Ali Belfaitah

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.

An Efficient and Recycling Catalyst for the One-Pot Three-Component Synthesis of Substituted 3,4-Dihydropyrimidin-2(1H)-ones

The Biginelli one-pot three-component cyclocondensation was applied in this work to prepare 3,4-dihydropyrimidinone and its analogues using the first derivative of lead, Pb(NO3)2, as a recycling catalyst, from a diversity of aromatic aldehydes, β-ketoesters and urea. The reaction was carried out in refluxing acetonitrile and afforded the target molecules in good to excellent yields. The method offers several advantages including high yields of the products, short reaction times and easy experimental workup procedure

Triethylamine Promoted Efficient Synthesis of 3,4-Dihydropyrimidin- 2(1H)-ones/thiones Using a Solvent-Free Biginelli Condensation

An efficient and simple protocol has been developed for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones by a one-pot three-component cyclocondensation reaction of an aromatic aldehyde, β-ketoester, and urea or thiourea under solvent-free conditions using triethylamine (Et3N) as catalyst for the Biginelli reaction.

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.

New (benz)imidazolopyridino tacrines as nonhepatotoxic, cholinesterase inhibitors for Alzheimer disease

AIM Due to the multifactorial nature of Alzheimers disease, there is an urgent search for new more efficient, multitarget-directed drugs. RESULTS This paper describes the synthesis, antioxidant and in vitro biological evaluation of ten (benz)imidazopyridino tacrines (7-16), showing less toxicity than tacrine at high doses, and potent cholinesterase inhibitory capacity, in the low micromolar range. Among them, compound 10 is a nonhepatotoxic tacrine at 1000 mM, showing moderate, but totally selective electric eel acetylcholinesterase inhibition, whereas molecule 16 is twofold less toxic than tacrine at 1000 μM, showing moderate and almost equipotent inhibition for electric eel acetylcholinesterase and equine butyrylcholinesterase. CONCLUSION (Benz)imidazopyridino tacrines (7-16) have been identified as a new and promising type of tacrines for the potential treatment of Alzheimers disease.

2-Hy­droxy­methyl-1,3-dimethyl­imidazolium iodide

The crystal packing of the title compound, C6H11N2O+·I−, can be described as intercalated layers lying parallel to (010), with the iodide ions located between the cations. A weak intramolecular C—H⋯O hydrogen bond occurs within the cation. In the crystal, intermolecular O—H⋯I hydrogen bonds result in the formation of a three-dimensional network and reinforce the cohesion of the ionic structure.

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.