Multicomponent Reactions of Dapsone Derivatives: Synthesis, Study of Potentially Active Antimicrobial Bis 4H- Pyran and Bis 1,4- Dihydropyridine Derivatives.
The synthesis of 4H-pyran derivatives 4a and 4b was accomplished through a one-pot, multi-component reaction strategy. This synthetic route involved the condensation of a dapsone derivative 2, various aromatic aldehydes, and malononitrile (3), with triethylamine functioning as the catalytic base to promote the cyclization process. Interestingly, when ammonium acetate was employed instead of malononitrile under similar reaction conditions, the pathway was redirected to afford the corresponding 1,4-dihydropyridine analogues, specifically compounds 5a and 5b. Furthermore, an alternative approach utilizing cyanoacetamide 6 in place of malononitrile, while still maintaining triethylamine as the catalyst, led to the formation of another 4H-pyran derivative, identified as compound 7. All synthesized compounds underwent comprehensive in vitro antimicrobial screening to assess their biological activity against a diverse panel of microorganisms. This panel included Gram-positive bacteria, namely Staphylococcus aureus and Bacillus subtilis, Gram-negative bacteria such as Escherichia coli, and fungal pathogens like Candida albicans and Aspergillus niger. The antimicrobial efficacy was evaluated by measuring zones of inhibition and comparing them to standard antibiotics. Among the tested compounds, derivatives 4b and 7 displayed remarkable antimicrobial activity, exhibiting inhibition zones and minimum inhibitory concentrations (MICs) comparable to established reference drugs, including gentamycin for antibacterial activity and ketoconazole for antifungal assays. These findings suggest that compounds 4b and 7 hold promise as potential candidates for the development of novel antimicrobial agents.
M. Dawoud, S., M. Keshk, E., M. Khalil, A., & Fekri, A. (2025). Multicomponent Reactions of Dapsone Derivatives: Synthesis, Study of Potentially Active Antimicrobial Bis 4H- Pyran and Bis 1,4- Dihydropyridine Derivatives.. Mansoura Journal of Chemistry, 68(3), 1-10. doi: 10.21608/mjcc.2025.385677.1009
MLA
Shrouk M. Dawoud; Eman M. Keshk; Abdel-Galil M. Khalil; Ahmed Fekri. "Multicomponent Reactions of Dapsone Derivatives: Synthesis, Study of Potentially Active Antimicrobial Bis 4H- Pyran and Bis 1,4- Dihydropyridine Derivatives.", Mansoura Journal of Chemistry, 68, 3, 2025, 1-10. doi: 10.21608/mjcc.2025.385677.1009
HARVARD
M. Dawoud, S., M. Keshk, E., M. Khalil, A., Fekri, A. (2025). 'Multicomponent Reactions of Dapsone Derivatives: Synthesis, Study of Potentially Active Antimicrobial Bis 4H- Pyran and Bis 1,4- Dihydropyridine Derivatives.', Mansoura Journal of Chemistry, 68(3), pp. 1-10. doi: 10.21608/mjcc.2025.385677.1009
VANCOUVER
M. Dawoud, S., M. Keshk, E., M. Khalil, A., Fekri, A. Multicomponent Reactions of Dapsone Derivatives: Synthesis, Study of Potentially Active Antimicrobial Bis 4H- Pyran and Bis 1,4- Dihydropyridine Derivatives.. Mansoura Journal of Chemistry, 2025; 68(3): 1-10. doi: 10.21608/mjcc.2025.385677.1009
)
View on SCiNiTO