oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
3-Benzyl-9-phenyl-2-tosyl-2,3,3a,4,9,9a-hexahydro-1H-pyrrolo[3,4-b]quinoline
K. Chinnakali,D. Sudha,M. Jayagobi,R. Raghunathan
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809044547
Abstract: In the title compound, C31H30N2O2S, the pyrrolidine ring adopts a twist conformation while the tetrahydropyridine ring is in a half-chair conformation. The two rings are trans-fused. The pyridine-bound phenyl ring forms dihedral angles of 17.7 (1) and 48.1 (1)°, respectively, with the tosyl and benzyl phenyl rings. The molecular structure is stabilized by an N—H...π interaction involving the benzyl phenyl ring. In the crystal structure, molecules translated by one unit along the a axis are linked into chains by C—H...π interactions involving the benzene ring of the tosyl group.
3-Benzyl-7-chloro-9-phenyl-2-tosyl-2,3,3a,4,9,9a-hexahydro-1H-pyrrolo[3,4-b]quinoline
K. Chinnakali,D. Sudha,M. Jayagobi,R. Raghunathan
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809045267
Abstract: In the title compound, C31H29ClN2O2S, the pyrrolidine ring adopts an envelope conformation with the methine C atom adjacent to the NH group as the flap atom. The tetrahydropyridine ring has a half-chair conformation. The two rings are trans-fused. The chlorobenzene ring and the adjacent phenyl ring form a dihedral angle of 77.9 (1)°. The benzyl phenyl and the tosyl phenyl rings are oriented at a dihedral angle of 88.0 (1)°. In the crystal, molecules are linked into chains along the a axis by N—H...Cl and C—H...Cl hydrogen bonds and the adjacent chains are cross-linked via C—H...π interactions.
3-Benzyl-7-bromo-9-phenyl-2-tosyl-2,3,3a,4,9,9a-hexahydro-1H-pyrrolo[3,4-b]quinoline
K. Chinnakali,D. Sudha,M. Jayagobi,R. Raghunathan
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809045875
Abstract: In the title compound, C31H29BrN2O2S, the pyrrolidine ring is in a twist conformation and the tetrahydropyridine ring adopts an envelope conformation with the methine C atom adjacent to the NH group as the flap atom; the two rings are trans-fused. The bromobenzene ring and the nearest phenyl ring form a dihedral angle of 82.72 (10)°. The benzyl phenyl and the tosyl phenyl rings are oriented at a dihedral angle of 75.57 (11)°. An intramolecular N—H...π interaction is observed. In the crystal, molecules are linked into chains running along [101] by C—H...O hydrogen bonds and the chains are cross-linked via weak C—H...π interactions.
3-Benzyl-7-methoxy-9-phenyl-2-tosyl-2,3,3a,4,9,9a-hexahydro-1H-pyrrolo[3,4-b]quinoline
K. Chinnakali,D. Sudha,M. Jayagobi,R. Raghunathan
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809044973
Abstract: In the title compound, C32H32N2O3S, the pyrrolidine ring adopts an envelope conformation with the methine C atom nearest to the phenyl ring as the flap atom. The tetrahydropyridine ring has a half-chair conformation. The two rings are trans-fused. The phenyl ring bound to the tetrahydropyridine is oriented almost perpendicular [dihedral angle = 86.35 (10)°] to the fused benzene ring. The dihedral angle between the benzylphenyl ring and the sulfonyl-bound phenyl ring is 69.43 (10)°. A very weak N—H...π interaction is observed in the molecular structure. In the crystal, molecules translated one unit along the b axis are linked into C(10) chains by C—H...O hydrogen bonds; adjacent chains are linked via C—H...π interactions, forming a two-dimensional network parallel to the bc plane.
3-Ethyl-9-phenyl-2-tosyl-2,3,3a,4,9,9a-hexahydro-1H-pyrrolo[3,4-b]quinoline  [cached]
D. Sudha,K. Chinnakali,M. Jayagobi,R. Raghunathan
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808000482
Abstract: In the molecule of the title compound, C26H28N2O2S, the pyrrolidine ring adopts an envelope conformation and the tetrahydropyridine ring is in a half-chair conformation; these two rings are trans-fused. The dihedral angle between the pyridine- and sulfonyl-bound benzene rings is 36.15 (5)°. In the crystalline state, the molecules are linked into a two-dimensional network parallel to the ab plane by C—H...O and C—H...π interactions.
Microwave-Assisted Synthesis of Substituted Hexahydro-pyrrolo[3,2-c]quinolines  [PDF]
Michal Neuschl,Darek Bogdal,Milan Potacek
Molecules , 2007, DOI: 10.3390/12010049
Abstract: New compounds with the ethyl hexahydro-1H-pyrrolo[3,2-c]quinoline-2-carboxylate skeleton were prepared by microwave-assisted intramolecular 1,3-dipolar cycloaddition reactions. The reactions were carried out under solvent-free conditions and compared with the same reaction in the presence of a solvent and a catalyst. Steric effects on the selectivity of the reaction were noted and evaluated.
N-[(3RS,4SR)-1-Benzyl-4-methylpiperidin-3-yl]-1-(4-methylphenylsulfonyl)-5-nitro-1H-pyrrolo[2,3-b]pyridin-4-amine  [cached]
Ellen Pfaffenrot,Dieter Schollmeyer,Stefan Laufer
Acta Crystallographica Section E , 2012, DOI: 10.1107/s160053681203961x
Abstract: The structure of the title compound, C27H29N5O4S, displays an intramolecular N—H...O hydrogen bond. The pyrrolo[2,3-b]pyridine core makes a dihedral angle of 85.5 (4)° with the benzyl residue and a dihedral angle of 89.4 (9)° with the tosyl ring. The nitro group is slightly twisted out of the plane of the planar pyrrolopyridine system [(—N—)C—C—N—O torsion angle = 4.61 (18)° and (—NH—)C—C—N—O = 6.46 (18)°].
1-Tosyl-4-[2-(trifluoromethyl)benzyl]piperazine  [cached]
S. Sreenivasa,H. C. Anitha,K. E. ManojKumar,J. Tonannavar
Acta Crystallographica Section E , 2013, DOI: 10.1107/s1600536813000317
Abstract: In the crystal structure of the title compound, C19H21F3N2O2S, the piperazine ring adopts a chair conformation. The dihedral angles between the mean plane of the piperazine ring and the tosyl and trifluoromethylphenyl rings are 74.52 (3) and 68.30 (2)°, respectively. The sulfonamide N atom deviates from the plane defined by the three attached atoms by 0.327 (1) . The crystal structure is stabilized by weak C—H...π interactions.
Polymorphism, Hydrogen Bond Properties, and Vibrational Structure of 1H-Pyrrolo[3,2-h]Quinoline Dimers  [PDF]
Alexandr Gorski,Sylwester Gawinkowski,Roman Luboradzki,Marek Tkacz,Randolph P. Thummel,Jacek Waluk
Journal of Atomic, Molecular, and Optical Physics , 2012, DOI: 10.1155/2012/236793
Abstract: Two forms of cyclic, doubly hydrogen-bonded dimers are discovered for crystalline 1H-pyrrolo[3,2-h]quinoline, a bifunctional molecule possessing both hydrogen bond donor and acceptor groups. One of the forms is planar, the other is twisted. Analysis of IR and Raman spectra, combined with DFT calculations, allows one to assign the observed vibrations and to single out vibrational transitions which can serve as markers of hydrogen bond formation and dimer structure. Raman spectra measured for samples submitted to high pressure indicate a transition from the planar towards the twisted structure. Formation of intermolecular hydrogen bonds leads to a large increase of the Raman intensity of the NH stretching band: it can be readily observed for the dimer, but is absent in the monomer spectrum.
Polymorphism, Hydrogen Bond Properties, and Vibrational Structure of 1H-Pyrrolo[3,2-h]Quinoline Dimers  [PDF]
Alexandr Gorski,Sylwester Gawinkowski,Roman Luboradzki,Marek Tkacz,Randolph P. Thummel,Jacek Waluk
Journal of Atomic and Molecular Physics , 2012, DOI: 10.1155/2012/236793
Abstract: Two forms of cyclic, doubly hydrogen-bonded dimers are discovered for crystalline 1H-pyrrolo[3,2-h]quinoline, a bifunctional molecule possessing both hydrogen bond donor and acceptor groups. One of the forms is planar, the other is twisted. Analysis of IR and Raman spectra, combined with DFT calculations, allows one to assign the observed vibrations and to single out vibrational transitions which can serve as markers of hydrogen bond formation and dimer structure. Raman spectra measured for samples submitted to high pressure indicate a transition from the planar towards the twisted structure. Formation of intermolecular hydrogen bonds leads to a large increase of the Raman intensity of the NH stretching band: it can be readily observed for the dimer, but is absent in the monomer spectrum. 1. Introduction In studies of the intermolecular hydrogen bond (HB), an important class of model compounds consists of molecules which can form both H-bonded dimers and complexes with water or alcohols [1]. Such molecules are usually characterized by the simultaneous presence of HB donor and acceptor groups. Whether the strength of the intermolecular HBs is greater for dimers or complexes depends on the relative positions of the donor and acceptor in the molecular frame. Interestingly, different structures and stoichiometries are often encountered for the same molecule. A well-known example is 7-azaindole (7AI, Figure 1), which forms doubly hydrogen bonded dimers in solution [2], while the X-ray data reveal a tetrameric structure in the crystalline state [3]. Different stoichiometries and structures are possible for the complexes of 7AI with methanol and water: 1?:?1, 1?:?2, and 1?:?3 species have been detected [4–9]. Figure 1: Various motifs of intermolecular HB formed by 7-azaindole. (a) Dimers and tetramers, (b) complexes with water. The crystal structure of multiply H-bonded dimers/oligomers seems to be determined by the interplay of H-bonding and longer range intermolecular interactions. For instance, 1-azacarbazole (1AC), a molecule closely related to 7AI, exists in the crystal in the form of planar, doubly hydrogen bonded dimers [10] (Figure 2). While there is no doubt that 1AC also forms dimers in solutions, various possible structures have been discussed [11–14]. Figure 2: The structure of dimers of 1-azacarbazole in the solid phase. 1H-pyrrolo[3,2-h]quinoline (PQ, Scheme 1) can be considered a counterpart to 7AI with regard to intermolecular HB characteristics. The NH group of PQ (HB-donor) and the pyridine nitrogen (HB-acceptor) are positioned three bonds
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.