Microwave-assisted Green Synthesis of β-Diketone Hydrazone Derivatives and Evaluation of their Antioxidant and Antibacterial Activities

Abstract

Background: A series of β-diketone hydrazones have been synthesized via condensation of isoniazid with series of β-diketone. The structures of the Schiff bases are established by elemental and spectroscopic techniques. The prepared compounds were screened for antibacterial and antioxidant potential by DPPH free-radical scavenging activity and Ferric reducing antioxidant power (FRAP) assays. Methods: β-diketone hydrazine derivatives were synthesized by simple condensation between various β-diketones and isoniazid. The titled compounds were synthesized following both conventional and microwave irradiation methods. The in vitro antibacterial activity of synthesized derivatives was evaluated against gram-positive (B. subtilis, S. aureus and S. pyogenes) and gram-negative (E. coli, and K. pneumonia) bacterial strains and expressed in terms of zone of inhibition and also screened for antioxidant activity. Results: The yield of products was appreciably increased in shorter reaction times with the aid of microwave-assisted synthesis. Therefore, it follows the green chemistry approach by making the above reactions eco-friendly. The synthesized compounds were characterized using FT-IR, 1H NMR, 13C NMR, and elemental analysis techniques. The spectroscopic techniques showed the formation of β-diketone hydrazone compounds. Theoretical data show good agreement with the experimental results. Some of the compounds displayed significant antibacterial and antioxidant potentials when compared to the standard drug. Conclusion: In the present research work, we report the synthesis of some novel β-diketone hydrazone derivatives. A high yield of compounds was noted under microwave-assisted reaction in shorter reaction times. The results revealed that the synthesized Schiff bases showed good radical scavenging activity.