Gamal A El-Hiti
King Saud University, Optometry, Faculty Member
Research Interests:
In the title compound, C12H7N3O2S, the dihedral angle between the planes of the thia-zolo-pyridine ring system (r.m.s. deviation = 0.005 Å) and the benzene ring is 3.94 (6)°. The nitro group is rotated by 7.6 (2)° from its attached ring.... more
In the title compound, C12H7N3O2S, the dihedral angle between the planes of the thia-zolo-pyridine ring system (r.m.s. deviation = 0.005 Å) and the benzene ring is 3.94 (6)°. The nitro group is rotated by 7.6 (2)° from its attached ring. In the crystal, extensive aromatic π-π stacking [shortest centroid-centroid separation = 3.5295 (9) Å] links the mol-ecules into (001) sheets.
In the title compound, C12H14N2S, the cyclo-hexane ring adopts a chair conformation with the exocyclic C-C bond in an equatorial orientation. The mean plane through the cyclo-hexane ring (all atoms) is twisted from the thia-zolo-pyridine... more
In the title compound, C12H14N2S, the cyclo-hexane ring adopts a chair conformation with the exocyclic C-C bond in an equatorial orientation. The mean plane through the cyclo-hexane ring (all atoms) is twisted from the thia-zolo-pyridine ring system (r.m.s. deviation = 0.013 Å) by 39.57 (6)°. In the crystal, mol-ecules form (100) sheets, although there are no specific directional inter-actions between them. The crystal stucture was refined as a two-component perfect twin.
In the title mol-ecule, C13H10N2S, the dihedral angle between the planes through the non-H atoms of the methylbenzene and thi-azo-lopyridine groups is 36.61 (5)°. In the crystal, the thi-azo-lopyridine groups of inversion-related... more
In the title mol-ecule, C13H10N2S, the dihedral angle between the planes through the non-H atoms of the methylbenzene and thi-azo-lopyridine groups is 36.61 (5)°. In the crystal, the thi-azo-lopyridine groups of inversion-related mol-ecules overlap, with a minimum ring-centroid separation of 3.6721 (9) Å. Furthermore, the methylbenzene groups from neighbouring mol-ecules inter-act edge-to-face at an angle of 71.66 (5)°. In addition, weak C-H⋯ N hydrogen bonds form chains exending along [100].
In the title mol-ecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H)-one mean plane, making a dihedral angle of 88.98 (9)°. In the crystal, mol-ecules related by an inversion centre are paired via π-π... more
In the title mol-ecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H)-one mean plane, making a dihedral angle of 88.98 (9)°. In the crystal, mol-ecules related by an inversion centre are paired via π-π overlap, indicated by the short distances of 3.616 (5) and 3.619 (5) Å between the centroids of the aromatic rings of neighbouring mol-ecules. Inter-molecular N-H⋯N and N-H⋯O hydrogen bonds form R 6 (6)(30) rings and C(5) chains, respectively, generating a three-dimensional network. Weak C-H⋯O inter-actions are also observed.
The mol-ecule of the title compound, C10H11N3O, is planar, including the ethyl group, as indicated by the N-C-C-C torsion angle of 1.5 (2)°. In the crystal, inversion-related mol-ecules are stacked along the a axis. Mol-ecules are... more
The mol-ecule of the title compound, C10H11N3O, is planar, including the ethyl group, as indicated by the N-C-C-C torsion angle of 1.5 (2)°. In the crystal, inversion-related mol-ecules are stacked along the a axis. Mol-ecules are oriented head-to-tail and display π-π inter-actions with a centroid-to-centroid distance of 3.6664 (8) Å. N-H⋯O hydrogen bonds between mol-ecules generate a 'step' structure through formation of an R 2 (2)(10) ring.
Bromine has been added to cis,trans,trans-1,5,9-cyclododecatriene under various reaction conditions. All expected direct addition products have been isolated, and their structures have been determined by microanalysis, NMR and X-ray... more
Bromine has been added to cis,trans,trans-1,5,9-cyclododecatriene under various reaction conditions. All expected direct addition products have been isolated, and their structures have been determined by microanalysis, NMR and X-ray crystallography. Advanced NMR techniques were used to determine solution conformations of several of the compounds, enabling comparison with the solid-state conformations obtained by crystallography.
Research Interests:
The acetylation of aryl ethers using acetic anhydride in the presence of zeolites under modest conditions in a solvent-free system gave the corresponding para-acetylated products in high yields. The zeolite can be recovered, regenerated... more
The acetylation of aryl ethers using acetic anhydride in the presence of zeolites under modest conditions in a solvent-free system gave the corresponding para-acetylated products in high yields. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used.
Research Interests:
Page 1. J. Org. Chem. 1983,48, 3401-3408 Regiospecific Electrophilic Substitution of Aminopyridines: Ortho Lithiation of 2-, 3-, and 4-(Pivaloy1amino)pyridines 3401 James A. Turner Agricultural Products Research, Dow Chemical USA, Walnut... more
Page 1. J. Org. Chem. 1983,48, 3401-3408 Regiospecific Electrophilic Substitution of Aminopyridines: Ortho Lithiation of 2-, 3-, and 4-(Pivaloy1amino)pyridines 3401 James A. Turner Agricultural Products Research, Dow Chemical USA, Walnut Creek, California 94598 ...
Research Interests:
The photostabilization of poly(methyl methacrylate) (PMMA) films having 2-(6-methoxynaphthalen-2-yl)propanoate and Sn(II), Ni(II), Zn(II) and Cu(II) complexes was investigated. The production of PMMA films containing such complexes (0.5%... more
The photostabilization of poly(methyl methacrylate) (PMMA) films having 2-(6-methoxynaphthalen-2-yl)propanoate and Sn(II), Ni(II), Zn(II) and Cu(II) complexes was investigated. The production of PMMA films containing such complexes (0.5% by weight) was carried out by the casting method using chloroform. The photostabilization activities of the compounds were determined by monitoring the hydroxyl index with irradiation time. The quantum yield of the chain scission (Φcs) for the complexes in PMMA films and the changes in the viscosity average molecular weight of PMMA with irradiation time were evaluated. The rate of photostabilization for PMMA in the presence of the additives was found to follow the order NiL2 > CuL2 > ZnL2 > SnL2 (L, ligand). Depending on the structure of the additive, such as a peroxide decomposer, UV absorption or a radical scavenger for the photostabilizer, several mechanisms are suggested.
Research Interests:
There are two mol-ecules in the asymmetric unit of the title compound, C11H16N2O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in... more
There are two mol-ecules in the asymmetric unit of the title compound, C11H16N2O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in one mol-ecule, one of the methyl C atoms is syn to the amide O atom [O-C-C-C = -0.8 (3)°] and in the other the equivalent torsion angle is 31.0 (2)°. In the crystal, the two independent mol-ecules are linked by a pair of N-H⋯N hydrogen bonds in the form of an R 2 (2)(8) loop to form a dimer. A C-H⋯O inter-action connects the dimers into [100] chains.
In the title mol-ecule, C9H10N2S, one of the methyl groups is almost co-planar with the thia-zolo-pyridine rings with a deviation of 0.311 (3) Å from the least-squares plane of the thia-zolo-pyridine group. In the crystal, weak C-H⋯N... more
In the title mol-ecule, C9H10N2S, one of the methyl groups is almost co-planar with the thia-zolo-pyridine rings with a deviation of 0.311 (3) Å from the least-squares plane of the thia-zolo-pyridine group. In the crystal, weak C-H⋯N hydrogen-bonding inter-actions lead to the formation of chains along [011].
In the title compound, C10H14N2O, the pyridine ring is inclined to the mean plane of the amide moiety [N-C(=O)C] by 17.60 (8)°. There is an intra-molecular C-H⋯O hydrogen bond present involving the carbonyl O atom. In the crystal,... more
In the title compound, C10H14N2O, the pyridine ring is inclined to the mean plane of the amide moiety [N-C(=O)C] by 17.60 (8)°. There is an intra-molecular C-H⋯O hydrogen bond present involving the carbonyl O atom. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains propagating along [100]. The tert-butyl group is disordered over two sets of sites with a refined occupancy ratio of 0.758 (12):0.242 (12).
In the mol-ecule of the title compound, C17H16N2OS, the almost planar methyl-sulfanylquinazoline group [the methyl C atom deviates by 0.032 (2) Å from the plane through the ring system] forms an inter-planar angle of 76.26 (4)° with the... more
In the mol-ecule of the title compound, C17H16N2OS, the almost planar methyl-sulfanylquinazoline group [the methyl C atom deviates by 0.032 (2) Å from the plane through the ring system] forms an inter-planar angle of 76.26 (4)° with the plane of the phenyl group. An intra-molecular O-H⋯N hydrogen bond is present between the quinazoline and hy-droxy groups. In the crystal, mol-ecules are stacked along the b-axis direction.
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In the title compound, C22H28N2, the dihedral angle between the planes of the phenyl ring and the di-hydro-quinazoline ring system (r.m.s. deviation = 0.030 Å) is 24.95 (7)° and both n-butane chains assume all-trans conformations. In the... more
In the title compound, C22H28N2, the dihedral angle between the planes of the phenyl ring and the di-hydro-quinazoline ring system (r.m.s. deviation = 0.030 Å) is 24.95 (7)° and both n-butane chains assume all-trans conformations. In the crystal, N-H⋯N hydrogen bonds link the mol-ecules into C(4) chains propagating in the [001] direction.
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Page 1. J. Org. Chem. 1983,48, 3401-3408 Regiospecific Electrophilic Substitution of Aminopyridines: Ortho Lithiation of 2-, 3-, and 4-(Pivaloy1amino)pyridines 3401 James A. Turner Agricultural Products Research, Dow Chemical USA, Walnut... more
Page 1. J. Org. Chem. 1983,48, 3401-3408 Regiospecific Electrophilic Substitution of Aminopyridines: Ortho Lithiation of 2-, 3-, and 4-(Pivaloy1amino)pyridines 3401 James A. Turner Agricultural Products Research, Dow Chemical USA, Walnut Creek, California 94598 ...
Research Interests:
The title compound, C9H8N2O, is almost planar, with the C atom of the meth-oxy group deviating from the mean plane of the quinazoline ring system (r.m.s. deviation = 0.011 Å) by 0.068 (4) Å. In the crystal, mol-ecules form π-π stacks... more
The title compound, C9H8N2O, is almost planar, with the C atom of the meth-oxy group deviating from the mean plane of the quinazoline ring system (r.m.s. deviation = 0.011 Å) by 0.068 (4) Å. In the crystal, mol-ecules form π-π stacks parallel to the b-axis direction [centroid-centroid separation = 3.5140 (18) Å], leading to a herringbone packing arrangement.
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In the title compound, C9H10BrClN2S, the di-methyl-thio-urea group is twisted from the benzene ring plane by 54.38 (6)°. In the crystal, the amino groups are involved in the formation of N-H⋯S hydrogen bonds, which link the mol-ecules... more
In the title compound, C9H10BrClN2S, the di-methyl-thio-urea group is twisted from the benzene ring plane by 54.38 (6)°. In the crystal, the amino groups are involved in the formation of N-H⋯S hydrogen bonds, which link the mol-ecules into chains along [010]. Weak C-H⋯Cl inter-actions further link these chains into layers parallel to the ab plane.
Research Interests:
In the title compound, C17H27N3OS2, the amide group is approximately coplanar with the pyridine ring [dihedral angle = 1.6 (1)°], whereas the di-thio-carbamate group is nearly perpendicular to the pyridine ring [dihedral angle =... more
In the title compound, C17H27N3OS2, the amide group is approximately coplanar with the pyridine ring [dihedral angle = 1.6 (1)°], whereas the di-thio-carbamate group is nearly perpendicular to the pyridine ring [dihedral angle = 76.7 (1)°]. In the crystal, pairs of weak C-H⋯O hydrogen bonds link the mol-ecules into inversion dimers.
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... Carbonylation of various organolithium reagents. A novel approach to heterocycles via intramolecular trapping of aromatic acyllithiums. Keith Smith, Gamal A. El-Hiti, Gareth J. Pritchard and Anna Hamilton J. Chem. Soc., Perkin Trans.... more
... Carbonylation of various organolithium reagents. A novel approach to heterocycles via intramolecular trapping of aromatic acyllithiums. Keith Smith, Gamal A. El-Hiti, Gareth J. Pritchard and Anna Hamilton J. Chem. Soc., Perkin Trans. ...