共查询到20条相似文献,搜索用时 15 毫秒
1.
Paul G. Jene James A. Ibers 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(6):705-707
The crystal structures of two elaborated‐porphyrin precursors have been determined. In the crystalline state, 2‐(1,3‐dithian‐2‐yl)benzaldehyde, C11H12OS2, has its dithiane ring in a slightly distorted chair conformation. The molecules pack in anti‐parallel chains. N‐{2‐[2‐(1,3‐Dioxan‐2‐yl)phenoxy]ethyl}phthalimide, C20H19NO5, is in a folded conformation. The dihedral angle between the phthalimide and phenyl planes is 80.07 (3)°. In the crystalline states, molecules stack on top of one another. 相似文献
2.
Stereoselective synthesis of 5‐[2‐(guanin‐9‐yl)‐ and 5‐[2‐(2‐aminopurin‐9‐yl)ethyl]‐2‐D‐ribo‐(1′,2′,3′,4′‐tetrahydroxybutyl)‐1,3‐dioxane, 2‐5, as potential prodrugs of penciclovir, has been accomplished in six steps from readily available 2,3,4,5‐tetra‐O‐acetyl‐aldehydo‐D‐ribose ( 6 ) and the 1,3‐diol 7 . It has been demonstrated that the use of boron trifluoride diethyl etherate (BF3·Et2O) in dichloromethane along with excess anhydrous copper(II) sulfate was crucial for the efficient formation of cyclic acetal 8 . In addition, the chromatographic separation of cis and trans isomers of the cyclic acetal at the bromide stage 10 was feasible, which was requisite for the successful stereoselective synthesis of the ribosyl derivatives 2–5 . 相似文献
3.
Peiwen Zhou James D. Fisher Richard J. Staples Ashwani Vij Nicholas R. Natale 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1146-1147
The title compound, C14H21NO5, possesses an isoxazolyl group in the axial position of the 1,3‐dioxanyl ring. The two rings are rotated about the bond joining them such that the two C(methyl)—C(dioxanyl)—C—C torsion angles are 92.1 (2) and ?84.1 (2)°. In this conformation, neither the methyl nor ethoxycarbonyl substituents on the isoxazole are presented towards the dioxanyl chair. 相似文献
4.
Burkhard Ziemer Lutz Grubert 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):e304-e304
The title molecule, C16H22O2, reveals Ci point symmetry in the crystal structure. The structure was disordered. The pyran ring is not planar; the O atom lies significantly out of the least‐squares plane (ten times the r.m.s. deviation of all six atoms). 相似文献
5.
6.
Guillaume Journot Reinhard Neier Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(3):o119-o122
In the title compounds, C11H18N2, (II), and C13H20N2O, (III), the pyrrolidine rings have twist conformations. Compound (II) crystallizes with two independent molecules (A and B) in the asymmetric unit. The mean planes of the pyrrole and pyrrolidine rings are inclined to one another by 89.99 (11) and 89.35 (10)° in molecules A and B, respectively. In (III), the amide derivative of (II), the same dihedral angle is much smaller, at only 13.42 (10)°. In the crystal structure of (II), the individual molecules are linked via N—H...N hydrogen bonds to form inversion dimers, each with an R22(12) graph‐set motif. In the crystal structure of (III), the molecules are linked via N—H...O hydrogen bonds to form inversion dimers with an R22(16) graph‐set motif. 相似文献
7.
Tomi Hsiao Robert M. Buchanan Mark S. Mashuta 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(4):o129-o130
The title compound, C17H18O3, prepared by microwave irradiation of benzophenone and dioxane, crystallizes in a racemic mixture that forms one‐dimensional chains via strong hydrogen bonding of the hydroxy group to the adjacent symmetry‐generated 1,4‐dioxan‐2‐yl group; the O—H...O distance is 1.99 (3) Å and the O—H...O angle is 160 (2)°. 相似文献
8.
Graldine Calvet Nicolas Blanchard Cyrille Kouklovsky Rgis Guillot 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(6):o365-o368
The crystal structures of 2,2‐dimethyl‐5‐nitroso‐1,3‐dioxan‐5‐yl benzoate, C13H15NO5, (I), 2,2‐dimethyl‐5‐nitroso‐1,3‐dioxan‐5‐yl 4‐chlorobenzoate, C13H14ClNO5, (II), and 5‐nitroso‐1,3‐dioxan‐5‐yl 4‐chlorobenzoate, C11H11NO5, (III), have been determined in order to gain insight into the conformational preference of α‐benzoyloxynitroso. Unfavourable 1,3‐diaxial interactions force (I) and (II) to crystallize in the 2,5 twist‐boat conformation, whereas compound (III), lacking this destabilizing interaction, crystallizes in the chair conformation. 相似文献
9.
W. Mark Barnett Russell G. Baughman Paula M. Secondo Charles J. Hermansen 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o565-o567
The crystal structures of the title compounds, alternatively called 2,2′‐(2,2′‐biimidazole‐1,1′‐diyl)diacetohydrazide monohydrate, C10H14N8O2·H2O, (I), and 3,3′‐(2,2′‐biimidazole‐1,1′‐diyl)dipropionohydrazide, C12H18N8O2, (II), respectively, have been determined. The molecules consist of half‐molecule asymmetric units related by a twofold rotation in (I) and by a center of inversion in (II). The imidazole rings of both molecules crystallize in a nearly coplanar fashion [dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively]. Both planar hydrazinocarbonylalkyl substituents are essentially planar and assume the E orientation. 相似文献
10.
Marciela Scarpellini Ademir Neves Adailton J. Bortoluzzi Antnio C. Joussef 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):356-358
In the title mononuclear complex, [Cu(C5H9N3)(C10H15N5)](ClO4)2, the CuII centre is surrounded by two N‐donor ligands, which impose a square‐pyramidal environment on the metal. The new tridentate ligand [2‐(imidazol‐4‐yl)ethyl][(1‐methylimidazol‐2‐yl)methyl]amine (HISMIMA) lies in the basal plane, while the histamine ligand occupies the apical and one of the basal positions around the CuII ion. 相似文献
11.
Hiroyuki Hosomi Shigeru Ohba Ken Ohmori Tetsuo Obitsu Yasuyuki Ogawa Yuichi Ishikawa Shosuke Yamamura Shigeru Nishiyama 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):e142-e143
The absolute configuration was determined for the title compound, (+)‐C18H24O3S, (I), which was prepared in a synthetic study on the natural products, bryostatins. 相似文献
12.
Alberto Insuasty Braulio Insuasty Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(1):74-76
The molecules of the title compound, C17H21N3OS, are characterized by a wide C—C—C angle at the methine C atom linking the aryl and thiazolidine rings, associated with a short repulsive intramolecular S...H contact between atoms in these two rings. A single piperidine–arene C—H...π hydrogen bond links pairs of molecules into centrosymmetric dimers. 相似文献
13.
Pierre Thury Martine Nierlich Bernardo Masci 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o14-o15
The title compound, 2,2′‐(3‐oxapentane‐1,5‐diyldioxy)diphenol, crystallizes as a methanol solvate, C16H18O5·CH4O. The methanol molecule, roughly perpendicular to the mean plane of the polyether molecule, is hydrogen bonded to the two polyether OH groups and to the central ether O atom. Possible C—H?π intermolecular interactions are present. 相似文献
14.
Michael J. Goldcamp Jeanette A. Krause Bauer Michael J. Baldwin 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e602-e603
Tris[2‐(benzoylamino)ethyl]amine [alternatively, N,N′,N′′‐(nitrilotriethyl)tribenzamide], C27H30N4O3, adopts a folded structure, forming a symmetrical cavity with an average depth of 7.3 Å and width ranging from 4.1–4.4 Å. The folded structure is a result of one intramolecular N—H?O hydrogen bond. A linear chain motif along the c axis best describes the extended intermolecular N—H?O hydrogen bonding. 相似文献
15.
Hang‐Ju Zhao Jian‐Ping Ma Qi‐Kui Liu Yu‐Bin Dong 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):716-720
A new 1,3,4‐oxadiazole‐containing bispyridyl ligand, namely 5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione (L), has been used to create the novel complexes tetranitratobis{μ‐5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione}zinc(II), [Zn2(NO3)4(C14H12N4OS)2], (I), and catena‐poly[[[dinitratocopper(II)]‐bis{μ‐5‐(pyridin‐4‐yl)‐3‐[2‐(pyridin‐4‐yl)ethyl]‐1,3,4‐oxadiazole‐2(3H)‐thione}] nitrate acetonitrile sesquisolvate dichloromethane sesquisolvate], {[Cu(NO3)(C14H12N4OS)2]NO3·1.5CH3CN·1.5CH2Cl2}n, (II). Compound (I) presents a distorted rectangular centrosymmetric Zn2L2 ring (dimensions 9.56 × 7.06 Å), where each ZnII centre lies in a {ZnN2O4} coordination environment. These binuclear zinc metallocycles are linked into a two‐dimensional network through nonclassical C—H...O hydrogen bonds. The resulting sheets lie parallel to the ac plane. Compound (II), which crystallizes as a nonmerohedral twin, is a coordination polymer with double chains of CuII centres linked by bridging L ligands, propagating parallel to the crystallographic a axis. The CuII centres adopt a distorted square‐pyramidal CuN4O coordination environment with apical O atoms. The chains in (II) are interlinked via two kinds of π–π stacking interactions along [01]. In addition, the structure of (II) contains channels parallel to the crystallographic a direction. The guest components in these channels consist of dichloromethane and acetonitrile solvent molecules and uncoordinated nitrate anions. 相似文献
16.
Pyrazolo[4,3‐d]pyrimidines, pyrazolo[4,3‐d]triazolino[4,3‐a]pyrimidines, 3‐(2‐thiazolyl)thiophenes, thiazolo[3,2‐a]pyridine and pyrazolo[1,5‐a]pyrimidines were synthesized from 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation and alternative synthesis route whenever possible. 相似文献
17.
Dennis R. Weller Henry H. Balfour Jr Heather E. Vezina 《Biomedical chromatography : BMC》2009,23(8):822-827
Acyclovir, ganciclovir and (R)‐9‐[4‐hydroxy‐2‐(hydroxymethyl)butyl]guanine are active in vitro against the Epstein–Barr virus (EBV) but their in vivo anti‐EBV activity is not well understood. We developed a novel, sensitive high‐performance liquid chromatography assay with ultraviolet detection for measuring acyclovir, ganciclovir and (R)‐9‐[4‐hydroxy‐2‐(hydroxymethyl)butyl]guanine in human plasma to identify quantitative relationships between in vitro anti‐EBV activity and therapeutic response. Characteristics of the assay include a low plasma volume (200 µL), perchloric acid protein precipitation, use of penciclovir as the internal standard, run times less than 8 min and a 50 ng/mL lower limit of quantification. The within‐ and between‐assay variability is 0.7–4.8 and 1.0–7.9%, respectively. Accuracy for all three drugs ranges from 89.5 to 106.4% for four quality controls (50, 100, 1000 and 10,000 ng/mL). This assay supports pharmacokinetic and pharmacodynamic studies of candidate anti‐EBV drugs in children and adults with EBV infections. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
18.
Simon J. Garden Marilza B. Corrêa Angelo C. Pinto James L. Wardell John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):o234-o238
In ethyl N‐[2‐(hydroxyacetyl)phenyl]carbamate, C11H13NO4, all of the non‐H atoms lie on a mirror plane in the space group Pnma; the molecules are linked into simple chains by a single C—H⋯O hydrogen bond. The molecules of ethyl N‐[2‐(hydroxyacetyl)‐4‐iodophenyl]carbamate, C11H12INO4, are linked into sheets by a combination of O—H⋯I and C—H⋯O hydrogen bonds and a dipolar I⋯O contact. Ethyl N‐[2‐(hydroxyacetyl)‐4‐methylphenyl]carbamate, C12H15NO4, crystallizes with Z′ = 2 in the space group P; pairs of molecules are weakly linked by an O—H⋯O hydrogen bond and these aggregates are linked into chains by two independent aromatic π–π stacking interactions. 相似文献
19.
Pavel Kurfürst Jaromír Marek Jn Van
o Jozef Csllei 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o494-o495
The title compound, C21H24FN2O2+·Cl−·C3H8O, is a potential drug designed as a hybrid compound with antihypertensive, antioxidant and β‐adrenolytic activity. The cation contains nearly planar benzofuran and fluorophenyl ring systems, as well as a piperazine ring adopting an almost perfect chair conformation. The benzofuran and piperazine moieties are connected by an ethyl chain, the moieties forming a dihedral angle of 163.12 (13)°. In the crystal structure, ions and propanol solvent molecules are linked via N—H⋯Cl and O—H⋯Cl bonds into linear (010) chains. 相似文献
20.
Jana Sopkov‐de Oliveira Santos Alexandre Bouillon Jean‐Charles Lancelot Sylvain Rault 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o582-o584
The crystal structure of the first reported non‐substituted N‐methyldioxazaborocane confirms that the presence of a methyl group attached to the N atom introduces an NB bond length that is longer than that in a simple dioxazaborocane ring. The presence of more N atoms in the vicinity of the B atom in the title compound [systematic name: 6a‐(6‐bromopyridin‐2‐yl)‐3a‐methyl‐2,3,4,5‐tetrahydro‐1,6‐dioxa‐3a‐aza‐6a‐borapentalene], C10H14BBrN2O2, does not modify significantly any structural parameter in the dioxazaborocane ring. On the other hand, a small asymmetry appears in the bond angles of the pyridine C atom next to the B atom. 相似文献