Hyperbranched 5-sulfosalicylic acid-TDI-chitosan decorated by Fe3O4 nanoparticles: a highly efficient solid acid organocatalyst for the synthesis of quinazoline derivatives under green conditions

Abstract

Abstract In this research, a new magnetic decorated hyperbranched chitosan by grafting of 5-sulfosalicylic acid using toluene-2,4-diisocyanate linker (CS-TDI-SSA-Fe3O4) was designed and prepared conveniently. The obtained magnetic biopolymeric nanomaterial was properly characterized by using FT-IR, EDX XRD, FESEM, TGA and VSM spectroscopic, microscopic, or analytical methods. The supramolecular CS-TDI-SSA-Fe3O4 nanocomposite was investigated, as a heterogeneous solid acidic organocatalyst, to promote three-component synthesis of 2,3-dihydroquinazoline-4(1H)-one derivatives under green chemistry conditions. The CS-TDI-SSA-Fe3O4 nanocatalyst was demonstraed to act as a highly efficient solid acid for the synthesis of various quinazoline derivatives, as an important pharmaceutical scaffold, through multicomponent strategy. The reaction proceeds very well in the presence of CS-TDI-SSA-Fe3O4 solid acid nanocatalyst in EtOH to afford corresponding 2,3-dihydroquinazoline-4(1H)-one derivatives in high to excellent yields. Key advantages of the present protocol are the use of a renewable and biopolymeric and biodegredable solid acid as well as simple procedure for preparation of the hybrid material. Furthermore, the CS-TDI-SSA-Fe3O4 catalyst can be used at least five times for the synthesis of quinazoline derivatives with a slight decrease in its catalytic activity.