共查询到20条相似文献,搜索用时 31 毫秒
1.
Tarek Kassem Valrie Rolland Jean Martinez Marc Rolland 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):1037-1039
We present the crystal and molecular structure of two key compounds of a new synthesis strategy for isomers of natural (2S,3R,4S)‐4‐hydroxyisoleucines, 2,3,5,6,7,8‐hexahydro‐3‐(1‐hydroxy‐1‐methyl‐2‐oxopropyl)‐6,8‐methano‐7,7,8a‐trimethyl‐5H‐1,4‐benzoxazin‐2‐one, C16H23NO4, and 2,3,5,6,7,8‐hexahydro‐3‐(1‐methyl‐2‐oxopropyl)‐6,8‐methano‐7,7,8a‐trimethyl‐5H‐1,4‐benzoxazin‐2‐one, C16H23NO3. A new optically pure chiral oxazinone auxiliary derived from (1R,2R,5R)‐2‐hydroxypinan‐3‐one was used. 相似文献
2.
Qiguang Wang Liang Xie Jianjun Zhai 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):197-198
The crystal structure of tylophorine B (or 2,3,6‐trimethoxyphenanthro[9,10‐f]indolizidine) as the benzene solvate, C23H25NO3·C6H6, has been determined. The compound was isolated from albizzia julibrissin and this is the first definitive report of the steochemistry of tylophorine. 相似文献
3.
Raphaël Frdrick Bernadette Norberg Franois Durant Frederic Ooms Johan Wouters 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o623-o626
The structures of three compounds, namely 7‐methoxy‐2‐[3‐(trifluoromethyl)phenyl]‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C19H11F3N2O2, (Id), 6‐methoxy‐2‐[3‐(trifluoromethyl)phenyl]‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C19H11F3N2O2, (IId), and 2‐methyl‐6‐(4,4,4‐trifluorobutoxy)‐9H‐indeno[1,2‐c]pyridazin‐9‐one, C16H13F3N2O2, (IIf), which are potent reversible type‐B monoamine oxidase (MAO‐B) inhibitors, are presented and discussed. Compounds (Id) and (IId) crystallize in a nearly planar conformation. The crystal structures are stabilized by weak C—H⋯O hydrogen bonds. The packing is dominated by π–π stacking interactions between the heterocyclic central moieties of centrosymmetrically related molecules. In compound (IIf), the trifluoroethyl termination is almost perpendicular to the plane of the ring. 相似文献
4.
Daniel E. Lynch Ian McClenaghan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(1):o1-o5
The crystal structures of four trifluoromethylnitrobenzene analogues (CF3)C6H3(NO2)[C4H8N2]R (where C4H8N2 is piperazinyl and R is ethyl carboxylate, CO2C2H5, or phenyl, C6H5), have been determined, and their conformations and packing arrangements are compared. The four compounds are ethyl 4‐[4‐nitro‐2‐(trifluoromethyl)phenyl]piperazine‐1‐carboxylate, (I), and ethyl 4‐[2‐nitro‐4‐(trifluoromethyl)phenyl]piperazine‐1‐carboxylate, (II), both C14H16F3N3O4, and 1‐[4‐nitro‐2‐(trifluoromethyl)phenyl]‐4‐phenylpiperazine, (III), and 1‐[2‐nitro‐4‐(trifluoromethyl)phenyl]‐4‐phenylpiperazine, (IV), both C17H16F3N3O2. All molecules adopt a rod‐like conformation, while the asymmetric units of (II) and (IV) contain two unique molecules that pack as monodirectional pairs. All molecules pack with C—H⋯O/F close contacts to all but one of the O atoms and to five of the 18 F atoms. 相似文献
5.
R. Malathi S. S. Rajan G. Suresh G. N. Krishnakumari G. Gopalakrishnan 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(8):o416-o418
Samaderin B, or (1R,2S,5R,5aR,7aS,11S,11aS,11bR,14S)‐1,7,7a,11,11a,11b‐hexahydro‐1,11‐dihydroxy‐8,11a,14‐trimethyl‐2H‐5a,2,5‐(methanoxymetheno)naphth[1,2‐d]oxepine‐4,6,10(5H)‐trione, C19H22O7, and samaderin C, or (1R,2S,5R,5aR,7aS,10S,11S,11aS,11bR,14S)‐7,7a,10,11,11a,11b‐hexahydro‐1,10,11‐trihydroxy‐8,11a,14‐trimethyl‐2H‐5a,2,5‐(methanoxymetheno)naphth[1,2‐d]oxepine‐4,6(1H,5H)‐dione, C19H24O7, were isolated from the seed kernels of Samadera indica and were shown to exhibit antifeedant activity against Spodoptera litura third‐instar larvae. The replacement of the carbonyl group in samaderin B by a hydroxy group in samaderin C causes conformational changes at the substitution site, but the overall conformation is not affected; however, the compounds pack differently in the crystal lattice. 相似文献
6.
Jose G. Trujillo‐Ferrara Efrn V. García‐Bez Itzia I. Padilla‐Martínez Francisco J. Martínez‐Martínez Norberto Farfan‐García 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o427-o430
In exo‐2‐(3,5‐dioxo‐10‐oxa‐4‐azatricyclo[5.2.1.02,6]dec‐8‐en‐4‐yl)phenyl acetate, C16H13NO5, the plane of the acetoxy group lies almost perpendicular to that of the phenyl ring [dihedral angle = 89.8 (1)°], in contrast with the smaller deviations found in the para isomer exo‐4‐(3,5‐dioxo‐10‐oxa‐4‐azatricyclo[5.2.1.02,6]dec‐8‐en‐4‐yl)phenyl acetate, C16H13NO5, these being 63.6 (1) and 37.0 (1)° for the two crystallographically independent molecules. Irrespective of the position of the acetoxy group, both compounds pack through soft C—H⋯X (X is O or phenyl) interactions, forming interlinked centrosymmetric tetramers in the bc plane. 相似文献
7.
Sara K. Metcalf Elizabeth M. Holt 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1228-1231
Diethyl 4‐(2,5‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (I), diethyl 4‐(3,4‐dimethoxyphenyl)‐2,6‐dimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C21H27NO6, (II), and diethyl 2,6‐dimethyl‐4‐(3,4,5‐trimethoxyphenyl)‐1,4‐dihydropyridine‐3,5‐dicarboxylate, C22H29NO7, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐dihydropyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors. 相似文献
8.
Arthur Camerman Andrew Hempel Donald Mastropaolo Norman Camerman 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(7):o417-o419
In the crystal structure of 2‐acetamido‐N‐benzyl‐2‐(methoxyamino)acetamide (3L), C12H17N3O3, the 2‐acetylaminoacetamide moiety has a linearly extended conformation, with an interplanar angle between the two amide groups of 157.3 (1)°. In 2‐acetamido‐N‐benzyl‐2‐[methoxy(methyl)amino]acetamide (3N), C13H19N3O3, the planes of the two amide groups intersect at an angle of 126.4 (4)°, resulting in a chain that is slightly more bent. The replacement of the methoxyamino H atom of 3L with a methyl group to form 3N and concomitant loss of hydrogen bonding results in some positional/thermal disorder in the methoxy(methyl)amino group. In both structures, in addition to classical N—H⋯O hydrogen bonds, there are also weak non‐standard C—H⋯O hydrogen bonds. The hydrogen bonds and packing interactions result in planar hydrophilic and hydrophobic areas perpendicular to the c axis in 3L and parallel to the ab plane in the N‐methyl derivative. Stereochemical comparisons with phenytoin have identified two O atoms and a phenyl group as molecular features likely to be responsible for the anticonvulsant activities of these compounds. 相似文献
9.
Shi‐Ping Yang Xi‐Bin Yu Ji‐Guang Huang Han‐Hong Xu 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):o392-o393
The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetrahydro‐8,9‐dimethoxy‐2‐(1‐methylethenyl)‐[1]benzopyrano[3,4‐b]furo[2,3‐h][1]benzopyran‐6(6H)‐one oxime], C23H23NO6, confirms that the molecule has an approximately V‐shaped structure. One of the rings has a typical cyclohexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation. 相似文献
10.
Giuseppe Bruno Francesco Nicol Archimede Rotondo Francesco Foti Francesco Risitano Giovanni Grassi 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o879-o883
Conformational analyses and a structural comparison of the four spiro compounds 3‐bromo‐1,9‐diphenyl‐4‐p‐tolyl‐7‐oxa‐1,2,8‐triazaspiro[4.4]nona‐2,8‐dien‐6‐one, (I), C24H18BrN3O2, 3‐bromo‐4‐(4‐methoxyphenyl)‐1,9‐diphenyl‐7‐oxa‐1,2,8‐triazaspiro[4.4]nona‐2,8‐dien‐6‐one, (II), C24H18BrN3O3, 3‐bromo‐4‐(4‐chlorophenyl)‐1,7,9‐triphenyl‐1,2,7,8‐tetraazaspiro[4.4]nona‐2,8‐dien‐6‐one, (III), C29H20BrClN4O, and 3‐bromo‐1,7,9‐triphenyl‐4‐p‐tolyl‐1,2,7,8‐tetraazaspiro[4.4]nona‐2,8‐dien‐6‐one, (IV), C30H22.89Br1.11N4O, are presented. The molecular structures are rather similar, which is as expected since the compounds are all products of concerted 1,3‐dipolar attack on (Z)‐4‐arylidene oxazolone and pyrazolone derivatives. The observed conformations tend to favour extended π conjugation of the benzene rings and other π systems, as shown by a comparison of selected geometric parameters of the four structures. 相似文献
11.
Robert J. Hinkle Robert McDonald 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(2):o117-o121
The crystal structures of [(Z)‐2‐methylbut‐1‐en‐1‐yl][4‐(trifluoromethyl)phenyl]iodonium trifluoromethanesulfonate, C12H13F3I+·CF3O3S?, (I), (3,5‐dichlorophenyl)[(Z)‐2‐methylbut‐1‐en‐1‐yl]iodonium trifluoromethanesulfonate, C11H12Cl2I+·CF3O3S?, (II), and bis{[3,5‐bis(trifluoromethyl)phenyl][(Z)‐2‐methylbut‐1‐en‐1‐yl]iodonium} bis(trifluoromethanesulfonate) dichloromethane solvate, 2C13H12F6I+·2CF3O3S?·CH2Cl2, (III), are described. Neither simple acyclic β,β‐dialkyl‐substituted alkenyl(aryl)idonium salts nor a series containing electron‐deficient aryl rings have been described prior to this work. Compounds (I)–(III) were found to have distorted square‐planar geometries, with each I atom interacting with two trifluoromethanesulfonate counter‐ions. 相似文献
12.
Mason A. Wolak Robert C. Finn Randy S. Rarig Craig J. Thomas Robert P. Hammond Robert R. Birge Jon Zubieta Watson J. Lees 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):o389-o393
Fluorinated indolylfulgides are a class of photochromic organic compounds that meet many of the requirements for use as optical memory media and optical switches. The X‐ray crystal structures of a series of five photochromic fluorinated indolylfulgides have been determined, namely (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,2‐trifluoroethylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (trifluoromethylisopropylideneindolylfulgide), C19H16F3NO3, (I), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,3‐pentafluoropropylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (pentafluoroethylisopropylideneindolylfulgide), C20H16F5NO3, (II), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐heptafluorobutylidene]‐4‐(1‐methylethylidene)dihydrofuran‐2,5‐dione (heptafluoropropylisopropylideneindolylfulgide), C21H16F7NO3, (III), (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,2‐trifluoroethylidene]‐4‐(tricyclo[3.3.1.13,7]decylidene)dihydrofuran‐2,5‐dione (trifluoromethyladamantylideneindolylfulgide), C26H24F3NO3, (IV), and (3Z)‐3‐[1‐(1,2‐dimethyl‐1H‐indol‐3‐yl)‐2,2,3,3,4,4,4‐heptafluorobutylidene]‐4‐(tricyclo[3.3.1.13,7]decylidene)dihydrofuran‐2,5‐dione (heptafluoropropyladamantylideneindolylfulgide), C28H24F7NO3, (V). The photochromic property of fulgides is based on the photochemically allowed electrocyclic ring closure of a hexatriene system to form a cyclohexadiene. For each fulgide examined, the bond lengths within the hexatriene system alternate between short and long, as expected. Comparing the structures of the five fulgides with each other demonstrates no significant difference in bond lengths, bond angles or dihedral angles within the hexatriene systems. The distance between the bond‐forming C atoms at each end of the hexatriene system does vary. Correlations of structural properties with optical properties are addressed. 相似文献
13.
David J. Wiedenfeld Vladimir N. Nesterov Mark A. Minton David R. Glass 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(12):o700-o702
Bis(2,5‐dimethoxy‐4‐methylphenyl)methane, C19H24O4, (IIa), was obtained and characterized as a minor product from the reaction of toluhydroquinone dimethyl ether (1,4‐dimethoxy‐2‐methylbenzene) with N‐(hydroxymethyl)trifluoroacetamide. Similarly, bis(2,5‐dimethoxy‐3,4,6‐trimethylphenyl)methane, C23H32O4, (IIb), was prepared from the corresponding reaction of trimethylhydroquinone dimethyl ether (2,5‐dimethoxy‐1,3,4‐trimethylbenzene). The molecules of (IIa) and (IIb) each lie on a twofold axis passing through the methylene group. The dihedral angle between the planar phenyl rings is 73.4 (1)° in (IIa) and 77.9 (1)° in (IIb). The external bond angles around the bridging methylene group are 116.6 (2) and 117.3 (2)° for (IIa) and (IIb), respectively. In (IIa), the methoxy substituents lie in the plane of the ring and are conjugated with the aromatic system, whereas in (IIb), they are almost perpendicular to the phenyl ring and are positioned on opposite sides. 相似文献
14.
Andrew Hempel Norman Camerman Donald Mastropaolo Arthur Camerman 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1225-1227
The crystal structure of the title compound contains four 2,4‐diamino‐5‐methyl‐6‐[(3,4,5‐trimethoxyanilino)methyl]quinazoline molecules, two dimethyl sulfoxide molecules and three water molecules in the asymmetric unit, i.e. 4C19H23N5O3·2C2H6OS·3H2O. All four quinazoline molecules adopt trans,gauche conformations. An extensive hydrogen‐bond network involving N?N base‐pairing interactions, as well as the dimethyl sulfoxide and water molecules, stabilizes the crystal structure. 相似文献
15.
Seik Weng Ng S. Shanmuga Sundara Raj Hoong‐Kun Fun Ibrahim Abdul Razak James M. Hook 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):966-968
catena‐Poly[dicyclohexylammonium [tributyltin‐μ‐(4‐oxo‐4H‐pyran‐2,6‐dicarboxylato‐O2:O6)]], (C12H24N)[Sn(C7H2O6)(C4H9)3], consists of 4‐oxo‐4H‐pyran‐2,6‐dicarboxylato groups that axially link adjacent tributyltin units into a linear polyanionic chain. The ammonium counter‐ions surround the chain, and each cation forms a pair of hydrogen bonds to the double‐bond carbonyl O atoms of the same dianionic group. The chain propagates in a zigzag manner along the c axis of the monoclinic cell. In catena‐poly[methyl(phenyl)ammonium [tributyltin‐μ‐(pyridine‐2,6‐dicarboxylato‐O2:O6)]], (C7H10N)[Sn(C7H3NO4)(C4H9)3], the pyridine‐2,6‐dicarboxylato groups also link the tributyltin groups into a chain, but the hydrogen‐bonded chain propagates linearly on the ac face of the monoclinic cell. 相似文献
16.
Wojciech M. Wolf 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1112-1115
The conformations of the two approximately isomorphous structures 4′‐{[benzoyl(4‐chlorophenylhydrazono)methyl]sulfonyl}acetanilide, C22H18ClN3O4S, and 4′‐{[benzoyl(4‐methoxyphenylhydrazono)methyl]sulfonyl}acetanilide, C23H21N3O5S, are stabilized by resonance‐assisted intramolecular hydrogen bonds linking the hydrazone moieties and sulfonyl groups. The stronger bond is observed in the former compound. The difference in electronic properties between the Cl atom and the methoxy group is too small to significantly alter the non‐bonding interactions of the sulfonyl and β‐carbonyl groups. 相似文献
17.
Masood Parvez Kristin Braitenbach 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):1216-1217
The structure of {3‐[(4‐fluorophenyl)methyl]‐1H‐benzimidazol‐2‐ylidene}{1‐[2‐(4‐methoxyphenyl)ethyl]‐4‐piperidin‐1‐io}ammonium tetrachlorocuprate(II), (C28H33FN4O)[CuCl4], contains diprotonated cations of astemizole hydrogen bonded to three Cl atoms in two different CuCl42? anions, with Cl?N distances in the range 3.166 (4)–3.203 (4) Å. The geometry around copper is flattened tetrahedral with significantly different Cu—Cl distances which lie in the range 2.1968 (14)–2.2861 (12) Å. The phenylethyl C atoms of the (4‐methoxyphenyl)ethyl group are disordered indicating the presence of two conformers in the crystals. 相似文献
18.
Caroline Charlier Bernadette Norberg Laurence Goossens Jean‐Pierre Hnichart Franois Durant 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o648-o652
Three related compounds containing a pyrazole moiety with vicinal phenyl rings featuring a methylsulfonyl substituent are described, namely 3‐methyl‐1‐[4‐(methylsulfonyl)phenyl]‐5‐phenyl‐1H‐pyrazole, C17H16N2O2S, ethyl 1‐[4‐(methylsulfonyl)phenyl]‐5‐phenyl‐1H‐pyrazole‐3‐carboxylate, C19H18N2O4S, and 1‐[4‐(methylsulfonyl)phenyl]‐3‐[3‐(morpholino)phenoxymethyl]‐5‐phenyl‐1H‐pyrazole, C27H27N3O4S. The design of these compounds was based on celecoxib, a selective cyclooxygenase‐2 (COX‐2) inhibitor, in order to study the influence of various substituents on COX‐2 and 5‐lipoxygenase (5‐LOX) inhibition. 相似文献
19.
Michael Bolte Alexander Degen Stephan Rühl 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):446-451
We have determined the crystal structures of 2,2′‐(4‐fluorophenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C23H27FO4, (I), 2,2′‐(4‐chlorophenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C23H27ClO4, (II), 2,2′‐(4‐hydroxyphenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C23H28O5, (III), 2,2′‐(4‐methylphenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C24H30O4, (IV), 2,2′‐(4‐methoxyphenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C24H30O5, (V), and 2,2′‐(4‐N,N′‐dimethylaminophenyl)methylenebis(3‐hydroxy‐5,5‐dimethyl‐2‐cyclohexen‐1‐one), C25H33NO4, (VI). Structures (III) to (VI) of these bis‐dimedone derivatives show nearly the same packing pattern irrespective of the different substituent in the para position of the aromatic ring. However, (II) does not fit into this scheme, although the Cl atom is a substituent not too different from the others. The different packing of the fluoro compound, (I), can be explained by the fact that it crystallizes with two molecules in the asymmetric unit, which show a different conformation of the dimedone ring. On the other hand, (I) shows a similar packing pattern to bis(2‐hydroxy‐4,4‐dimethyl‐6‐oxo‐1‐cyclohexenyl)phenylmethane, a compound containing an aromatic ring without any substituent and with Z′ = 2. 相似文献
20.
Russell G. Baughman Daniel J. Brink Jill M. Butler Pamela R. New 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):528-531
The first single‐crystal studies of three bis‐transoid Cu–hydroxamate salts, bis(3‐methoxy‐4,N‐dimethylbenzohydroxamato‐O,O′)copper(II), [Cu(C10H12NO3)2], bis(4‐chloro‐N‐methylbenzohydroxamato‐O,O′)copper(II), [Cu(C8H7ClNO2)2], bis(N‐methyl‐3,5‐dinitrobenzohydroxamato‐O,O′)copper(II)–chloroform (1/2), [Cu(C8H6N3O6)2]·2CHCl3, are presented. The Cu atom in each of the title compounds sits at a center of inversion and displays a nearly square‐planar geometry with the hydroxamate‐O atoms connected to it in a syn configuration. The N atoms are in a transoid configuration. Each five‐membered Cu–hydroxamate ring is planar, thus providing evidence that a planar N atom is present in each ring. The phenyl groups are twisted with respect to the hydroxamate group by ~40–54°. The angular strain of the sp2 carbonyl oxygen is significant (~10° from ideal). 相似文献