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1,4-Dihydroquinoxaline-2,3-dione–5-nitroisophthalic acid–water (1/1/1)
Ming-Feng Wang
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811020873
Abstract: The asymmetric unit of the title compound, C8H6N2O2·C8H5NO6·H2O, contains molecules of 1,4-dihydroquinoxaline-2,3-dione, 5-nitroisophthalic acid and a solvent water. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N—H...O and O—H...O hydrogen bonds.
5,5'-(1,4-Phenylenedimethylylidene)bis(1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione)  [PDF]
Abdullah Mohamed Asiri,Salman A. Khan
Molbank , 2010, DOI: 10.3390/M667
Abstract: A novel compound, 5,5'-(1,4-phenylenedimethylylidene)bis(1,3-diethyl-2-thioxodihydropyrimidine-4,6(1 H,5 H)-dione) ( 3) has been synthesized by condensation of 1,3-diethyl-2-thiobarbituric acid and terephthalaldehyde in anhydrous ethanol in the presence of pyridine. The structure of this compound was established by elemental analysis, IR, 1H-NMR, 13C-NMR and EI-MS spectral analysis.
2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho[2,3-e][1,4]dithiine-5,10-dione  [cached]
Miguel Angel Méndez-Rojas,Sylvain Bernès,Aarón Pérez-Benítez,María Fernanda Romero Zarazúa
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811039079
Abstract: The title molecule, C13H4O2S5, is folded by 47.83 (6)° along the S...S vector of the [1,4]dithiine six-membered ring, with the naphthoquinone and [1,3]dithiole-2-thione moieties being nearly planar [largest deviations from least-squares planes = 0.028 (2) and 0.016 (1) , respectively]. This boat conformation is close to that observed in the analogous compound [Mendez-Rojas et al. (2001). J. Chem. Crystallogr. 31, 17–28] including a 2-oxo group [folding angle: 42.3 (1)° at 213 (2) K]. Both compounds are indeed isomorphous, and the small difference in the folding angle probably results from the involvement of the thioxo group of the title compound in intermolecular S...S contacts [3.5761 (13) ]. In the crystal structure, molecules are stacked in the [100] direction, with dithiole rings making π–π interactions. In a stack, alternating short and long separations are observed between the centroids of dithiole rings, 3.5254 (17) and 4.7010 (18) .
Etude théorique de la cyclocondensation [4+2] de N,N-diméthyl- N-(3-oxo-cyclohexe-1-enyl)-formamidine avec les 9H-carbazole 1,4-dione substitués et activés par le brome
T Beguemsi, D Sissouma, L Bede, RB N'guessan, YT N'guessan
Afrique Science: Revue Internationale des Sciences et Technologie , 2007,
Abstract: Theoretical study of [4+2] cyclocondensation of N,N-dimethyl-N-(3-oxocyclohexe-1-enyl)-formamidine with substituted and bromo-activated 9Hcarbazole1,4-dione A theoretical study of hetero-Diels-Alder reaction between N,N-diméthyl-N-(3-oxocyclohexe-1-enyl)-formamidine (aza-diene) and substituted 9H-carbazole-1,4-dione. This reaction is regioselective and is an effective method for synthesizing calothrixin B and its analogues. The rich-electron substituted dienophiles permit to acces to the major adducts. The theoretical results are consistent with experience.
Hanane Benzeid,El Mokhtar Essassi,Nathalie Saffon,Bernard Garrigues
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809034266
Abstract: The compound, C15H16N2O2, features a pyrroline ring fused with a seven-membered diazepine ring; the latter system adopts a boat conformation (with the methine C atom as the prow and the two C atoms of the aromatic ring as the stern). A CH2–CH2 segment of the pyrroline ring is disordered over two positions in a 1:1 ratio.
Chao Ma,Zhen-Zhong Wang,Li Pan,Yu Tian
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536811052962
Abstract: The title compound, C12H11BrN2O2, was prepared by an intra-cyclization reaction of (S)-1-(5-bromo-2-nitrobenzyl)-5-oxopyrrolidine-2-carboxylic acid methyl ester in the presence of EtOH/Fe. The five-membered pyrrolidinone ring adopts an approximate envelope conformation, while the seven-membered diazepanone ring displays a twisted boat conformation. Intermolecular classical N—H...O hydrogen bonds and weak C—H...O interactions help to stabilize the crystal structure.
(11aS)-8-Hydroxy-7-methoxy-2,3,5,10,11,11a-hexahydro-1H-pyrrolo[2,1-c][1,4]benzodiazepine-3,11-dione  [cached]
Dong-Mei Zhao,Chao Ma,Yu Sha,Jing-Hong Liu
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536807066056
Abstract: The title chiral compound, C13H14N2O4, was prepared by an intracyclization reaction of methyl (S)-1-(4-hydroxy-5-methoxy-2-nitrobenzyl)-5-oxopyrrolidine-2-carboxylate in the presence of ethanol and iron. The five-membered substituted pyrrole ring adopts an approximate envelope conformation, while the seven-membered substituted diazepine ring displays a twist-boat conformation. Intermolecular O—H...O and N—H...O hydrogen bonding helps to stabilize the crystal structure.
Marc Weisser,Dieter Schollmeyer,Stefan Laufer
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811036233
Abstract: The mean plane of the pyrazolone ring [maximum deviation = 0.054 (1) ] of the title compound, C14H15N3O2, is oriented at a dihedral angle of 36.05 (7)° with respect to the phenyl ring. The methyl group is slightly disposed [distance = 0.864 (2) ] out of the mean plane of the pyrazolone ring to which it is attached.
1,4-Diphenylbutane-1,4-dione  [cached]
Zhigang Wang
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808038798
Abstract: The asymmetric unit of the title compound, C16H14O2, contains one half-molecule, located on a twofold rotation axis. In the molecule, the two benzene rings form a dihedral angle of 72.28 (2)°.
Mustafa Tombul,Adnan Bulut,Kutalm?? Güven,Orhan Büyükgüng?r
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808003218
Abstract: In the crystal structure of the title compound, [Fe2(C5H5)2(C14H12O2)], each carbonyl group is coplanar with the adjacent cyclopentadienyl ring, thus maximizing the π-orbital overlap and electronic interactions between the groups. In the crystal structure, there are inter- and intramolecular C—H...O contacts.
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