Immobilized Ni on TMEDA@βSiO₂@αSiO₂@Fe₃O₄: as a novel magnetic nanocatalyst for preparation of pyrido[2,3-d:6,5-d′]dipyrimidines

In the current body of research, a very quick and effectual procedure for the synthesis of pyrido[2,3-d:6,5-d′]dipyrimidines has been developed. This method is accomplished through the one-pot multi-component reaction of 2-thiobarbituric acid, NH₄OAc and aldehydes utilizing Ni-TMEDA@βSiO₂@αSiO₂@Fe₃O₄ as a novel mesoporous nanomagnetic catalyst at room temperature. This protocol is one of the few reports of the preparation of these derivatives without the use of conventional heating as well as energies such as microwave and ultrasound radiation. The characterization of the prepared catalyst was well accomplished by different techniques such as FT-IR, ICP-OES, SEM, TEM, BET, XRD, VSM, TGA, EDX and Elemental mapping. This organometallic catalyst was reusable for seven times with negligible decrement in its catalytic performance. In addition, all of the products were produced with high TON and TOF values, which demonstrates that our catalyst has a very high level of activity in the preparation of pyrido[2,3-d:6,5-d′]dipyrimidines.