Design and synthesis of novel piperazine unit condensed 2,6-diarylpiperidin-4-one derivatives as antituberculosis and antimicrobial agents

A new series of 1-[2-(4-ethoxycarbonylpiperazine-1-yl)acetyl]-2,6-diarylpiperidin-4-ones (3a-3j) has been synthesized by conventional method and were characterized by IR, elemental analysis, mass spectral, 1 H NMR, C-13 NMR, and single crystal X-ray diffraction analysis. The synthesized compounds were evaluated for their antituberculosis activity against Mycobacterium tuberculosis H37Rv (ATCC-27294) and also its antimicrobial activity were examined against five familiar bacterial and fungal strains. Among the synthesized compounds, compounds 3e-3j exhibit higher inhibition potency (16 mu g/ml) against M. tuberculosis H37Rv. Furthermore, compounds containing fluoro substituent in the phenyl ring at C-2 and C-6 positions of the piperidin-4-one motif (compounds 3c, 3d, and 3i) exerted better antibacterial and antifungal activity than the other phenyl-substituted compounds.