212386-71-5Relevant articles and documents
Synthesis process of 2, 3-difluoro-4-alkoxy phenol
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Paragraph 0034-0036; 0038-0040, (2020/04/06)
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.
Preparation method of 2, 3-difluoro-4-alkoxy phenol
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Paragraph 0017-0018, (2018/02/04)
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.
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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, (2016/11/17)
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.