Synthesis, Characterization of TiO₂-Based Nanostructure as Efficient Catalyst for the Synthesis of New Heterocycles Benzothiazole-Linked Pyrrolidin-2-One: Catalytic Performances Are Particle’s Size Dependent

Nano and micro-rutile TiO₂ structures were prepared via sol–gel and hydrothermal approaches, respectively. The as-prepared structures were subjected to various characterizations; morphological by Scanning electron microscopy, structural using both X-ray diffraction and Raman spectroscopy and elemental analysis by X-ray photoelectron spectroscopy. The catalytic ability of the two synthesized TiO₂ structures were evaluated against the synthesis of new heterocyclic compounds pyrrolidinone linked to benzothiazole moiety. These scaffolds have been prepared from substituted amines and available 2-aminothiophenol using the as-prepared TiO₂ as a heterogeneous catalyst, under ultrasonic irradiation. Our results indicate that the hydrothermal-prepared TiO₂ provide lower catalytic activity with respect to the sol-gel prepared one.