Nano-kaolin/Ti/FeO: a magnetic reusable nano-catalyst for the synthesis of pyrimido[2,1-]benzothiazoles.

Herein, nano-kaolin/Ti/FeO as a new magnetic nano-catalyst was synthesized, and its structural properties were characterized using various techniques such as Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), a vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA) and energy-dispersive X-ray spectroscopy (EDX). This catalyst was used for the synthesis of pyrimido[2,1-]benzothiazoles the one-pot condensation of 2-aminobenzothiazole, an aldehyde and β-keto ester under solvent-free conditions at 100 °C. This simple protocol has many advantages such as easy workup, high product yields, short reaction times and reusability of the catalyst.

FeO@nano-cellulose/Cu(ii): a bio-based and magnetically recoverable nano-catalyst for the synthesis of 4-pyrimido[2,1-]benzothiazole derivatives.

FeO@nano-cellulose/Cu(ii) as a green bio-based magnetic catalyst was prepared through co-precipitation of Fe and Fe ions in an aqueous suspension of nano-cellulose. The mentioned magnetically heterogeneous catalyst was characterized by FT-IR, XRD, VSM, FESEM, TEM, XRF, EDS and TGA. In this research, the synthesis of 4-pyrimido[2,1-]benzothiazole derivatives was developed a three component reaction of aromatic aldehyde, 2-aminobenzothiazole and ethyl acetoacetate using FeO@nano-cellulose/Cu(ii) under solvent-free condition at 80 °C.