A range of fluorinated 2-styrylchromones (5a–g) of which six were new (5a–f) were prepared in three steps using the Baker-Venkataraman rearrangement along with two methoxylated derivatives (5h-i) and a methylenedioxy derivative (5j) and screened for their antibacterial activity using Gram-positive bacteria (Staphylococcus aureus, sciuri, andxylosusas well asBacillus subtilis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, andKlebsiella pneumonia). The compounds were most effective againstB. subtilisfollowed byS. aureusand a single strain ofE. coli(ATCC 25922). Difluorination on the phenyl ring was shown to enhance antibacterial activity, and fluorine substitution at the 6 position was shown to be far superior to substitution at the 7 position. In comparison to tetracycline, the activity indices of the fluorinated styrylchromones ranged from 0.50 to 0.75 againstB. subtilis. The crystal structure of 2′-fluoro-2-styrylchromone is also presented, and the molecule was shown to be planar.

A series of novel 5-((10H-phenothiazin-10yl)methyl)-4-(substitutedbenzylideneamino)-4H-1,2,4-triazole-3-thiol derivatives (6a-i) have been synthesized from compound (1) through a multi-step reaction. The key intermediate (5) afforded a series of title compounds (6a-i) on condensation with various suitable aldehydes in the presence of H 2 SO 4 . The structures of novel compounds were characterized based on their elemental analysis, IR, 1 H-NMR, 13 C-NMR and MS spectral data. All these novel compounds were screened for their in vitro antioxidant activity by employing nitric oxide, hydrogen peroxide, and DPPH radical scavenging assays. The compounds 6d, 6e and 6i demonstrated potent antioxidant activity as these contain the electron-releasing groups.

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Seven fluorinated derivatives of diethyl-2-(benzylthio)-2,3-dihydro-1H-imidazole-4,5-dicarboxylate (a-g) as well as a nitro and chloro derivative (h-i) were prepared in five steps from glycine, ethyl formate, diethyl oxalate, potassium thiocyanate and substituted benzyl bromides. The structures of the synthesised compounds were elucidated and verified using 1 H, 13 C and 2D NMR spectroscopy where appropriate. The synthesised compounds exhibited concentration dependent antiplatelet aggregation activity on both the thrombin and ADP-induced platelet aggregation. The 4-nitro and 4-fluoro compounds exhibited the highest activity from the compounds tested, with IC 50 values of 1.06 and 1.20 mM for the thrombininduced assay and 18.57 and 12.91 mM in the ADP-induced platelet aggregation assay respectively. Three of the compounds, the 3 00 ,4 00 -difluoro (6c), 4 00 -nitro (6h) and 3 00 -chloro (6i) derivatives, have reasonable activity in both of the assays and could have potential as broad spectrum antiplatelet inhibitors. With the exception of 6c, the fluoro derivatives were not as active as the nitro and chloro compounds.

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