Synthesis, characterization, and antimicrobial effect of bisbenzylidene derivatives of cyclohexanone and cyclopentanone

Abstract

Dibenzylidene derivatives of cyclohexanone and cyclopentanone were synthesized by reacting appropriate aromatic aldehyde, such as benzaldehyde, anisaldehyde and piperonal, to obtain dibenzylidene derivatives of cyclohexanone and cyclopentanone using the Claisen- Schmidt condensation reaction. The reaction was catalysed with 30% sodium hydroxide solution at 0-10°C and was kept in the refrigerator for 7 days. The progress of the reaction was monitored using TLC in a solvent system (Ethyl acetate: Methanol 1:1), and thereafter treated with acetic acid and the precipitates collected, dried and recrystallized in methylated spirit, filtered and dried. The yield, melting point and spectral analysis were determined. The antimicrobial assay was carried out using the broth dilution method at 512, 256, 128, 64, 32, 16, 8, 4, 2, and 1μg/mL against S. aureus, Escherichia spp., Bacillus spp, Klebsiella spp. and Candida albicans. The yield of the compounds ranges (50.3-99%), the melting point ranges (108- 246°C) and the spectral analyses conformed as projected. This was revealed by ¹H, ¹³C-NMR, and HRMS (ESI) data. The compounds had no antibacterial effect at the concentration assessed.