摘要:
A process for producing a 3-alkoxy-2-amino-6-fluoro bicyclo[3.1.0]hexane-2,6-dicarboxylic acid derivative represented by the formula (I) or a salt thereof, which includes converting a compound represented by the formula (VI) or a salt thereof to the compound represented by the formula (I) or a salt thereof.
摘要:
The present invention relates to a method of radiolabelling carbon nanotubes, to the radiolabelled carbon nanotubes that can be obtained by implementing this method, and to applications thereof.
摘要:
A process is provided herein for the high yield production of high purity glacial methacrylic acid (“HPMAA”) that is substantially pure, specifically 99% pure or greater, with water content of 0.05% or less and low levels of other impurities, including HIBA, acrylic acid, MOMPA, methacrolein and others. This improved process comprises providing a crude MAA stream and purifying the crude methacrylic acid stream in a series of successive distillation steps involving two distillation columns. The inventive process is capable producing high purity methacrylic acid product that is especially suitable for the production of specialty MAA polymers.
摘要:
Hydrocarbon-based compounds containing at least one nitrile function are converted into compounds containing at least one carboxylic function, and into ester compounds from the carboxylic compounds thus obtained; such conversion entails reacting the nitrile compound with a hydroxyl basic compound in solution in a solvent at a temperature of between 80 and 150° C., in eliminating the ammonia formed, in reacting the salt obtained with a mineral acid, and then in recovering the compound containing at least one carboxylic function and, optionally, esterifying the acids obtained by reaction with an alcohol.
摘要:
The present invention relates to halogen-containing aromatic compounds and methods thereof. The present invention relates a halogen-containing aromatic acid dianhydride, halogen-containing aromatic tetranitrile compound, halogen-containing m-phenylenediamine compound and fluorine compound, and a method thereof.
摘要:
A method for preparing aromatic compounds including 1,4-difluoropyromellitic dianhydride represented by formula (12): ##STR1## and 1,4-difluoropyromellitic acid represented by formula (15): ##STR2## by dehydrating or hydrolyzing and dehydrating precursors.
摘要:
Nucleophilic substitution reactions on halobenzenes or triflyl substituted benzenes are carried out in the presence of catalysts. In particular the present invention provides a process leading to optionally substituted hydroxybenzoic, alkanoyloxybenzoic, formyloxybenzoic and alkoxybenzoic acids and optionally substituted hydroxybenzonitriles and alkoxybenzonitriles from substituted 2,6-dihalobenzenes, 2-halo-6-triflylbenzene and 2,6-ditriflylbenzenes.
摘要:
Nucleophilic substitution reactions on halobenzenes are carried out in the presence of catalysts. In particular the present invention provides a process leading to optionally substituted hydroxybenzoic and alkoxybenzoic acids and optionally substituted hydroxybenzonitriles and alkoxybenzonitriles from substituted 2,6-dihalobenzenes.
摘要:
A perfluorinated polyimide comprising a repeating unit represented by general formula (1): ##STR1## and a perfluorinated poly(amic acid) comprising a repeating unit represented by general formula (6): ##STR2## wherein R.sub.1 is a tetravalent organic group; and R.sub.2 is a divalent organic group, provided that chemical bonds between carbon atoms and monovalent elements contained in R.sub.1 and R.sub.2 are exclusively carbon-to-fluorine bonds; methods for preparing them; and optical material including the perfluorinated polyimide. 1,4-Bis(3,4-dicarboxytrifluorophenoxy)-tetrafluorobenzene dianhydride, 1,4-difluoropyromellitic anhydride, 1,4-bis(3,4-dicarboxytrifluorophenoxy)-tetrafluorobenzene, 1,4-difluoropyromellitic acid, and 1,4-bis(3,4-dicyanotrifluorophenoxy)-tetrafluorobenzene as well as methods preparing them. The perfluorinated polyimide has a thermal stability and has a low optical loss in an optical communication wavelength region (0.8 to 1.7 .mu.m).