Synthesis and antimycobacterial screening of new N-(4-(5-aryl-3-(5-methyl-1,3,4-oxadiazol-2-yl)-1H-pyrazol-1-yl)phenyl)-4-amide derivatives

This article demonstrates the synthesis, characterization and the study of in vitro antitubercular activities of twenty four new N-(4-(5-aryl-3-(5-methyl-1,3,4-oxadiazol-2-yl)-1H-pyrazol-1-yl)phenyl)-4-amide derivatives (8a–x). The antitubercular activity of the compounds against Mycobacterium tuberculosis H37Rv (MTB) revealed that 2-chloro-N-(4-(5-(4-chlorophenyl)-3-(5-methyl-1,3,4-oxadiazol-2-yl)-1H-pyrazol-1-yl)phenyl)benzamide (8n) is the most promising lead molecule with a MIC of 1.56 μg/mL, while the corresponding unsubstituted benzamide derivative (8o) is the next most active molecule with a MIC of 3.13 μg/mL. Interestingly, the pyrazole intermediate 5b containing chlorophenyl and N-acylcarbohydrazide substituents also showed significant activity (MIC = 3.13 μg/mL). Further, the active molecules did not show toxicity against a normal NIH 3T3 cell line, signifying their suitability for further drug development.

Graphical abstractA new series of pyrazole-oxadiazole derivatives were designed and synthesized. The in vitro antitubercular activities of the molecules against Mycobacterium tuberculosis H37 Rv (MTB) were evaluated.Figure optionsDownload full-size imageDownload as PowerPoint slide