Design, Synthesis, and Spectral Characterization of Novel Benzothiazole-Based Heterocycles Containing Oxadiazole, Triazole, and Pyrazole Moieties

Benzothiazole derivatives are an important class of heterocyclic compounds that have attracted considerable attention due to their diverse pharmacological properties and potential therapeutic applications. This study presents the synthesis of a series of benzothiazole-based compounds through multi-step reactions starting from 4-hydroxybenzaldehyde and 2-aminothiophenol. The synthesized compounds were characterized using spectral techniques including IR and NMR (¹H and ¹³C). The structural elucidation confirms the successful formation of functionalized benzothiazole frameworks, including oxadiazole, triazole, and pyrazole derivatives. These structures offer valuable scaffolds for further pharmaceutical development, particularly in the design of antimicrobial and anticancer agents. After preparing the benzothiazole-2-phenol ring, ethyl acetate was loaded onto phenol using alpha-bromo ethyl acetate. The ester was then converted to hydrazide, which underwent a series of subsequent reactions with carbon disulfide and basic medium was converted to oxadiazole-2-thiol, where the oxygen atom was replaced by the hydrazide group to give the triazole ring. The hydrazide was further converted to pyrazole by reaction with acetylacetone and ethyl acetoacetate. Finally, the disubstituted triazole ring was prepared by melting and slowly cooling the hydrazide