- 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 0026; 0027; 0028
(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 0085; 0089; 0093-0094
(2018/10/11)
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- The compound, composition, and display device
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PROBLEM TO BE SOLVED: To provide a compound capable of elevating an upper limit temperature where a SmC (smectic-C) phase of a liquid crystal can exist, broadening a temperature width of the SmC phase or enlarging a tilt angle of the SmC phase, and to provide a liquid crystal composition comprising the compound and a display element including the liquid crystal composition.SOLUTION: [1] The compound is expressed by general formula (i) shown below. In general formula (i), R and R' each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 9 carbon atoms; A1, A2 and A3 each independently represent a 1,4-phenylene group or a 2,3-difluoro-1,4-phenylene group; m represents an integer of 1 to 10; and Y represents a cyclohexylene group, a phenylene group, a bicyclooctylene group or a dialkylsilylene group.
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Paragraph 0187-0189
(2017/07/26)
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- FUSED PENTACYCLIC ANTI - PROLIFERATION COMPOUNDS
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The present invention relates to novel compounds of formula (I) wherein X, Q, R1, R2, R3, R4, R5, R6, R7, R8, R21, R22 and R23 are as defined herein. The compounds of formula (I) are inhibitors of telomerase enzyme function and are accordingly useful for the treatment cellular proliferation disorders, such as cancer
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