Novel Method for Directly Nitration of OH-, SH-and NHR-Functions in Organic Molecules by Means of in Situ Generated Carbonic Acid Dinitrate
申请人:Pietrzik Nikolas
公开号:US20120232257A1
公开(公告)日:2012-09-13
The invention relates to a nitration method having the following principles: a phosgene species is converted with two equivalent silver nitrates into a double-mixed anhydride of carbonic acid and nitric acid, known here as carbonic acid dinitrate (I). Said operation is carried out in situ, and the formed dinitrate decomposes spontaneously. In addition to carbon dioxide, nitrate ions and nitronium ions are formed, said ions comprising electrophiles which are necessary for nitration. The solution which is used is acetonitrile, and is insignificant if the alcohol species is dissolved or suspended. The necessary equivalent silver nitrates are introduced into the system and optionally heated or cooled to the desired temperature. Subsequently, the acid chloride is introduced slowly, drop by drop or slowly little by little. Phosgene, diphosgene, triphosgene and chloroformic acid ester can be used as carbonic acid dichloride and monochloride, and their thiocarbonic acid analogues. A brown colouration and precipitated silver chloride display the formation of the carbonic acid reactants, said brown colouration rapidly discolouring due to an immediate reaction of the nitronium ions with the substrate with is to be nitrated. Towards the end of the addition of phosgene, the brown colouration remains for longer and longer until it no longer disappears. Then, it is stirred for another hour at room temperature. In the event of high acid-sensitive educts, non-nucleophilic nitrogen bases such as DBU can be added to the system in order to intercept the formation of nitric acid.
该发明涉及一种硝化方法,具有以下原则:一种光气物种与两当量的硝酸银反应,形成碳酸和硝酸的双混合酐,此处称为碳酸硝酸酐(I)。该操作在原位进行,形成的硝酸酐会自发分解。除了二氧化碳外,还会生成硝酸根离子和硝化离子,这些离子包括必要的硝化所需的亲电子体。所使用的溶液是乙腈,如果醇类物种被溶解或悬浮,就不重要。必要的等当量硝酸银被引入系统,并可根据需要加热或冷却至所需温度。随后,缓慢地滴加或逐渐加入酸氯化物。光气、二光气、三光气和氯甲酸酯可用作碳酸二氯化物和一氯化物,以及它们的硫氧化碳酸类似物。褐色变色和沉淀的氯化银显示了碳酸反应物的形成,由于硝化离子与待硝化底物的立即反应,该褐色变色会迅速褪色。在加入光气的过程中,褐色变色会越来越持续,直到不再消失。然后,在室温下再搅拌一个小时。在存在高酸敏感试剂的情况下,可以向系统中添加非亲核氮碱,如DBU,以截获硝酸的形成。