Patent Application
20080090026
The following examples are intended to explain the invention without limiting it. Above and below, percentage data denote per cent by weight, unless indicated otherwise; all temperatures are indicated in degrees Celsius.
The following abbreviations and acronyms are used:
furthermore:
Unless explicitly stated otherwise, all concentrations in the present application are given as percent by weight, and refer to the corresponding mixture or mixture component, unless explicitly stated otherwise.
Unless explicitly stated otherwise, all temperature values in the present application, like for example the melting point T(C,N), the transition from the smectic (S) to the nematic (N) phase T(S,N), and the clearing point T(N,I), are given in degrees Celsius (° C.).
All physical properties are or have been determined according to “Merck Liquid Crystals, Physical Properties of Liquid Crystals”, Status November 1997, Merck KGaA, Germany, and are valid for a temperature of 20° C., and Δn is determined at 589 nm and Δε at 1 kHz, unless explicitly stated otherwise.
The display used for measurement of the capacitive threshold voltage has two plane-parallel outer plates at a separation of 4 μm and electrode layers with alignment layers of rubbed polyimide on top on the insides of the outer plates, which produce a homeotropic edge alignment of the liquid-crystal molecules.
The polymerizable compounds are polymerized in the display by UV irradiation, for example with a strength of 28 mW/cm2, for the prespecified time, with a voltage (usually 10 V to 30 V alternating current) being applied to the display at the same time.
The tilt angle is determined by a rotating crystal experiment (Autronic-Melchers TBA-105). A small value (i.e. a large deviation from the 90° angle) here corresponds to a large tilt.
The compound is described as the racemate by S. Zheng and D. Y. Sogah, Polymer Preprints 2001, 42(1), 452-453, and is obtained analogously in optically active form from (+)-R-1,1′-bi-2-naphthol.
Phase behavior: Tg 12° C. I
Compound (15) is prepared analogously:
Phase behavior: Tg 16 C 128 I
12.0 g (25.7 mmol) of (±)-6,6′-dibromo[1,1′]binaphthalinyl-2,2′-diol, 11.5 g (41 mmol) of sodium metaborate octahydrate and 800 mg of bistriphenylphosphinepalladium(II) chloride are initially introduced in 100 ml of water and 20 ml of THF, 0.13 ml of hydrazine hydrate is added, and a solution of 7.0 g (57 mmol) of benzeneboronic acid in 80 ml of THF is added dropwise. The batch is subsequently heated under reflux overnight, added to water and extracted three times with MTB ether. The combined org. phases are washed with water and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is filtered through silica gel with toluene/ethyl acetate (19:1) and evaporated, and the product is recrystallized once each from toluene/cyclohexane (1:1) and isopropanol, giving (±)-6,6′-diphenyl[1,1′]binaphthalinyl-2,2′-diol as colorless crystals.
MS(EI): m/e (%)=438 [M+] (100).
6.6 g (14.5 mmol) of (±)-6,6′-diphenyl[1,1′]binaphthalinyl-2,2′-diol and 11 ml (80 mmol) of triethylamine are dissolved in 350 ml of dichloromethane, and 3.7 ml (37.8 mmol) of methacryloyl chloride are added with ice-cooling. The batch is stirred overnight at room temp. and evaporated, and the residue is chromatographed on silica gel with toluene/ethyl acetate (19:1). Crystallization of the crude product from diethyl ether gives colorless crystals of m.p. 180° C. (racemate).
The pure, optically active enantiomers of (2) can be obtained analogously to the synthesis described above from commercially available (R)-(CAS No. 65283-60-5) or (S)-6,6′-dibromo[1,1′]binaphthalinyl-2,2′-diol (CAS No. 80655-81-8).
Compound (3) is prepared as follows:
Starting from 5,6,7,8,5′,6′,7′,8′-octahydro[1,1′]binaphthalenyl-2,2′-diol, which is accessible by the method of D. J. Cram et al., J. Org. Chem. 1981, 46, 393-406, by catalytic hydrogenation of [1,1′]-binaphthalenyl-2,2′-diol, reaction with acryloyl chloride analogously to Examples 1 and 2 gives 2′-acryloyloxy-5,6,7,8,5′,6′,7′,8′-octahydro[1,1′]binaphthalenyl-2-yl acrylate as colorless solid.
The following compounds are prepared analogously (Me=methyl, Ph=phenyl):
Compound (16):
The starting material 4,4′-dibromo[1,1′]binaphthalinyl-2,2′-diol is prepared by the method of M. Noji, M. Nakajima, K. Koga, Tetrahedron Lett. 1994, 35, 7983-7984, from 4-bromo-2-naphthol, prepared by the method of M. S. Newman, V. Sankaran, D. R. Olson, J. Am. Chem. Soc. 1976, 98, 3237-3241. The enantiomers are separated by HPLC (column: Chiralpak AD-H 20 μm, eluent: ethanol).
5.66 g (12.7 mmol) of 4,4′-dibromo[1,1′]binaphthalinyl-2,2′-diol and 9.5 g (29.2 mmol) of caesium carbonate are initially introduced in 75 ml of DMF, and 1.4 ml (13.4 mmol) of 1,3-dibromopropane are added at 80° C. The batch is left to stir overnight, added to water and extracted with toluene. The combined org. phases are evaporated, and the residue is filtered through silica gel with toluene, giving 9,17-dibromo-13,14-dihydro-12H-naphtho[2,1,10,13-fgh][1,5]dioxonine as colorless crystals.
1H-NMR (400 MHz, CDCl3):
δ=1.99 (mc, 2 H, —OCH2CH2CH2O—), 4.35 (mc, 4 H, —OCH2CH2CH2O—), 7.26 (mc, 4 H, Ar—H), 7.48 (ddd, J=1.4 Hz, J=6.64 Hz, J=8.56 Hz, 2 H, Ar—H), 7.78 (s, 2 H, Ar—H), 8.27 (d, J=8.6 Hz, 2 H, Ar—H).
4.00 g (8.26 mmol) of 9,17-dibromo-13,14-dihydro-12H-naphtho-[2,1,10,13-fgh][1,5]-dioxonine are dissolved in 100 ml of dioxane, 5.0 g (50.9 mmol) of potassium acetate, 6.5 g (25.1 mmol) of bis(pinacolato)-diboron and 400 mg (0.545 mmol) of 1,1′-bis(diphenylphosphino)ferrocene-palladium(II) chloride are added, and the mixture is heated under reflux for 4 h. The batch is subsequently added to water, extracted with MTB ether and dried over sodium sulfate. The solvent is removed in vacuo, the residue is filtered through silica gel with heptane/ethyl acetate (2:1), evaporated and taken up in 200 ml of acetone, 9 g (45 mmol) of sodium periodate and 3.2 g (45 mmol) of ammonium acetate are added, and the mixture is left to stir overnight at room temp. and at 45° C. until conversion is complete (TLC). The solvent is subsequently removed in vacuo, water is added to the residue, and the mixture is extracted with MTB ether. The combined org. phases are dried over sodium sulfate. Removal of the solvent gives 13,14-dihydro-12H-naphtho[2,1,10,13-fgh][1,5]dioxonine-9,17-diyl-9,17-diboronic acid, which is employed in the next step without purification.
2.6 g (6.4 mmol) of 13,14-dihydro-12H-naphtho[2,1,10,13-fgh][1,5]-dioxonine-9,17-diyl-9,17-diboronic acid are initially introduced in 50 ml of THF, 2 ml of water and 2.2 ml of glacial acetic acid are added, and 3.5 ml (36 mmol) of 35 p.c. hydrogen peroxide are subsequently added slowly with ice-cooling. The batch is left to stir at room temp. for 3 h, diluted with water and extracted with MTB ether. The combined org. phases are washed with ammonium iron(II) sulfate solution and water, dried over sodium sulfate and evaporated. Chromatography of the crude product on silica gel with heptane/MTB ether (1:4) gives 9,17-dihydroxy-13,14-dihydro-12H-naphtho[2,1,10,13-fgh][1,5]dioxonine as colorless solid.
1H-NMR (400 MHz, CDCl3): δ=1.95 (mc, 2 H, —OCH2CH2CH2O—), 4.31 (mc, 4 H, —OCH2CH2CH2O—), 5.40 (s, 2 H, OH), 6.84 (s, 2 H, Ar—H), 7.26 (mc, 4 H, Ar—H), 7.36 (ddd, J=4.0 Hz, J=4.0 Hz, J=8.1 Hz, 2 H, Ar—H), 8.16 (d, J=8.4 Hz, 2 H, Ar—H).
1.20 g (3.35 mmol) of 9,17-dihydroxy-13,14-dihydro-12H-naphtho-[2,1,10,13-fgh][1,5]dioxonine are dissolved in 30 ml of toluene, and dicyclohexylcarbodiimide in 20 ml of toluene and 150 mg of N,N-dimethylaminopyridine are added. 0.85 ml (10 mmol) of acrylic acid is subsequently added, and the batch is left to stir overnight. After addition of 0.5 g of oxalic acid dihydrate, the mixture is left to stir for a further 2 h, the precipitated solid is filtered off, the filtrate is evaporated, the residue is chromatographed on silica gel with heptane/ethyl acetate (6:1), and the crude product is recrystallized from ether/ethyl acetate, giving 13,14-dihydro-12H-naphtho[2,1,10,13-fgh][1,5]dioxonine-9,17-diyl dimethacrylate as colorless solid.
Phase behavior: Tg 157 C 240 I
Specific rotation (c=0.5, CH2Cl2): [a]20D=−210.5
The nematic LC host mixture N1 is formulated as follows:
0.3% of a polymerizable monomeric compound from Examples 1 to 4 is added to the LC mixture N1, and the resultant mixtures are introduced into VA e/o test cells (rubbed at 90°, VA-polyimide alignment layer, layer thickness d≈4 μm). Each cell is irradiated for 20 minutes with UV light with an intensity of 28 mW/cm2 with application of a voltage of 10 V (alternating current), causing polymerization of the monomeric compound. In a second series of experiments, 0.006% of the photoinitiator Irgacure 651 is additionally added to the LC/monomer mixture, and the exposure time is shortened to 2 minutes. Before and after the UV irradiation, the tilt angle is determined by a rotating crystal experiment (Autronic-Melchers TBA-105). The results are shown in Table 1.
As can be seen from Table 1, a significant increase in the tilt (i.e. reduction in the tilt angle) after polymerization can be achieved with the monomers according to the invention, in particular without use of a photoinitiator.
The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
While the invention has been illustrated with respect to the production and of particular compounds, it is apparent that variations and modifications of the invention can be made without departing from the spirit or scope of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 048 274.3 | Oct 2006 | DE | national |
