Immobilization of Cu(II) on MWCNTs@L-His as a new high efficient reusable catalyst for the synthesis of pyrido[2,3-d:5,6-d′]dipyrimidine derivatives

Abstract

In this research, a new heterogeneous organometallic catalyst was prepared through Cu(II) Immobilization on l-Histidine Functionalized multi-walled carbon nanotubes (MWCNTs@L-His/Cu(II)). Catalyst was prepared using a simple method and characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), thermal analysis (TGA), inductively coupled plasma optical emission spectrometry (ICP-OES) and Brunauer Emmett Teller (BET) techniques. A clean, rapid and efficient synthesis of pyrido[2,3-d:5,6-d′]dipyrimidine derivatives was accomplished in high to excellent yields and short reaction times via one-pot three-component condensation reaction of barbituric acid or 1,3-dimethylbarbituric acid, 6-aminouracil and aromatic aldehydes in the presence of MWCNTs@L-His/Cu(II) under reflux conditions. This new catalyst can be easily separated from the reaction mixture and recovered several times without a significant loss of activity.