Abdelmalek Bouraiou

Synthesis, crystal structure and antibacterial activity of new highly functionalized ionic compounds based on the imidazole nucleus

Several new highly functionalized imidazolium derivatives were synthesized, via appropriate synthetic routes, using imidazole, 1-methylimidazole and 2-phenyl-1-methylimidazole as key intermediates. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella thipymurium using disk-diffusion and MIC methods. Crystal X-ray structures are reported for six compounds.

Imidazopyranotacrines as Non-Hepatotoxic, Selective Acetylcholinesterase Inhibitors, and Antioxidant Agents for Alzheimer's Disease Therapy

Herein we describe the synthesis and in vitro biological evaluation of thirteen new, racemic, diversely functionalized imidazo pyranotacrines as non-hepatotoxic, multipotent tacrine analogues. Among these compounds, 1-(5-amino-2-methyl-4-(1-methyl-1H-imidazol-2-yl)-6,7,8,9-tetrahydro-4H-pyrano[2,3-b]quinolin-3-yl)ethan-1-one (4) is non-hepatotoxic (cell viability assay on HepG2 cells), a selective but moderately potent EeAChE inhibitor (IC50 = 38.7 ± 1.7 μM), and a very potent antioxidant agent on the basis of the ORAC test (2.31 ± 0.29 μmol·Trolox/μmol compound).

Methyl 2-(2-methyl-4-nitro-1H-imidazol-1-yl)acetate

In the crystal of the title compound, C7H9N3O4, molecules are linked by weak C—H⋯O hydrogen bonds into chains along the a-axis direction. The dihedral angle between the ring and the nitro group is 3.03 (6), while that between the ring and the acetate group is 85.01 (3)°.

4,5-Dibromo-1,2-dimethyl-1H-imidazol-3-ium bromide.

In the title salt, C5H7Br2N2 +·Br−, the cation and anion are connected by an N—H⋯Br hydrogen bond. In the crystal, there are intercalated layers parallel to (10-2) in which bromide ions are located between the cations. Weak intermolecular C—H⋯Br hydrogen bonds are also observed.

2-(2-Chloro-6,7-dimethyl­quinolin-3-yl)-2,3-dihydro­quinolin-4(1H)-one

In the title molecule, C20H17ClN2O, the dihedral angle between the mean plane of the quinoline ring system and the benzene ring of the dihydroquinolinone moiety is 57.84 (8)°. In the crystal, molecules are linked into centrosymmetric dimers via pairs of intermolecular N—H⋯N hydrogen bonds. These dimers are further stabilized by weak π–π stacking interactions between pyridine rings with a centroid–centroid distance of 3.9414 (12) Å.

Synthesis of New 3-heteroaryl-2-phenylquinolines and their Pharmacological Activity as Antimicrobial Agents

Some new unfused tricyclic aromatic systems containing various heterocyclic cores were synthesized. These compounds were prepared in good yields via appropriate routes using 6-methyl-2-phenylquinoline-3-carbaldehyde as a key intermediate. The antibacterial activity of the prepared compounds was evaluated against: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumonia and Salmonella thipymurium using the disk-diffusion method. The minimum inhibitory concentration (MIC) was determined for the tested compounds.

The diastereoisomers 2‐[(S/R)‐2‐chloro‐3‐quinolyl]‐2‐[(R)‐1‐(4‐methoxyphenyl)ethylamino]acetonitrile at 100 K

In the structures of the two enantiopure diastereoisomers of the title compound, C(20)H(18)ClN(3)O, which crystallize in different space groups, the molecules are very similar as far as bond distances and angles are concerned, but more substantial differences are observed in some torsion angles. The crystal structures of both molecules can be described as zigzag layers along the c axis. The packing is stabilized by hydrogen-bond interactions of N-H...O, C-H...Cl and C-H...pi types for 2-[(R)-2-chloro-3-quinolyl]-2-[(R)-1-(4-methoxyphenyl)ethylamino]acetonitrile, and of N-H...N, C-H...O and C-H...pi types for 2-[(S)-2-chloro-3-quinolyl]-2-[(R)-1-(4-methoxyphenyl)ethylamino]acetonitrile, resulting in the formation of two- and three-dimensional networks.

Crystal structure of {bis­[(1H-benzimid­azol-2-yl-κN3)meth­yl]sulfane}dichloridomercury(II)

In the asymmetric unit of the title compound, [HgCl2(C16H14N4S)], the HgII cation is linked to two Cl atoms and two imidazole N atoms of the chelating bis[(1H-benzimidazol-2-yl)methyl]sulfane ligand, forming a slightly distorted tetrahedral environment. The substitued imidazole rings of the ligand are almost perfectly planar [with maximum deviations of 0.017 (3) and 0.012 (3) Å] and form a dihedral angle of 42.51 (5)°. The crystal packing can be described as alternating layers parallel to (010). In this arrangement, N—H⋯Cl hydrogen bonds between the N—H groups of the benzimidazole moieties and chloride ligands are responsible for the formation of the chain-like packing pattern along [010] exhibiting a C(6) graph-set motif.

2-Chloro­quinoline-3-carboxylic acid

The crystal structure of the title compound, C10H6ClNO2, can be described by two types of crossed layers which are parallel to (110) and (10). The crystal packing is stabilized by intermolecular C—H⋯O and O—H⋯N hydrogen bonds, resulting in the formation of a two-dimensional network and reinforcing the cohesion of the structure.

(3RS,4SR)-Methyl 4-(2-chloro-5,8-di­methoxy­quinolin-3-yl)-1-phenyl­pyrrolidine-3-carboxyl­ate

The molecule of the title compound, C23H23ClN2O4, contains a quinolyl unit linked to a functionalized pyrrolidine system with a 3,4-trans arrangement of the substituents. The unit cell contains two stereoisomers that have the absolute stereochemistry 3S,4R and 3R,4S. The pyrrolidine ring adopts a twist conformation with pseudo-rotation parameters P = 258.2 (3)° and τ(M) = 35.3 (1)°. The packing is stabilized by C—H⋯π interactions and offset π–π stacking (centroid-to-centroid distance = 3.849 Å, interplanar distance = 3.293 Å and slippage = 1.994 Å) between phenyl rings, leading to a two-dimensional network.