a mono- or polyfluorinated C.sub.1-C.sub.10 alkyl or alkoxy group, R.sup.03, R.sup.04 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 15 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by —C≡C—, —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —C(O)O—, —OC(O)—, —C(O)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another and, optionally, independently of one another, R.sup.03 may also denote ethynyl (i.e. —C≡CH) and R.sup.04 may also denote H, and R.sup.05 and R.sup.06 each, independently of one another, denote a halogenated or unsubstituted alkyl radical having 1 to 6 C atoms, where, in addition, one or more CH.sub.2 groups in these radicals may each be replaced, independently of one another, by —C≡C—, —CH═CH—, —CF═CF—, —CF═CH—, —CH═CF—, —C(O)O—, —OC(O)—, —C(O)—, —O— or —S— in such a way that O or S atoms are not linked directly to one another, and one or more compounds of formula VI ##STR00214## in which L61 denotes R.sup.61 and, in the case where Z.sup.61 and/or Z.sup.62 denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X.sup.61, L62 denotes R.sup.62 and, in the case where Z.sup.61 and/or Z.sup.62 denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X.sup.62, R.sup.61 and R.sup.62, independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or un-fluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, X.sup.61 and X.sup.62, independently of one another, denote F or Cl, —CN, —NCS, —SF.sub.5, fluorinated alkyl or alkoxy having 1 to 7 C atoms or fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 C atoms, or —NCS, one of Z.sup.61 and Z.sup.62 denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and ##STR00215## independently of one another, denote ##STR00216## said liquid crystalline medium having a birefringence of 0.200 to 0.90.

2. The liquid crystal medium according to claim 1, wherein one or more compounds of formula IA are compounds of formulae IA-1 to IA-7 ##STR00217## wherein R.sup.03 and R.sup.04 denote alkyl having 1 to 7 C atoms.

3. The liquid crystal medium according to claim 1, comprising one or more compounds of formula I ##STR00218## wherein ##STR00219## denotes ##STR00220## L.sup.1 denotes H, alkyl having 1 to 6 C atoms, cycloalkyl having 3 to 6 C atoms or cycloalkenyl having 4 to 6 C atoms, X.sup.1 denotes H or alkyl having 1 to 3 C atoms or halogen, R.sup.11 to R.sup.14 independently of one another, denote unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and alternatively one of R.sup.13 and R.sup.14 or both also denote H.

4. The liquid crystal medium according to claim 1, wherein one or more compounds of formula VI are compounds of the formula VI-1a ##STR00221## wherein R.sup.21 and R.sup.22 have the meaning indicated in claim 1.

5. The liquid crystal medium according to claim 1, additionally comprising one or more of the following components, components C to F: a strongly dielectrically positive component, component C, which has a dielectric anisotropy of 10 or more at a temperature of 20° C. and a frequency of 1 kHz, a strongly dielectrically negative component, component D, which has a dielectric anisotropy of −5 or less at a temperature of 20° C. and a frequency of 1 kHz, a component, component E, which consists of compounds having seven or more five- or six-membered rings and has a dielectric anisotropy in the range from more than −5.0 to less than 10.0 at a temperature of 20° C. and a frequency of 1 kHz, and/or a component, component F, which and consists of compounds having up to six five- or six-membered rings and also has a dielectric anisotropy in the range from more than −5.0 to less than 10.0 at a temperature of 20° C. and a frequency of 1 kHz.

6. A process for the preparation of a liquid-crystal medium according to claim 1, comprising mixing one or more compounds of formula M with one or more further compounds and/or with one or more additives.

7. A high-frequency technology component, that is a phase shifter, varactor, wireless or radio wave antenna array, or matching circuit adaptive filter, comprising in said component a liquid-crystal medium according to claim 1.

8. A microwave antenna array, comprising in said array a liquid-crystal medium according to claim 1.

Description

EXAMPLES

(1) The following examples illustrate the present invention without limiting it in any way. However, it becomes clear to the person skilled in the art from the physical properties what properties can be achieved and in what ranges they can be modified. In particular, the combination of the various properties which can preferably be achieved is thus well defined for the person skilled in the art.

Synthesis Example S1

Step 1

(2) ##STR00205##
16.3 g (0.67 mol) magnesium turnings are placed in a round bottom flask under 90 ml THF and 70 ml of 1-brom-4-hexyl benzene (150 g, 0.622 mol) in 400 ml THF are added slowly. The reaction is started by addition of one drop of bromine. Once the reaction has started, the rest of the hexylbromide solution is added in such a way that the reaction is kept under reflux. After the addition is complete, the reaction is refluxed for 1 h, cooled to −25° C. and diluted with 100 ml THF. Then, 75 ml (0.67 mol) trimethylborate in 90 ml THF are added so that the temperature is kept between −25° C. and 0° C. Another 100 ml THF are added and the reaction is stirred 1 h at 0 to 5° C. Water is added and the mixture is acidified with hydrochloric acid. Extraction with MTB ether followed by evaporation of the solvent yields 4-hexylbenzene boronic acid as a colourless solid (purity 86% by HPLC).

Step 2

(3) ##STR00206##

(4) 22.7 g (15 mmol) sodiumtetraborate-tetrahydrate are dissolved in 100 ml water and 1.4g (2 mmol) bis(triphenylphosphino)palladium(II)chloride and two drops of hydrazinium hydroxide are added. After 5 min, 25 g 4-hexylbenzene boronic acid of step 1 and 20.4 g 1-bromo-3,5-difluorobenzene (10 mmol) in 100 ml THF are added and the reaction is refluxed overnight. The solvent is evaporated and the residue is filtered with n-heptane through silica to give 1,3-difluoro-5-(4-hexylphenyl)benzene as colourless crystals.

Step 3

(5) ##STR00207##
29.3 g 1,3-difluoro-5-(4-hexylphenyl)benzene are dissolved in 350 ml THF, cooled to −70° C. and 42 ml hexyllithium (30% in hexane, 0.104 mol) are added dropwise. The mixture is stirred at −65° C. for one hour and 15.4 ml (0.135 mol) in trimethylborate in 50 ml THF are added dropwise. After an additional hour, it is warmed to −10° C. and hydrolysed with conc. hydrochloric acid. The solution is washed with water, the solvent is removed i. vac. and the residue is treated with hot heptane, filtered off and dried, to give 2,6-difluoro-4-(4-hexylphenyl)benzene boronic acid as colourless solid.

Step 4

(6) ##STR00208##
40 ml water, 4.4 g (52.2 mmol) sodium carbonate, 10 g (31 mmol) 2,6-difluoro-4-(4-hexylphenyl)benzene boronic acid and 4.8 g (26 mmol) 2-cyano-5-bromopyrimidine are dissolved in 80 ml THF under inert atmosphere and 27 mg bis(tert-butylphospino)palladium(0) (52 mmol) are added. The reaction is refluxed for 4 h and stirred at room temp. overnight. The solvent is removed i. vac. and the crude product is purified by column chromatography with toluene on silica. Crystallisation from isopropanol yields 5-[4-(4-hexylphenyl)-2,6-difluoro-phenyl]pyrimidine-2-carbonitrile (PUM-6-N) as colourless crystals.

(7) In analogy to example S1, the following compounds are obtained:

(8) TABLE-US-00005 09 Ex- am- Phase ple R.sup.M sequence Δϵ Δn γ.sub.1 S1 n-C.sub.6H.sub.13 K 98 55.0 0.2696 2080 N 146.3 I S2 n-C.sub.3H.sub.7— K 122 N 169.1 I S3 n-C.sub.4H.sub.9 K 118 66.7 0.2815 1559 N 152.6 I S4 n-C.sub.5H.sub.11 K 118 55.2 0.2875 N 155.6 I S5 C.sub.2H.sub.5— S6 n-C.sub.7H.sub.15 S7 CH.sub.2═CH—CH.sub.2 S8 CH.sub.2═CH—(CH.sub.2).sub.2— S9 CH.sub.2═CH—(CH.sub.2).sub.3— S10 CH.sub.2═CH—(CH.sub.2).sub.4— S11 CH.sub.2═CH—(CH.sub.2).sub.5— S12 E-CH.sub.3—CH═CH—CH.sub.2— S13 E-CH.sub.3—CH═CH—(CH.sub.2).sub.2— S14 E-CH.sub.3—CH═CH—(CH.sub.2).sub.3— S15 E-CH.sub.3—CH═CH—(CH.sub.2).sub.4—

Use Examples

(9) Comparative Example C-1 and Mixture Example M-1 are prepared and characterised as shown in the following tables.

Comparative Example C-1

(10) TABLE-US-00006 Composition Compound No. Abbreviation c [%] 1 CCP-V-1 8.0 2 PPTUI-3-2 8.0 3 PPTUI-3-4 15.0 4 PPTUI-4-4 30.0 5 CPGP-5-2 3.0 6 CPGP-5-3 3.0 7 PTPI(1)-4-A1 29.0 8 UMU-6-N 4.0 Σ 100.0 Physical properties T(N, I) = 122° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5219 Δε (20° C., 1 kHz) = 3.8 ε.sub.∥ = 6.7 γ.sub.1 (20° C.) = 582 mPa .Math. s K.sub.1 = 13.8 K.sub.3 = 24.2 V.sub.0 = 2.00 V

Mixture Example M-1

(11) TABLE-US-00007 Composition Compound No. Abbreviation c [%] 1 CCP-V-1 8.0 2 PPTUI-3-2 8.0 3 PPTUI-3-4 15.0 4 PPTUI-4-4 30.0 5 CPGP-5-2 3.0 6 CPGP-5-3 3.0 7 PTPI(1)-4-A1 29.0 8 PUM-6-N 4.0 Σ 100.0 Physical properties T(N, I) = 125° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5220 Δε (20° C., 1 kHz) = 3.4 ε.sub.∥ = 6.2 γ.sub.1 (20° C.) = 561 mPa .Math. s K.sub.1 = 13.7 K.sub.3 = 26.4 V.sub.0 = 2.12 V

(12) TABLE-US-00008 TABLE 1 Example ε.sub.r, ∥ tan δ.sub.ε r, ∥ ε.sub.r, ⊥ tan δ.sub.ε r, ⊥ Δε.sub.r τ η C-1 3.12 0.0028 2.39 0.0098 0.73 0.234 24.0 M-1 3.13 0.0030 2.40 0.0095 0.73 0.232 24.5

(13) The comparison of Comparative Example C-1 and Mixture Example M-1 above shows that surprisingly, by using PUM-6-N instead of UMU-6-N a liquid-crystal mixture (M-1) with higher clearing temperature and lower rotational viscosity can be achieved. At the same M-1 has very similar excellent application properties with even an improved material η.

(14) Mixture examples M-2 to M-6 are prepared and characterised as shown in the following tables.

Mixture Example M-2

(15) TABLE-US-00009 Composition Compound No. Abbreviation c [%] 1 PPTUI-3-2 10.0 2 PPTUI-3-4 16.0 3 PPTUI-4-4 30.0 4 CC-3-V 9.0 5 PTPI(1)-4-A1 30.0 6 PUM-6-N 5.0 Σ 100.0 Physical properties T(N, I) = 103° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5203 Δε (20° C., 1 kHz) = 3.9 ε.sub.∥ = 6.7 γ.sub.1 (20° C.) = 377 mPa .Math. s K.sub.1 = 11.6 K.sub.3 = 19.8 V.sub.0 = 1.83 V

Mixture Example M-3

(16) TABLE-US-00010 Composition Compound No. Abbreviation c [%] 1 CCP-V-1 7.0 2 PPTUI-3-2 8.0 3 PPTUI-3-4 15.0 4 PPTUI-4-4 30.0 5 CPGP-5-2 3.0 6 CPGP-5-3 3.0 7 PTPI(1)-4-A1 29.0 8 PUM-6-N 5.0 Σ 100.0 Physical properties T(N, I) = 125° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5221 Δε (20° C., 1 kHz) = 4.0 ε.sub.∥ = 6.9 γ.sub.1 (20° C.) = 565 mPa .Math. s K.sub.1 = 13.8 K.sub.3 = 23.2 V.sub.0 = 1.96 V

Mixture Example M-4

(17) TABLE-US-00011 Composition Compound No. Abbreviation c [%] 1 PPTUI-3-2 10.0 2 PPTUI-3-4 16.0 3 PPTUI-4-4 30.0 4 CC-3-V 10.0 5 PTPI(1)-4-A1 30.0 6 PUM-6-N 4.0 Σ 100.0% Physical properties T(N, I) = 102° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5191 Δε (20° C., 1 kHz) = 3.3 ε.sub.∥ = 6.1 γ.sub.1 (20° C.) = 370 mPa .Math. s K.sub.1 = 11.4 K.sub.3 = 21.6 V.sub.0 = 1.96 V

Mixture Example M-5

(18) TABLE-US-00012 Composition Compound No. Abbreviation c [%] 1 PPTUI-3-2 10.0 2 PPTUI-3-4 17.0 3 PPTUI-4-4 30.0 4 CC-4-V 10.0 5 PTPI(1)-4-A1 30.0 6 PUM-6-N 3.0 Σ 100.0% Physical properties T(N, I) = 102.5° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5200 Δε (20° C., 1 kHz) = 2.7 ε.sub.∥ = 5.4 γ.sub.1 (20° C.) = 386 mPa .Math. s K.sub.1 = 11.2 K.sub.3 = 21.9 V.sub.0 = 2.16 V

Mixture Example M-6

(19) TABLE-US-00013 Composition Compound No. Abbreviation 1 PPTUI-3-2 10.0 2 PPTUI-3-4 16.0 3 PPTUI-4-4 30.0 4 CCP-V-1 10.0 5 PTPI(1)-4-A1 30.0 6 PUM-6-N 4.0 Σ 100.0% Physical properties T(N, I) = 115° C. n.sub.e (20° C., 589.3 nm) > 1.860 n.sub.o (20° C., 589.3 nm) = 1.5225 Δε (20° C., 1 kHz) = 3.4 ε.sub.∥ = 6.2 γ.sub.1 (20° C.) = 498 mPa .Math. s K.sub.1 = 12.3 K.sub.3 = 23.7 V.sub.0 = 2.01 V

(20) TABLE-US-00014 TABLE 2 Example ε.sub.r, ∥ tan δ.sub.ε, r, ∥ ε.sub.r, ⊥ tan δ.sub.ε, r, ⊥ Δε.sub.r τ η M-2 3.09 0.0032 2.40 0.0103 0.69 0.225 21.9 M-3 3.14 0.0030 2.40 0.0093 0.74 0.236 25.4 M-4 3.09 0.0032 2.40 0.0100 0.69 0.223 22.4 M-5 3.10 0.0032 2.41 0.0099 0.69 0.223 22.6 M-6 3.12 0.0030 2.40 0.0099 0.72 0.232 23.4

(21) As shown in Table 2, the mixtures containing PUM-n-N do all show high material qualities (η) and low loss (τ) which makes them very well suitable for applications in the microwave region and/or millimetre wave region, in particular for phase shifters.