S. Ponnuswamy

2-Chloro-1-(3,3-dimethyl-2,6-di­phenyl­piperidin-1-yl)ethanone

In the title compound, C21H24ClNO, the piperidine ring adopts a chair conformation. The two phenyl rings are inclined to one another by 20.7 (1)°, and are inclined to the mean plane of the four planar atoms of the piperidine ring by 87.64 (10) and 70.8 (1)°. The molecular structure features short intramolecular C—H⋯Cl and C—H⋯O contacts. In the crystal, there are no significant intermolecular interactions present.

1-Acetyl-c-3,t-3-dimethyl-r-2,c-6-diphenyl-piperidin-4-one.

In the title compound, C21H23NO2, the piperidine ring adopts a distorted boat conformation. The two phenyl rings form dihedral angles of 64.6 (1) and 87.8 (1)° with the best plane through the piperidine ring. The crystal packing is governed by intermolecular C—H⋯O interactions.

r-2,c-6-Bis(4-chlorophenyl)-c-3,t-3-dimethylpiperidin-4-one

In the title molecule, C19H19Cl2NO, the piperidine ring adopts a chair conformation and the dihedral angle between the two benzene rings is 77.23 (7)°. In the crystal structure, molecules are linked by N—H⋯O and C—H⋯O hydrogen bonds, and a weak C—H⋯π interaction is also observed.

Synthesis, characterisation, stereochemistry and antimicrobial activity of N 5-piperazino- and N 5-morpholinoacetyl-2,2,4-trimethyl-1, 5-benzodiazepines

AbstractThree 1,5-benzodiazepines viz., N5-chloroacetyl-, N5-piperazinoacetyl- and N5-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepines have been synthesized. The structural characterisation and the conformational preferences of the compounds have been carried out using IR, 1D and 2D NMR spectral data. The NMR spectral data show that the N-acetyltetrahydro-1,5-benzodiazepines prefer to exist in boat conformation with exo orientation of >C=O at N5 position in the solution state. The X-ray crystal structure of N5-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepine also supports boat conformation in the solid state. The antimicrobial activity for N-acetyltetrahydro-1,5-benzodiazepines have been carried out. N-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepine demonstrated better antibacterial and antifungal activities. Graphical AbstractThe preferred conformations, antibacterial and antifungal activities of N5-chloroacetyl-, N5-piperazinoacetyl- and N5-morpholinoacetyl-2,2,4-trimethyl-1H-1,5-benzodiazepines are reported.

Crystal structure of 1-[2,4-bis(4-methoxy-phenyl)-3-azabicyclo[3.3.1]nonan-3-yl]ethanone.

In the title compound, C24H29NO3, the azabicycle contains two six-membered rings, viz. a cyclohexane ring and a piperidine ring. The first adopts a chair conformation and the second a half-chair conformation. The dihedral angle between their mean planes is 86.21 (13)°, indicating that they are almost perpendicular to one another. The dihedral angle between the planes of the 4-methoxyphenyl rings is 17.51 (13)°, and they make dihedral angles of 81.9 (3) and 81.3 (3)° with the ethan-1-one group. In the crystal, molecules are linked by C—H⋯π interactions forming chains along [10-1].

1-Dichloro­acetyl-t-3,t-5-dimethyl-r-2,c-6-diphenyl­piperidin-4-one

In the title compound, C21H21Cl2NO2, the piperidine ring adopts a distorted boat conformation. The phenyl rings substituted at the 2- and 6-positions of the piperidine ring subtend angles of 87.9 (7) and 70.8 (9)°, respectively, with the best plane through the piperidine ring. In the crystal, molecules are connected by C—H⋯O and C—H⋯Cl interactions into layers in the ab plane.

2-Chloro-1-(2,4,4-trimethyl-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-1-yl)ethanone

In the title compound, C14H19ClN2O, the diazepine ring adopts a boat conformation. The Cl atom of the chloroacetyl group is trans to the N atom of the diazepine ring. In the crystal, the molecules form chains running along the diagonal of the ac plane through N—H⋯O hydrogen bonds.

Crystal Structures of 1, 5-Diacetyl-2, 2, 4-trimethyl-1H-tetrahydro-1, 5-benzodiazepine (DARTMBD) and N 5-Ethoxycarbonyl-2-methyl-2, 4-diphenyl-1H-tetrahydro-1, 5-benzodiazepine (ECRPMBD)

The benzodiazepines, namely 1, 5-Diacetyl-2, 2, 4-trimethyl-1H-tetrahydro-1, 5-ben- zodiazepine (C16H22N2O2), (DARTMBD, CCDC 716181) and N 5-Ethoxycarbonyl-2-methyl-2, 4-diphenyl-1H-tetrahydro-1, 5-benzodiazepine (C25H26N2O2), (ECRPMBD, CCDC 716182) possess potential pharmacological activities. DARTMBD crystallizes in monoclinic space group P21/c with cell parameters: a = 10.0582(3) Å, b = 9.6019(3) °, c = 16.0837(4) °, β = 103.100(1)°, and V = 1512.91(8) °3; ECRPMBD crystallizes in triclinic system, Pī with two crystallographically independent molecules in the asymmetric unit. The cell parameters are: a = 12.2807(4) °, b = 12.8410(5) °, c = 13.9714(4) °, α = 90.626(2)°, β = 105.200(3)°, γ = 100.324(2)°, and V = 2087.84(12)°3. Both the structures were solved by direct methods and refined by full-matrix least-squares procedures to final R-values of 0.0552 and 0.0487, respectively. The benzodiazepine ring in both the structures adopts twist-boat conformation. In DARTMBD, the dimer formation occurs through C–H…O intermolecular interactions whereas in ECRPMBD, the molecules are stabilized by N–H…O, and C–H…O types of hydrogen bonds.

5-Dichloro-acetyl-4-methyl-2,3,4,5-tetra-hydro-1H-1,5-benzodiazepin-2-one hemihydrate.

There are two crystallographically independent organic molecules in the asymmetric unit of the title compound, C12H12Cl2N2O2·0.5H2O. The benzodiazepine ring adopts a distorted boat conformation in both molecules. The crystal packing is controlled by N—H⋯O, C—H⋯O and O—H⋯O intra- and intermolecular hydrogen bonds. A graph-set motif of R 3 3(14) dimer formation by a combination of N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds stabilizes the molecules and extends along a axis.

3,3-Dimethyl-cis-2,6-di-p-tolyl­piperidin-4-one

In the title molecule, C21H25NO, the piperidine ring adopts a chair conformation. The benzene rings and one of the methyl groups attached to the piperidine ring have equatorial orientations. The dihedral angle between the two benzene rings is 72.53 (9)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds. Weak C—H⋯π interactions involving the benzene rings are also present in the crystal structure.