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Borges Da Silva R.,Federal University of Rio de Janeiro | Teixeira R.I.,Federal University of Rio de Janeiro | Wardell J.L.,Institute Tecnologia em Farmacos Farmanguinhos | Wardell J.L.,University of Aberdeen | And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2017

In the present study a series of N-phenyl-1,10-phenanthroline-2-amine derivatives were obtained by heating 2-chlorophenanthroline with aniline derivatives under solvent free conditions in good to excellent yields. The N-phenyl-1,10-phenanthroline-2-amines were employed as substrates in a copper(ii)-catalyzed C-H amination reaction to give derivatives of the novel heterocyclic system benzo[4,5]imidazo[1,2-a][1,10]phenanthroline. The structure of these compounds was predicted to be helical by DFT calculations and single crystal X-ray diffraction of an example of this system confirmed the non-planar helical structure. The luminescence properties of the parent heterocyclic system were characterized. © The Royal Society of Chemistry.

De Souza M.V.N.,Institute Tecnologia em Farmacos Farmanguinhos | Wardell S.M.S.V.,CHEMSOL | Loureno M.C.S.,Institute Pesquisa e Clinica Evandro Chargas IPEC
Journal of Molecular Structure | Year: 2011

Thermolysis of (R*,S*)-(2-{[2,8- bis(trifluoromethyl)quinolin-4-yl](hydroxy)∼methyl}piperidin-1-ium) tetraphenylborate, (±)-erythro-mefloquinium tetraphenylborate, 3, in solution or neat, provides the oxazaborolidine derivative, diphenyl[(R *,S*)-(2,8-bis(trifluoromethyl)quinolin-4-yl)] piperidin-2-yl-methanolato-O,N]boron, 2. Crystal structures of solvates of 2 and 3 are reported. As shown by the 1H NMR spectrum, 2 undergoes a conformation equilibrium in solution. Both 2 and 3 exhibit important anti-tubercular activities as indicated by the minimum inhibitory concentrations (MIC) of 50 and 12.5 μg/ml, respectively, in in vitro assays against M. tuberculosis H37Rv ATTC 27294. © 2011 Elsevier B.V. All rights reserved.

Wardell S.M.S.V.,CHEMSOL | Skakle J.M.S.,University of Aberdeen | Tiekink E.R.T.,University of Malaya
Zeitschrift fur Kristallographie | Year: 2011

The crystal and molecular structures of three racemic erythro-(R* , S* )-(± )-α -2-piperidinyl-2, 8-bis(trifluoromethyl)-4- quinolinemethanol n-nitrobenzoates, n = 2, 3, and 4, are described. The cations uniformly adopt an L-shaped geometry with protonation leading to a piperidin-1-ium ring in each case. A non-planar arrangement is found for the anion in (1; n = 2), owing to steric congestion, but almost planar arrangements are found in each of the anions in (2; n = 3) and (3; n = 4). Supramolecular chains are found in each of the crystal structures but these are sustained by different hydrogen bonding synthons. More efficient crystal packing in (3; n = 4) is correlated with a single synthon as opposed to two distinct synthons in each of (1; n = 2) and (2; n = 3). Crystal data for (1; n = 2): monoclinic, P21/n, a = 13.2144(6), b = 8.1028(2), c = 22.9724(9) Å , β = 105.919(1)° V = 2365.41(15) Å 3, Z = 4, R = 0.053. Crystal data for (2; n = 3): monoclinic, P21/n, a = 6.8389(2), b = 12.8432(4), c = 26.7910(9) Å , β = 90.868(2)° , V = 2352.87(13) Å 3, Z = 4, R = 0.044. Crystal data for (3; n = 4): monoclinic, P21/n, a = 16.9854(8), b = 6.5069(2), c = 20.2083(9) Å , β = 92.116(2), V = 2231.94(16) Å 3, Z = 4, R = 0.065. © by Oldenbourg Wissenschaftsverlag, Mü nchen.

Wardell S.M.S.V.,CHEMSOL | Tiekink E.R.T.,University of Malaya | De Lima G.M.,Federal University of Minas Gerais
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

In the title salt, (C17H17F6N 2O)2[Sn(C6H5)2Cl 4], the complete anion is generated by crystallograaphic inversion symmetry, giving a trans-SnC2Cl4 octa-hedral coordination geometry for the metal atom. In the cation, the quinoline residue is almost normal to the other atoms, so that the ion has an L-shaped conformation [the C - C - C - C torsion angle linking the fused-ring systems is 100.9 (7)°]; the six-membered piperidin-1-ium ring has a chair conformation. An intra-molecular N - H⋯O inter-action occurs. In the crystal, N - H⋯Cl and O - H⋯Cl hydrogen bonds link the components into a supra-molecular chain propagating along the a axis. C - H⋯Cl inter-actions are also present.

Wardell S.M.S.V.,CHEMSOL | Howie A.H.,University of Aberdeen | Tiekink E.R.T.,University of Malaya
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the title compound, C24H26N4O 2, the complete mol-ecule is generated by the application of twofold symmetry. The pyrazole ring is approximately planar [r.m.s. deviation = 0.026 Å] and the benzene ring is twisted out of this plane [dihedral angle = 21.94 (7)°]. A twist in the mol-ecule about the central C-C bond [1.566 (3) Å] is also evident [C-C-C-C torsion angle = 44.30 (14)°]. Supra-molecular layers in the bc plane are formed in the crystal packing via C-H⋯O and C-H⋯π inter-actions.

De Souza M.V.N.,Institute Tecnologia em Farmacos Farmanguinhos | De Lima Ferreira M.,Institute Tecnologia em Farmacos Farmanguinhos | Wardell S.M.S.V.,CHEMSOL | Tiekink E.R.T.,University of Malaya
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

In the nearly planar title compound (r.m.s. deviation for the 24 non-H atoms = 0.064 Å), C18H16ClN3O 2, the conformation about the N=C bond is E. Supra-molecular chains propagated by glide symmetry along [001] are found in the crystal packing. These are sustained by N-H⋯N hydrogen bonds with the quinoline N atom being the acceptor. The chains are connected into a three-dimensional architecture by π-π inter-actions involving all three aromatic rings [centroid-centroid distances = 3.5650 (9)-3.6264 (9) Å].

Nogueira A.F.,Federal University of Fluminense | Vasconcelos T.R.A.,Federal University of Fluminense | Wardell J.L.,Centra de Desenvolvimento Tecnologico em Saude CDTS | Wardell S.M.S.V.,CHEMSOL
Zeitschrift fur Kristallographie | Year: 2011

Structures of hydrazones, [1: 2-(l,3-benzothiazolyl)-NH-N=CH-C 6C 3-XY], prepared from arenecarbaldehydes and 2-hydrazinyl-l,3-benzothiazole, are reported. Compounds include unsolvated species, (1: X = 4-C1, 4-Br, 4-NMe 2; Y = H), [1: X,Y = 2,4-Me 2, 2,4-(OMe) 2], and solvated ones, [(1: X = 4-OH; Y = H) • H 20], [(1: X = 3-OMe; Y = 4-OH) • H 20], and [(1: X = 2-OH; Y = 5-NO 2)DMSO]. The solvated compound, [(1: X = 2-OH; Y = 5-NO 2) • DMSO], exists in the imino form in contrast to the (E)-2-(l,3-benzothiazolyl)-NH-N=CH-Ar form exhibited by the other compounds. Common intermolecular interactions in the non-solvated compounds, (1: X = 4-C1, 4-Br, 4-NMe 2; Y = H) and [1: X,Y = 2,4-Me 2, 2,4-(OMe) 2], are strong dimer forming N-H⋯ N hydrogen bonds and weaker π ⋯ π interactions. The latter involve the benzothazole rings, except in [1: X,Y = 2,4-(OMe) 2], where the π • π interactions involve thiazole and C 6C 3(OMe) 2rings. The dimer forming N-H • N in-termolecular hydrogen bonds and π ⋯ π stacking interactions persist in the hydrate, [(1: X = 3-OMe; Y = 4-OH) • H 20], but not in the other solvates, [(1: X = 4-OH; Y = H) • H 20] and [(1: X = 2-OH; Y = 5-NO 2) • DMSO]. For [(1: X = 4-OH; Y = H) • H 20], the important direct links between [(1: X = 4-OH; Y = H) are chain forming O-H ⋯ N hydrogen bonds, supplemented by π ⋯ π in teractions. For all solvated compounds, the solvate molecules are involved in indirect links between the hydrazone molecules. In the case of [(1: X = 2-OH; Y = 5-NO 2) • DMSO], present in the imino form, a network of rings is generated from the hydrogen bonding interactions of the DMSO solvate with the N-H and N-O(nitro) moieties of (1: X = 2-OH; Y = 5-NO 2). © Oldenbourg Wissenschaftsverlag, München.

Rodrigues F.A.R.,Federal University of Ceará | Bomfim I.D.S.,Federal University of Ceará | Cavalcanti B.C.,Federal University of Ceará | Pessoa C.,Federal University of Ceará | And 5 more authors.
Chemical Biology and Drug Design | Year: 2014

A series of 23 racemic mefloquine-oxazolidine derivatives, 4-[3-(aryl)hexahydro[1,3]oxazolo[3,4-a]pyridin-1-yl]-2,8-bis(trifluoromethyl) quinolines, derived from (R, S)-(±)-mefloquine and arenealdehydes, have been evaluated for their activity against four cancer cell lines (HCT-8, OVCAR-8, HL-60, and SF-295). Good cytotoxicities have been determined with IC50 values ranging from 0.59 to 4.79 μg/mL. In general compounds with aryl groups having strong electron-releasing substituents, such as HO and MeO, or electron-rich heteroaryl groups, for example imidazol-2-y-l, are active. However, other factors such as steric effects may play a role. As both the active and non-active conformations of the mefloquine-oxazolidine derivatives are similar, it is concluded that molecular conformations do not play a significant role either. This study is the first to evaluate mefloquine derivatives as antitumor agents. The mefloquine-oxazolidine derivatives are considered to be useful leads for the rational design of new antitumor agents. A series of twenty three racemic mefloquine-oxazolidine derivatives have been evaluated for their activity against 3-5 cancer cell lines SF-295, HCT-116, OVCAR-8, HCT-8 and HL-60. Cytotoxicities have been determined with IC 50 values ranging from 0.59 to 4.79 μg/mL. © 2013 John Wiley & Sons A/S.

PubMed | Federal University of Rio de Janeiro, CHEMSOL and University of Aberdeen
Type: Published Erratum | Journal: Organic & biomolecular chemistry | Year: 2017

Correction for Copper(ii) catalyzed synthesis of novel helical luminescent benzo[4,5]imidazo[1,2-a][1,10]phenanthrolines via an intramolecular C-H amination reaction by Ramon Borges da Silva, et al., Org. Biomol. Chem., 2017, DOI: 10.1039/c6ob02508k.

PubMed | Institute Tecnologia em Farmacos Farmanguinhos, Institute Pesquisa Clinica Evandro Chagas Ipec Av Brazil and CHEMSOL
Type: Journal Article | Journal: Scientia pharmaceutica | Year: 2017

Both sonochemical and classical methodologies have been employed to convert camphor, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one, CH

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