Regio- and stereospecific assembly of dispiro[indoline-3,3′-pyrrolizine-1′,5′′-thiazolidines] from simple precursors using a one-pot procedure : synthesis, spectroscopic and structural characterization, and a proposed mechanism of formation

The authors thank 'Centro de Instrumentación Científico-Técnica of Universidad de Jaén' for data collection. The authors thank COLCIENCIAS, Universidad del Valle, the Consejería de Innovación, Ciencia y Empresa (Junta de Andalucía, Spain) and the Universidad de Jaén for financial support. JQ thanks the AUIP for a scholarship granted for a stay at the Universidad de Jaén.The synthesis and characterization of three new di­spiro­[indoline-3,3′-pyrrolizine-1′,5′′-thia­zolidine] com­pounds are reported, together with the crystal structures of two of them. (3RS,1′SR,2′SR,7a′SR)-2′-(4-Chloro­phen­yl)-1-hexyl-2′′-sulfanyl­idene-5′,6′,7′,7a′-tetra­hydro-2′H-di­spiro­[indoline-3,3′-pyrrolizine-1′,5′′-thia­zolidine]-2,4′′-dione, C28H30ClN3O2S2, (I), (3RS,1′SR,2′SR,7a′SR)-2′-(4-chloro­phen­yl)-1-benzyl-5-methyl-2′′-sulfanyl­idene-5′,6′,7′,7a′-tetra­hydro-2′H-di­spiro­[in­doline-3,3′-pyrrolizine-1′,5′′-thia­zolidine]-2,4′′-dione, C30H26ClN3O2S2, (II), and (3RS,1′SR,2′SR,7a′SR)-2′-(4-chloro­phen­yl)-5-fluoro-2′′-sulfanyl­idene-5′,6′,7′,7a′-tetra­hydro-2′H-di­spiro­[indoline-3,3′-pyrrolizine-1′,5′′-thia­zolidine]-2,4′′-dione, C22H17ClFN3O2S2, (III), were each isolated as a single regioisomer using a one-pot reaction involving L -proline, a substituted isatin and (Z)-5-(4-chloro­benzyl­idene)-2-sulfanyl­idene­thia­zolidin-4-one [5-(4-chloro­benzyl­idene)rhodanine]. The com­positions of (I)–(III) were established by elemental analysis, com­plemented by high-resolution mass spectrometry in the case of (I); their constitutions, including the definition of the regiochemistry, were established using NMR spectroscopy, and the relative configurations at the four stereogenic centres were established using single-crystal X-ray structure analysis. A possible reaction mechanism for the formation of (I)–(III) is proposed, based on the detailed stereochemistry. The mol­ecules of (I) are linked into simple chains by a single N—H⋯N hydrogen bond, those of (II) are linked into a chain of rings by a combination of N—H⋯O and C—H⋯S=C hydrogen bonds, and those of (III) are linked into sheets by a combination of N—H⋯N and N—H⋯S=C hydrogen bonds.Publisher PDFPeer reviewe

Synthesis of N-substituted 3-(2-aryl-2-oxoethyl)-3-hydroxyindolin-2-ones and their conversion to N-substituted (E)-3-(2-aryl-2-oxoethylidene)indolin-2-ones : synthetic sequence, spectroscopic characterization and structures of four 3-hydroxy compounds and five oxoethylidene products

The authors thank `Centro de Instrumentación Científico-Técnica' of Universidad de Jaén and its staff for data collection. They also thank Universidad del Valle, Universidad Pedagógica y Tecnológica de Colombia (project SGI-2829), Universidad de Jaén and the Consejería de Innovación, Ciencia y Empresa (Junta de Andalucía, Spain), for financial support. DB also thanks the Asociación Universitaria Iberoamericana de Postgrado for financial support.An operationally simple and time-efficient approach has been developed for the synthesis of racemic N-substituted 3-(2-aryl-2-oxoeth­yl)-3-hy­droxy­indolin-2-ones by a piperidine-catalysed aldol reaction between aryl methyl ketones and N-alkyl­isatins. These aldol products were used successfully as strategic inter­mediates for the preparation of N-substituted (E)-3-(2-hetaryl-2-oxo­ethyl­idene)indolin-2-ones by a stereoselective dehydration reaction under acidic conditions. The products have all been fully characterized by 1H and 13C NMR spectroscopy, by mass spectrometry and, for a representative selection, by crystal structure analysis. In each of (RS)-1-benzyl-3-hy­droxy-3-[2-(4-meth­oxy­phen­yl)-2-oxoeth­yl]indolin-2-one, C24H21NO4, (Ic), and (RS)-1-benzyl-3-{2-[4-(di­methyl­amino)­phen­yl]-2-oxoeth­yl}-3-hy­droxy­indolin-2-one, C25H24N2O3, (Id), inversion-related pairs of mol­ecules are linked by O—H⋯O hydrogen bonds to form R22(10) rings, which are further linked into chains of rings by a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds in (Ic) and by C—H⋯π(arene) hydrogen bonds in (Id). The mol­ecules of (RS)-1-benzyl-3-hy­droxy-3-[2-oxo-2-(pyridin-4-yl)eth­yl]indolin-2-one, C22H18N2O3, (Ie), are linked into a three-dimensional framework structure by a combination of O—H⋯N, C—H⋯O and C—H⋯π(arene) hydrogen bonds. (RS)-3-[2-(Benzo[d][1,3]dioxol-5-yl)-2-oxoeth­yl]-1-benzyl-3-hy­droxy­indolin-2-one, C24H19NO5, (If), crystallizes with Z′ = 2 in the space group P and the mol­ecules are linked into com­plex sheets by a combination of O—H⋯O, C—H⋯O and C—H⋯π(arene) hydro­gen bonds. In each of (E)-1-benzyl-3-[2-(4-fluoro­phen­yl)-2-oxo­ethyl­idene]indolin-2-one, C23H16FNO2, (IIa), and (E)-1-benzyl-3-[2-oxo-2-(thiophen-2-yl)ethylidene]indolin-2-one, C21H15NO2S, (IIg), the mol­ecules are linked into simple chains by a single C—H⋯O hydrogen bond, while those of (E)-1-benzyl-3-[2-oxo-2-(pyridin-4-yl)ethyl­idene]indolin-2-one, C22H16N2O2, (IIe), are linked by three C—H⋯O hydrogen bonds to form sheets which are further linked into a three-dimensional structure by C—H⋯π(arene) hydrogen bonds. There are no hydrogen bonds in the structures of either (E)-1-benzyl-3-[2-(4-meth­oxy­phen­yl)-2-oxo­ethyl­idene]indolin-2-one, C24H19NO3, (IIc), or (E)-1-benzyl-5-chloro-3-[2-(4-chloro­phen­yl)-2-oxo­ethyl­idene]indolin-2-one, C23H15Cl2NO2, (IIh), but the mol­ecules of (IIh) are linked into chains of π-stacked dimers by a combination of C—Cl⋯π(arene) and aromatic π–π stacking inter­actionPublisher PDFPeer reviewe

4-Styrylquinolines from cyclocondensation reactions between (2-aminophenyl)chalcones and 1,3-diketones : crystal structures and regiochemistry

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión de la Universidad Industrial de Santander (proyecto No. 2497, to AP); Universidad de Jaén, the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía, Spain) and Centro de Instrumentación Científico–Técnica of the Universidad de Jaén (UJA) (to JC).Structures are reported for two matched sets of substituted 4-styryl­quino­lines which were prepared by the formation of the heterocyclic ring in cyclo­condensation reactions between 1-(2-amino­phen­yl)-3-aryl­prop-2-en-1-ones with 1,3-dicarbonyl com­pounds. (E)-3-Acetyl-4-[2-(4-meth­oxy­phen­yl)ethen­yl]-2-methyl­quino­line, C21H19NO2, (I), (E)-3-acetyl-4-[2-(4-bromo­phen­yl)ethen­yl]-2-methyl­quino­line, C20H16BrNO, (II), and (E)-3-acetyl-2-methyl-4-{2-[4-(tri­fluoro­meth­yl)phen­yl]ethen­yl}quino­line, C21H16F3NO, (III), are isomorphous and in each structure the mol­ecules are linked by a single C—H...O hydrogen bond to form C(6) chains. In (I), but not in (II) or (III), this is augmented by a C—H...π(arene) hydrogen bond to form a chain of rings; hence, (I)–(III) are not strictly isostructural. By contrast with (I)–(III), no two of ethyl (E)-4-[2-(4-meth­oxy­phen­yl)ethen­yl]-2-methyl­quino­line-3-carboxyl­ate, C22H21NO3, (IV), ethyl (E)-4-[2-(4-bromo­phen­yl)ethen­yl]-2-methyl­quino­line-3-carboxyl­ate, C21H18BrNO2, (V), and ethyl (E)-2-methyl-4-{2-[4-(tri­fluoro­meth­yl)phen­yl]ethen­yl}quino­line-3-carboxyl­ate, C22H18F3NO2, (VI), are isomorphous. The mol­ecules of (IV) are linked by a single C—H...O hydrogen bond to form C(13) chains, but cyclic centrosymmetric dimers are formed in both (V) and (VI). The dimer in (V) contains a C—H...π(pyrid­yl) hydrogen bond, while that in (VI) contains two independent C—H...O hydrogen bonds. Comparisons are made with some related structures, and both the regiochemistry and the mechanism of the heterocyclic ring formation are discussed.Publisher PDFPeer reviewe

Conversion of 3-amino-4-arylamino-1H-isochromen-1-ones to 1-arylisochromeno[3,4-d][1,2,3]triazol-5(1H)-ones : synthesis, spectroscopic characterization and the structures of four products and one ring-opened derivative

The authors thank 'Centro de Instrumentación Científico-Técnica of Universidad de Jaén' for data collection. The authors thank Universidad de Ciencias Aplicadas y Ambientales (UDCA), Universidad Nacional de Colombia, the Consejería de Innovación, Ciencia y Empresa (Junta de Andalucía, Spain) and the Universidad de Jaén for financial support.An efficient synthesis of 1-aryl­isochromeno[3,4-d][1,2,3]triazol-5(1H)-ones, involving the diazo­tization of 3-amino-4-aryl­amino-1H-isochromen-1-ones in weakly acidic solution, has been developed and the spectroscopic characterization and crystal structures of four examples are reported. The mol­ecules of 1-phenyl­isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H9N3O2, (I), are linked into sheets by a combination of C—H⋯N and C—H⋯O hydrogen bonds, while the structures of 1-(2-methyl­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C16H11N3O2, (II), and 1-(3-chloro­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, C15H8ClN3O2, (III), each contain just one hydrogen bond which links the mol­ecules into simple chains, which are further linked into sheets by π-stacking inter­actions in (II) but not in (III). In the structure of 1-(4-chloro­phen­yl)isochromeno[3,4-d][1,2,3]triazol-5(1H)-one, (IV), isomeric with (III), a combination of C—H⋯O and C—H⋯π(arene) hydrogen bonds links the mol­ecules into sheets. When com­pound (II) was exposed to a strong acid in methanol, qu­anti­tative conversion occurred to give the ring-opened transesterification product methyl 2-[4-hy­droxy-1-(2-methyl­phen­yl)-1H-1,2,3-triazol-5-yl]benzoate, C17H15N3O3, (V), where the mol­ecules are linked by paired O—H⋯O hydrogen bonds to form centrosymmetric dimers.Publisher PDFPeer reviewe

Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedlander reactions between (2-aminophenyl)chalcones and acetone

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión of the Industrial University of Santander (grant No. 2680 to AP); Universidad de Jaén and the Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucá, Spain) (award to JC).Three new 2-methyl-4-styryl­quinoline derivatives have been synthesized in high yields using Friedländer reactions between chalcones [1-(2-amino­phen­yl)-3-aryl­prop-2-en-1-ones] and acetone, and characterized using IR, 1H and 13C NMR spectroscopy, and mass spectrometry, and by crystal structure analysis. In (E)-4-(4-fluoro­styr­yl)-2-methyl­quinoline, C18H14FN, (I), the mol­ecules are joined into cyclic centrosymmetric dimers by C—H⋯N hydrogen bonds and these dimers are linked into sheets by π–π stacking inter­actions. The mol­ecules of (E)-2-methyl-4-[4-(tri­fluoro­meth­yl)styr­yl]quinoline, C19H14F3N, (II), are linked into cyclic centrosymmetric dimers by C—H⋯π hydrogen bonds and these dimers are linked into chains by a single π–π stacking inter­action. There are no significant hydrogen bonds in the structure of (E)-4-(2,6-di­chloro­styr­yl)-2-methyl­quinoline, C18H13Cl2N, (III), but mol­ecules related by translation along [010] form stacks with an inter­molecular spacing of only 3.8628 (2) Å. Comparisons are made with the structures of some related com­pounds.Publisher PDFPeer reviewe

Synthesis, and spectroscopic and structural characterization of three new styrylquinoline–benzimidazole hybrids

Funding for this research was provided by: Vicerrectoría de Investigación y Extensión of the Industrial University of Santander (grant No. 2680)Three new 4-styryl­quinoline–benzimidazole hybrids have been synthesized using a reaction sequence in which 2-methyl­quinoline precursors first undergo selective oxidation by selenium dioxide to form the corresponding 2-formyl­quinoline inter­mediates, followed by oxidative cyclo­condensation reactions with benzene-1,2-diamine to yield the hybrid products. The formyl inter­mediates and the hybrid products have all been fully characterized using a combination of IR, 1H and 13C NMR spectroscopy, and high-resolution mass spectrometry, and the structures of the three hybrid products have been determined using single-crystal X-ray diffraction. Ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-chloro­styr­yl)quinoline-3-carboxyl­ate, C27H20ClN3O2, (IIIa), and ethyl (E)-2-(1H-ben­zo[d]imidazol-2-yl)-4-(2-meth­oxy­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O3, (IIIb), both crystallize in the solvent-free form with Z′ = 1, but ethyl (E)-2-(1H-benzo[d]imidazol-2-yl)-4-(4-methyl­styr­yl)quinoline-3-carboxyl­ate, C28H23N3O2, (IIIc), crystallizes as a partial hexane solvate with Z′ = 3, and the ester group in one of the independent mol­ecules is disordered over two sets of atomic sites having occupancies of 0.765 (7) and 0.235 (7). The mol­ecules of (IIIc) enclose continuous channels which are occupied by disordered solvent mol­ecules having partial occupancy. In all of the mol­ecules of (IIIa)–(IIIc), the styryl­quinoline fragment is markedly nonplanar. Different combinations of N—H⋯O and C—H⋯π hydrogen bonds generate supra­molecular assemblies which are two-dimensional in (IIIb) and (IIIc), but three-dimensional in (IIIa). Comparisons are made with the structures of some related com­pounds.Publisher PDFPeer reviewe

Estudio motivacional sobre el aprendizaje de la religión en Educación Básica mediante las TIC

La motivación es un aspecto que sirve de motor para despertar el interés en asimilar una unidad curricular en particular. Esta investigación tiene como objetivo determinar las causas que provocan desmotivación en el estudiantado de Educación General Básica (EGB) de una institución educativa religiosa modelo y su influencia en el interés por aprender sobre religión, con el fin de incorporar las TIC como estrategia motivacional de enseñanza. Metodológicamente, se trata de una investigación bajo el paradigma positivista de carácter no experimental, ex post facto y transversal, de naturaleza descriptiva y causal, con un diseño documental y de campo. El tipo y nivel de profundidad del estudio es descriptivo y explicativocorrelacional con la participación de una muestra de 268 estudiantes y ocho docentes de religión. Se diseñaron dos tipos de cuestionarios, uno dirigido al estudiantado y otro a los/as docentes. La hipótesis consistió en verificar si a mayor motivación y satisfacción del estudiantado, mayor aprendizaje de la religión en Educación Básica. Los resultados evidencian la presencia de un bajo nivel de motivación y satisfacción en el estudiantado a causa de deficiencias en el ambiente de aprendizaje, así como al uso de metodologías de enseñanza tradicionales que limitan la participación activa del estudiantado. Se resalta la necesidad de aplicar metodologías alternativas que incorpore las TIC para incrementar la motivación estudiantil, y, por ende, el rendimiento académico.//Motivation is an aspect that serves as a motor to awaken interest in assimilating a particular curricular unit. This research aims to determine the causes that cause demotivation in the students of Basic General Education (EGB) of a model religious educational institution and its influence on the interest in learning about religion, in order to incorporate ICT as a motivational teaching strategy. Methodologically, it is an investigation under the positivist paradigm of a non-experimental, ex post facto and transversal nature, of a descriptive and causal nature, with a documentary and field design. The type and depth level of the study is descriptive and explanatory-correlational with the participation of a sample of 268 students and eight religion teachers. Two types of questionnaires were designed, one aimed at students and the other at teachers. The hypothesis consisted in verifying if greater motivation and satisfaction of the students, greater learning of religion in Basic Education. The results show the presence of a low level of motivation and satisfaction in the student body due to deficiencies in the learning environment, as well as the use of traditional teaching methodologies that limit the active participation of the student. The need to apply alternative methodologies that incorporate ICT to increase student motivation and, therefore, academic performance is highlighted

Easy synthesis of new series of pteridine analogs: di- and tetra-hydropyrimido[4,5-d]pyrimidines via 5-pyrimidinecarbaldehydes

Pyrimidine-5-carbaldehyde derivatives, of easy access, were selected as precursors for the synthesis of mimic pteridine derivatives 5,6-dihydropyrimido[4,5-d]pyrimidines and 5,6,7,8- tetrahydropyrimido[4,5-d]pyrimidines via 4-amino-(5-aminomethyl)pyrimidine intermediates. Straightforward procedures allow a quick access to these compounds. The dihydro derivatives were prepared means of a final cyclocondensation carried out with orthoesters, catalysed by acid and assisted by microwaves irradiation under solvent free conditions. The final cyclocondensation with carbonyl compounds forming the tetrahydro derivatives was done under mild conditions, in which stereochemical induction was carried out on the building of this skeleton, and stereochemistry assignments corroborated by theoretical calculations.Fil: de la Torre, José M.. Universidad de Jaén; EspañaFil: Nogueras, Manuel. Universidad de Jaén; EspañaFil: Borkowski, Eduardo Jorge. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Suvire, Fernando D.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Enriz, Ricardo Daniel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cobo, Justo. Universidad de Jaén; Españ

Two isomeric reaction products: hydrogen-bonded sheets in methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate and hydrogen-bonded chains of edge-fused rings in methyl 3-nitro-4-[(5-phenyl-1H-pyrazol-3-yl)amino] benzoate

In methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate, C17H14N4O4, the molecules are linked into complex sheets by a combination of N-H center dot center dot center dot N, N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds. In the isomeric methyl 3-nitro-4-[(5-phenyl- 1H-pyrazol-3-yl)amino] benzoate, molecules exhibit a polarized molecular-electronic structure and are linked into chains of edge-fused rings by a combination of N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds