Showing papers by "Senthamaraikannan Kabilan published in 2008"
TL;DR: Antibacterial activities evaluated against a wide number of bacterial pathogens revealed that 19, 27 against Staphylococcus aureus,27 against Enterococcus faecalis, and 19, 21, 23, and 27 against Enteritis faecium are significantly good at lowest MIC(90) (16 microg/mL).
84 citations
TL;DR: The observed chemical shifts and coupling constants suggest that compounds 8-13 adopt normal chair conformation with equatorial orientation of all the substituents while compound 14 contributes significant boat conformation along with the predominant chair conformed in solution.
21 citations
TL;DR: The 1H and 13C NMR spectra of 2,4,6,8‐tetraaryl‐3,7‐diazabicyclo and O‐benzyl oximes indicate that the compounds exist in chair‐boat conformation with equatorial and axial orientation of the aryl groups in the chair and boat forms, respectively.
Abstract: The 1H and 13C NMR spectra of 2,4,6,8-tetraaryl-3,7-diazabicyclo[3.3.1]nonan-9-ones (1–2), oximes (3–8) and O-benzyl oximes (9–12) were recorded. The chemical shifts were unambiguously assigned using 1D and 2D NMR spectral data. The results clearly indicate that the compounds exist in chair-boat conformation with equatorial and axial orientation of the aryl groups in the chair and boat forms, respectively. Since the molecules are flexible and dynamic in solution, the chair and boat forms are mutually interconvertible. In 3–12, because of the effect of oximation/oximination, all the protons in the heterobicyclic systems gave distinct signals except the benzylic protons of the boat form. In all synthesized compounds, the aryl group protons at C-6,8 are shielded by the aryl groups at C-2,4 and therefore appear in the lower frequency region than the aryl groups at C-2,4. Copyright © 2008 John Wiley & Sons, Ltd.
15 citations
TL;DR: In the title compound, C19H19F2NO, the piperidinone ring adopts a chair conformation, generating centrosymmetric dimers of R 2 2(14) and R2 2(24) rings.
Abstract: In the title compound, C19H19F2NO, the piperidinone ring adopts a chair conformation. The crystal packing is stabilized by C—H⋯O and C—H⋯F intermolecular interactions, generating centrosymmetric dimers of R22(14) and R22(24) rings.
5 citations
TL;DR: In the title compound, C23H26BrNO4, the piperidinone ring adopts a boat conformation and a weak C—H⋯Br intramolecular interaction is observed.
Abstract: In the title compound, C23H26BrNO4, the piperidinone ring adopts a boat conformation. The dihedral angle between the two benzene rings is 70.9 (1)°. The two methoxy groups are close to coplanar with the attached benzene rings [C—C—O—C torsion angles of 6.3 (5) and 16.4 (4)°]. A weak C—H⋯Br intramolecular interaction is observed. In the crystal structure, molecules are linked into a chain along [101] by intermolecular C—H⋯O hydrogen bonds. A short intermolecular Br⋯O contact [3.063 (2) A] is observed.
4 citations
TL;DR: In the title compound, C22H23N3O2S2, the five-membered ring is planar and the C5S ring adopts a chair conformation, generating a chain and a centrosymmetric dimer, respectively.
Abstract: In the title compound, C22H23N3O2S2, the five-membered ring is planar and the C5S ring adopts a chair conformation. The crystal packing is stabilized by intermolecular N—H⋯O and C—H⋯O interactions, generating a chain and a centrosymmetric dimer, respectively.
2 citations