||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
894 , 2016-03-07 , Wiley-VCH
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.