Synthesis, characterization, and antimicrobial activity of novel heterocyclic compounds containing a ferrocene unit via Michael addition reaction

A series of novel heterocyclic compounds containing a ferrocene unit were synthesized by reacting ferrocenylchalcone with pyrazolyl amine or triazolyl amine via Michael addition reaction. A novel synthetic route of ferrocenylchalcones was developed in which cinnamic acid and ferrocene were used as starting materials and phosphorus pentachloride was used as acylating agent. The structure of these newly synthesized compounds was confirmed by IR, elemental analysis, 1H NMR, and 13C NMR. The antibacterial activity and minimum inhibitory concentration (MIC) of all compounds were screened for Escherichia coli, Saccharomyces aureus, Streptococcus, Actinomycete, and Saccharomyces cerevisiae in vitro by filter paper disc diffusion method, and agar dilution method, respectively. The compounds 4a–c exhibited moderate to excellent antibacterial activity in comparison to Ampicillin used as reference drug and MIC values between 1 and 64 μg/mL. Among these tested compounds, 4a, 4b show the best inhibitory activity.