Synthesis of new biologically active compounds containing linked thiazolyl-thiazolidinone heterocycles

A new series of 1,3-benzothiazol-2-yl)-1,3-thiazolan-4-one 5a-j has been synthesized by the reaction of 2-(4-methylphenyl)-3-(5,5,7-trimethyl-4,5,6,7-tetrahydro-1,3-benzothiazol-2-yl)-1,3-thiazolan-4-one 4 with aryl aldehydes. Chemical structures of all the new compounds were established by IR, 1H, 13C NMR, MS and elemental data. The compounds 5a-j were evaluated for their antibacterial activity against Gram-positive bacteria viz. Bacillus subtilis (MTCC 441), Bacillus sphaericus (MTCC 11), Staphylococcus aureus (MTCC 96) and Gram-negative bacteria viz. Pseudomonas aeruginosa (MTCC 741), Klebsiella aerogenes (MTCC 39), Chromobacterium violaceum (MTCC 2656). Amongst them, compounds containing [(4-chlorophenyl)methylidene] moiety 5b, [(3-nitrophenyl)methylidene] moiety 5d and [(2-thienyl)methylidene] moiety 5j showed significant antibacterial activity, almost equal/more than the activity of the standard drug Streptomycin. Further, the compounds 5a-j were also screened for their antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), and Trichophyton mentagrophytes (IFO 40996). Most of these new compounds showed appreciable activity against test bacteria and fungi and emerged as potential molecules for further development.