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The synthesis and antimicrobial activity of novel Zn(II) metal complexes derived from three novel heterocyclic Schiff base ligands 8-[(Z)-{[3-(N-methylamino)propyl]imino}methyl]-7-hydroxy-4-methyl-2H-chromen-2-one, 2-[(E)-{[4-(1H-1,2,4-triazol-1-ylmethyl)phenyl]imino}methyl]phenol, and (4S)-4-{4-[(E)-(2-hydroxybenzylidene)amino]benzyl}-1,3-oxazolidin-2-one have been described. These Schiff base ligands and metal complexes are characterised by spectroscopic techniques. According to these data, we propose an octahedral geometry to all the metal complexes. Antimicrobial activity of the Schiff base ligand and its metal complexes was studied against Gram negative bacteria: E. coli and Pseudomonas fluorescens, Gram positive bacteria: Staphylococcus aureus, and also against fungi, that is, C. albicans and A. niger. Some of the metal complexes show significant antifungal activity (MIC < 0.2 μg/mL). The “in vitro” data has identified [Zn(NMAPIMHMC)2]·2H2O, [Zn(TMPIMP)2]·2H2O, and [Zn(HBABO)2]·2H2O as potential therapeutic antifungal agents against C. albicans and A. niger.

A series of substituted 2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamides derivatives 5a-5m were synthesized through multi-step reactions. To achieve the synthesis of the desired compounds monobromo and dibromo substituted 2-amino-γ-picoline was reacted with ethyl 2-chloroacetoacetate. The crude ethyl ester subjected to hydrolysis in presence of lithium hydroxide to get 2a and 2b, with imidazo[1,2-a]pyridine-3-carboxylic acid to get 3a-3b, on treatment with substituted amines 4a-4g to get desired product 5a-5m in presence of EDCI and HOBt. The substituted imidazo[1,2-a]pyridine-3-carboxamides are characterized by FTIR, 1 H-NMR, 13 C-NMR and mass spectra. These newly synthesized compounds were tested in vitro for their antimycobacterial activity. The preliminary results of antituberculosis study showed that most of the synthesized compounds 5a-5m demonstrated moderate to good antituberculosis activity. Among the tested compounds 5b, 5d and 5e were found to be the most active with minimum inhibitory concentration (MIC) of 12.5 μg/mL against Mycobacterium tuberculosis (H37 RV strain) ATCC No-27294.