摘要:
A method of removing alkalinity and salt from a nitroaromatic product downstream of water washing to remove mineral acids and alkaline washing to remove salts of organic acids, comprises washing the product stream with an acidic aqueous solution, prior to the step of removing excess organic reactant, by steam stripping or distillation. Acid removed from the stripper or column is recycled back for use in the acidic washing. The acidic washing is done instead of the neutral washing step of the prior art. It removes residual salt and decreases the level of entrained colloidal water in the nitroaromatic product.
摘要:
Verfahren zur Herstellung von 4-Chlor-2-methyl-5-nitro-phenol (I) dadurch gekennzeichnet, daß ein 4-Chlor-2-methyl-phenyl-sulfonat der Formel (II) worin R einen der Reste Methyl, Ethyl, Trifluormethyl, Phenyl oder Tolyl bedeutet, zunächst in 5-Stellung nitriert wird und sodann das entstandene 4-Chlor-2-methyl-5-nitro-phenylsulfonat durch saure oder alkalische Abspaltung des Sulfonylrestes in die Verbindung der Formel (I) überführt wird. Das Verfahren geht von einem technisch verfügbaren und preiswerten Ausgangsstoff aus und ermöglicht die isomerenreine Herstellung von (I) in sehr guter Ausbeute.
摘要:
Eine sichere Herstellung von Na-Nitropropandiol-1,3 aus der Reaktionslösung von Nitromethan und Paraformaldehyd durch Zugabe von Natriummethylat wird durch Verdampfungskühlung des Methanols erreicht, wobei nun Reaktionstemperaturen von 35 bis 50° C einhaltbar sind.
摘要:
Ein Verfahren zur Herstellung von Diisocyanaten durch Umsetzung von zweiwertigen Alkoholen oder von Nitrophenoxyalkanolen mit Nitrochlorbenzol zu den entsprechenden Dinitroverbindungen, Überführung dieser Dinitroverbindungen in die entsprechenden Diamine und deren anschließenden Phosgenierung, wobei man die erstgenannte Umsetzung in Gegenwart von stark polaren, aprotischen Lösungsmitteln und in Gegenwart von gepulvertem Natrium- und/oder Kaliumhydroxid durchführt, die bevorzugten, nach diesem Verfahren erstmals erhältlichen Diisocyanate und deren Verwendung als Aufbaukomponente bei der Herstellung von Polyurethankunststoffen.
摘要:
Aromatic compounds are nitrated in the vapor phase via a process comprising contacting the aromatic compounds with a nitrating agent in the presence of a nitration promoting catalyst. Such catalysts are prepared by contacting a Group 4b-Group 3b metal oxide composition represented by the empirical formula:
wherein M' is at least one element selected from Group 4b of the Periodic Table of the Elements, M 2 is at least one element selected from Group 3b of the Periodic Table of the Elements, a is 1, b is 0 to 20, c is a number taken to satisfy the average valences of M' and M 2 in the oxidation states in which they exist in the composition, x is 1, and y is 0 to c, with a catalytically effective amount of sulfur trioxide. The catalysts are particularly effective to catalyze the vapor phase nitration of chlorobenzene and are characterized in such reaction by providing a para/ortho isomer distribution ratio of at least about 2/1.
摘要翻译:芳族化合物在气相中通过包括在硝化促进催化剂存在下使芳族化合物与硝化剂接触的方法进行硝化。 通过使由经验式:(M 1 a m 2 b O c)x(NO 2)y表示的第4b族第3b族金属氧化物组合物接触而制备这种催化剂,其中M 1为选自下组的至少一种元素 元素周期表的第4b条中,M 2为选自元素周期表第3b族中的至少一种元素,a为1,b为0至20,c为满足平均化合价数 的M 1和M 2在其存在于组合物中的氧化态中,x为1,y为0至c,具有催化有效量的三氧化硫。 催化剂特别有效地催化氯苯的气相硝化,其特征在于通过提供至少约2/1的对位/邻位异构体分配比来进行这种反应。
摘要:
There is provided a method for producing a nitrobenzene compound that can be implemented by a simple operation under mild conditions without using a special reaction apparatus. [Solution] The present invention provides a method for producing a nitrobenzene compound represented by general formula (2), wherein R 1 and R 5 are the same or different, and each is a halogen atom or another functional group, and R 2 , R 3 , and R 4 are the same or different, and each is a hydrogen atom or another functional group, comprising oxidizing an aniline compound represented by general formula (1), wherein R 1 , R 2 , R 3 , R 4 , and R 5 are the same as described above, with hydrogen peroxide in the presence of a tungsten compound under an acidic condition, followed by oxidation with hydrogen peroxide under a neutral to alkaline condition.
摘要:
There is provided a method for producing a nitrobenzene compound that can be implemented by a simple operation under mild conditions without using a special reaction apparatus. [Solution] The present invention provides a method for producing a nitrobenzene compound represented by general formula (2), wherein R 1 and R 5 are the same or different, and each is a halogen atom or another functional group, and R 2 , R 3 , and R 4 are the same or different, and each is a hydrogen atom or another functional group, comprising oxidizing an aniline compound represented by general formula (1), wherein R 1 , R 2 , R 3 , R 4 , and R 5 are the same as described above, with hydrogen peroxide in the presence of a tungsten compound under an acidic condition, followed by oxidation with hydrogen peroxide under a neutral to alkaline condition.
摘要:
Die Erfindung betrifft einen optimierten Rohrreaktor zur adiabatischen Mononitrierung von Aromaten, halogenierten Aromaten und halogenierten Kohlenwasserstoffen.