Synthesis and Antimycobacterial Activity of a Novel Series of Isonicotinylhydrazide Derivatives

A novel series of 14 new isonicotinyl hydrazide derivatives 2a – g , 3a – g containing a 4‐thiazolidinone / 2‐azetidinone nucleus were synthesized by reacting N′‐substituted arylidene / heteroarylidene isonicotinyl hydrazide 1a – g with thioglycollic acid in the presence of dry benzene and with chloroacetyl chloride in the presence of triethylamine, respectively. Structures of all newly synthesized compounds were characterized on the basis of elemental analyses and spectral data (IR and ¹H‐NMR). All the title compounds were tested for their in‐vitro antimycobacterial activity against Mycobacterium tuberculosis H₃₇Rv using Alamar‐Blue susceptibility test, and the activity is expressed as the minimum inhibitory concentration (MIC) in μg/mL. Among the series, compounds 2b , 2g , 3b , and 3g displayed an encouraging antimycobacterial activity profile as compared to that of the reference drugs isoniazid / rifampicin.