Cu(II)/citric acid grafted to chitosan by dendritic units of melamine as a novel and highly efficient heterogeneous catalyst for the synthesis of 2-aminobenzothiazole derivatives

In this paper, a new cross-linked chitosan by G1 dendrimer from melamine terminated by citric acid groups to support Cu(II) nanoparticles (CS@CA-Me-CA@Cu) was designed and prepared. Subsequently, the prepared nanocomposite was characterized using different spectroscopic, microscopic and analytical techniques such as FTIR, XRD, FESEM, TGA and EDX. The supramolecular CS@CA-Me-CA@Cu demonstrates higher thermal and chemical stability than its components. In addition, in order to investigate the catalytic performance of the CS@CA-Me-CA@Cu bio-based nanocomposite it was used, as a Lewis acidic and green heterogeneous catalyst, for the preparation of 2-aminobenzothiazole derivatives under green conditions. Also, other advantages of this new bio-based nanocomposite include easy preparation, high catalytic activity, recyclability, and reuse with a gradual decreasing in its catalytic activity.