- Synthesis process of 2, 3-difluoro-4-alkoxy phenol
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The invention discloses a synthesis process of 2, 3-difluoro-4-alkoxy phenol, and belongs to the technical field of organic synthesis. The process comprises the following steps: using 2, 3-difluorophenylalkyl ether as a raw material, carrying out lithiation by use of n-butyllithium under an ultralow temperature condition, reacting with boric acid ester, adding an alkali for quenching to obtain 2,3-difluoro-4-alkoxy benzene borate, oxidizing in the presence of hydrogen peroxide, and performing acidolysis to obtain 2, 3-difluoro-4-alkoxy phenol, so that the purity of the purified product can reach more than 99.95 %, the impurity content is less than 50ppm, and the requirements of electronic-grade products are met. Boric acid and the alkali can form salt, the salt is dissolved in water and subjected to a homogeneous reaction for an oxidation reaction during oxidation in the presence of the hydrogen peroxide, the reaction conditions are mild, impurities are few, the product purity is high, the solvent can be recycled, and industrial production is easy to achieve.
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Paragraph 0034-0036; 0038-0040
(2020/04/06)
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- 2,3-difluorobenzene negative dielectric anisotropy liquid crystalline compound as well as preparation method and application thereof
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The invention relates to a 2,3-difluorobenzene negative dielectric anisotropy liquid crystalline compound. The compound has a structure shown in formula I, wherein ring A is 1,4-phenylene or 1,4-phenylene of which 1-4 hydrogen atoms are substituted by fluorine atoms; R is alkyl or alkoxy with 1-12 carbon atoms; n is integer of 2-8. The invention further provides a preparation method of the liquidcrystalline compound and application thereof in the field of liquid crystal display. The compound has the advantages of being high in negative dielectric anisotropy, high in liquid crystal intersolubility, and low in rotating viscosity and is capable of improving a liquid crystal material; the compound has an important application value. The formula is shown in the description.
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Paragraph 0049; 0053; 0057-0058
(2018/10/11)
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- Preparation method of 2, 3-difluoro-4-alkoxy phenol
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Relating to the technical field of organic synthesis, the invention discloses a preparation method of 2, 3-difluoro-4-alkoxy phenol. 2, 3-difluorobenzene ether, n-butyllithium, trimethyl borate, acetic acid and hydrogen peroxide are adopted as the raw materials, tetrahydrofuran is taken as the solvent, and by means of organic lithiation, boration, oxidization, pulping filtration and other steps, a 2, 3-difluoro-4-alkoxy phenol product can be obtained. The method provided by the invention has the advantages of cheap and easily available raw materials, mild reaction conditions, simple aftertreatment operation, low production cost, a total yield up to more than 66%, and product purity of more than 99.9%, and is suitable for industrialized production.
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Paragraph 0017-0018
(2018/02/04)
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- With double-cyclooctane of the liquid crystal compound, preparation method and application thereof
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The invention discloses a liquid crystal compound containing bicyclooctane as well as a preparation method and application thereof. The compound is shown by a formula I. The compound shown by the formula I has good light and thermal stability, high negative dielectric anisotropy, higher clearing point, and good intersolubility with other liquid crystal, and has a simple synthetic route, low cost and good practical value.
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Paragraph 0149-0151
(2016/10/09)
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- A transformer having negative dielectric anisotropy liquid crystal compound monofluoroethylene, and using this liquid crystal display element and a liquid crystal composition
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A liquid crystal compound having general physical properties necessary for a liquid crystal compound, a high stability to heat, light or the like, a small viscosity, a suitable refractive index anisotropy, a suitable dielectric anisotropy and steep electro-optic characteristics, a wide temperature range of a nematic phase and an excellent compatibility with other liquid crystal compounds, and a liquid crystal compound especially having a wide temperature range of a nematic phase. A compound represented by formula (1). with, for example, R1 and R2 are alkyl having 1 to 10 carbons; A1 is 1,4-cyclohexylene; A2 is 2,3-difluoro-1,4-phenylene; X is fluorine or chlorine; Z1 and Z2 are a single bond; and p and q is 0 or 1.
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- LIQUID CRYSTALLINE COMPOUND WITH NEGATIVE DIELECTRIC ANISOTROPY, LIQUID CRYSTAL COMPOSITION USING SAME, AND LIQUID CRYSTAL DISPLAY ELEMENT
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The invention provides a liquid crystal compound having general physical properties necessary for the liquid crystal compound, namely, stability to heat, light and so forth, a small viscosity, a refractive index anisotropy having a suitable magnitude value, a dielectric anisotropy having a suitable magnitude value, steep electrooptical characteristics, a wide temperature range of a nematic phase, and an excellent compatibility with other liquid crystal compounds, in particular, a liquid crystal compound having a wide temperature range of the nematic phase; a compound represented by formula (i): wherein, for example, R1 and R2 are alkyl having 1 to 8 carbons or alkenyl having 2 to 8 carbons; ring A1 is trans-1,4-cyclohexylene or 1,4-phenylene; ring A2 is trans-1,4-cyclohexylene or 2,3-difluoro-1,4-phenylene; Q1 and Q2 are fluorine or chlorine; and h is 0, 1 or 2.
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- LIQUID CRYSTALLINE COMPOUND HAVING NEGATIVE DIELECTRIC ANISOTROPY, AND LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY ELEMENT EACH COMPRISING SAME
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The invention provides a liquid crystal compound having general physical properties necessary for a liquid crystal compound, that is to say, stability to heat, light or the like, a small viscosity, a suitable value of refractive index anisotropy, a suitable value of dielectric anisotropy, steep characteristics electro-optic characteristics, a wide temperature range of a nematic phase and an excellent compatibility with other liquid crystal compounds, and a liquid crystal compounds especially having a wide temperature range of a nematic phase. A compound represented by formula (1). For example, R1 and R2 are each independently alkyl having 1 to 9 carbons or alkenyl having 2 to 9 carbons, alkoxy having 1 to 8 carbons or alkenyloxy having 2 to 8 carbons; Q1 and Q4 are each independently fluorine or chlorine; Q2 and Q3 are each independently hydrogen, fluorine or chlorine, and one of Q2 and Q3 is hydrogen; Z is -CH2O or -COO-; and h is 1 or 2.
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- LIQUID CRYSTAL COMPOSITION AND LIQUID CRYSTAL DISPLAY DEVICE
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A liquid crystal composition is provided that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or is properly balanced regarding at least two characteristics. An AM device is provided that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The liquid crystal composition contains a specific compound having especially negatively large dielectric anisotropy as the first component,a specific bicyclic compound having a small viscosity as the second component, a specific compound having a high maximum temperature as the third component, a specific compound having a negatively large dielectric anisotropy, a low minimum temperature as the fourth component. The liquid crystal composition has a negative dielectric anisotropy. The liquid crystal display device contains the liquid crystal composition.
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Page/Page column 13
(2009/12/04)
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