Functionalized Multi-Walled Carbon Nanotubes (f-MWCNT) as Highly Efficient and Reusable Heterogeneous Catalysts for the Synthesis of Acridinedione Derivatives

Addressed herein, carboxylic acid groups were immobilized onto carbon nanotubes and their catalytic properties were examined for the first time for the synthesis of acridinedione derivatives, opening new paths in the investigation of catalysis and their comparison with carbon-based materials. An efficient methodology for the synthesis of acridinedione derivatives has been achieved by one-pot, multi-component condensation of dimedone, substitute aromatic aldehydes, various aromatic amines and, in the presence of the easily available, inexpensive, and nontoxic f-MWCNTs as versatile biodegradable catalysts. At this method, f-MWCNTs carrying simple carboxylic acid functionalities catalyze the model reaction in ethanol providing the product in a quantitative yield. This highly monodisperse catalyst is one of the most efficient catalysts which gives the highest yield of products in the shortest time. Its high-yield efficiency, clean, eco-friendly, simple work-up procedure, and easy purification are regarded to be the main advantages of this method. The synthesized compounds are characterized using spectroscopic (IR, H-1-NMR, C-13-NMR and HRMS) techniques.