Organic Communications Articles

Novel chalcone derivatives, containing 4,7-ethanoisoindole-1,3-dione units were synthesized starting from 1,3-cyclohexadine (4) and maleic anhydride (5). Addition of maleic anhydride (5) to 1,3-cyclehexadine (4) gave an endo-adduct, 3a,4,7,7a-tetrahydro-4,7-ethano-2-benzofuran-1,3-dione (6), in 90% yield. Heating the solution of the adduct dione (6) and 1-(4-aminophenyl)ethanone (7) in the presence of Et3N in toluene at 110 oC for 24 hours afforded 2-(4-acetylphenyl)-3a,4,7,7a-tetrahydro-1H-4,7-ethanoisoindole-1,3-dione (8) in high
yield. Piperidine-catalyzed addition of benzaldehyde derivatives (9a-i) to the compound 8 in CH2Cl2 at 55 oC gave the expected chalcone derivatives (10-i) in the range of 42% - 96% yields. The antibacterial activities of the chalcone derivatives (10a-i) were evaluated against human pathogenic microorganism and the compounds showed low activity compared to the standard, name of the standard.

SO42-/SnO2-Catalyzed efficient one-pot synthesis of 7,8-dihydro-2H-chromen-5-ones by formal [3+3]
cycloaddition and 1,8-dioxo-octahydroxanthenes via a Knoevenagel condensation is described with good yields
under mild reaction conditions. The catalyst could be reused several times without loosing its catalytic
efficiency.

The effect of metal salts on the oxidation reaction of (acetylphenyl)ferrocenes was determined. For
the p- and m-isomers, the effect was accelerated, but for the o-isomer, the effect was suppressed. This
suppressing effect was related to the chelate ring containing the substrate and the metal ion.