Synthesis and antibacterial activity of fluorinated carbazoles

In our previous studies, fluorine-substituted carbazoles were synthesized, and these compounds showed promising potential against Gram-positive bacterial stains, including Methicillin-resistant Staphylococcus aureus . However, only three compounds with two F substituents on the 2,4-positions of carbazole showed antibacterial potency against both Gram-positive and Gram-negative bacterial strains. A series of new compounds with two F substituents on the 2,4-positions of carbazole, besides three known ones, were synthesized. The structures were confirmed by infrared spectroscopy, 1 H & 13 C nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry. Eight compounds showed antibacterial activity. 2,4,6-Trifluoro-9 H -carbazole ( 2 ), with simple structure, showed potential antibacterial activity against the multidrug resistant NDM-1-producing strains which are not inhibited by commonly used antibiotics. Its water-soluble salt was synthesized but showed less activity.