- Kinetics and process parameter studies in highly selective air oxidation of side-chain alkyl groups in picolines, 2-methylnaphthalene, and pseudocumene
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Picolines, 2-methylnaphthalene, and pseudocumene were oxidized by air in acetic acid medium. Process parameters and kinetics of the reaction were studied from the viewpoint of proces research and development. Use of lithium chloride as the promoter was worth considering for this oxidation to obtain a higher rate of reaction. At 170 °C and at a reactant concentration of 15% w/v, 52% conversion of β-picoline with a selectivity of 97% was achieved in 8 h.
- Mukhopadhyay, Sudip,Chandalia, Sampatraj B.
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Read Online
- Photo-induced deep aerobic oxidation of alkyl aromatics
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Oxidation is a major chemical process to produce oxygenated chemicals in both nature and the chemical industry. Presently, the industrial manufacture of benzoic acids and benzene polycarboxylic acids (BPCAs) is mainly based on the deep oxidation of polyalkyl benzene, which is somewhat suffering from environmental and economical disadvantage due to the formation of ozone-depleting MeBr and corrosion hazards of production equipment. In this report, photo-induced deep aerobic oxidation of (poly)alkyl benzene to benzene (poly)carboxylic acids was developed. CeCl3 was proved to be an efficient HAT (hydrogen atom transfer) catalyst in the presence of alcohol as both hydrogen and electron shuttle. Dioxygen (O2) was found as a sole terminal oxidant. In most cases, pure products were easily isolated by simple filtration, implying large-scale implementation advantages. The reaction provides an ideal protocol to produce valuable fine chemicals from naturally abundant petroleum feedstocks. [Figure not available: see fulltext.].
- Wang, Chang-Cheng,Zhang, Guo-Xiang,Zuo, Zhi-Wei,Zeng, Rong,Zhai, Dan-Dan,Liu, Feng,Shi, Zhang-Jie
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p. 1487 - 1492
(2021/07/10)
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- A method of preparing 1,2,4,5-benzenetetracarboxylic acid or trimellitic acid from pinacol
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The invention relates to a method of preparing 1,2,4,5-benzenetetracarboxylic acid or trimellitic acid from pinacol. The method includes a first step of selectively dehydrating the pinacol in an acid/ionic liquid catalytic system to generate 2,-3-dimethyl-1,3-butadiene; a second step of subjecting the 2,-3-dimethyl-1,3-butadiene and maleate or acrylate to a D-A cycloaddition/dehydrogenation tandemreaction to generate an aromatic ring product; and a third step of subjecting the aromatic ring product to hydrolysis and oxidation to prepare the 1,2,4,5-benzenetetracarboxylic acid or the trimellitic acid. The catalytic system adopted in the method is green, and can be recycled. The raw material is a biomass-based platform chemical, and is cheap and easily available. All reaction processes aresimple. The pinacol dehydration reaction, the dehydrogenation reaction of a D-A product and an oxidation reaction are high in activity and selectivity. The novel method for preparing the 1,2,4,5-benzenetetracarboxylic acid and the trimellitic acid which are fine chemicals from the pinacol that is a lignocelluloses based platform chemical is provided by the invention.
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Paragraph 0069; 0072; 0074-0075
(2018/04/01)
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- PRODUCTION OF TRI-METHYL BENZENE DERIVATIVES
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The present invention relates to the production of tri-functional aromatic molecules from diformylfuran, in particular to the production of tri-methyl benzene derivatives such as for example trimellitic acid or 1,2,4-tri(aminomethyl)benzene from diformylfuran and its derivatives.
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Page/Page column 22; 23
(2019/01/08)
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- Method for preparing trimellitic acid by means of catalytic oxidation of Anderson type heteropolyacid
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The invention discloses a method for preparing trimellitic acid by means of catalytic oxidation of Anderson type heteropolyacid. The method comprises the following steps: enabling 1, 2, 4-trimethylbenzene, used as a raw material, to be subjected to an oxidation reaction in a solvent in action of a catalyst, an oxidizing agent and an additive; after the oxidation reaction is completed, carrying outaftertreatment to obtain trimellitic acid, wherein the catalyst is Anderson structure heteropolyacid, the additive is a weakly alkaline substance, the solvent is fatty carboxylic acid, the oxidationreaction temperature is 80-150 DEG C, the reaction gage pressure is 1.0-5.0MPa, and the reaction time is 1-24h. The catalyst adopted by the method has very high reaction activity and specific selectivity and can be recycled; hydrogen peroxide, air or oxygen is used as the oxidizing agent, so that the cost is lowered, the generation of three wastes can be reduced, and the method is environmentallyfriendly; the method is mild in reaction conditions, simple and convenient to operate and high in product yield, thus being suitable for industrial production.
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Page/Page column 0035-0044; 0047
(2018/09/08)
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- A trimellitic acid synthesis method (by machine translation)
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The invention belongs to the technical field of organic chemical industry, in particular to a trimellitic acid synthesis method. In order to trimellitic anhydride as the starting material, by esterification reaction to produce 1, 2, 4 - benzene citric acid three-methyl ester, 1, 2, 4 - benzene citric acid three-methyl ester hydrolysis reaction to obtain the trimellitic acid. The method of the invention the operation is simple, mild reaction conditions, the use of the reagent is easy cheap, simple post-treatment, do not need column chromatography, easy monitoring of the end point of the reaction, the yield is higher, can realize industrial production. (by machine translation)
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Page/Page column 4; 5
(2018/11/22)
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- Method for synthesizing trioctyl trimellitate
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The invention discloses a method for synthesizing trioctyl trimellitate, and relates to the technical field of polymers. The method includes the following steps: carrying out an oxidation reaction to obtain trimellitic acid, carrying out an esterification reaction on trimellitic acid and octanol to obtain trioctyl trimellitate, and carrying out extraction and purification on the trioctyl trimellitate to obtain the trioctyl trimellitate. The trioctyl trimellitate is synthesized from 1,2,4-trimethylbenzene through directly reacting the generated trimellitic acid with octanol without separation or purification in the stage for the oxidation preparation of 1,2,4-trimethylbenzene. The method for synthesizing trioctyl trimellitate through a one-step process has the advantages of reduction of synthesis steps, avoiding of the use of trimellitic anhydride with high price and high corrosion, and significant reduction of the synthesis cost of the trioctyl trimellitate.
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Paragraph 0018; 0020; 0022
(2017/10/12)
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- Sustainable production of pyromellitic acid with pinacol and diethyl maleate
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Herein, we report an unprecedented and sustainable route to synthesize pyromellitic acid (PMA), a monomer of polyimide, with pinacol and diethyl maleate which can be derived from lignocellulose. Analogously, a sustainable route to trimellitic acid (TMA) was also developed using pinacol and acrylate as the feedstocks.
- Hu, Yancheng,Li, Ning,Li, Guangyi,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
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supporting information
p. 1663 - 1667
(2017/06/05)
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- Continuous production method of trimellitic acid
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The invention discloses a continuous production method of trimellitic acid. The method comprises the following processes of premixing, oxidation, coarse crystallization, filtration and recrystallization, which are sequentially performed, and comprises the following specific processes of (1) performing premixing: mixing raw materials namely unsym-trimethyl benzene, a solvent namely acetic acid, main catalysts namely cobalt acetate and manganese acetate, and a cocatalyst namely tetrabromoethane, and performing preheating to 60-120 DEG C, wherein the mass ratio of the unsym-trimethyl benzene to the acetic acid is 1 to (2-10); (2) performing oxidation: performing 2-4 continuous oxidation stages which are in series connection, and enabling the reaction temperature of the later oxidation stage to be higher than that of the previous oxidation stage; (3) performing coarse crystallization: performing coarse crystallization and then performing centrifugal separation; (4) performing filtration: dissolving crude trimellitic acid in water of 80-100 DEG C, controlling the percentage by mass of the trimellitic acid to be 15-35%, and filtering a hot solution when the solution is still hot; and (5) performing recrystallization: performing recrystallization and then performing centrifugal separation. According to the method disclosed by the invention, the trimellitic acid products with high conversion rate, high yield and high purity can be obtained.
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Paragraph 0039-0042
(2017/06/03)
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- Production Of Terephthalic Acid Via Reductive Coupling Of Propiolic Acid Or Propiolic Acid Derivatives
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A method of making terephthalic acid via reductive coupling of two molecules of propiolic acid or propiolic acid derivatives is presented. The reductive coupling can be catalyzed by compounds comprising metals, and propiolic acid or propiolic acid derivatives can be produced from acetylene and carbon dioxide. At least 4 of the 8 carbons in the terephthalic acid are non-fossil-derived.
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Paragraph 0036; 0037
(2016/10/04)
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- Naphthalenes Oxidation by Aqueous Sodium Hypochlorite Catalyzed by Ruthenium Salts under Phase-Transfer Catalytic Conditions
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Highly effective and fast oxidation of naphthalene(s) to phthalic acid(s) under biphasic conditions using nominal catalyst loading (0.5 mol%) of ruthenium chloride, 2.5 mol% tetrabutyl ammonium bromide as phase transfer catalyst and inexpensive aqueous sodium hypochlorite (NaOCl) as reagent has developed. Recovery, regeneration and reuse of the catalytic system add its merit to green chemistry.
- Patil, Rajendra D.,Sasson, Yoel
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p. 991 - 997
(2016/04/20)
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- PREPARATION METHOD OF TRIMELLITIC ACID
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The present invention relates to a manufacturing method of trimellitic acid comprising a liquid-phase oxidation reaction step for trimethylbenzene under the presence of a mixed catalyst of a metal compound, a bromine compound, and an imide compound. In the present specification, the manufacturing method of trimellitic acid capable of preventing excess byproduct production or corrosion of production facilities and capable of providing high-purity trimellitic acid with high efficiency can be provided.COPYRIGHT KIPO 2015
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Paragraph 0052-0055
(2016/12/22)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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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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- 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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p. 735 - 738
(2013/05/09)
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- PROCESS FOR PRODUCING AROMATIC POLYCARBOXYLIC ACID
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A process for producing an aromatic polycarboxylic acid in which all alkyl groups are converted into carboxyl groups in a high yield by decreasing a residual amount of an intermediate product is provided. The process comprises oxygen-oxidizing an aromatic compound having a plurality of alkyl groups (e.g., durene) in the presence of a catalyst containing a cyclic imino unit having an N—OR group (wherein R represents a hydrogen atom or a protecting group for a hydroxyl group) and a transition metal co-catalyst (e.g., a cobalt compound, a manganese compound, and a zirconium compound) under heating in a lower-temperature zone and a higher-temperature zone to produce an aromatic polycarboxylic acid in which a plurality of alkyl groups are oxidized into carboxyl groups. In an initial stage of the reaction, the reaction may be conducted in a first lower-temperature zone (a reaction temperature of 60 to 120° C. and a second lower-temperature zone (an intermediate temperature zone) (a reaction temperature of 100 to 140° C.); and then, in a latter stage of the reaction, the reaction may be conducted in a higher-temperature zone (a reaction temperature of 110 to 150° C.).
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Page/Page column 14
(2011/04/18)
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- PROCESS FOR PRODUCTION OF HIGH-PURITY TRIMELLITIC ACID
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Provided is a process for the production of high-purity trimellitic acid including subjecting a dimethylbenzaldehyde and/or an oxidized derivative of the dimethylbenzaldehyde to liquid-phase oxidation with molecular oxygen in an aqueous solvent containing a catalyst to produce trimellitic acid, in which: 3,4-dimethylbenzaldehyde and/or 3,4-dimethylbenzoic acid are/is used as a raw material; a catalyst containing 0.05 to 1 part by mass of one or more kinds of metals selected from the group consisting of cobalt, manganese, and nickel, 0.0001 to 0.0015 part by mass of metallic iron and/or iron obtained from a water-soluble iron salt, and 1 to 5 parts by mass of bromine with respect to 100 parts by mass of the aqueous solvent is used as the catalyst; and the liquid-phase oxidation is conducted at a temperature of 200 to 250°C. According to the process of the present invention, there can be provided high-quality, high-purity trimellitic acid with extremely small amounts of by-products such as an intermediate of oxidation, an addition compound, and an organobromine compound in high yield. In addition, the residual ratio of bromine used as a catalyst is high, and hence a production cost is curtailed.
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Page/Page column 7
(2011/01/12)
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- Process and Catalyst for Oxidizing Aromatic Compounds
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Catalytic compositions for conversion of substituted aromatic feed materials to oxidized products comprising aromatic carboxylic acid derivatives of the substituted aromatic feed materials comprise at least two metal or metalloid elements, at least one of which is palladium, platinum, vanadium or titanium, and at least one of which is a Group 5, 6, 14 or 15 metal or metalloid. A process for oxidizing substituted aromatic feed materials comprises contacting the feed material with oxygen in the presence of such a catalytic composition in a liquid reaction mixture.
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Page/Page column 18
(2009/04/24)
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- Process for the production of trimellitic acid
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Trimellitic acid is produced by oxidation of pseudocumene in acetic acid at temperatures between 130 and 240° C. in the presence of a catalyst composition containing cobalt, manganese and bromine. The process comprises the stages of: (i) simultaneously fe
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Page/Page column 3-4
(2009/03/07)
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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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- 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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- Process for the purification of a crude carboxylic axid slurry
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Disclosed is a process to produce a purified carboxylic acid product. The process comprises removing impurities from a crude carboxylic acid slurry in a solid-liquid displacement zone to form a slurry product. The slurry product if further treated in a st
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Page/Page column 4
(2008/06/13)
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- Production method of highly pure pyromellitic dianhydride
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A method of producing pyromellitic dianhydride. The method includes a step of heating a crude pyromellitic acid in the absence of acetic anhydride to convert a part of pyromellitic acid to pyromellitic anhydride, and a subsequent step of heating the resultant mixture in the presence of acetic anhydride to complete the anhydrization of pyromellitic acid. The pyromellitic dianhydride by the method contains little pyromellitic monoanhydride and other monoanhydrides derived from impurities and is less discolored. The pyromellitic dianhydride has particle properties not causing plugging, etc. during its transportation, storage and use.
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Page/Page column 7
(2008/06/13)
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- Aerobic oxidation of trimethylbenzenes catalyzed by N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst
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The oxidation of trimethylbenzenes was examined with air or O2 using N,N′,N″-trihydroxyisocyanuric acid (THICA) as a key catalyst. Thus, 1,2,3-, 1,2,4-, and 1,3,5-trimethylbenzenes under air (20 atm) in the presence of THICA (5 mol %), Co(OAc)2 (0.5 mol %), Mn(OAc)2, and ZrO(OAc)2 at 150 °C were oxidized to the corresponding benzenetricarboxylic acids in good yields (81-97%). In the aerobic oxidation of 1,2,4-trimethylbenzene by the THICA/Co(II)/Mn(II) system, remarkable acceleration was observed by adding a very small amount of ZrO(OAc)2 to the reaction system to form 1,2,4-benzenetricarboxylic acid in excellent yield (97%). In contrast, no considerable addition effect was observed in the oxidation of 1,3,5-trimethylbenzene. This aerobic oxidation by the present catalytic system provides an economical and environmentally benign direct method to benzenetricarboxylic acids, which are very important polymer materials.
- Hirai, Naruhisa,Tatsukawa, Yoshinobu,Kameda, Michiko,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 6695 - 6699
(2007/10/03)
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- PROCESS FOR THE PRODUCTION OF TRIMELLITIC ACID
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Trimellitic acid is produced by oxidation of pseudocumene in acetic acid at temperatures between 130 and 240 °C in the presence of a catalyst composition containing cobalt, manganese and bromine. The process comprises the stages of: (i) simultaneously fee
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Page/Page column 7-10
(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 3-4
(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 11
(2008/06/13)
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- Process for producing trimellitic acid
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A process for producing trimellitic acid which comprises step A for oxidizing pseudocumene, thereby obtaining a reaction mixture comprising dimethyl benzoic acid, dimethyl benzyl alcohol, and dimethyl benzaldehyde, step B for separating dimethyl benzoic acid, dimethyl benzyl alcohol and dimethyl benzaldehyde from the reaction mixture obtained in step A, step C for oxidizing dimethyl benzyl alcohol separated in step B, thereby obtaining dimethyl benzoic acid and dimethyl benzyl aldehyde and then feeding dimethyl benzoic acid and dimethyl benzyl aldehyde thus obtained to step B, and step D for oxidizing dimethyl benzoic acid and/or dimethyl benzaldehyde separated in step B, thereby obtaining trimellitic acid.
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- METHOD OF PRODUCING TRIMELLITIC ACID
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Disclosed is a method of producing trimellitic acid through the liquid-phase oxidation of pseudocumene in acetic acid. The oxidation comprises a) conducting a first oxidation using an initial oxidizing catalytic system at 120-200?é for 5-20 min in an oxidizing reactor, said initial oxidizing catalytic system comprising at least three compounds selected from the group consisting of cobalt compound, manganese compound, zirconium compound and bromine compound; b) conducting a second oxidation in situ at 160-220?é for 30-60 min under addition of an additional catalytic system, said additional catalytic system comprising at least two compounds selected from the group consisting of cobalt compound, manganese compound, zirconium compound, and bromine compound; and c) completing the oxidation of pseudocumene at a temperature from 180 to 230?é for a time from 5 to 20 min without the addition of catalysts into the reactor. The pressure is adjusted in the range from 100 to 450 psig over the steps a), b) and c).
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- Process for the oxidative purification of terephthalic acid
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Disclosed is a process to produce a purified carboxylic acid slurry. The process comprises removing impurities from a crystallized product in a solid liquid displacement zone to form the purified carboxylic acid slurry. The process produces purified carbo
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- Is it possible to achieve highly selective oxidations in supercritical water? Aerobic oxidation of methylaromatic compounds
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We have demonstrated that different methylaromatic compounds [1,4-dimethylbenzene (p-xylene), 1,3-dimethylbenzene (m-xylene), 1,2-dimethylbenzene (o-xylene), 1,3,5-trimethylbenzene (mesitylene) and 1,2,4-trimethylbenzene (pseudocumene)] can be aerobically oxidized in supercritical water (scH2O) using manganese(II) bromide as catalyst to give corresponding carboxylic acids in the continuous mode over a sustained period of time in good yield. No partially oxidized intermediates (i.e., toluic acid and benzaldehydes) were detected for the dimethylbenzenes and mesitylene reactions. By fine tuning pressure and temperature, ScH2O becomes a solvent with physical properties suitable for single-phase oxidation since both organic substrate and oxygen are soluble in scH2O. There is a strong structural similarity of metal/bromide coordination compounds in the active oxidation solvents (acetic acid and scH2O) which does not exist in the much less active H2O at lower temperatures. This may account for the successful catalysis of the reactions reported herein. Aromatic acids produced by the loss of one methyl group occurred in all of these reactions, i.e., 3-6percent benzoic acid formed during the oxidation of the dimethylbenzenes. Part of this loss is thought to be due to thermal decarboxylation. The thermal decarboxylation process is monitored via Raman spectroscopy.
- Garcia-Verdugo, Eduardo,Venardou, Eleni,Barry Thomas,Whiston, Keith,Partenheimer, Walter,Hamley, Paul A.,Poliakoff, Martyn
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p. 307 - 316
(2007/10/03)
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- Naaladase inhibitors for treating retinal disorders and glaucoma
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The present invention relates to pharmaceutical compositions and methods for treating a retinal disorder or glaucoma using NAALADase inhibitors.
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- PRODUCTION OF AROMATIC CARBOXYLIC ACIDS
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A process for the production of an aromatic carboxylic acid comprising contacting in the presence of a catalyst, within a continuous flow reactor, one or more precursors of the aromatic carboxylic acid with an oxidant, such contact being effected with sai
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- Naaladase inhibitors for treating amyotrophic lateral sclerosis
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The present invention relates to pharmaceutical compositions and methods for treating amyotrophic lateral sclerosis using NAALADase inhibitors.
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- Benzenedicarboxylic acid derivatives
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New benzenedicarboxylic acid derivative compounds; pharmaceutical compositions, diagnostic methods, and diagnstic kits that include those compounds; and methods of using those compounds for inhibiting NAALADase enzyme activity, detecting diseases where NAALADase levels are altered, effecting neuronal activity, effecting TGF-β activity, inhibiting angiogenesis, and treating glutamate abnormalities, neutopathy, pain, compulsive disorders, prostate diseases, cancers, and glaucoma.
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- Process for producing aromatic polycarboxylic acid
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A process for producing a polycarboxylic acid which comprises performing liquid phase oxidation of polyalkyl-substituted aromatic aldehyde and/or oxide derivative of polyalkyl-substituted aromatic aldehyde as raw material for oxidation with molecular oxygen at two stages in water solvent in the presence of a catalyst comprising bromine or both bromine and a heavy metal(s) at a temperature of 180 to 280 °C , thereby producing trimellitic acid or pyromellitic acid, wherein said liquid phase oxidation is performed in a continuous operation at the first stage and in a continuous operation or in a batch operation at the second stage and a total amount of bromine in said catalyst is divided to add separately at each the first stage and the second stage.
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- REACTIVE ORGANOSILICON COMPOUNDS
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Organosilicon compounds are described which contain a cyclic organic moiety between at least two reactive silane groups. The compounds are useful in coatings, adhesives, and sealants, and the like.
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- Novel crystal form of a perinone dye
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A novel crystal form of C.I. Solvent Orange 60 gives a higher space-time yield in dye synthesis and is more easily finished.
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- Process for producing aromatic polycarboxylic acid
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A process for producing a polycarboxylic acid which comprises performing liquid phase oxidation of polyalkyl-substituted aromatic aldehyde and/or oxide derivative of polyalkyl-substituted aromatic aldehyde as raw material for oxidation with molecular oxygen at two stages in water solvent in the presence of a catalyst comprising bromine or both bromine and a heavy metal(s) at a temperature of 180 to 280 ° C., thereby producing trimellitic acid or pyromellitic acid, wherein said liquid phase oxidation is performed in a continuous operation at the first stage and in a continuous operation or in a batch operation at the second stage and a total amount of bromine in said catalyst is divided to add separately at each the first stage and the second stage.
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- Process for producing trimellitic anhydride
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A process for producing trimellitic anhydride which comprises performing liquid phase oxidation of pseudocumene containing 5% by weight or above of dimethyl bezaldehyde as a raw material for oxidation with air in aliphatic monocarboxylic acid having 1 to 5 carbon atoms as a solvent in the presence of a catalyst comprising both each metal of cobalt, manganese and zirconium and bromine to obtain trimellitic acid and then heat dehydrating trimellitic acid thus obtained or heat treating trimellitic acid thus obtained in the presence of a catalyst comprising 10 ppm or above of Ni thereby producing trimellitic anhydride.
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- Process for the production of trimellitic acid and process for the production of trimellitic acid anhydride
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A process for the production of a trimellitic acid by oxidizing dialkyl aromatic aldehyde and/or its oxide derivative in a liquid phase, the oxidation being carried out in a lower aliphatic carboxylic acid solvent having a water content of 5 to 70% by weight in the presence of a catalyst containing a heavy metal and bromine or being carried out in a solvent containing a lower aliphatic carboxylic acid in the presence of a bromine-manganese catalyst system containing zirconium and/or cerium, and a process for the production of high-quality trimellitic acid anhydride from the trimellitic acid.
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- Oxidation of alkylaromatic hydrocarbons over V2O5-Sb2O3/TiO2 catalyst
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Monoalkylbenzenes, polymethylbenzenes, para-substituted toluenes and monomethylnaphthalenes were oxidized in the vapor phase by oxygen-containing gas in the presence of water over a Sb2O3-promoted V2O5/TiO2 catalyst. This type of catalyst yields carboxylic acids with high selectivity. In the oxidation of substituted alkylbenzenes only alkyl groups were oxidized. No products of oxidative dimerization were detected. Only in the oxidation of methylnaphthalenes, also products of aromatic ring oxidation are formed. A correlation between experimental data and results of quantum-chemical calculations of bond dissociation energies is discussed.
- Antol, Marcel,Cvengrosova, Zuzana,Vrabel, Imrich,Lesko, Jan,Hronec, Milan
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p. 1481 - 1490
(2007/10/03)
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- Use of benzazoles UV absorbers, new benzazoles and a process for their preparation
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Compounds which, per molecule, contain at least 2 benzazolyl groups are outstandingly suitable as UV absorbers for sunscreen compositions.
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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 producing trimellitic acid
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It is a process for producing trimellitic acid (trimellitic acid, 1, 2, 4-tricarboxylic acid) by oxidizing pseudocumene with a molecular oxygen containing gas. More particularly, pseudocumene is oxidized into trimellitic acid by introducing a molecular oxygen containing gas in an acetic acid solvent in the presence of oxidizing catalysts, wherein the oxidization reactions in two different stages which have different ranges of temperature and different compositions of catalyst, respectively.
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- Process for producing 2,6-naphthalenedicarboxylic acid
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Disclosed in the present invention is a process for producing 2,6-naphthalenedicarboxylic acid comprising oxidizing 2,6-diisopropylnaphthalene or its partially oxidized intermediate with molecular oxygen in a solvent containing at least 50% by weight of an aliphatic monocarboxylic acid, having not more than three carbon atoms, in the presence of a catalyst composed of (i) a heavy metal comprising cobalt and/or manganese and (ii) bromine, and a salt of an inorganic acid having an acid dissociation constant Ka smaller than 1.34×10-5 (at 25° C.) and a vapor pressure lower than that of the aliphatic monocarboxylic acid used as the solvent. According to the process of this invention, 2,6-naphthalenedicarboxylic acid of high bulk density can be obtained in a high yield and with high purity.
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- Process for producing naphthalenedicarboxylic acid together with trimellitic acid
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Disclosed herein is a process for producing 2,6-naphthalenedicarboxylic acid together with trimellitic acid comprising oxidizing 2,6-diisopropylnaphthalene with molecular oxygen in the presence of a catalyst comprising a heavy metal(s) and bromine.
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- Method for oxidizing alkyl groups on pyridine, quinoline and benzene ring compounds to carboxylic acids under basic conditions
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There is provided a novel process for the preparation of carboxylic acids from alkyl groups under basic conditions utilizing oxides of copper, cobalt and silver.
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- COBALT CARBONYL CATALYZED POLYCARBONYLATION OF POLYHALOGENATED AROMATICS UNDER PHOTOSTIMULATION
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Cobalt carbonyl catalyzed polycarbonylation of much less reactive polychlorobenzenes could be easily achieved under photostimulation in aqueous sodium hydroxide.All these reactions could be performed without any organic solvent(in some cases, ethanol was used as a co-solvent) and any phase transfer catalyst.
- Kashimura, Tsugunori,Kudo, Kiyoshi,Mori, Sadayuki,Sugita, Nobuyuki
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p. 299 - 302
(2007/10/02)
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