80751-38-8Relevant academic research and scientific papers
Direct Synthesis of Cyclic Imides from Carboxylic Anhydrides and Amines by Nb2O5 as a Water-Tolerant Lewis Acid Catalyst
Ali, Md. A.,Moromi, Sondomoyee K.,Touchy, Abeda S.,Shimizu, Ken-Ichi
, p. 891 - 894 (2016/03/15)
In the 20 types of heterogeneous and homogenous catalysts screened, Nb2O5 showed the highest activity for the synthesis of N-phenylsuccinimide by dehydrative condensation of succinic anhydride and aniline. Nb2O5 was used in the direct imidation of a wide range of carboxylic anhydrides with NH3 or amines with various functional groups and could be reused. Kinetic studies showed that the Lewis acid Nb2O5 catalyst was more water tolerant than both the Lewis acidic oxide TiO2 and the homogeneous Lewis acid ZrCl4, which resulted in higher yields of imides through the use of Nb2O5. Int-imidation tactics: A general method for the direct synthesis of cyclic imides from cyclic anhydrides with amines (or ammonia) under solvent-free conditions is reported. Kinetic studies indicate that the Lewis acid sites of Nb2O5 are highly water tolerant, which results in high catalytic activity for imidation even in the presence of water formed during the reaction. The catalyst can be recovered and reused four times without a marked decrease in yield.
Versatile and sustainable synthesis of cyclic imides from dicarboxylic acids and amines by Nb2O5 as a base-tolerant heterogeneous lewis acid catalyst
Ali, Md. Ayub,Siddiki, S. M. A. Hakim,Kon, Kenichi,Hasegawa, Junya,Shimizu, Kenichi
supporting information, p. 14256 - 14260 (2015/01/09)
Catalytic condensation of dicarboxylics acid and amines without excess amount of activating reagents is the most atom-efficient but unprecedented synthetic method of cyclic imides. Here we present the first general catalytic method, proceeding selectively and efficiently in the presence of a commercial Nb2O5 as a reusable and base-tolerant heterogeneous Lewis acid catalyst. The method is effective for the direct synthesis of pharmaceutically or industrially important cyclic imides, such as phensuximide, N-hydroxyphthalimide (NHPI), and unsubstituted cyclic imides from dicarboxylic acid or anhydrides with amines, hydroxylamine, or ammonia.
