Palladium-Catalyzed Sonogashira Synthesis of Alkynyl Derivatives of Quinoline-5, 8-Dione


  • Mercy A. Ezeokonkwo
  • Sunday N. Okafor
  • Evelyn U. Godwin-Nwakwasi
  • F. N. Ibeanu


Alkynylquinoline-5, 8-diones, Palladium Catalysis, Sonogashira protocol, Terminal alkynes.


The synthesis of various alkynylquinoline-5,8-diones is reported. The intermediate 6,7-dibromoquinoline-5,8-dione was obtained by nitrosation of 8-hydroxyquinoline, followed by reduction and subsequent bromination and oxidation. The coupling reaction of 6,7-dibromoquinoline-5,8-dione with various terminal alkynes via Palladium catalysis gave the alkynylquinoline-5,8-diones in good to excellent yields (50-85% ). The chemical structures of the products were confirmed using spectroscopic methods, which include UV/Visible spectrophotometer, Fourier Transform-Infrared (FT-IR) Spectroscopy, 1H and 13C-NMR Spectroscopy. In vitro antimicrobial activity screening carried out on the compounds against bacterial strains: Escherichia coli 1, Escherichia coli 12, Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeroginosa, showed that the synthesized compounds have significant activities (MIC= 0.15-3.20), against the tested organisms. However, compound 5e did not inhibit the growth of Pseudomonas aeroginosa.

Author Biography




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How to Cite

Ezugwu, J. A., Ezeokonkwo, M. A., Okafor, S. N., Godwin-Nwakwasi, E. U., & Ibeanu, F. N. (2017). Palladium-Catalyzed Sonogashira Synthesis of Alkynyl Derivatives of Quinoline-5, 8-Dione. Asian Journal of Applied Sciences, 5(6). Retrieved from

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