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 alpha-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 C=N bond in thiazolidinone is trans with respect to N-N bond. Anti-mycobacterial 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. (C) 2009 Elsevier Masson SAS. All rights reserved.