Nano-Fe3O4 attached to Crosslinked sulfonated polyacrylamide (Cross-PAA-SO3H) as high performance catalyst for the synthesis of thiazoles under ultrasonic irradiations

Nano-Fe3O4 attached to Cross-linked sulfonated polyacrylamide (Cross-PAA-SO3H), as a superior catalyst, has been utilized for the preparation of 3-alkyl-4-phenyl-1,3-thiazole-2(3H)-thione derivatives through a threecomponent reaction of phenacyl bromide or 4-methoxyphenacyl bromide, carbon disulfide, and primary amine. The best results were gained in ethanol, and it was also found that the reaction gives convincing results in the presence of cross-PAA-SO3H@nano-Fe3O4 (5 mg) under ultrasonic irradiation. The structures of the products were fully established on the basis of their 1H NMR, 13C NMR and FT-IR spectra. A proper, atomeconomical, straightforward one-pot multicomponent synthetic route for the synthesis of 1,3-thiazoles in good yields has been devised using cross-linked sulfonated polyacrylamide (Cross-PAA-SO3H) attached to nano-Fe3O4. The remarkable advantages of this methodology are short reaction times, high to excellent yields, operational simplicity, low catalyst loading and reusability of the catalyst. The catalyst has been characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray powder diffraction (XRD), energy dispersive spectroscopy (EDS), thermo- gravimetric analysis (TGA) and vibratingsample magnetometer (VSM).