An expeditious and environmentally benign synthesis of dispiro-3-phenylpyrrolothiazoles in ACI/EG eutectic mixture and its antioxidant and antimicrobial activities against urinary tract pathogens

摘要

The present study reveals the robust and facile methodology for the synthesis of massively selective dispiro?3?phe?nylpyrrolothiazole hybrids via one?pot 1,3?dipolar cycloaddition reaction by environmentally supported solvents andto evaluate their biological activities. The quaternary ammonium salt eutectic mixture, acetylcholine iodide?ethyleneglycol (ACI/EG) medium brings an efcient environment for the synthesis of dispiropyrrolothiazole with excellentyield in shorter reaction time than imidazolium ionic liquids. The eutectic mixture was recovered and reused withoutany signifcant drop in their catalytic activity. Among the eight synthesized compounds 4a–h, halogen derivativesare exhibiting signifcant antimicrobial activities against selected uropathogens pathogens. Interestingly, chloro andbromo derivatives exhibits the minimum inhibitory concentration (MIC) of 12.5 μg/ml and 6.25 μg/ml towards Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus respectively. In addition, the IC50 values of DPPH radicalswith synthesized compounds are interesting, particularly compounds 4a, 4d and 4e shows lower than the controlBHA indicating their potent scavenging ability of free radicals.