Synthesis and characterization of N′-(11H-indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazonamides as potential antimicrobial agents

Abstract

A series of new N′-(11H-indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazonamides 3a–3j was synthesized in excellent yields from the reaction of N³-substituted benzohydrazonamides 1 and 2-(11H-indeno[1,2-b]quinoxalin-11-ylidene)malononitrile 2 in dichloromethane or with 11H-indeno[1,2-b]quinoxalin-11-one 4 in ethyl acetate at ambient temperature. The new compounds have been characterized and screened for biological activity. Some of them showed significant antibacterial and antifungal activities. In particular, compounds 3c and 3e showed interesting activities as antibacterial agents while compounds 3a 3c, 3e, 3g, and 3i showed high antifungal activities.

Graphical Abstract

Keywords:

• Antimicrobial activity
• 11H-indeno[1,2-b]quinoxalin-11-one
• 2-(11H-indeno[1,2-b]quinoxalin-11-ylidene)malononitrile
• N′-(11H-indeno[1,2-b]quinoxalin-11-ylidene)benzohydrazonamide

Acknowledgments

Prof. Mohsen A.-M. Gomaa is deeply indebted to the Deutsche Forschungsgemeinschaft (DFG) for awarding DFG fellowship. Thanks are also due to Prof. Dr. Georg Manolikakes at Fachbereich Organische Chemie, TU Kaiserslautern, Kaiserslautern, for measuring NMR and HRMS spectra.