Synthesis and in vitro antimicrobial activity of novel N-(6-chlorobenzo[d]thiazol-2-yl) hydrazine carboxamide derivatives of benzothiazole class

Abstract

In this study, a series of novel 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole (6a–g) and 1,3,4-oxadiazole (7a–g, 8) were synthesized from N-(6-chlorobenzo[d]thiazol-2-yl) hydrazine carboxamide derivatives of benzothiazole class. Antimicrobial properties of the title compound derivatives were investigated against one Gram (+) bacteria (Staphylococcus aureus), three Gram (−) bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and five fungi (Candida albicans, Aspergillus niger, Aspergillus flavus, Monascus purpureus and Penicillium citrinum) using serial plate dilution method. The investigation of antibacterial and antifungal screening data revealed that all the tested compounds showed moderate to good inhibition at 12.5–100 µg/mL in DMSO. It has been observed that triazolo-thiadiazole derivatives are found to be more active than 1,3,4-oxadiazole derivatives against all pathogenic bacterial and fungal strains.

Keywords::

• N-(6-chlorobenzo[d]thiazol-2-yl) hydrazine carboxamide
• 1,2,4-triazolo-[3,4-b]-1,3,4-thiadiazole
• 1,3,4-oxadiazole
• antimicrobial activity

Acknowledgements

The authors are thankful to the Head of the Department, Pharmaceutical Chemistry for providing laboratory facilities, Central Drug Research Institute (CDRI) for spectral analysis of the compounds. Authors are also thankful to Dr. Qadir, Head, IGIB, New Delhi for providing bacterial and fungal strains.

Declaration of interest

The authors report no conflict of interest.