Shaaban K. Mohamed

Synthesis and biological activity of dihydroimidazole and 3,4-dihydrobenzo[4,5]imidazo[1,2-a][1,3,5]triazins.

Reaction of 2-guanidinobenzimidazole with halogenated active methylenes and ketones gave dihydroimidazole and 3,4-dihydrobenzo[4,5]imidazo [1,2-a][1,3,5]triazin derivatives in very good yield. The anti-bacterial evaluation of the newly synthesized products against broad spectrum of bacteria was performed. Most of products showed high inhibitory effect. All compounds have been characterized based on IR, (1)H NMR, (13)C NMR and Mass spectra.

4-(1-Allyl-4,5-diphenyl-1H-imidazol-2-yl)-N,N-dimethyl­aniline

The title compound, C26H25N3, crystallizes with four independent molecules, 1–4, in the asymmetric unit of the triclinic unit cell. The allyl substituents on the imidazole rings adopt similar conformations in all four molecules. The imadazole and the 4-and 5-substituted phenyl rings of two pairs of molecules in the asymmetric unit stack parallel to (110). In contrast, the dimethylaniline systems in these pairs of molecules are almost normal to one another, with dihedral angles of 85.84 (10) and 85.65 (10)° between the benzene rings of the two dimethylaniline fragments of molecules 1 and 2, and 3 and 4, respectively. The crystal structure features an extensive series of C—H⋯π interactions that link the molecules into undulating rows along the c axis. The crystal studied was a pseudo-merohedral twin with twin law [-100, 0-10, 111] and the BASF parameter refined to 0.513 (3).

3-Amino-1-phenyl-1H-benzo[f]chromene-2-carbonitrile

In the title compound, C20H14N2O, the phenyl ring is almost normal to the naphthalene ring system with a dihedral angle of 86.72 (9)°. The 4H-pyran ring fused with the naphthalene ring system has a boat conformation. In the crystal, molecules are linked into a helical supramolecular chain along the b axis via N—H⋯N hydrogen bonds. The chains are consolidated into a three-dimensional architecture by C—H⋯π interactions.

Synthesis of Dihydroimidazole Derivatives under Solvent Free Condition andTheir Antibacterial Evaluation

Reaction of 2-guanidinobenzoxazole with several halogenated active methylene compounds has revealed formation of the corresponding dihydroimidazole derivatives under solvent free conditions in excellent yield. The anti-bacterial evaluation of the newly synthesized products against different types of Gram-positive and Gramnegative bacteria was performed. Most of products showed high inhibitory effect. The structure of all compounds has been characterized by on IR, 1H-NMR, 13C-NMR, Mass spectrum and some X-ray diffractions.

2-(2,6-Di­chloro­phen­yl)-1-pentyl-4,5-diphenyl-1H-imidazole

The title compound, C26H24Cl2N2, crystallizes with two independent molecules (1 and 2) in the asymmetric unit. In molecule 1, the two phenyl and 2,6-dichlorophenyl rings are inclined to the imidazole ring at angles of 74.12 (14), 26.13 (14) and 67.30 (14)°, respectively. In molecule 2, due to the different molecular environment in the crystal, the corresponding angles are different, viz. 71.72 (15), 16.14 (15) and 80.41 (15)°, respectively. In the crystal, molecules 1 and 2 are linked by C—H⋯Cl interactions, and inversion-related 2 molecules are linked by C—H⋯π interactions. There are no other significant intermolecular interactions present.

2-[2-(4-Meth­oxy­phen­yl)-4,5-diphenyl-1H-imidazol-1-yl]ethanol

In the title compound, C24H22N2O2, the central imidazole ring makes dihedral angles of 49.45 (8), 88.94 (9) and 19.43 (8)° with the benzene ring and the two phenyl rings, respectively. The dihedral angle between the phenyl rings is 77.86 (9)°, and they form dihedral angles of 49.06 (9) and 67.31 (8)° with the benzene ring. In the crystal, molecules are linked by O—H⋯N hydrogen bonds, forming chains along the b axis. These chains are connected by C—H⋯O hydrogen bonds, forming a two-dimensional network parallel to (100). In addition, C—H⋯π interactions are also observed. The terminal C and O atoms of the ethanol group are disordered over two sets of sites with an occupancy ratio of 0.801 (5):0.199 (5).

1-(Adamantan-1-ylcarbon-yl)-3-(2,6-difluoro-4-hy-droxy-phen-yl)thio-urea.

In the title molecule, C18H20F2N2O2S, the 2,6-difluoro-4-hydroxyphenyl ring and the carbonylthiourea group are each essentially planar, with maximum deviations of atoms from their mean planes of 0.0113 (14) and 0.1017 (15) Å, respectively; the dihedral angle between these two planes is 71.03 (6)°. An intramolecular N—H⋯O hydrogen bond occurs. In the crystal, N—H⋯O and O—H⋯S hydrogen bonds connect the molecules into chains running diagonally across the bc plane. C—H⋯S and C—H⋯F contacts are also observed.

10-(2-Hy-droxy-eth-yl)-9-(2-hy-droxy-phen-yl)-3,3,6,6-tetra-methyl-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione.

The dihydropyridine ring in the title compound, C25H31NO4, adopts an envelope conformation with the methine C atom representing the flap. The cyclohexenone rings also adopt envelope conformations with the C atoms bearing the methyl C atoms representing the flaps. The phenolic hydroxy group forms an intramolecular hydrogen bond to one of the two keto O atoms. The hydroxy group of the N-bonded alkyl chain forms an intermolecular hydrogen bond to the other keto O atom of an adjacent molecule. The latter hydrogen bond leads to the formation of a helical chain running along the b axis.

1-{[(Z)-Cyclo­pentyl­idene]amino}-3-phenyl­thio­urea

The sample of the title compound, C12H15N3S, chosen for study consisted of triclinic crystals twinned by a 180° rotation about the a axis. The five-membered ring adopts a twisted conformation. The dihedral angle between the phenyl ring and the mean plane of the thiourea unit is 78.22 (8)°. In the crystal, molecules are linked via pairs of N—H⋯S hydrogen bonds forming inversion dimers.

3,3,6,6-Tetra­methyl-9-[6-(3,3,6,6-tetra­methyl-1,8-dioxo-2,3,4,5,6,7,8,9-octa­hydro-1H-xanthen-9-yl)pyridin-2-yl]-2,3,4,5,6,7,8,9-octa­hydro-1H-xanthene-1,8-dione

In the title molecule, C39H45NO6, the two tetramethyloctahydroxanthen-1,8-dione substituents are arranged approximately parallel to each other and approximately perpendicular to the plane of the pyridine ring. The six-membered xanthene rings adopt flattened boat conformations with the O and methine C atoms deviating from the plane of the other four atoms.