Synthesis and anti-mycobacterial activity of (E)-N'-(monosubstituted-benzylidene)isonicotinohydrazide derivatives.

A series of 22 (E)-N'-(monosubstituted-benzylidene)isonicotinohydrazide derivatives have been synthesized and evaluated for their in vitro antibacterial activity against Mycobacterium tuberculosis H(37)Rv using Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC) in mug/mL. Compounds 2f, 2g, 2j, 2k and 2q exhibited a significant activity (0.31-0.62 microg/mL) when compared with first line drugs such as isoniazid (INH) and rifampicin (RIP) and could be a good starting point to develop new lead compounds in the fight against multi-drug resistant tuberculosis.

2,4-Difluorobenzaldehyde benzoylhydrazone and 2,4-dichlorobenzaldehyde benzoylhydrazone are isostructural at 120 K with Z' = 2: complex sheets built from N-H...O, C-H...O and C-H...pi(arene) hydrogen bonds.

At 120 K, 2,4-difluorobenzaldehyde benzoylhydrazone, C14H10F2N2O, (I), and 2,4-dichlorobenzaldehyde benzoylhydrazone, C14H10Cl2N2O, (II), are isomorphous and isostructural in P2(1)/n with Z' = 2. In each structure, eight independent hydrogen bonds, viz. two of N-H...O type, five of C-H...O type and one of C-H...pi(arene) type, link the molecules into complex sheets, within which two independent one-dimensional substructures can be identified.