Synthesis and antibacterial activity of some 3-(5-aryl-4H-pyrazol-3-yl).

ABSTRACT

A series of 3-(5-aryl-4H-pyrazol-3-yl)anthracen-10(9H)-ones were synthesized from anthracen-10(9H)-one (1) and studied for their in vitro antibacterial activity. Anthracen- 10(9H)-one after Friedel crafts acetylation with acetyl chloride yielded 3-acetylanthracen- 10(9H)-one (2) which on further reaction with substituted aromatic aldehydes in the presence of catalytic amount of sodium hydroxide in water and ethanol furnished the corresponding 3-(3-arylacryloyl)anthracen-10(9H)-ones (3a-g) as intermediate compounds, which on further reaction with hydrazine hydrate in absolute ethanol formed the title compounds 3-(5-aryl-4H-pyrazol-3-yl)anthracen-10(9H)-ones (4a-g). These compounds were characterized by elemental analysis, IR, Mass and 1H-NMR spectral data. All the compounds were evaluated for their in vitro antibacterial activity against two gram positive strains (Bacillus subtilis and Staphylococcus aureus) and two gram negative strains (Escherichia coli and Pseudomonas aeruginosa) taking ciprofloxacin as a standard drug. Some of the compounds showed significant antibacterial activity.