ISOTHIOCYANATO TOLANE DERIVATIVES

Abstract

The present invention relates to isothiocyanato tolane derivatives of formula I

##STR00001##

in which the occurring groups have the meanings indicated in claim 1, to a process for their preparation, to liquid-crystalline media comprising same and to high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, in particular for microwave phased-array antennas.

Claims

1. A compound of formula I ##STR00134## in which R.sup.1 denotes an alkyl or alkoxy 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—, —CF.sub.2O—, —OCF.sub.2—, —CH═CH—, ##STR00135## —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, R.sup.L on each occurrence, identically or differently, denotes alkyl, alkoxy, alkenyl, alkenyloxy or alkoxyalkyl, each having up 10 C atoms, or cycloalkyl or cycloalkenyl having up to 7 C atoms or alkylcycloalkyl, alkylcycloalkenyl, alkenylcycloalkyl or alkenylcycloalkenyl having up to 10 C atoms, L.sup.1, L.sup.2, L.sup.3, L.sup.4, L.sup.5 and L.sup.6 independently of one another, denote H, F, Cl, CF.sub.3 or R.sup.L, where at least one of the groups L.sup.1, L.sup.2, L.sup.3 and L.sup.4 denotes R.sup.L, Y.sup.1 and Y.sup.2 independently of one another, denote H, F or Cl.

2. The compound of formula I according to claim 1, where L.sup.5 and L.sup.6 both denote H.

3. The compound of formula I according to claim 1, where Y.sup.1 denotes F.

4. The compound of formula I according to claim 1, where Y.sup.1 and Y.sup.2 both denote F.

5. The compound of formula I according to claim 1, where R.sup.L on each occurrence, identically or differently, denotes alkyl or alkenyl having 1 to 5 C atoms, or cycloalkyl or cycloalkenyl having 3 to 6 C atoms.

6. The compound of formula I according to claim 1, where one of L.sup.1, L.sup.2, L.sup.3 and L.sup.4 denotes F.

7. The compound of formula I according to claim 1, where the compound is selected from the following sub-formulae: ##STR00136## in which R.sup.1 has the meaning given in claim 1 R.sup.L on each occurrence, the same or differently, denotes alkyl or alkenyl having 1 to 5 C atoms, or cycloalkyl or cycloalkenyl each having 3 to 6 C atoms.

8. A method comprising including a compound of formula I according to claim 1 in a liquid-crystal medium.

9. A liquid-crystal medium, characterised in that it comprises one or more compounds of formula I according to claim 1.

10. The medium according to claim 9, where the medium additionally comprises one or more compounds of formula II ##STR00137## in which L.sup.11 denotes R.sup.11 or X.sup.11, L.sup.12 denotes R.sup.12 or X.sup.12, R.sup.11 and R.sup.12, independently of one another, denote unfluorinated alkyl or unfluorinated alkoxy having 1 to 17, preferably having 3 to 10, C atoms or unfluorinated alkenyl, unfluorinated alkynyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15, preferably 3 to 10, C atoms, preferably alkyl or unfluorinated alkenyl, X.sup.11 and X.sup.12, independently of one another, denote F, Cl, Br, —CN, —NCS, —SCN, SF.sub.5, fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, preferably CF.sub.3, OCF.sub.3, Cl, F or NCS, p, q, independently of one another, denote 0 or 1, Z.sup.11 to Z.sup.13, independently of one another, denote trans-CH═CH—, trans-CF═CF—, —C≡C— or a single bond, ##STR00138## independently of one another, denote ##STR00139## and L on each occurrence, independently of one another, denotes branched or unbranched alkyl, alkenyl or alkynyl having 1 to 12 C atoms, in which, independently of one another, one or more “—CH.sub.2—” groups may also be replaced by 0, or denotes C.sub.3-C.sub.6 cycloalkyl, C.sub.3-C.sub.6 cycloalkenyl, fluorinated alkyl or alkenyl, fluorinated alkoxy or alkenyloxy, F, Cl, Br, CN, NCS, SCN or SF.sub.5.

11. A compound of formula I* ##STR00140## in which the occurring groups have the meanings indicated for formula I in claim 1.

12. Process for the preparation of a compound of formula I, characterised in that a compound of formula I* of claim 11 is transferred into a compound of formula I ##STR00141##

13. A method which comprises including a liquid-crystal medium according to claim 9 in a component for high-frequency technology.

14. Component for high-frequency technology, characterised in that it comprises a liquid crystal medium according to claim 9.

15. Component according to claim 14, where the component is suitable for operation in the microwave range.

16. Component according to claim 14, where the component is an LC based antenna element, a phase shifter, a tunable filter, a tunable metamaterial structure, a matching network or a varactor.

17. Microwave antenna array, characterised in that it comprises one or more components according to claim 14.

Description

SYNTHESIS EXAMPLES

Example 1: 5-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-1,3-difluoro-2-isothiocyanato-benzene (1)

Step 1: 4-[2-(4-bromo-2-ethyl-phenyl)ethynyl]-2,6-difluoro-aniline

[0113] ##STR00094##

[0114] To a solution of 4-bromo-2-ethyl-1-iodobenzene (95.0 g, 0.3 mol) in triethylamine (200 mL) and THF (450 mL), Pd(PPh.sub.3).sub.2Cl.sub.2 (4.0 g, 5.8 mmol) and CuI (1.1 g, 5.8 mmol) are added. The resulting solution is cooled to 0° C. and a solution of 4-ethynyl-2,6-difluroaniline (45.0 g, 0.29 mol) in triethylamine (100 mL) is added dropwise. The reaction mixture is allowed to warm to ambient temperature and stirred overnight before it is filtered and concentrated under reduced pressure. The residue is purified by flash chromatography (petrol ether/toluene) to give 4-[2-(4-bromo-2-ethyl-phenyl)ethynyl]-2,6-difluoro-aniline as colourless crystals.

Step 2: 4-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-2,6-difluoro-aniline

[0115] ##STR00095##

[0116] To a suspension of K.sub.3PO.sub.4 (40.8 g, 0.19 mol) in toluene (300 mL) and water (26 drops), Pd(dba).sub.2 (1.47 g, 2.65 mmol) and SPhos (1.10 g, 2.69 mmol) are added. The resulting mixture is stirred for 10 min at room temp. before 4-[2-(4-bromo-2-ethyl-phenyl)ethynyl]-2,6-difluoro-aniline (43.0 g, 0.13 mol), n-pentane boronic acid (22.4 g, 0.19 mol) and toluene (130 mL) are added. The reaction mixture is stirred under reflux for 20 h and treated with water. The aqueous phase is separated and extracted with methyl tert-butyl ether. The combined organic phases are washed with water and sat. NaCl solution, dried over Na.sub.2SO.sub.4, filtered and concentrated under vacuo. The residue is purified by flash chromatography (petrol ether/methyl tert-butyl ether) to give 4-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-2,6-difluoro-aniline as a yellowish oil.

Step 3: 5-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-1,3-difluoro-2-isothiocyanato-benzene (1)

[0117] ##STR00096##

[0118] A solution of 4-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-2,6-difluoro-aniline (38.8 g, 0.12 mol) in dichloromethane (490 mL) and DMF (18 mL, 0.24 mol) is treated with thiocarbonyl diimidazole (42.1 g, 0.24 mol) at room temperature. The resulting mixture is stirred overnight at the same temperature and over additional two days at 32° C. before it is filtered and concentrated under reduced pressure. The residue is purified by flash chromatography (petrol ether) recrystallization from petrol ether to give 5-[2-(2-ethyl-4-n-pentyl-phenyl)ethynyl]-1,3-difluoro-2-isothiocyanato-benzene as colourless crystals.

[0119] .sup.1H NMR: δ=7.38 ppm (d, J=7.8 Hz, 1H), 7.11-7.05 (m, 3H), 7.01 (dd, J=7.8, 1.7 Hz, 1H), 2.82 (q, J=7.6 Hz, 2H), 2.63-2.55 (m, 2H), 1.68-1.57 (m, 2H), 1.41-1.25 (m, 7H), 0.93-0.86 (m, 3H);

[0120] EI-MS: 369.0.

[0121] Phase sequence: Tg −68 K 34 I

[0122] Δε: 12.1

[0123] Δn: 0.3003

[0124] Clp: −52.8° C.

[0125] γ.sub.1: 112 mPa s

[0126] In analogy to Example 1 the following compounds are obtained:

Synthesis Example 2

[0127] ##STR00097##

[0128] .sup.1H NMR: 7.32 (d, J=1.7 Hz, 1H), 7.29-7.24 (m, 1H), 7.13 (d, J=7.8 Hz, 1H), 7.11-7.05 (m, 2H), 2.71-2.57 (m, 4H), 1.64-1.53 (m, 2H), 1.36 (hept, J=3.8, 3.2 Hz, 4H), 1.23 (t, J=7.5 Hz, 3H), 0.96-0.86 (m, 3H).

[0129] EI-MS: 369.1.

[0130] Phase sequence: Tg −59 K 51 I

[0131] Δε: 13.9

[0132] Δn: 0.2691

[0133] Clp: −84.6° C.

[0134] γ.sub.1: 140 mPa s

Synthesis Example 3

[0135] ##STR00098##

[0136] .sup.1H NMR: 7.38 (d, J=7.9 Hz, 1H), 7.31 (dd, J=16.7, 1.3 Hz, 1H), 7.21 (dd, J=7.9, 1.6 Hz, 1H), 7.11-7.05 (m, 2H), 2.80 (q, J=7.6 Hz, 2H), 2.40 (t, J=7.0 Hz, 2H), 1.64 (h, J=7.2 Hz, 2H), 1.27 (t, J=7.6 Hz, 3H), 1.06 (t, J=7.4 Hz, 3H).

[0137] EI-MS: 365.1.

[0138] Phase sequence: K 85 I

[0139] Δε: 12.5

[0140] Δn: 0.4024

[0141] Clp: −34.1° C.

[0142] γ.sub.1: 288 m Pa s

Synthesis Example 4

[0143] ##STR00099##

[0144] .sup.1H NMR: 7.34 (d, J=8.1 Hz, 2H), 7.28-7.22 (m, 2H), 7.13-7.04 (m, 2H), 2.78 (q, J=7.5 Hz, 2H), 2.44 (t, J=7.0 Hz, 2H), 1.65 (h, J=7.2 Hz, 2H), 1.24 (t, J=7.6 Hz, 3H), 1.06 (t, J=7.4 Hz, 3H).

[0145] EI-MS: 365.2.

[0146] Phase sequence: K 77 I

[0147] Δε: 16.3

[0148] Δn: 0.3964

[0149] Clp: −21.0° C.

[0150] γ.sub.1: 229 m Pa s

Synthesis Example 5

[0151] ##STR00100##

[0152] .sup.1H NMR: 7.40 (d, J=7.9 Hz, 1H), 7.29 (s, 1H), 7.19 (dd, J=7.9, 1.6 Hz, 1H), 7.16-7.09 (m, 2H), 6.92 (d, J=1.5 Hz, 1H), 2.42 (t, J=7.1 Hz, 2H), 2.31 (ddd, J=13.6, 8.5, 5.2 Hz, 1H), 1.66 (h, J=7.3 Hz, 2H), 1.28 (s, 2H), 1.07 (t, J=7.3 Hz, 5H), 0.79 (dt, J=6.7, 4.8 Hz, 2H).

[0153] EI-MS: 377.0.

[0154] Phase sequence: K 110 I

Synthesis Example 6

[0155] ##STR00101##

[0156] .sup.1H NMR: 7.32-7.26 (m, 2H), 7.06-7.00 (m, 1H), 6.89 (dd, J=7.9, 1.6 Hz, 1H), 6.60 (d, J=1.8 Hz, 1H), 2.53-2.43 (m, 2H), 2.27-2.18 (m, 1H), 1.56-1.45 (m, 2H), 1.23 (ddt, J=13.5, 9.6, 6.0 Hz, 4H), 1.01-0.91 (m, 2H), 0.85-0.75 (m, 3H), 0.68 (dtd, J=6.4, 4.7, 1.4 Hz, 2H).

[0157] EI-MS: 381.1.

[0158] Phase sequence: K 63 I

[0159] Δε: 10.9

[0160] Δn: 0.2807

[0161] Clp: −70.1° C.

[0162] γ.sub.1: 203 m Pa s

Synthesis Example 7

[0163] ##STR00102##

[0164] .sup.1H NMR: 7.40 (d, J=7.8 Hz, 1H), 7.15-7.07 (m, 3H), 7.03 (dd, J=7.8, 1.7 Hz, 1H), 2.65-2.57 (m, 2H), 2.49 (s, 3H), 1.69-1.58 (m, 2H), 1.42-1.28 (m, 4H), 0.95-0.90 (m, 3H).

[0165] EI-MS: 355.0.

[0166] Phase sequence: Tg −67 K 40 N (−23.9) I

[0167] Δε: 14.9

[0168] Δn: 0.3366

[0169] Clp: −7.4° C.

[0170] γ.sub.1: 133 mPa s

Synthesis Example 8

[0171] ##STR00103##

[0172] .sup.1H NMR: 7.29 (d, J=1.7 Hz, 1H), 7.27 (dd, J=7.9, 1.6 Hz, 1H), 7.12 (d, J=7.7 Hz, 1H), 7.10-7.07 (m, 2H), 2.63-2.56 (m, 2H), 2.30 (s, 3H), 1.62-1.54 (m, 2H), 1.36 (h, J=3.7 Hz, 4H), 0.96-0.87 (m, 3H).

[0173] EI-MS: 355.1.

[0174] Phase sequence: K 44 I

[0175] Δε: 16.8

[0176] Δn: 0.3172

[0177] Clp: −28.2° C.

[0178] γ.sub.1: 152 mPa s

Synthesis Example 9

[0179] ##STR00104##

[0180] .sup.1H NMR: 7.11-7.06 (m, 2H), 6.90 (s, 2H), 2.56-2.51 (m, 2H), 2.45 (s, 6H), 1.64-1.55 (m, 2H), 1.32 (ddt, J=11.3, 8.2, 5.4 Hz, 4H), 0.90 (t, J=7.0 Hz, 3H).

[0181] EI-MS: 369.1.

[0182] Phase sequence: K 66 I

[0183] Δε: 11.2

[0184] Δn: 0.3051

[0185] Clp: −47.6° C.

[0186] γ.sub.1: 175 mPa s

Synthesis Example 10

[0187] ##STR00105##

[0188] .sup.1H NMR: 7.24 (s, 1H), 7.10-7.04 (m, 2H), 6.99 (s, 1H), 2.60-2.52 (m, 2H), 2.41 (s, 3H), 2.25 (s, 3H), 1.55 (ddt, J=10.0, 7.1, 5.1 Hz, 2H), 1.35 (dq, J=7.2, 3.5 Hz, 4H), 0.94-0.88 (m, 3H).

[0189] EI-MS: 379.1.

[0190] Phase sequence: K 63 I

[0191] Δε: 13.1

[0192] Δn: 0.2883

[0193] Clp: −63.8° C.

[0194] γ.sub.1: 212 mPa s

Synthesis Example 11

[0195] ##STR00106##

Synthesis Example 12

[0196] ##STR00107##

Synthesis Example 13

[0197] ##STR00108##

Synthesis Example 14

[0198] ##STR00109##

Synthesis Example 15

[0199] ##STR00110##

Synthesis Example 16

[0200] ##STR00111##

Synthesis Example 17

[0201] ##STR00112##

Synthesis Example 18

[0202] ##STR00113##

Synthesis Example 19

[0203] ##STR00114##

Synthesis Example 20

[0204] ##STR00115##

Synthesis Example 21

[0205] ##STR00116##

Synthesis Example 22

[0206] ##STR00117##

Synthesis Example 23

[0207] ##STR00118##

Synthesis Example 24

[0208] ##STR00119##

Synthesis Example 25

[0209] ##STR00120##

Synthesis Example 26

[0210] ##STR00121##

Synthesis Example 27

[0211] ##STR00122##

Synthesis Example 28

[0212] ##STR00123##

Synthesis Example 29

[0213] ##STR00124##

Synthesis Example 30

[0214] ##STR00125##

Synthesis Example 31

[0215] ##STR00126##

Synthesis Example 32

[0216] ##STR00127##

Synthesis Example 33

[0217] ##STR00128##

[0218] .sup.1H NMR (400 MHz, Chloroform-d) δ 7.21 (d, J=1.6 Hz, 1H), 7.16 (dd, J=7.9, 1.7 Hz, 1H), 7.12-7.05 (m, 2H), 6.41-6.21 (m, 2H), 2.46 (s, 3H), 2.20 (td, J=7.3, 5.9 Hz, 2H), 1.55-1.45 (m, 2H), 0.96 (t, J=7.4 Hz, 3H).

[0219] EI-MS: 353.1

[0220] Phase sequence: K 49 N 69.2 I

[0221] Δε: 17.1

[0222] Δn: 0.4378

[0223] Clp: 68.4° C.

[0224] γ.sub.1: 334 m Pa s

Synthesis Example 34

[0225] ##STR00129##

[0226] .sup.1H NMR (500 MHz, Chloroform-d) δ 7.33 (d, J=7.9 Hz, 1H), 7.17-7.06 (m, 2H), 7.06-6.97 (m, 2H), 6.34-6.15 (m, 2H), 2.75 (q, J=7.6 Hz, 2H), 2.19-2.08 (m, 2H), 1.53-1.37 (m, 4H), 1.22 (t, J=7.6 Hz, 3H), 0.89 (t, J=7.4 Hz, 3H).

[0227] Phase sequence: K 73 I

[0228] Δε: 14.5

[0229] Δn: 0.4197

[0230] Clp: 13.2° C.

Synthesis Example 35

[0231] ##STR00130##

[0232] .sup.1H NMR (400 MHz, Chloroform-d) δ 7.42 (d, J=7.9 Hz, 1H), 7.30 (s, 2H), 7.14-7.04 (m, 2H), 6.66-6.55 (m, 1H), 6.17 (dt, J=15.5, 7.0 Hz, 1H), 2.69 (q, J=7.5 Hz, 2H), 2.23 (qd, J=7.1, 1.5 Hz, 2H), 1.52 (h, J=7.3 Hz, 2H), 1.21 (t, J=7.5 Hz, 3H), 0.97 (t, J=7.3 Hz, 3H). EI-MS: 367.2

[0233] Phase sequence: K 65 I

[0234] Δε: 15.9

[0235] Δn: 0.3534

[0236] Clp: −26.7° C.

[0237] γ.sub.1: 271 mPa s

Synthesis Example 36

[0238] ##STR00131##

[0239] .sup.1H NMR (400 MHz, Chloroform-d) δ 7.18 (d, J=1.6 Hz, 2H), 7.13-7.06 (m, 2H), 7.05 (d, J=1.7 Hz, 1H), 2.62 (q, J=7.6 Hz, 4H), 1.24 (t, J=7.6 Hz, 6H). EI-MS: 327.1

[0240] Phase sequence: K 113 I

[0241] Δε: 8.4

[0242] Δn: 0.1764

[0243] Clp: −194.8° C.

[0244] γ.sub.1: 36 mPa s

Synthesis Example 37

[0245] ##STR00132##

Synthesis Example 38

[0246] ##STR00133##

Use Examples

[0247] A nematic liquid-crystal medium N-1 having the composition and properties as indicated in the following table is prepared.

TABLE-US-00006 Composition Compound No. Abbreviation Physical properties 1 BCH-3F.F 12.0% T(N, I) = 92° C. 2 BCH-5F.F 10.0% Δn (20° C., 589.3 nm) = 0.0969 3 ECCP-30CF3 5.0% Δε (20° C., 1 kHz) = 5.2 4 ECCP-50CF3 5.0% γ.sub.1 (20° C.) = 134 mPa .Math. s 5 CBC-33F 2.0% 6 CBC-53F 2.0% 7 CBC-55F 2.0% 8 PCH-6F 8.0% 9 PCH-7F 6.0% 10 CCP-20CF3 8.0% 11 CCP-30CF3 12.0% 12 CCP-40CF3 7.0% 13 CCP-50CF3 11.0% 14 PCH-5F 10.0% Σ 100.0%

Mixture Examples

[0248] The Mixture Example M-1 is prepared from liquid-crystal host material N-1 above and the compound 1 of Synthesis Example 1 and consists of 90% by weight of N-1 and 10% by weight of compound 1. Accordingly, the Mixture Examples M-2 to M-10 and M-33 to M-35 are each prepared from liquid-crystal host material N-1 and compounds 2 to 10 and 33 to 35 of Synthesis Examples 2 to 10 and 33 to 35, respectively, and also consist of 90% of N-1 and 10% of compound 2 to 10 and 33 to 35, respectively.

TABLE-US-00007 TABLE 1 Properties of mixtures M-1 to M-10 and N-1 (comparison) at 19 GHz (20° C.) Mixture ε.sub.r, ∥ tan δ.sub.ε r, .sub.∥ ε.sub.r, ⊥ tan δ.sub.ε .sub.r, ⊥ τ η M-1 2.5453 0.0050 2.2306 0.0120 0.1237 10.3 M-2 2.5437 0.0051 2.2370 0.0118 0.1206 10.2 M-3 2.5960 0.0048 2.2620 0.0117 0.1287 11.0 M-4 2.5568 0.0052 2.2336 0.0116 0.1264 10.9 M-5 — — — — — — M-6 2.5513 0.0049 2.2414 0.0117 0.1215 10.4 M-7 2.5865 0.0050 2.2724 0.0122 0.1215 10.0 M-8 2.5787 0.0051 2.2713 0.0121 0.1192  9.9 M-9 2.5849 0.0049 2.2741 0.0120 0.1203 10.0 M-10 2.5708 0.0050 2.2668 0.0117 0.1183 10.1 M-33 2.6260 0.0048 2.2917 0.0121 0.1273 10.5 M-34 2.6191 0.0050 2.3083 0.0120 0.1186  9.9 M-35 2.6042 0.0050 2.2876 0.0120 0.1216 10.1 N-1 2.56  0.0049 2.29  0.0126 0.107   8.5

[0249] As can be seen from the data in Table 1, the use of a compound of formula I according to the invention results in an improvement of the material quality (η) of the medium N-1 due to a decrease of the dielectric loss.