- Preparation of 2,6-naphthalic acid by liquid phase oxidation of 2,6-diisopropyl naphthalene
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An orthogonal experiment was carried out and the effects of bromine, metal ions additives and organic nitrogen compounds on the yield of 2,6-naphthalic acid were discussed. The results shown that influence order for the yield of 2,6-naphthalic acid in the
- Peng, Ge
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Read Online
- Discovery of MINC1, a GTPase-activating protein small molecule inhibitor, targeting MgcRacGAP
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The Rho family of Ras superfamily small GTPases regulates a broad range of biological processes such as migration, differentiation, cell growth and cell survival. Therefore, the availability of small molecule modulators as tool compounds could greatly enhance research on these proteins and their biological function. To this end, we designed a biochemical, high throughput screening assay with complementary follow-up assays to identify small molecule compounds inhibiting MgcRacGAP, a Rho family GTPase activating protein involved in cytokinesis and transcriptionally upregulated in many cancers. We first performed an in-house screen of 20,480 compounds, and later we tested the assay against 342,046 compounds from the NIH Molecular Libraries Small Molecule Repository. Primary screening hit rates were about 1% with the majority of those affecting the primary readout, an enzyme-coupled GDP detection assay. After orthogonal and counter screens, we identified two hits with high selectivity towards MgcRacGAP, compared with other RhoGAPs, and potencies in the low micromolar range. The most promising hit, termed MINC1, was then examined with cell-based testing where it was observed to induce an increased rate of cytokinetic failure and multinucleation in addition to other cell division defects, suggesting that it may act as an MgcRacGAP inhibitor also in cells.
- Van Adrichem, Arjan J.,Fagerholm, Annika,Turunen, Laura,Lehto, Anna,Saarela, Jani,Koskinen, Ari,Repasky, Gretchen A.,Wennerberg, Krister
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Read Online
- Cerium-based metal organic frameworks with UiO-66 architecture: Synthesis, properties and redox catalytic activity
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A series of nine Ce(IV)-based metal organic frameworks with the UiO-66 structure containing linker molecules of different sizes and functionalities were obtained under mild synthesis conditions and short reaction times. Thermal and chemical stabilities were determined and a Ce-UiO-66-BDC/TEMPO system was successfully employed for the aerobic oxidation of benzyl alcohol.
- Lammert, Martin,Wharmby, Michael T.,Smolders, Simon,Bueken, Bart,Lieb, Alexandra,Lomachenko, Kirill A.,De Vos, Dirk,Stock, Norbert
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Read Online
- Preparation method of dimethyl 2, 6-naphthalate
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The invention discloses a preparation method of dimethyl 2, 6-naphthalate. Specifically, the preparation method of the dimethyl 2, 6-naphthalate disclosed by the invention comprises the following steps: carrying out esterification reaction on 2, 6-naphthalic acid and methanol under a pressurization condition in the presence of a catalyst, and filtering without further purification to obtain the dimethyl 2, 6-naphthalate, wherein the mass ratio of the methanol to the 2, 6-naphthalic acid is (3: 1)-(25: 1), the reaction temperature ranges from 100 DEG C to 150 DEG C. According to the preparation method disclosed by the invention, the operation is simplified, the yield of the dimethyl 2, 6-naphthalate is improved, and meanwhile, the purity of the dimethyl 2, 6-naphthalate is maintained.
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- Preparation method of 2,6-naphthalene dicarboxylic acid
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The invention relates to a preparation method of 2,6-naphthalene dicarboxylic acid, and solves the problem of high content of 2-acetyl-6-naphthalene dicarboxylic acid in crude 2, 6-naphthalene dicarboxylic acid generated by air oxidation of 2, 6-diisopropylnaphthalene in the prior art. The problem is well solved by adopting the preparation method of 2,6-naphthalene dicarboxylic acid, which comprises the following steps of: (1) adding acetic acid and a compound containing Co, Mn, Br and K into a reaction kettle; (2) controlling the temperature of the reaction kettle to be 160-220 DEG C and the pressure to be 2-3MPa, and adding 2, 6-diisopropylnaphthalene and sufficient gas containing free oxygen into the reaction kettle; and (3) reacting for at least 0.5 hour, and then adding a permanganate alkali metal salt and continuing to react for at least 10 minutes.
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Paragraph 0035-0097
(2021/11/10)
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- Method for preparing aromatic carboxylic acid compound
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The invention discloses a method for preparing an aromatic carboxylic acid compound. The method comprises the following steps: 1) heating carbon dioxide and hydrosilane in the presence of a copper catalyst in a reaction medium A; and 2) adding a reaction medium B, aryl halide, a palladium catalyst and a base to the reaction mixture in the step 1), sealing the reaction system, and performing a heating reaction. The method has the advantages that raw materials are simple and easy to obtain, the raw materials are cheap and stable, the catalyst is common, easy to obtain and stable, the reaction conditionsaremild, the aftertreatment is simple, the yield is high, and the like.
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Paragraph 0141-0143; 0156-0158; 0177
(2020/02/14)
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- Method for preparing high-purity naphthalic acid by taking beta-methylnaphthalene as raw material
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The invention discloses a method for preparing high-purity naphthalic acid by taking beta-methylnaphthalene as a raw material. The method comprises the following steps of (1) preparation of an acylation solution, wherein propionyl chloride is added into nitrobenzene and anhydrous aluminium trichloride, and it is controlled that the temperature is below 0 DEG C, so that a mixed solution is mixed into a uniform and transparent solution; (2) an acylation reaction, wherein the acylation solution obtained in step (1) is added into a nitrobenzene solution of 2-methylnaphthalene dropwise, it is controlled that the temperature is below 0 DEG C, and the acylation reaction is carried out; (3) hydrolysis of an acylate, wherein distilled water is added into the product obtained in step (2) for cleaning until the pH value of a mixed solution is 6-7; (4) reduced pressure distillation, wherein the product obtained in step (3) is subjected to reduced pressure distillation, the acylate flows out at 165-180 DEG C, cooling is carried out, and a white solid is obtained; (5) purification of the acylate, wherein the product obtained in step (4) is purified by using a recrystallization method, 2-methyl-6-propiononaphthone is obtained, and vacuum drying is carried out; (6) an oxidation reaction, wherein the product obtained in step (5) is synthesized into 2,6-NDA through an air liquid phase oxidationreaction technology.
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Paragraph 0032; 0034; 0035; 0037; 0038; 0040
(2019/10/01)
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- Method for preparing high-purity naphthalic acid by taking naphthalene as raw material
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The invention discloses a method for preparing high-purity naphthalic acid by taking naphthalene as a raw material. The method comprises the following steps of 1) an alkylation reaction, wherein naphthalene, 1-isopropylnaphthalene and a catalyst are added into a reaction kettle, propylene is introduced for heating for a reaction, and diisopropylnaphthalene is obtained; 2) rectification/crystallization separation, wherein crude 2,6-diisopropylnaphthalene is obtained through rectification, and then high-purity 2,6-diisopropylnaphthalene is obtained through a crystallization method; 3) an oxidation reaction, wherein one or a mixture of a Co-Mn-Br catalyst, glacial acetic acid and propionic acid serves as a solvent, oxygen-containing gas is used for oxidizing diisopropylnaphthalene, and 2,6-naphthalic acid is obtained through liquid-phase synthesis; 4) purification, wherein an object obtained in step 3 is subjected to solid-liquid separation, washing and drying, and 2,6-naphthalic acid solid powder is obtained.
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Paragraph 0038-0043
(2019/09/05)
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- METHOD FOR PRODUCING 2,6-NAPHTHALENE DICARBOXYLIC ACID
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An object of the present invention is to provide a method for producing high-purity 2,6-NDA having a small alkali metal content. The present invention relates to a method for producing a high-purity 2,6-naphthalene dicarboxylic acid, comprising a purification step of washing a crude 2,6-naphthalene dicarboxylic acid having a specific surface area of 2 m2/g or more in the presence of an aqueous medium under a temperature condition of 90° C. or more and less than 200° C.
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Paragraph 0069-0071; 0073-0078; 0080-0082; 0084; 0085; 0091
(2019/05/15)
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- Tandem one-pot CO2 reduction by PMHS and silyloxycarbonylation of aryl/vinyl halides to access carboxylic acids
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The present study discloses the synthesis of aryl/vinyl carboxylic acids from Csp2-bound halides (Cl, Br, I) in a carbonylative path by using silyl formate (from CO2 and hydrosilane) as an instant CO-surrogate. Hydrosilane provides hydride for reduction and its oxidation product silanol serves as a coupling partner. Mono-, di-, and tri-carboxylic acids were obtained from the corresponding aryl/vinyl halides.
- Paridala, Kumaraswamy,Lu, Sheng-Mei,Wang, Meng-Meng,Li, Can
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supporting information
p. 11574 - 11577
(2018/10/31)
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- Method for preparing 2, 6-naphthalic acid through oxidizing 2-methyl-6-propionyl naphthalene
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The invention belongs to the technical field of chemical synthesis, and concretely relates to a method for preparing 2, 6-naphthalic acid through oxidizing 2-methyl-6-propionyl naphthalene. The methodcomprises the steps of adopting the 2-methyl-6-propionyl naphthalene as a raw material, adopting a Co-Mn-Br-based catalyst as a main catalyst in a continuous oxidation reactor, adopting kali salt, sodium salt or nickel salt as a cocatalyst, adopting one of glacial acetic acid or propionic acid or a mixture of the glacial acetic acid and the propionic acid as a solvent, and continuously feeding oxygen-containing gas into the oxidation reactor for continuously oxidizing the 2-methyl-6-propionyl naphthalene to synthesize the 2, 6-naphthalic acid. The method is liquid phase continuous reaction, has less side reaction, stable product quality and simple and controllable process, and can be used for preparing the high-yield high-purity 2, 6-naphthalic acid.
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Paragraph 0026-0050
(2018/03/26)
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- Linker Installation: Engineering Pore Environment with Precisely Placed Functionalities in Zirconium MOFs
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Precise placement of multiple functional groups in a highly ordered metal-organic framework (MOF) platform allows the tailoring of the pore environment, which is required for advanced applications. To realize this, we present a comprehensive study on the linker installation method, in which a stable MOF with coordinatively unsaturated Zr6 clusters was employed and linkers bearing different functional groups were postsynthetically installed. A Zr-MOF with inherent missing linker sites, namely, PCN-700, was initially constructed under kinetic control. Twelve linkers with different substituents were then designed to study their effect on MOF formation kinetics and therefore resulting MOF structures. Guided by the geometrical analysis, linkers with different lengths were installed into a parent PCN-700, giving rise to 11 new MOFs and each bearing up to three different functional groups in predefined positions. Systematic variation of the pore volume and decoration of pore environment were realized by linker installation, which resulted in synergistic effects including an enhancement of H2 adsorption capacities of up to 57%. In addition, a size-selective catalytic system for aerobic alcohol oxidation reaction is built in PCN-700 through linker installation, which shows high activity and tunable size selectivity. Altogether, these results exemplify the capability of the linker installation method in the pore environment engineering of stable MOFs with multiple functional groups, giving an unparalleled level of control.
- Yuan, Shuai,Chen, Ying-Pin,Qin, Jun-Sheng,Lu, Weigang,Zou, Lanfang,Zhang, Qiang,Wang, Xuan,Sun, Xing,Zhou, Hong-Cai
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supporting information
p. 8912 - 8919
(2016/07/30)
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- Production of aromatic carboxylic acid
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PROBLEM TO BE SOLVED: To provide a production method of an aromatic carboxylic acid (except for terephthalic acid) by liquid phase oxidation of an alkyl group-containing aromatic hydrocarbon using a molecular oxygen-containing gas in the presence of a catalyst comprising a heavy metal compound and a bromine compound in a solvent containing a lower aliphatic carboxylic acid, the method providing an aromatic carboxylic acid with stable qualities by reducing fluctuations in the catalyst component in the liquid phase oxidation reaction system. SOLUTION: The method includes: cooling an oxidation reaction slurry obtained by liquid phase oxidation to separate into an aromatic carboxylic acid crystal and an oxidation reaction mother liquid, using 25 to 95% of the oxidation reaction mother liquid as a recycling mother liquid in a circulated manner in the liquid phase oxidation system, while purging the rest of the oxidation reaction mother liquid as a purge mother liquid to the outside of the system to recover the catalyst component. In the recovering process, a plurality of pyridine ring-containing chelate resin columns is used; and the recovered catalyst liquid from an elution step is retained in a recovered catalyst liquid tank for 1.5 to 6 hours and then introduced into the liquid phase oxidation reaction system. COPYRIGHT: (C)2012,JPOandINPIT
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Paragraph 0053
(2017/01/02)
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- METHOD FOR PRODUCING A PURIFIED NAPHTHALENE DICARBOXYLIC ACID
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A method for producing a purified naphthalenedicarboxylic acid includes steps of mixing a naphthalenedicarboxylic acid-containing material and an amine in a mixed liquid of water and an organic solvent to give a crystal of a naphthalenedicarboxylic acid amine salt; and obtaining a purified naphthalenedicarboxylic acid from the crystal of the naphthalenedicarboxylic acid amine salt, wherein (1) in the step of forming the naphthalenedicarboxylic acid amine salt by adding an amine to the slurry that contains water, an organic solvent and a naphthalenedicarboxylic acid, the amine addition rate is from 0.002 to 0.4 mol/min relative to one mol of the naphthalenedicarboxylic acid, or (2) an amine is added to the aqueous solution prepared by dissolving the naphthalenedicarboxylic acid amine salt in water, or to the liquid prepared through solid-liquid separation of the aqueous solution to insolubilize and precipitate the metal component, and the precipitated metal component is removed through solid-liquid separation.
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Paragraph 0202-0203
(2014/07/23)
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- Studies on calcined cow bone and pyrolyzed wood, suitable supports for immobilizing hybrid nano particles of Co-Mn as new catalysts for oxidation of 2,6-diisopropyl naphthalene
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Catalytic oxidation of 2,6-diisopropylnaphthalene (2,6-DIPN) to 2,6-naphthalene dicarboxylic acid (2,6-NDCA) was studied with two new catalysts prepared by immobilization of Co/Mn nano-hybrid particles over calcined cow bone, and pyrolyzed wood. The catalysts have the advantage of very cheap supports, and easy catalyst recovery. The effects of Co/Mn atomic ratio, reaction time and temperature, oxygen pressure, amount of catalyst, and the support on the conversion of 2,6-DIPN and product/intermediate yields were investigated. There was an interesting synergistic effect of cobalt and manganese catalysts. The maximum product (2,6-NDCA) yield was 100%, obtained at a Co/Mn atomic ratio of 10 supported on pyrolyzed wood. Lower cobalt concentration resulted the lower 2,6-NDCA yield, which was ascribed to the intermediate products formation. The catalysts were characterized in detail by SEM/EDS, BET surface area, and TEM measurements. Transmission electron microscopy (TEM) measurements indicated nanoparticles (diameter of about 2-5 nm) on the surface of the supports.
- Mardani Ghahfarrokhi, Atefeh,Moshiri, Parisa,Ghiaci, Mehran
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- The first porous MOF with photoswitchable linker molecules
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We synthesized a porous twofold interpenetrated MOF [Zn2(NDC) 2(1)] (coined CAU-5) using 3-azo-phenyl-4,4′-bipyridine (1), 2,6-naphthalenedicarboxylic acid, and Zn(NO3)2· 6H2O. The azo-functionality protrudes into the pores, and can be switched, by irradiation with UV light (365 nm), from the thermodynamically stable trans-isomer to the cis-isomer. Back-switching was achieved thermally and with an irradiation wavelength of λmax = 440 nm.
- Modrow, Antje,Zargarani, Dordaneh,Herges, Rainer,Stock, Norbert
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experimental part
p. 4217 - 4222
(2011/06/18)
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- Purification Method of Crude Naphthalene Dicarboxylic Acid Using Microorganism and 2,6-Naphthalene Dicarboxylic Acid in Crystalline Form Obtained by Using the Same
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Disclosed is a method for purifying a crude naphthalene dicarboxylic acid using microorganism. According to the purification method, a crude naphthalene dicarboxylic acid is purified by reacting a microorganism having the ability to convert 2-formyl-6-naphthoic acid to 2,6-naphthalene dicarboxylic acid with a crude naphthalene dicarboxylic acid, adding an acidic solution to the reaction solution under particular conditions, stirring the mixed solution to crystallize the crude naphthalene dicarboxylic acid, washing the crystallized crude naphthalene dicarboxylic acid, and drying the washed product to obtain 2,6-naphthalene dicarboxylic acid in a pure crystalline form. Advantageously, the purification method enable production of high-purity crystalline 2,6-naphthalene dicarboxylic acid on an industrial scale in an environmentally friendly manner.
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Page/Page column 5
(2010/04/23)
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- OXIDATION OF ALKYLARENES IN EXPANDED LIQUID REACTION MIXTURE
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A C8-C2O alkylarene is converted to an arene carboxylic acid in an oxidation reactor by reacting the alkylarene with oxygen under oxidation conditions in the presence of an MC catalyst or bromine-free oxidation catalyst in a volumetrically expanded liquid reaction mixture in which a preferred solvent comprises a homogeneous phase of a monocarboxylic acid and carbon dioxide under elevated pressure, carbon dioxide partial pressure and temperature conditions.
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Page/Page column 21
(2008/12/06)
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- Hydrogenation process for high-purity naphthalenedicarboxylic acid
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The present invention relates to a process of hydrogenation reaction of 2,6-naphthalenedicarboxylic acid comprising the steps of calculating an amount of hydrogen to remove impurities such as formylnaphthoic acid, naphthalenecarboxylate bromide and high molecule organic impurities of heavy substances, and inputting a fixed quantity of hydrogen calculated. Consequently, higher purity 2,6-naphthalenedicarboxylic acid may be obtained in high yield.
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Page/Page column 2-3
(2008/12/05)
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- Method for producing naphthalenedicarboxylic acid
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A method for producing naphthalenedicarboxylic acid comprising the steps of: dissolving 2,6-dimethylnaphthalene in acetic acid solvent; oxidizing the product from the dissolution process using oxygen and a diluent gas; crystallizing naphthalenedicarboxylic acid that has been produced from the oxidation process; and separating the crystallized naphthalenedicarboxylic acid, wherein the amount of the diluent gas being discharged from and recycled to the oxidation process is controlled during the oxidation process, and the amount of mother liquor being recycled to the dissolution process after crystallization is controlled during the separation process, is provided.
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Page/Page column 5-6
(2008/06/13)
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- Method for producing naphthalenedicarboxylic acid
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A method for producing naphthalenedicarboxylic acid comprising the steps of: dissolving 2,6-dimethylnaphthalene in acetic acid solvent; oxidizing the product from the dissolution process using oxygen and a diluent gas; crystallizing naphthalenedicarboxylic acid that has been produced from the oxidation process; and separating the crystallized naphthalenedicarboxylic acid, wherein the amount of the diluent gas being discharged from and recycled to the oxidation process is controlled during the oxidation process, and the amount of mother liquor being recycled to the dissolution process after crystallization is controlled during the separation process, is provided.
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Page/Page column 4
(2008/06/13)
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- PURIFICATION METHOD OF CRUDE NAPHTHALENE DICARBOXYLIC ACID USING MICROORGANISM AND 2,6-NAPHTHALENE DICARBOXYLIC ACID IN CRYSTALLINE FORM OBTAINED BY USING THE SAME
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Disclosed is a method for purifying a crude naphthalene dicarboxylic acid using a microorganism. According to the purification method, a crude naphthalene dicarboxylic acid is purified by reacting a microorganism having the ability to convert 2-formyl-6-naphthoic acid to 2,6-naphthalene dicarboxylic acid with a crude naphthalene dicarboxylic acid, adding an acidic solution to the reaction solution under particular conditions, stirring the mixed solution to crystallize the crude naphthalene dicarboxylic acid, washing the crystallized crude naphthalene dicarboxylic acid, and drying the washed product to obtain 2,6-naphthalene dicarboxylic acid in a pure crystalline form. Advantageously, the purification method enables production of high- purity crystalline 2,6-naphthalene dicarboxylic acid on an industrial scale in an environmentally friendly manner.
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Page/Page column 12-17
(2008/06/13)
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- Preparation method of naphthalene dicarboxylic acid
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The present invention relates to a method for the preparation of naphthalene dicarboxylic acid, and more particularly, to a method for the preparation of naphthalene dicarboxylic acid by oxidizing dimethylnaphthalene with oxygen in air in the presence of acetic acid solvent using the metal catalysts of cobalt and manganese, and using bromine as a reaction initiator, wherein the temperature of said oxidation reaction is 155 to 180° C. The method for the preparation of naphthalene dicarboxylic acid of the invention enables the preparation of naphthalene dicarboxylic acid having high purity with a high yield in an economical way at a low temperature.
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Page/Page column 4-5
(2008/06/13)
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- Anthracene and other polycyclic aromatics as activators in the oxidation of aromatic hydrocarbons
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The present invention relates to the liquid phase oxidation of aromatic hydrocarbons in the presence of at least one heavy metal oxidation catalyst and bromine, which is activated by at least one of anthracene or another polycyclic aromatic compound to produce aromatic carboxylic acids.
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Page/Page column 9-11
(2008/06/13)
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- Method for preparing 2,6-naphthalene dicarboxylic acid
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Disclosed is an improved method for preparing 2,6-naphthalene dicarboxylic acid from di-lower alkyl 2,6-naphthalene dicarboxylate, which is characterized in that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specified amount of water in the presence of specified amount of hydrophobic organic solvent and an additive; that hydrolyzing di-lower alkyl 2,6-naphthalene dicarboxylate in a specific amount of a mixed solvent of non-water miscible alcohol and water; or in that di-lower alkyl 2,6-naphthalene dicarboxylate is hydrolyzed in two steps wherein the 1st step comprises hydrolyzing said ester in a water miscible organic solvent in the presence of a small amount of water, and the 2nd step comprises further hydrolyzing the reaction.
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Page/Page column 5
(2008/06/13)
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- Synthesis of aromatic carboxylic acids by carbonylation of aryl halides in the presence of epoxide-modified cobalt carbonyls as catalysts
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A new procedure was developed for synthesis of aromatic and heteroaromatic acids and their derivatives (esters, salts) by carbonylation of the corresponding aryl halides. The acids are selectively formed in a high yield under very mild conditions. Highly active catalytic systems, base-containing alcoholic solutions of cobalt carbonyl modified with epoxides, were used to activate aryl halides. 2005 Pleiades Publishing, Inc.
- Boyarskii,Zhesko,Lanina
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p. 1844 - 1848
(2007/10/03)
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- RECOVERY OF 2,6-NAPHTHALENE DICARBOXYLIC ACID FROM POLYESTERS
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This invention concerns a method for recycling polyesters comprising the hydrolysis of polyesters containing repeat units derived from 2,6-naphthalene dicarboxylic acid in the presence of a carboxylic acid which gives pure 2,6-naphthalene dicarboxylic acid suitable for use as a monomer.
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- Process for producing a high purity aromatic polycarboxylic acid
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A process for producing a high purity aromatic polycarboxylic acid (APA) by purification of a crude APA comprises: (I) aging a slurry of the crude APA in a first dispersion medium at 180 to 300° C. for 10 minutes or longer under stirring; (II) introducing the aged slurry of the APA into a column for substituting dispersion media, bringing the slurry into contact with a second dispersion medium and separating the resultant fluid into a fluid of the first dispersion medium containing impurities and a slurry of the second dispersion medium containing crystals of the high purity APA; and (III) separating the crystals of the high purity APA from the slurry of the second dispersion medium. A high purity APA having excellent hue and particle diameter can be industrially advantageously produced while the construction of the process is simplified and the consumption of energy is decreased.
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Page/Page column 4-5
(2008/06/13)
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- METHOD FOR REFINING 2,6-NAPHTHALENE DICARBOXYLIC ACID
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The present invention relates to a method for refining 2,6-naphthalene dicarboxylic acid, and particularly to a method for refining 2,6-naphthalene dicarboxylic acid comprising recrystallizing crude 2,6-naphthalene dicarboxylic acid in the form of an amine salt using a solvent comprising a protic polar solvent selected from the group consisting of an alcohol, water, and a mixture thereof, and an acetate. In accordance with the invention, 2,6-naphthalene dicarboxylic acid can be obtained with excellent purity and color, and at the same time, it can be obtained in an economical and environmentally friendly way because the acetate, which is a byproduct of the oxidation process, is used as a solvent.
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- Method for purifying crude naphthalenedicarboxylic acid
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The invention provides a method for purifying a crude naphthalenedicarboxylic acid comprising the steps of mixing a crude naphthalenedicarboxylic acid and a water/alcohol solvent to esterify a part of the naphthalenedicarboxylic acid, thereby dissolving a naphthalenedicarboxylic ester into the solvent, and then contacting the resulting reaction mixture with hydrogen in the presence of a hydrogenation catalyst to hydrogenate impurities which are contained in the crude naphthalenedicarboxylic acid and which are capable of being hydrogenated, thereby dissolving and removing hydrogenation products into the water/alcohol solvent. A mixture of a naphthalene dicarboxylic acid and a naphthalenedicarboxylic ester with reduced impurity contents, or a high-purity naphthalenedicarboxylic acid can be obtained.
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- Formation of 2,6-Naphthalenedicarboxylic Acid by the Co-Mn-Br-Catalyzed Autoxidation of 2,6-Diethylnaphthalene in Acetic Acid
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In order to elucidate the reaction mechanism and the optimum reaction conditions for the formation of 2,6-naphthalenedicarboxylic acid (NDCA), the Co(OAc)2-Mn(OAc)2-NaBr-catalyzed oxidation of 2,6-diethylnaphthalene by molecular oxygen was carried out in acetic acid.The oxidation of the ethyl groups to carboxyl groups proceeded mainly via groups and partly via 1-hydroxyethyl and 1-acetoxyethyl groups.A synergistic catalytic effect due to Co and Mn acetates was observed not only on the rate of oxidation but also on the selective formation of NDCA.The rate of oxidation was strongly retarded at higher concentrations of the substrate, showing that the naphthalene nucleus terminates the chain reaction step of the oxidation.A high concentration of metal catalyst resulted in an increase of acetoxyethylnaphthoic acid.At the optimum reaction conditions, a nearly 90percent yield of NDCA was obtained along with small amounts of substituted naphthoic and trimellitic acids.The differences in the yield of NDCA from 2,6-dimethyl, 2,6-diethyl, and 2,6-diisopropylnaphthalenes were compared under similar reaction conditions and are discussed.
- Kamiya, Yoshio,Hama, Takashi,Kijima, Ichiro
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p. 204 - 210
(2007/10/02)
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- Process for recovery of aromatic acid from waste polyester resin
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Processes are disclosed for recovery and purification of dibasic aromatic acids from waste polyester film, fiber, bottles, manufacturing residues, and other manufactured articles. The processes comprises: depolymerizing polyester resin in a solvent under conditions suitable for hydrolysis of ester bonds to obtain a mixture containing a solution of aromatic acid and impurities consisting of alcohol and/or other components of the resin; burning impurities in a liquid-phase oxidation with an oxygen-containing gas in the presence of an oxidation catalyst at elevated pressures and temperatures, to obtain an oxidation product containing the desired aromatic acid; and crystallizing and separating from the oxidation system a resulting crude dibasic aromatic acid. Crude acid is, optionally, hydrogenated in an aqueous solution at elevated temperatures and pressures in the presence of hydrogen and an insoluble metal-containing catalyst, which is thereupon separated from the aqueous solution, and purified dibasic aromatic acid recovered by crystallization and mechanical separation from the aqueous solution. Purified terephthalic acid has, typically, a L*-value in a range of from about 95 to about 100, an a*-value in a range of from about -1 to about +1, and a b*-value in a range of from about 0.5 to about 2.
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- Process for purification of naphthalenedicarboxylic acid
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A process for purifying a crude naphthalenedicarboxylic acid containing impurities and coloring substances obtained by the oxidation of a di-substituted naphthalene, dispense with the use of a large amount of alkali or acid, and producing a naphthalenedicarboxylic acid having a high purity and good color effectively and in a high recovery is disclosed, which comprises dissolving the crude naphthalenedicarboxylic acid in a mixed solvent comprising an amine compound and an alcohol and conducting crystallization.
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- Process for introducing a carboxyl group to an aromatic carboxylic acid or a derivative thereof
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Disclosed is a process for introducing a carboxyl group to an aromatic carboxylic acid or a derivative thereof, which comprises reacting a starting aromatic carboxylic acid, such as a benzoic acid, a biphenylcarboxylic acid, a naphthalenecarboxylic acid, a diphenylcarboxylic acid, or a derivative thereof, with a carbon tetrahalide in the presence of a cyclodextrin and an alkali metal hydroxide, thereby introducing a carboxyl group to the aromatic ring of the starting aromatic carboxylic acid or the derivative thereof in substitution for a hydrogen atom bonded thereto. By the process of the present invention, a desired aromatic polycarboxylic acid or a derivative thereof can be easily obtained with high selectivity.
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- Process for preparing 2,6-naphthalenedicarboxylic acid
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A process for preparing 2,6-naphthalenedicarboxylic acid comprising oxidation reaction of 2,6-diisopropylnaphthalene or an oxidation product thereof with molecular oxygen in a solvent containing an aliphatic carboxylic acid in the presence of a catalyst comprising cobalt and manganese as heavy metals and a bromine compound is disclosed, in which said oxidation reaction is carried out in the presence of at least one nitrogen-containing compound selected from the group consisting of a pyridine compound, ammonia, a carboxylic acid ammonium salt, urea, a urea derivative, an amine, and a carboxylic acid amide. 2,6-Naphthalenedicarboxylic acid can be obtained at higher purity and in increased yield.
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- Oxidation of dialkyl polyaromatics to dicarboxypolyaromatics
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A process for the production of poly-aromatic acids is disclosed in which the alkyl substituents of an alkyl substituted poly-aromatic compound are oxidized with an oxygen containing gas in the presence of a catalytic amount of a halogen-free metal catalyst composition, the oxidation being carried out in an organic aliphatic carboxylic acid solvent having from 2 to about 7 carbon atoms.
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- Process for producing 2,6-naphthalenedicarboxylic acid from 2,6-diisopropylnaphthalene
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A process for producing 2,6-naphthalenedi-carboxylic acid (NDA) which comprises oxidizing 2,6--diisopropylnaphthalene (DIPN) or its oxidation derivative with a gas containing molecular oxygen in a solvent containing at least 70 % by weight of at least one aliphatic monocarboxylic acid selected from the group consisting of acetic acid and propionic acid; wherein the oxidation is carried out (a) using at least 1.5 parts by weight per part by weight of the entire reaction mixture composed of the material to be oxidized, its intermediates and product from these which are present in the oxidastion reaction system, (b) using a catalyst comprising manganese, or a heavy metal mixture composed of cobalt and manganese with a manganese content of not more than 20 atomic percent, bromium and potassium in an amount satisfying the following expressions (i) to (v) simultaneously wherein X, Y, Z and W are the gram atoms, in atomic percent, of cobalt, manganese, bromine and potassium,respectively, per mole of the starting 2,6--diisopropylnaphthalene or its oxidation derivative, and (c) at a temperature in the range of 180 to 220 °C.
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- Method for the preparation of 2,6-naphthalene dicarboxylic acid
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Disclosed is a method for the preparation of 2,6-naphthalene dicarboxylic acid from 2-acyl-6-alkyl naphthalene, especially 2-acetyl-6-methylnaphthalene, by oxidation in two steps with oxygen or air. The catalyst in the first oxidation is based on manganese. The catalyst in the second oxidation is based on cobalt with bromine added. The addition of 6-alkyl-2-naphthoic acid to the reaction in the second oxidation, in portions or in a continuous manner, results in very good yields having high purities.
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