Background: In the present study, chalcones were synthesized from 2-hydroxy-1-
acetonaphthone and substituted aromatic aldehydes were synthesized by Claisen Schmidt condensation
reaction using potassium hydroxide as a base. The synthesized chalcones were purified by recrystallization
from ethanol and evaluated for antibacterial activity by well diffusion method. The antibacterial
activity was evaluated against Bacillus licheniformis, Bacillus species, Escherichia coli and Staphylococcus
aureus using Ciprofloxacin as a standard.
Methods: The target molecules were prepared by reacting 2-hydroxy-1-acetonaphthone and various
substituted aromatic aldehyde in the presence of suitable condensing agents. The structure of synthesized
compounds was confirmed on the basis of elemental analysis, IR, 1H NMR and 13C NMR spectral
data. These synthesized compounds were also screened for antibacterial activity.
Results: In the present study, free hydroxyl group in position 2 or 4 of aldehyde ring of synthesized
chalcones appears to be a very important requirement in increasing the activity (2-5 and 8-13). When
the hydroxyl group in position 4 is alkylated (14, 15), the chalcones become less active. When more
complex substituent is present on the aldehyde ring (6, 7) there is a decrease in the activity.
Conclusion: Newly synthesized chalcones (1-15) show good and moderate antibacterial activity. We
believe that the new hydroxy substituted (in aldehyde ring) chalcones (2-5 and 8-13) reported in this
work may provide an interesting insight for further optimization.