Antar A. Abdelhamid

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.

Crystal structure of 4-[1-(2-hy­droxy­prop­yl)-4,5-diphenyl-1H-imidazol-2-yl]benzoic acid

In the title compound, C25H22N2O3, the central imidazole ring makes dihedral angles of 48.43u2005(10), 20.23u2005(10) and 75.38u2005(11)° with the benzene ring and the two phenyl rings, respectively. The phenyl ring adjacent to the N-bonded 2-hydroxypropyl group shows the greatest twist, presumably to minimize steric interactions. In the crystal, molecules are linked by O—H⋯N, O—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. In addition, C—H⋯π interactions are also observed.

2-(4-Meth-oxy-phen-yl)-1-pentyl-4,5-di-phenyl-1H-imidazole.

The title compound, C27H28N2O, is a lophine (2,4,5-triphenyl-1H-imidazole) derivative with an n-pentyl chain on the amine N atom and a 4-methoxy substituent on the benzene ring. The two phenyl and methoxybenzene rings are inclined to the imidazole ring at angles of 25.32u2005(7), 76.79u2005(5) and 35.42u2005(7)°, respectively, while the methoxy substituent lies close to the plane of its benzene ring, with a maximum deviation of 0.126u2005(3)u2005Å for the methoxy C atom. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds generate R 2 2(22) loops. These dimers are stacked along the a-axis direction.

2-(4-Chloro­phen­yl)-4,5-diphenyl-1-(prop-2-en-1-yl)-1H-imidazole

The title compound, C24H19ClN2, crystallizes with two independent molecules in the asymmetric unit. The prop-2-enyl substituents on the imidazole rings adopt similar conformations in the two molecules. The 4-and 5-substituted phenyl rings and the benzene ring make dihedral angles of 67.06u2005(8), 5.61u2005(8) and 41.09u2005(8)°, respectively, with the imadazole ring in one molecule and 71.53u2005(8), 28.85u2005(8) and 41.87u2005(8)°, respectively, in the other. The crystal structure features C—H⋯π interactions and weak π–π stacking interactions [centroid–centroid distances = 3.6937u2005(10) and 4.0232u2005(10)u2005Å] between the chlorophenyl rings, which form a three-dimensional supramolecular structure.

Morpholinium hydrogen sulfate (MHS) ionic liquid as an efficient catalyst for the synthesis of bio-active multi-substituted imidazoles (MSI) under solvent-free conditions

Abstract Morpholinium hydrogen sulfate as an ionic liquid was employed as a catalyst for the synthesis of a biologically active series of multi-substituted imidazoles by a four-component reaction involving the combination of benzil with different aromatic aldehydes, ammonium acetate, and 1-amino-2-propanol under solvent-free conditions. The key advantages of this method are shorter reaction times, very high yield, and ease of processing. Furthermore, the resulting products can be purified by a non-chromatographic method and the ionic liquid catalyst is reusable. All of these novel compounds have been fully characterized from spectral data. The X-ray crystal structures of two representative molecules are also detailed.

Sol–gel Derived Mixed Oxide Zirconia: Titania Green Heterogeneous Catalysts and Their Performance in Acridine Derivatives Synthesis

Various zirconia content in ZrO2–TiO2 mixed oxide catalysts (xxa0=xa05, 10, 20 ZrO2 wt%) were synthesized by cost-effective sol–gel process and characterized by different techniques, i.e. XRD diffraction patterns, TG–DTA analyses, FTIR spectroscopy, N2 adsorption/desorption measurements, and TEM microscope. The investigation of the acidic/basic properties was studied by means of FTIR spectroscopy using pyridine as an adsorbed molecule. Characterization estimates exhibit that the deposition by ZrO2 improves the surface properties of TiO2 structures and increase the TiO2 surface area up to 92xa0m2/g. TEM results affirmed the homogeneous distribution of ZrO2 particles on the surface of TiO2 of particle size in the range of 12–17xa0nm. The performance of the prepared zirconia–titania catalysts with different concentration ratios in acridine derivates synthesis from hydroxyl-benzaldehyde was studied. The results of catalytic test reveal that, the activity of ZrO2–TiO2 catalysts was significantly enhanced by depositing an optimum amount ratio of ZrO2 reach to 10xa0% to raise the yield to 95, 97 and 99xa0%. This can be attributed to the higher its surface area and its performance as basic site catalyst in the studied test.Graphical Abstract

Prop-2-en-1-yl 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoate

The title compound, C25H20N2O2, crystallized with two molecules in the asymmetric unit, in one of which the atoms of the terminal propenyl group are disordered over two sets of sites, with a refined occupancy ratio of 0.870u2005(4):0.130u2005(4). The central imidazole ring makes dihedral angles of 25.51u2005(11), 40.73u2005(11) and 27.36u2005(11)° with the three pendant rings in one molecule and 22.56u2005(10), 60.72u2005(10) and 5.85u2005(10)° in the other. In the crystal, molecules are linked by N—H⋯N and C—H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features C—H⋯π interactions and π–π stacking [centroid–centroid distances = 3.8834u2005(18) and 3.9621u2005(17)u2005Å] interactions.

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

In the title compound, C26H25ClN2, the phenyl rings and the 2-(4-chlorophenyl) group make dihedral angles of 30.03u2005(11), 67.49u2005(12) and 41.56u2005(11)°, respectively, with the imidazole ring. In the crystal, the molecules interact with each other via very weak C—H⋯π contacts, forming layers parallel to (110).

9-(3-Bromo-5-chloro-2-hy­droxy­phen­yl)-10-(2-hy­droxy­eth­yl)-1,2,3,4,5,6,7,8,9,10-deca­hydro­acridine-1,8-dione

In the title compound, C21H21BrClNO4, the dihydropyridine ring adopts a flattened boat conformation. The 3-bromo-5-chloro-2-hydroxyphenyl ring forms a dihedral angles of 84.44u2005(7)° with the dihydropyridine mean plane. The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, with an S(8) ring motif. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds link the molecules, forming a three-dimensional network.

Crystal structure of 9-(3-bromo-5-chloro-2-hydroxy­phen­yl)-10-(2-hy­droxy­eth­yl)-3,3,6,6-tetra­methyl-3,4,6,7,9,10-hexa­hydro­acridine-1,8(2H,5H)-dione

The structure of a hydroacridine with significant pharmaceutical potential is reported. The acridinone ring system is in the shape of a shallow V with the majority of the ring system substituents on its convex surface; a plethora of classical and non-classical hydrogen bonds stack the molecules into interconnected columns.