No abstract

A series of novel methylene-bis-chalcones was prepared by the reaction of 5,5'-methylene-bis-salicylaldehyde with different acetophenones, subsequent treatment of methylene-bis-chalcones with urea/ thiourea gave the corresponding methylene-bis-pyrimidinones/ methylene-bis-mercaptopyrimidines in good yields. Characterization of the new compounds has been done by means of IR, 1 H NMR, MS and elemental analysis. The antibacterial, antitubercular and antifungal activity of the compounds has also been evaluated.

A series of novel bis-chalcones 3 were prepared by the reaction of 5,5'-methylene-bis-salicylaldehyde 2 with various acetophenones, subsequent treatment of 3 with thiourea or guanidine resulted to the corresponding bis-thiazines or bispyrimidines in good yields. All the new compounds have been characterized by IR, 1 H NMR, MS and elemental analysis. The antibacterial, antifungal and anti-inflammatory activities of the compounds have also been evaluated.

A new class of methylene‐bis‐4,6‐diarylbenzo[d]isoxazoles 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h, 8i was synthesized by the reaction of methylene‐bis‐aryl‐6‐hydroxymethylene‐2‐cyclohexenone 6 with hydroxylamine hydrochloride, followed by aromatization with DDQ. Chemical structures of the newly synthesized compounds were elucidated by their IR, 1H NMR, 13C NMR, MS, and elemental analyses. Furthermore, all the compounds were screened for their antifungal activity against various fungi and compared with their monomeric compounds. Among the synthesized compounds, 8b, 8g, and 8i were found to be the most active against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), and Trichophyton mentagrophytes (IFO 40996). It is interesting to note that the compounds 8a, 8g, and 8i showed fungicidal activity toward C. albicans at the concentration of 3.12 μg/mL, which is less than the concentration of standard Amphotericin B. J. Heterocyclic Chem., 46, 497 (2009).

A series of novel methylene-bis-fused pyrazoles 12a-e and methylene-bis-2-(4-methylsulfonyl)-phenyl substituted fused pyrazoles 15a-d have been synthesized by the reaction of methylene-bis-aryl-6-hydroxymethylene-2-cyclohexenones 10 with hydrazine hydrate or (4-methylsulfonyl)-phenyl hydrazine 13. Chemical structures of all the newly synthesized compounds were elucidated by their IR, 1 H NMR, 13 C NMR, and MS spectral data. The compounds 15a-d were evaluated for their cyclooxygenase-2 (COX-2) inhibitory activity, and the compound 15b showed appreciable COX-2 inhibition and selectivity. Further, all the new compounds were screened for their antimicrobial activity against Gram-positive, Gram-negative bacteria, and fungi. Amongst the screened compounds, 12c, 15a, and 15b were found to be the most active against almost all the test bacteria. The compound 15b displayed notable antibacterial activity against Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p), Micrococcus luteus (IFC 12708), Proteus vulgaris (ATCC 3851), and Salmonella typhimurium (ATCC 14028), equal to that of ampicillin. Similarly, these compounds also showed potent antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), and Trichophyton mentagrophytes (IFO 40996).