Four indole-3-carbaldehyde semicarbazone derivatives, 2-((5-bromo-1H-indol-3-yl)methylene)hydrazinecarboxamide (1), 2-((5-chloro-1H-indol-3-yl)methylene)hydrazinecarboxamide (2), 2-((5-methoxy-1H-indol-3-yl)methylene)hydrazinecarboxamide (3), and 2-((4-nitro-1H-indol-3-yl)methylene)hydrazinecarboxamide (4) were synthesized and characterized by ESI-MS and spectroscopic (FT-IR, 1H NMR, and 13C NMR) techniques. The two-dimensional NMR (in acetone-d6) spectral data revealed that the molecules 1 and 2 in solution are in the cisE isomeric form. This evidence is supported by DFT calculations at the B3LYP/6-311++G(d,p) level of theory where it was shown that the corresponding most stable conformers of the synthesized compounds have a cisE geometrical configuration, in both the gas and liquid (acetone and DMSO) phases. The in vitro antibacterial activity of compounds 1–4 was determined against ...

Eight new phenylisoxazole isoniazid derivatives, 3-(2'-fluorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (1), 3-(2'-methoxyphenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (2), 3-(2'-chlorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (3), 3-(3'-clorophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (4), 3-(4'-bromophenyl)isoxazole-5-carbaldehyde isonicotinylhydrazone (5), 5-(4'-methoxiphenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (6), 5-(4'-methylphenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (7), and 5-(4'-clorophenyl)isoxazole-3-carbaldehyde isonicotinylhydrazone (8), have been synthesized and characterized by FT-IR, 1H-NMR, 13C-NMR, and mass spectral data. The 2D NMR (1H-1H NOESY) analysis of 1 and 2 confirmed that these compounds in acetone-d6 are in the trans(E) isomeric form. This evidence is supported by computational calculations which w...