Ultrasound-assisted synthesis of novel 1,2,3-triazoles coupled diaryl sulfone moieties by the CuAAC reaction, and biological evaluation of them as antioxidant and antimicrobial agents.

A series of 1,2,3-triazoles coupled diaryl sulfone containing compounds were synthesized by the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) reaction in benign solvents under ultrasound irradiation. In situ formation of azides from α-bromoketones together with the CuAAC reaction in one pot allowed safe handling and good availability of azides for the development of a small library of compounds. The sonication reduced reaction time and increased yields compared to otherwise same conditions. All synthesized compounds were evaluated for antibacterial, antifungal and antioxidant activities. Compounds 3b, 6b and 9e-9g were found to be the most potent antifungal agents with minimal inhibitory concentration (MIC) at 25 μg/mL; moreover other compounds revealed good to moderate antimicrobial activity. Compound 8e showed an excellent antioxidant activity using a DPPH free radical scavenging assay.