89-32-7Relevant articles and documents
Preparation method for pyromellitic dianhydride
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Paragraph 0012; 0026; 0029; 0030; 0033; 0036, (2019/05/02)
The invention discloses a preparation method for pyromellitic dianhydride. The preparation method comprises the following steps: (1) reacting metachlorotoluene and dichloroethane for 0.5 to 5 hours inan organic solvent under the catalytic action of aluminium trichloride or ferric chloride, generating 2,2'4,4'5,5'-hexamethyldiphenyl ethane, hydrolysing, and removing the solvent to obtain a crude product of the 2,2'4,4'5,5'-hexamethyldiphenyl ethane; and (2) heating and gasifying the crude product of the 2,2'4,4'5,5'-hexamethyldiphenyl ethane, oxidizing through air at the reaction temperature of 350 to 500 DEG C under the action of a catalyst, and collecting the product to obtain the pyromellitic dianhydride. According to the preparation method for the pyromellitic dianhydride disclosed bythe invention, the product selectivity can reach over 90 percent, the yield is good, the cost is low, and industrial production can be realized.
MOLECULAR PROBES FOR CHEMILUMINESCENCE IMAGING AND IN VIVO DETECTION OF TARGET MOLECULES
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Paragraph 0047, (2016/12/22)
Chemiluminescence imaging probes for in vivo detection of biological molecules, events, or processes. The CLI probes may feature a portion of a fluorescein molecule and a portion of a luminol molecule. The fluorescein molecule and luminol molecule may be linked by a non-xanthenic aromatic ring. The CLI probes are generally non-toxic and soluble in aqueous solutions such as PBS. The CLI probes may be used to detect specific molecules in vivo.
METHOD FOR PRODUCING CARBOXYLIC ACID ANHYDRIDE, METHOD FOR PRODUCING CARBOXYLIC IMIDE, AND METHOD FOR MANUFACTURING ELECTROPHOTOGRAPHIC PHOTOSENSITIVE MEMBER
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Paragraph 0115, (2017/01/19)
A method for producing a carboxylic acid anhydride includes heating a composition containing a specific compound in a solvent to yield the carboxylic acid anhydride. The solvent is an aprotic polar solvent having a boiling point of 50° C. or more.
A visual volumetric hydrogel sensor enables quantitative and sensitive detection of copper ions
Wu, Rui,Zhang, Shenghai,Lyu, Jitong,Lu, Fang,Yue, Xuanfeng,Lv, Jiagen
supporting information, p. 8078 - 8081 (2015/05/20)
We propose a visual volumetric sensor with 5,6-dicarboxylic fluorescein cross-linked amine-functionalized polyacrylamide hydrogel. The sensor undergoes volume response to Cu2+ ions at the μM level, which enables naked-eye quantitative detection by reading the graduation on a pipette.
Thermal stability of ionic nets with CuII ions coordinated to di-2-pyridyl ketone: Reversible crystal-to-crystal phase transformation
Bravo-García, Laura,Barandika, Gotzone,Bazán, Bego?a,Urtiaga, Miren Karmele,Arriortua, María Isabel
, p. 117 - 123 (2015/04/22)
Supramolecular networks are crystalline materials based on connections between metal ions through organic ligands. In this sense, the combination of polycarboxylate anions and dipyridyl ligands is an effective strategy to produce extended structures. However, sometimes the 3D arrangement results in an ionic network, and this is the case for the novel compounds [Cu((py)2C(OH)2)2](H2bta) (1) and [Cu((py)2C(OH)2)2](fum) (2) where (py)2C(OH)2 is the gem-diol of di-2-pyridyl ketone ((py)2CO), H2bta2- is the divalent anion of 1,2,4,5-benzenetetracarboxylic acid (H4bta), and fum2- is the divalent anion of fumaric acid (butenedioic acid). Both compounds were synthesized and structurally characterized by means of single crystal X-ray diffraction and IR spectroscopy. The thermal behavior of both compounds was analyzed through TG/DTA and TDX, concluding that the thermal stability is influenced by the dehydration of the coordinated molecules and counter-anions. Additionally, 13C NMR measurements were performed to analyze the reversible crystal-to-crystal phase transformation observed for 1.
Bronsted base-assisted boronic acid catalysis for the dehydrative intramolecular condensation of dicarboxylic acids
Sakakura, Akira,Ohkubo, Takuro,Yamashita, Risa,Akakura, Matsujiro,Ishihara, Kazuaki
supporting information; experimental part, p. 892 - 895 (2011/05/02)
Bronsted base-assisted boronic acid catalysis for the dehydrative self-condensation of carboxylic acids is described. Arylboronic acid bearing bulky (N,N-dialkylamino)methyl groups at the 2,6-positions can catalyze the intramolecular dehydrative condensation of di-and tetracarboxylic acids. This is the first successful method for the catalytic dehydrative self-condensation of carboxylic acids.(Figure Presented)
METHOD FOR PRODUCING CARBOXYLIC ANHYDRIDE AND ARYLBORONIC ACID COMPOUND
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Page/Page column 10-11, (2012/01/13)
When phthalic acid is heated in heptane under azeotropic reflux conditions in the presence of a catalytic amount of an arylboronic acid compound (such as 2,6-(diisopropylaminomethyl)phenylboronic acid or 2,6-bis(diisopropylaminomethyl)phenylboronic acid), phthalic anhydride is obtained in high yield.
An inexpensive and efficient synthetic method for the preparation of pyromellitic dianhydride promoted by ionic liquid
Hu, Yu Lin,Lu, Ming,Liu, Xiao Bin,Zhang, Sheng Bin,Ji, Zhan Hui,Lu, Ting Ting
experimental part, p. 63 - 74 (2010/10/19)
In this article, pyromellitic dianhydride could be successfully obtained in 76.7% total yield by an aerobic oxidation of 1,4-bis(chloromethyl)-2,5- dimethylbenzene or 1,5-bis(chloromethyl)-2,4- dimethylbenzene catalyzed by VO(acac)2/Cu(2-Eth)2/DABCO in [hmim]OTf and a subsequent dehydration of pyromellitic acid upon heating with acetic anhydride. The starting materials including 1,2-bis(chloromethyl)-4,5-dimethylbenzene were prepared by dichloromethylation of their corresponding xylene catalyzed by [C12mim]Br in aqueous media. ARKAT USA, Inc.
Esters of pyromellitic acid. Part I. Esters of achiral alcohols: Regioselective synthesis of partial and mixed pyromellitate esters, mechanism of transesterification in the quantitative esterification of the pyromellitate system using orthoformate esters, and a facile synthesis of the ortho pyromellitate diester substitution pattern
Paine III, John B.
, p. 4929 - 4939 (2008/12/21)
(Chemical Equation Presented) Mild conditions and reversible anhydride formation allow a relative differentiation to be made of the four equivalent carbonyl groups of pyromellitic dianhydride (PMDA, benzene-1,2,4,5- tetracarboxylic dianhydride) in esterification, leading to regioselective methods to generate a wide range of partially or totally esterified products or products bearing differing esterifying groups at the different positions. Pyromellitate monoester anhydrides form efficiently in dichloromethane/ triethylamine from 1 equiv of the alcohol. Under the same conditions, two different alcohols can be made to react sequentially. With 2 equiv of an alcohol, the usual mixture of meta and para diesters is obtained, separated by crystallization from HOAc. Meta and para dibenzyl pyromellitates served as regiospecific sources of other diesters, by further esterification followed by hydrogenolysis. Refluxing orthoformate triesters were found to effect quantitative esterification of the pyromellitate system under autocatalytic conditions; minor ester exchange with pre-existing esters (0-5% of total product) was ascribed to reversible anhydride formation. For general esterification with alcohols, partial ester acid chlorides were obtained using oxalyl chloride. Pyromellitate triesters afforded the ortho diester anhydrides upon distillation, thereby providing facile entry into the mostly novel ortho substitution pattern in this system. The requisite triesters were prepared by selective saponification or by the prior incorporation of one benzyl ester substituent, which could be removed by catalytic hydrogenolysis. The various benzyl esters of pyromellitates hydrogenolyzed smoothly to release the carboxylic acid groups without disturbance of pyromellitate aromaticity.
PROCESS FOR OXIDATION OF ORGANIC COMPOUNDS
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Page/Page column 17, (2008/06/13)
A method oxidizes an organic compound with oxygen in the presence of a catalyst, in which the catalyst contains a N-hydroxy- or N-(substituted oxy)-imide compound derivable from at least one selected from a target product, a reaction intermediate, and a reaction byproduct, and the catalyst is produced from at least one component selected from the target product, reaction intermediate, and reaction byproduct each formed as a result of the reaction and is used in the oxidation reaction so as to make up for a loss of the catalyst due to denaturation in the reaction. The method can easily and inexpensively make up for a loss of the catalyst denaturated in the course of reaction.
