R. Hema

3-(4-Chlorobenzoyl)-7-(N,N-dimethylamino)-1-phenylindolizine and 3-(2,4-dichlorobenzoyl)-7-(N,N-dimethylamino)-1-phenylindolizine.

In both of the title compounds, C(23)H(19)ClN(2)O, (I), and C(23)H(18)Cl(2)N(2)O, (II), the molecular packing is influenced by weak intermolecular C-H.O and C-H.pi interactions, but despite the chemical similarity of the compounds, the packing in (II) is entirely different from that observed in (I).

9-(2,4-Di-fluoro-phen-yl)-3,3,6,6-tetra-methyl-3,4,5,6,7,9-hexa-hydro-2H-xanthene-1,8-dione.

In the title compound, C23H24F2O3, the central pyran ring has a flat-boat conformation, whereas the two fused cyclohexenone rings adopt envelope conformations, with the C atom bearing the dimethyl substituent being the flap atom in each case. The pyran ring mean plane and the difluorophenyl ring are almost normal to each other, making a dihedral angle of 87.55 (4)°. In the crystal, molecules are linked by pairs of C—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. The F atom at position 2 on the difluorophenyl ring is disordered over the 2- and 6-positions, and has a refined occupancy ratio of 0.932 (3):0.068 (3).

2,4-Bis(4-fluoro­phen­yl)-1,5-dimethyl-3-aza­bicyclo­[3.3.1]nonan-9-one

The asymmetric unit of the title compound, C22H23F2NO, contains two independent molecules, A and B. The bicyclic system adopts a twin-chair conformation in both molecules. The dihedral angles between the fluorophenyl rings are 55.27 (8) and 56.37 (7)° in molecules A and B, respectively. The NH groups are not involved in hydrogen bonding due to the steric hindrance of fluorophenyl groups. The crystal structure features weak C—H⋯O interactions.

2,4-Bis(furan-2-yl)-1,5-dimethyl-3-aza-bicyclo-[3.3.1]nonan-9-one.

In the title compound, C18H21NO3, the bicyclic ring system adopts a twin-chair conformation. The two methyl groups attached to the bicycle are in an equatorial orientation for both rings. One of the furan rings is disordered over two orientations with an occupancy ratio of 0.686 (6):0.314 (6). In the crystal, very long N—H⋯O hydrogen bonds connect the molecules into a chain perpendicular to the ac plane.

2-(2,4-Di­fluoro­phen­yl)-4,5-dimethyl-1-(4-methyl­phen­yl)-1H-imidazole monohydrate

The asymmetric unit of the title compound, C18H16F2N2·H2O, contains two independent molecules (A and B), and two independent water molecules of crystallization. In molecule A, the imidazole ring makes dihedral angles of 47.46 (7) and 60.98 (6)° with the 2,4-difluorophenyl and methylphenyl rings, respectively. The corresponding angles in molecule B are 45.85 (7) and 62.78 (7)°, respectively. The dihedral angle between the two benzene rings is 64.98 (7)° in molecule A and 65.53 (7)° in molecule B. In the crystal, the two independent molecules are linked by O—H⋯N and O—H⋯O hydrogen bonds, forming chains propagating along [100]. These chains are linked via C—H⋯F hydrogen bonds, forming slab-like two-dimensional networks lying parallel to (001).

16α,17α-Ep-oxy-17β-(1H-imidazol-1-yl)androst-4-en-3-one monohydrate.

In the title compound, C22H28N2O2·H2O, rings B and C adopt chair conformations. Ring A adopts an envelope conformation, with the non-fused C atom adjacent to the fused C atom bearing a methyl group as the flap atom. Ring D also adopts an envelope conformation, with the fused C atom not bearing a methyl group as the flap atom. The water molecule links the molecules via O—H⋯O and O—H⋯N hydrogen bonds, forming zigzag chains which run parallel to the c axis. Weak C—H⋯O interactions also occur.