- Preparation method of 4, 5-difluorophthalic acid
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The invention discloses a preparation method of 4, 5-difluorophthalic acid. The specific method comprises the following steps: S1: synthesis of 4, 5-difluoro-1, 2-phthalonitrile: adding 4, 5-difluoro-1, 2-dihalobenzene and polymethylhydrosiloxane into a reaction container, stirring and dissolving with N, N-dimethylacetamide, carrying out reaction, cooling after the reaction is finished, adding tri(dibenzylideneacetone)dipalladium and 1, 1 '-bis (diphenylphosphine) ferrocene under the protection of nitrogen, slowly adding zinc cyanide for reaction, cooling after the reaction is finished, adding water, adjusting the pH to 8 by using a sodium bicarbonate solution under vigorous stirring, stirring for 2 hours, standing, filtering, washing, and eluting and purifying by using an ethyl acetate mixed solvent of petroleum ether to obtain an off-white solid intermediate 4, 5-difluoro-1, 2-dicyanobenzene; and S2, synthesis of 4, 5-difluoro-1, 2phthalic acid. The process is safe, efficient, easy to operate, low in equipment requirement, low in raw material cost and easy for industrial production.
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- Preparation method of aromatic dicarboxylic acid derivative
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The invention provides a preparation method of an aromatic dicarboxylic acid derivative, wherein the preparation method comprises the following steps: step 1, carrying out a coupling reaction on dihalogenated aromatic hydrocarbon and metal cyanide at a temperature of 40-200 DEG C under metal catalysis in a solvent, and carrying out extraction layering concentration to obtain a dicyano compound after the reaction is finished; and step 2, carrying out a hydrolysis reaction on the obtained dicyanogen compound at the temperature of 60-200 DEG C under an acidic condition, and carrying out post-treatment to obtain the final product. According to the preparation method of the aromatic dicarboxylic acid derivative, dihalogenated aromatic hydrocarbon reacts with metal cyanide and then is hydrolyzedunder the acidic condition to obtain aromatic acid or the derivative thereof, and the preparation method has the remarkable advantages that the raw materials are cheap and easy to obtain, operation is easy and convenient, the yield is high, three wastes are easy to dispose, the product quality is high, and the substrate tolerance is good.
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Paragraph 0025; 0045-0048
(2021/03/11)
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- Process for the preparation of eight fluorine substituted phthalocyanine
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The invention relates to a method for preparing octafluoro-substituted phthalocyanine. According to the method, easily available 4,5-dichlorophthalic acid serving as a raw material is subjected to five-step reactions, namely acetic anhydride dehydration, aniline imidization, potassium fluoride fluorination, hydrolysis and one-step condensation to obtain a target product, namely an octafluoro-substituted phthalocyanine compound. The method has the advantages of low raw material cost, mild reaction condition, safe experiment operation, simple post-treatment, relatively high target product yield, high purity and the like. A novel method is provided to preparation for synthesizing octafluoro-substituted phthalocyanine compounds, synthesis researches of octafluoro-substituted phthalocyanine compounds are promoted, and more possibility is provided to application of the octafluoro-substituted phthalocyanine compounds serving as semiconductor materials in researches of dye-sensitized solar cells, organic thin-film transistors and other aspects. The method can be easily industrialized, and the obtained product has high purity and stable quality.
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Paragraph 0035; 0039; 0043
(2017/04/07)
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- Indanyl-piperazine compounds
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A compound selected from those of formula (I): wherein: R3 represents a hydrogen atom, and R1 and R2 together with the carbon atoms carrying them form a benzene, naphthalene or quinoline ring structure, each of the ring structures being optionally substituted, ?or R1 represents a hydrogen atom, and R2 and R3 together with the carbon atoms carrying them form a benzene, naphthalene or quinoline ring structure, each of the ring structures being optionally substituted, n represents 1 or 2, —X— represents a group selected from —(CH2)m—O-Ak-, —(CH2)m—NR4-Ak-, —(CO)—NR4-Ak- and —(CH2)m—NR4-(CO)—, ?m represents an integer between 1 and 6 inclusive, Ak represents an optionally substituted alkylene chain, and R4 represents a hydrogen atom or an alkyl group, Ar represents an aryl or heteroaryl group, its enantiomers, diasteroisomers, and addition salts thereof with a pharmaceutically acceptable acid. Medical products containing the same which are useful in the treatment of conditions requiring a serotonin reuptake inhibitor and/or NK1 antagonist.
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Page/Page column 39
(2010/11/24)
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- Intermediates in the preparation of 4,5-difluoroanthranillic acid
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Compounds of the formula STR1 which are intermediates in the preparation of 4,5-difluoroanthranilic acid, an intermediate itself in the synthesis of quinolone antibacterials, and methods of preparing these intermediates.
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