An Efficient Copper-Mediated Route for the Synthesis of 2-Substituted Benzothiazoles from Dithioesters and Investigation of their Anti-bacterial Activities

An efficient one-pot synthesis of 2-aryl/aroyl benzothiazoles has been developed through copper-mediated condensation of 2-chloroaniline with dithioesters. The method provides good isolated yields and exhibits broad functional group tolerance, accommodating both electron-donating and electron-withdrawing groups on the substrate. A series of synthesized compounds was evaluated for their antibacterial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella paratyphi. Among the series, compounds 4n, 5q, and 5r exhibited a significant inhibitory effect against the tested pathogens. Compound 5r demonstrated potential as an effective compound in both the agar well diffusion assay and broth microdilution assay. Additionally, compounds 4n, 5q, and 5r displayed strong inhibitory effects on biofilm formation of the pathogens in both the Crystal violet assay and MTT assay at a concentration of 10 mM. These findings highlight the promising antimicrobial and anti-biofilm properties of these compounds, indicating their potential for further investigation as potential therapeutic agents against the tested pathogens.