共查询到20条相似文献,搜索用时 15 毫秒
1.
Jana Sopkov‐de Oliveira Santos Valrie Collot Sylvain Rault 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1503-1504
The crystal structure of 7‐nitro‐1H‐indazole, C7H5N3O2, an inhibitor of nitric oxide synthase, shows the existence of an intramolecular hydrogen bond between an O atom of the nitro group and the NH group of the indazole ring. The crystal packing consists of intermolecular hydrogen bonding and indazole?indazole interactions. 相似文献
2.
Frdric Ooms Bernadette Norberg Emre M. Isin Neal Castagnoli Cornelis J. Van der Schyf Johan Wouters 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e474-e475
The title compound, C7H5N3O2, is an inhibitor of nitric oxide synthase and monoamine oxidase. The N1H tautomer crystallized as a dimer and adopts a planar conformation assisted by intramolecular hydrogen bonding. 相似文献
3.
Manuela Ramos Silva Vnia M. Moreira Cludia Cardoso Ana Matos Beja Jorge A. R. Salvador 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(4):o217-o219
The title compounds, 17‐(1H‐indazol‐1‐yl)androsta‐5,16‐dien‐3β‐ol, (I), and 17‐(2H‐indazol‐2‐yl)androsta‐5,16‐dien‐3β‐ol, (II), both C26H32N2O, have an indazole substituent at the C17 position. The six‐membered B ring of each compound assumes a half‐chair conformation. A twist of the steroid skeleton is observed and reproduced in quantum‐mechanical ab initio calculations of the isolated molecule using a molecular orbital Hartree–Fock method. In the 1H‐indazole derivative, (I), the molecules are joined in a head‐to‐head fashion via O—H...O hydrogen bonds, forming chains along the a axis. In the 2H‐indazole derivative, (II), the molecules are joined in a head‐to‐tail fashion with one of the N atoms of the indazole ring system acting as the acceptor. The hydrogen‐bond pattern consists of zigzag chains running along the b axis. Substituted steroids have proven to be effective in inhibiting androgen biosynthesis through coordination of the Fe atoms of some enzymes, and this study shows that indazole‐substituted steroids adopt twisted conformations that restrict their intermolecular interactions. 相似文献
4.
María AngelesGarcía Concepcin Lpez RosaM. Claramunt Ahmed Kenz Marcel Pierrot Jos Elguero 《Helvetica chimica acta》2002,85(9):2763-2776
Two desmotropes, 3‐phenyl‐1H‐pyrazole ( 1a ) and 5‐phenyl‐1H‐pyrazole ( 1b ) have been isolated and the conditions for their interconversion established. The X‐ray structure of 1b has been determined (a=10.862(1), b=5.7620(5), c=12.927(2) Å, β=111.435(2)°, space group P21/c), and both tautomers 1a and 1b were characterized by NMR in the solid state (13C‐ and 15N‐CPMAS). In the case of 3‐phenyl‐1H‐indazole ( 2a ), two concomitant polymorphs have been analyzed by X‐ray crystallography, and their NMR spectral properties were determined. The low‐melting‐point polymorph, at 106.7°, contains three molecules in the asymmetric unit (a=41.086(1), b=7.3860(2), c=23.391(1) Å, β=117.697(1)°, space group C2/c) and the high‐melting‐point one, 115.3°, six molecules (a=13.7818(4), b=13.7976(5), c=18.9445(5) Å, α=94.300(3), β=95.131(3), γ=119.428(3)°, space group P‐1). Here, too, it has been experimentally determined how to transform one form into the other. Density‐functional‐theory calculations at the B3LYP/6‐31G** level have been performed in both examples to rationalize the stability of the different tautomers. 相似文献
5.
Kiran S. Hon Hemantkumar N. Akolkar Bhausaheb K. Karale 《Journal of heterocyclic chemistry》2019,56(6):1780-1786
A series of novel 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles was synthesized in three steps from 5‐(1‐methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones. 5‐(1‐Methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones were converted into 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles upon methylation followed by treatment with aq. KMnO4. The reaction of 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles with Raney nickel resulted in desulphonylation to afford corresponding 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles. All the new synthesized compounds were characterized by spectral techniques. 相似文献
6.
Reddeppareddy Dandu Ming Tao Kurt A. Josef Edward R. Bacon Robert L. Hudkins 《Journal of heterocyclic chemistry》2007,44(2):437-440
A regiospecific approach to each N‐methyl‐5‐(1H‐indol‐2‐yl)‐6,7‐dihydro‐2H‐indazole isomer is reported. The 1‐methyl isomer 1 was prepared from 5‐bromo‐1‐methyl‐6,7‐dihydro‐1H‐indazole 3 and indole‐2‐boronate 5 by palladium catalyzed Suzuki coupling. The 2‐methyl regioisomer 2 was synthesized via addition of lithium (1‐carboxylato‐1H‐indole‐2‐yl)lithium 6 with 2‐methyl‐2,4,6,7‐tetrahydro‐indazol‐5‐one 8 followed by acid catalyzed dehydration. 相似文献
7.
8.
David J. Nielsen Claudio Pettinari Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o542-o544
Low‐temperature studies of the simple variously substituted imidazole types 4‐phenyl‐1H‐imidazole, C9H8N2, 1‐benzyl‐1H‐imidazole, C10H10N2, and 1‐mesityl‐1H‐imidazole, C12H14N2, extend comparisons between parent imidazole species and their derivatives, the pronounced double‐bond localization opposite the substituted N atom common to simple neutral species being redistributed aromatically on protonation. 相似文献
9.
Lian Ee Khoo Yiqun Zhang Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):e350-e351
The title compound, C17H13NO4, exists as a planar molecule; adjacent molecules are linked by electrostatic C—H?O [C?O = 3.318 (4) and 3.455 (4) Å] interactions into a linear chain. 相似文献
10.
Jürgen Brüning Alexander Peters Jan W. Bats Martin U. Schmidt 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(1):o1-o4
Single crystals of the title compound, C9H10N3O3+·Cl−·H2O, were obtained by recrystallization from hydrochloric acid. The cations stack along the crystallographic a direction. The 2,3‐dioxo‐1,4‐dihydroquinoxaline group shows a significant deviation from planarity [r.m.s. deviation from the best plane = 0.063 (2) Å]. Hydrogen bonding links the cations, chloride anions and water molecules to form an extended three‐dimensional architecture. 相似文献
11.
Frank Seela Anup M. Jawalekar Henning Eickmeier 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o387-o389
In the title compound, C12H13N3O5, the conformation of the glycosylic bond is anti [torsion angle = −105.3 (2)°]. The 2′‐deoxyribofuranose moiety adopts an S‐type sugar pucker and the orientation of the exocyclic C—C bond is −sc (trans). 相似文献
12.
Tian‐Zhu Zhang Chun‐Yan Wei Guo‐Hai Xu Se‐Won Park 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(2):o86-o88
The title compound, daphnoretin, C19H12O7, was isolated from the leaves of Stellera chamaejasme L. Two independent molecules are present in the asymmetric unit, with similar conformations. Each of the independent molecules is composed of two chromene systems connected by an ether bridge. The dihedral angles between the mean planes of the two chromene systems are 86.9 (2) and 81.9 (3)°. Molecules form chains via hydrogen bonds and adjacent chains are parallel to each other. 相似文献
13.
Yasushi Kai Jun Sakamoto Takashi Nakagawa Nobuko Kanehisa Masahiro Katsura 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e596-e597
In the title compound, C14H10N4, all the atoms are close to being coplanar (r.m.s. deviation 0.0098 Å) except for the imino H atoms. The molecule forms a one‐dimensional chain through intermolecular N—H?N hydrogen bonds. 相似文献
14.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(2):91-96
Subtle modifications of N‐donor ligands can result in complexes with very different compositions and architectures. In the complex catena‐poly[[bis{1‐[(1H‐benzotriazol‐1‐yl)methyl]‐1H‐imidazole‐κN 3}copper(II)]‐μ‐benzene‐1,3‐dicarboxylato‐κ3O 1,O 1′:O 3], {[Cu(C8H4O4)(C10H9N5)2(H2O)]·2H2O}n , each CuII ion is six‐coordinated by two N atoms from two crystallographically independent 1‐[(1H‐benzotriazol‐1‐yl)methyl]‐1H‐imidazole (bmi) ligands, by three O atoms from two symmetry‐related benzene‐1,3‐dicarboxylate (bdic2−) ligands and by one water molecule, leading to a distorted CuN2O4 octahedral coordination environment. The CuII ions are connected by bridging bdic2− anions to generate a one‐dimensional chain. The bmi ligands coordinate to the CuII ions in monodentate modes and are pendant on opposite sides of the main chain. In the crystal, the chains are linked by O—H…O and O—H…N hydrogen bonds, as well as by π–π interactions, into a three‐dimensional network. A thermogravimetric analysis was carried out and the fluorescence behaviour of the complex was also investigated. 相似文献
15.
Ftima C. Teixeira Carla Lucas M. Joo M. Curto Antnio P. S. Teixeira M. Teresa Duarte Vnia Andr 《Heteroatom Chemistry》2016,27(1):3-11
Novel tetraethyl ethylene‐1,1‐bisphosphonate esters derived from 1H‐indazole, 1H‐pyrazolo[3,4‐b]pyridine, and 1H‐pyrazolo[3,4‐b]quinoline were synthesized by a Michael addition reaction of tetraethyl ethylidene‐1,1‐bisphosphonate with the corresponding heterocycle, using conventional heating and microwave‐assisted methods. The microwave‐assisted method provides shorter reaction times and better yields. The hydrolysis of bisphosphonates afforded the corresponding bisphosphonic acids or salt, using concentrated hydrochloric acid or TMSBr/collidine, respectively. All new compounds were fully characterized, and their structures were assigned using 1H, 31P, and 13C NMR and IR spectroscopies and mass spectrometry. The molecular structure of compound 6 was confirmed by X‐ray diffraction studies. 相似文献
16.
Heng‐Shan Dong Yan‐Fei Wang Guo‐Liang Shen Bin Quan Wang‐Jun Dong 《Journal of heterocyclic chemistry》2012,49(1):149-153
Some new compounds (E)‐3‐aryl‐1‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐prop‐2‐en‐1‐ones 5a–e were prepared by 1‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐ethanone and various aromatic aldehydes. Then one pot reaction was happened by compounds 5a–e with hydrazine hydrate in acetic acid or propionic acid, respectively, to give the title compounds 1acyl‐5‐aryl‐3‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐4,5‐dihydro‐1H‐pyrazoles 6a–i . All structures were established by MS, IR, CHN, 1H‐NMR and 13C‐NMR spectral data. J. Heterocyclic Chem., (2012). 相似文献
17.
Shimazawa R Sano H Tanatani A Miyachi H Hashimoto Y 《Chemical & pharmaceutical bulletin》2004,52(4):498-499
Thalidomide has been found to exhibit weak nitric oxide synthase (NOS)-inhibitory activity. Structural development studies of thalidomide showed that some N-2,6-dimethylphenylhomophthalimide analogs possess NOS-inhibiting activity. 相似文献
18.
A novel conversion of 2, 4‐diaryl‐2, 3‐dihydro‐1 H‐1, 5‐benzodiazepins into 2, 4‐diaryl‐3 H‐1, 5‐benzodiazepines by the reaction with m‐chloroperbenzoic acid (MCPBA) was reported. 相似文献
19.
Lijuan J. Wang Margaret L. Grapperhaus Barnett S. Pitzele Timothy J. Hagen Kam F. Fok Jeffrey A. Scholten Dale P. Spangler Mihaly V. Toth Gina M. Jerome William M. Moore Pamela T. Manning James A. Sikorski 《Heteroatom Chemistry》2002,13(1):77-83
The efficient syntheses of two new types of conformationally constrained S‐[2‐[(1‐iminoethyl)amino]ethyl]homocysteine derivatives, 1‐amino‐3‐[2[(1‐iminoethyl)amino]ethylthio]cyclobutane carboxylic Acid ( 5 ) and (4S)‐4‐[[2‐[(1‐Iminoethyl)amino]ethyl]thio]‐L‐proline ( 6 ), are reported. These molecules represent the first attempts to probe conformational constraint near the α‐amino acid moiety of known homocysteine‐based inhibitors of nitric oxide synthase. Targets 5 and 6 were evaluated as potential inhibitors of the three human isoforms of nitric oxide synthase. © 2002 John Wiley & Sons, Inc. Heteroatom Chem 13:77–83, 2002; DOI 10.1002/hc.1109 相似文献
20.
Saifidin Safarov Muhamacho Ahmadovich Kukaniev Heinz Kolshorn Herbert Meier 《Journal of heterocyclic chemistry》2005,42(6):1105-1109
2‐Amino substituted 7H‐1,3,4‐thiadiazolo[3,2‐α]pyrimidin‐7‐ones 11a‐e were prepared by the reaction of 2‐bromo‐5‐amino‐1,3,4‐thiadiazole ( 1b ) and diketene ( 8 ), subsequent cyclocondensation ( 9b → 3b ) and displacement of the bromo substituents by the reaction with primary or secondary amines ( 3b → 11a‐e ). The hydrogen atom 6‐H in the heterobicycle 3b is replaced by a Cl or Br atom in the transformation of 3b → 14a,b. The 2‐bromo‐6‐chloro compound 14a reacts chemoselectively in the 2‐position with dimethylamine ( 14a → 15 ). The structure elucidations are based on one‐ and two‐dimensional NMR techniques including a heteronuclear NOE measurement. 相似文献