Synthesis, spectral and biological evaluation of some new thiazolidinones and thiazoles based on t-3-alkyl-r-2,c-6-diarylpiperidin-4-ones

A stereospecific synthesis of some thiazolidinones and thiazoles was achieved conveniently through certain α-halo keto agents and reactivity of chloroacetyl chloride was successfully enhanced by CsF–Celite + CH3COONa. NMR studies revealed that the configuration of N–N bond is found to be anti with respect to C-3 alkyl group while CN bond in thiazolidinone is trans with respect to N–N bond. Antimycobacterial activity tested against Mycobacterium tuberculosis indicated that compounds 19, 20, 24, 29, 30 and 32 exhibited twofold enhanced potency than Rifampicin. Similarly, antimicrobial screening studies pointed out that compounds 21 and 28 exceptionally noticed promising activities and particularly, 21 against Staphylococcus aureus and, 24 and 32 against Rhizopus sp. exhibited onefold elevated inhibition potency whereas 21 against Klebsiella pneumoniae showed twofold improved potency than Ciprofloxacin and Amphotericin B.

Graphical abstractAntimycobacterial and antimicrobial screening of the synthesized compounds revealed that substitution of electron withdrawing or donating substituents at the para position of the phenyl groups besides methyl group at N-1 and C-3 exerted better biological profiles.Figure optionsDownload full-size imageDownload as PowerPoint slide