Similar molecular constitutions but different conformations and different supramolecular assemblies in two related fused tetracyclic benzo[b]pyrimido[5,4-f]azepine derivatives

2016 ◽  
Vol 72 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Lina M. Acosta Quintero ◽  
Isidro Burgos ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell

A simple and effective two-step approach to tricyclic pyrimidine-fused benzazepines has been adapted to give the tetracyclic analogues. In (RS)-8-chloro-6-methyl-1,2,6,7-tetrahydropyrimido[5′,4′:6,7]azepino[3,2,1-hi]indole, C15H14ClN3, (I), the five-membered ring adopts an envelope conformation, as does the reduced pyridine ring in (RS)-9-chloro-7-methyl-2,3,7,8-tetrahydro-1H-pyrimido[5′,4′:6,7]azepino[3,2,1-ij]quinoline, C16H16ClN3, (II). However, the seven-membered rings in (I) and (II) adopt very different conformations, with the result that the methyl substituent occupies a quasi-axial site in (I) but a quasi-equatorial site in (II). The molecules of (I) are linked by C—H...N hydrogen bonds to formC(5) chains and inversion-related pairs of chains are linked by a π–π stacking interaction. A combination of a C—H...π hydrogen bond and two C—Cl...π interactions links the molecules of (II) into complex sheets. Comparisons are made with some similar fused heterocyclic compounds.

Author(s):  
Jairo Quiroga ◽  
Dayana Pantoja ◽  
Justo Cobo ◽  
Christopher Glidewell

In the title compound, C31H29N3O2, the reduced pyridine ring adopts a conformation intermediate between the envelope and half-chair forms. The aryl rings of the benzyl and phenyl substituents are nearly parallel and overlap, indicative of an intramolecular π–π stacking interaction. A combination of two C—H...O hydrogen bonds and one C—H...N hydrogen bond links the molecules into a bilayer havingtert-butyl groups on both faces.<!?tpb=19.5pt>


2009 ◽  
Vol 65 (6) ◽  
pp. o1309-o1309
Author(s):  
Bijan Etemadi ◽  
Reza Kia ◽  
Hashem Sharghi ◽  
Mona Hosseini Sarvari

The molecule of the title compound, C20H20N2O6, lies across a crystallographic inversion centre, the asymmetric unit comprising one half-molecule. An intramolecular O—H...N hydrogen bond generates a six-membered ring, producing anS(6)ring motif. Pairs of intermolecular C—H...O hydrogen bonds link neighbouring molecules into a layer withR22(38) ring motif. The crystal structure is further stabilized by the intermolecular C—H...π interactions.


Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
S. Maharani ◽  
R. Ranjith Kumar ◽  
P. L. Nilantha Lakshman

The title compound, C23H21N3, comprises a 2-amino-3-cyanopyridine ring fused with a cyclopentane ring. The later adopts an envelope conformation with the central methylene C atom as the flap. The benzyl and andp-tolyl rings are inclined to one another by 56.18 (15)°, and to the pyridine ring by 81.87 (14) and 47.60 (11)°, respectively. In the crystal, molecules are linked by pairs of N—H...Nnitrilehydrogen bonds, forming inversion dimers with anR22(12) ring motif. The dimers are linked by C—H...π and π–π interactions [centroid–centroid distance = 3.7211 (12) Å], forming a three-dimensional framework.


2012 ◽  
Vol 68 (6) ◽  
pp. o1614-o1615
Author(s):  
Tong Yu ◽  
Hai-Yan Tian ◽  
Xiao-Feng Yuan ◽  
Shu-Zhi Hu ◽  
Ren-Wang Jiang

The title compound, C24H30O5, is the didehydro product of the steroid hellebrigenin (systematic name: 3β,5,14-trihydroxy-19-oxo-5β-bufa-20,22-dienolide). It consists of three cyclohexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclohexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Å and is β-oriented at the C atom of ring D to which it is attached. There is an O—H...O hydrogen bond in the molecule involving the hydroxy groups. In the crystal, O—H...O hydrogen bonds link the molecules into chains propagating along [010]. The chains are linked by C—H...O contacts into a three-dimensional network.


2015 ◽  
Vol 71 (9) ◽  
pp. o636-o636
Author(s):  
Nadiah Ameram ◽  
Farook Adam

In the title compound, C16H17N3OS, a benzoyl thiourea derivative, the planes of the pyridine and benzene rings are inclined to one another by 66.54 (9)°. There is an intramolecular N—H...O hydrogen bond present forming anS(6) ring motif. In the crystal, molecules are linkedviapairs of N—H...N hydrogen bonds, forming inversion dimers, which are reinforced by pairs of C—H...S hydrogen bonds. The dimers are linkedviaC—H...π interactions, forming ribbons along [010].


IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Gao-Ju Wen ◽  
Ming-Xin Wang ◽  
Lian-Shuai Gu

In the title compound, C18H22N4O3, the benzene ring is twisted by 63.29 (15)° with respect to the pyridine ring. In the crystal, molecules are linked by N—H...O hydrogen bonds and C—H...π interactions, forming slabs parallel to theacplane.


IUCrData ◽  
2016 ◽  
Vol 1 (12) ◽  
Author(s):  
Ahmed Moussaif ◽  
Youssef Ramli ◽  
Nada Kheira Sebbar ◽  
El Mokhtar Essassi ◽  
Joel T. Mague

The asymmetric unit of the title compound, C9H8N2S, consists of two independent molecules (AandB) differing in the conformation of the thiazole ring: twisted for moleculeAand planar for moleculeB. In the crystal, molecules stack along thecaxis in alternatingAandBlayers. Within the layers, molecules are linked by C—H...π interactions, and inversion-relatedBmolecules are linked by offset π–π interactions [inter-centroid distance = 3.716 (1) Å]. The two molecules are also linked by a C—H...N hydrogen bond, which results finally in the formation of a three-dimensional structure.


2017 ◽  
Vol 73 (10) ◽  
pp. 1483-1487
Author(s):  
P. Sivakumar ◽  
S. Israel ◽  
G. Chakkaravarthi

The title salt (I), C6H8N+·C20H17O8−, comprises a 2-methylpyridinium cation and a 2,3-bis(4-methylbenzoyloxy)succinate mono-anion while the salt (II), 2C6H8N+·2C20H17O8−·5H2O, consists of a pair of 4-methylpyridinium cations and 2,3-bis(4-methylbenzoyloxy)succinate mono-anions and five water molecules of solvation in the asymmetric unit. In (I), the dihedral angle between the aromatic rings of the anion is 40.41 (15)°, comparing with 43.0 (3) and 85.7 (2)° in the conformationally dissimilar anion molecules in (II). The pyridine ring of the cation in (I) is inclined at 23.64 (16) and 42.69 (17)° to the two benzene moieties of the anion. In (II), these comparative values are 4.7 (3), 43.5 (3)° and 43.5 (3), 73.1 (3)° for the two associated cation and anion pairs. The crystal packing of (I) is stabilized by inter-ionic N—H...O, O—H...O and C—H...O hydrogen bonds as well as weak C—H...π interactions, linking the ions into infinite chains along [100]. In the crystal packing of (II), the anions and cations are also linked by N—H...O and O—H...O hydrogen bonds involving also the water molecules, giving a two-dimensional network across (001). The crystal structure is also stabilized by weak C—H...O and C—H...π interactions.


Author(s):  
Ying Liang ◽  
Li-Qiao Shi ◽  
Zi-Wen Yang

In the title compound, C19H13ClF2N2O2, the conformation of the N—H bond in the amide segment isantito the C=O bond. The molecule is not planar, with dihedral angles between the central benzene ring and the outer benzene and pyridyl rings of 73.35 (7) and 81.26 (6)°, respectively. A weak intramolecular C—H...O hydrogen bond occurs. In the crystal, N—H...N, C—H...O and C—H...F hydrogen bonds lead to the formation of dimers. The N—H...N inversion dimers are linked by π–π contacts between adjacent pyridine rings [centroid–centroid = 3.8541 (12) Å] and C—H...π interactions. These contacts combine to stack the molecules along theaaxis.


Author(s):  
Qi-Di Zhong ◽  
Sheng-Quan Hu ◽  
Hong Yan

In the title compound, C13H12N2O2(I), the mean planes of the pyrrole and benzyl rings are approximately perpendicular, forming a dihedral angle of 87.07 (4) °. There is an intramolecular N—H...O hydrogen bond forming an S(7) ring motif. In the crystal, molecules are linkedviaa pair of N—H...O hydrogen bonds forming inversion dimers. C—H...O hydrogen bonds link the dimers into chains along direction [10-1]. The chains are further linked by weak C—H...π interactions forming layers parallel to theacplane.


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