Crystal and molecular structure of heptacyclo [9,6,1,14,7,114,17,02,10,03,8,01,13]-eicosa-3(8),5,12,15-tetrene-9, 18-dione

The title compound C₂₀H₁₆O₂ crystallizes in the monoclinic space group P 2₁ witha=6.0310(5)Å,b=13.9396(6)Å,c=8.5560(5)Å, =100.354(8)°,V=770.60(8)ų, andZ=2. The crystal structure has been solved by vector-search methods and refined by fullmatrix least-squares toR=0.05 for 4788 reflections (1>2(1)). The title compound has been prepared in the course of a study on cyclopentanoid natural products.     

The crystal and molecular structure of 6,8,15,16b,16c,17-hexahydro-16b,16c-diphenyl-7H,16H-6a,7a,15a,16a-tetraazanaphtho[5,6]azulano[2,1,8-ij]naptho[f]azulene-7,16-dione

The crystal and molecular structure of a clip containing molecule is described. The structure was solved by vector search methods and refined by least squares methods toR _l=0.0768 [I>2(I)]. Crystal data: C₄₀H₃₀N₄O₂·HCCl₃, triclinic, space group ,a=9.302(2),b=12.981(2),c=15.765(2)Å, =65.91(2)°, =76.40(2)°, =80.15(1)°,V=1682.9(4)ų, Z=2.     

Crystal and molecular structure of 6-0-acetylgrayanotoxin III

The crystal and molecular structure of a grayanotoxin III derivative, 6-0-acetylgrayanotoxin III is presented. The crystal is orthorhombic, space group P2₁2₁2₁, witha=15.582(3),b=21.304(3),c=6.339(3)Å,V=2104(1) ų Z=4. The structure was solved by direct methods and refined by full matrix least-squares methods to a finalR=0.047 for 1763 independent reflections withF ₀>3 (F ₀) The molecule is based on a tetracyclic structure consisting of two five-membered, one six-membered, and one seven-membered ring with various conformations.     

Crystal and molecular structure of (2R,3R)-2-exo-((1R)-1-hydroxy-2-methyl-propyl)-3-exo-hydroxymethyl-bicyclo[2.2.1]-hept-5-ene,C12H20O2

The stereogeometry of the title compound which was prepared by a stereoselective addition reaction, has been proved by an X-ray diffraction analysis. Crystal data: monoclinic, P2₁,a=10.495(16),b=8.392(16),c=13.209(20) Å, =93.80(8),Z=4. The crystal structure has been solved by vector search methods and refined toR=0.05 for 782 observed reflections.     

Crystal and molecular structure of 10,20-epoxy-grayanotoxin-II

The photooxidation with HgO in benzene and the hydrolysis with 2%-KOH in methanol of the grayanotoxin (GTX) derivative (4) gave a 10,20-epoxy-grayanotoxin-II(5). The crystal structure of (5) has been determined by X-ray diffraction at room temperature. The crystal is monoclinic, space group P2₁, with a = 14.248(10) Å, b = 6.670(10) Å, c = 9.990(10) Å, = 105.507(8)°, V = 914.9(2) ų, Z = 2. The structure was solved by direct methods and refined by full-matrix least squares methods to a final R1 = 0.046 (wR2 = 0.0833) for 1161 independent reflections. The molecule has a pentacyclic structure consisting of two five-membered, one six-membered, one seven-membered, and one three-membered rings. The three-membered ring is connected with the seven-membered ring by spiro-type bond.     

Crystal structure oftrans-tetrachlorobis[2-(2-1H-imidazolyl)-1H-imidazolium]cadmium(II), [Cd(H3biim)2Cl4]

The reaction between cadmium(II) chloride and 2,2'-bi-1H-imidazole (H₂biim) in an acidic solution affords [Cd(H₃biim)₂Cl₄] (H₃biim=2-(2-1H-imidazolyl)-1H-imidazolium) in 63% yield. The compound crystallizes in the triclinic space groupP1, wherea=8.072(2),b=8.100(2),c=8.593(2) Å, =75.89(2), =62.94(2), =63.29(1)°,V=446.4(2) ų, andZ=1. The central Cd atom exhibits an octahedral geometry composed of a Cl₄N₂ core. The Cd-N bond distance is 2.392(2) Å. Cd–Cl distances are 2.5919(9) and 2.671(1) Å.     

Synthesis and structure determination of 7a-Aza-B-homostigmast-5-eno [7a, 7-d] tetrazole-3β-yl chloride (C29H47N4Cl)

7a-Aza-B-homostigmast-5-eno [7a, 7-d] tetrazole-3β-yl chloride (C₂₉H₄₇N₄Cl) was synthesized for its crystallographic analysis and to investigate the role of intra- and intermolecular interactions in steroids. It crystallizes in the monoclinic space group C2 with unit cell parameters: a = 38.481(2), b = 6.661(3), c = 11.111 (6) ?, β = 94.49 (4)^o; λ( MoKα) = 0.71069 ?, V = 2839(2) ?³, and Z = 4. The structure has been solved by direct methods using X-ray diffraction techniques. The final reliability index for the computed structure is 0.0597 for 1252 observed reflections. Except the five-membered ring, all other rings of the steroid nucleus exist in non-planar conformations. The structure is stabilized by C–H···N intermolecular interaction.Supplementary material CCDC-267926 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.an.uk/uk/conts/retrieving.html or from the Cambridge Crystallographic Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, United Kingdom; Fax: $+$44(0) 1223-336033; e-mail: deposit@ccdc.cam.ac.uk.     

Crystal structure of the molecular adduct of 5-mono[(4-nitrophenyl)azo]-25,26,27,28-tetrahydroxycalix[4]arene with chloroform (1:1)

The crystal structure of the molecular adduct of 5-mono[(4-nitrophenyl)azo]-25,26,27,28-tetrahydroxycalix[4]arene (2) with chloroform (C₃₄H₂₇N₃O₆ CHCl₃) was determined by X-ray crystallographic analysis. It was found to possess a monoclinic space group P2(1)/n, with a = 15.9306(13) Å, b = 10.6293(9) Å, c = 20.3194(17) Å, = 110.480(2)° and D_calc = 1.428 Mg/m³ for _Z = 4. Crystal data indicated that the calix[4]arene moiety of 2 exists in a distorted-cone conformation with intramolecular hydrogen bonds.     

Crystal and molecular structure of 1-vinyl-3-methyl-imidazolium iodide,C6H9N2I

The title compound crystallizes with two independent molecules in the unit cell. The two molecules arecis-trans isomers. Crystal data: orthorhombic, P2₁2₁2₁,a=7.0417(6),b=9.5341(9),c=25.411(2) Å,Z=8. The crystal structure has been solved by automated Patterson methods and refined toR=0.024 for 1843 observed reflections.     

Synthesis and Crystal Structure of [2-(4-chlorobenzoyloxy)-5-methylphenyl]-(4-methylphenyl)methanone

[2-(4-Chlorobenzoyloxy)-5-methylphenyl]-(4-methylphenyl)methanone was synthesized and characterized by spectroscopic and X-ray diffraction methods. The molecule crystallizes in the monoclinic space group P2₁/c with cell parameters a = 13.7530(19) Å, b = 10.0560(19) Å, c = 13.469(3) Å, β = 100.630(7)° and Z = 4. There is a large discrepancy between the carbonyl group bond lengths of ketone and the ester. The structure exhibits intermolecular hydrogen bonds of the type C–H···O.     

Crystal structure of a cyclobutane derivative: 4,8-dibromo-3,7-diketo-3, 4,4a,4b,7,8,8a,8b-octahydrodibenzo- [a,g] -biphenylene

The crystal structure of a cyclobutane derivative, 4,8-dibromo-3,7-diketo-3,4,4a,4b,7,8,8a,8b-octahydrodibenzo-[a,g]-biphenylene (C₂₀H₁₄O₂Br₂), has been determined from 1614 intensities collected with a four-circle diffractometer and refined by three-dimensional least-squares techniques. The crystals are monoclinic, space groupP2₁/c, with four molecules in a unit cell of dimensionsa = 10·863 ± 0·006,b = 21·060 ± 0·011,c = 7·772 ± 0·005 Å and β = 105·33 ± 0·04 °. The cyclobutane ring was found to have a bent configuration with a dihedral angle of 157 °.     

Crystal and molecular structure of 5-carbamyl-5H-dibenzo[b,f] azepine

The structure of the title compound has been determined by direct methods from diffractometer data, and refined by full-matrix least squares. Crystals are monoclinicP2₁/n,a=7.534(1),b=11.150(2),c=13.917(3) Å,=92.94(4)°,Z=4,D _x=1.34 (3) g cm^–3,R=0.084 for 1259 observed reflections. The azepine ring has a boat conformation. The fused benzene rings are planar. Molecules are packed as hydrogen-bonded dimers through the carboxamide groups. The atomic charge distribution over the fused ring system is approximately symmetrical.     

Crystal and molecular structure of (2E,4S,10R)-4-hydroxy-2-undecen-10-olide (nor-patulolide C), C11H18O3

The stereogeometry and absolute configuration of the title compound has been proved by an X-ray diffraction analysis. Crystal data: monoclinic, P2₁,a=7.7976(2),b=7.8288(2),c=8.9791(4) Å, =90.331(4)^o, Z=2. The crystal structure has been solved by vector search methods and refined toR=0.042 for 1798 observed reflections.     

Synthesis,Characterization, Crystal and Molecular Structure Analysis of 2,6-Dimethyl-3-acetyl-5-carbomethoxy-4-(3-nitrophenyl)-1,4-dihydropyridine

Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5), respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2₁/c with cell parameters a = 12.860(2) ?, b = 7.4950(6) ?, c = 16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C4. The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C3 and C5 are oriented in −antiperiplanar and +synperiplanar conformations, respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O. Index Abstract  A novel unsymmetrical dihydropyridine, possessing carboxymethyl and carbomethoxy groups at C(3) and C(5) respectively, has been produced using a modified Hantzsch synthesis, under solvent free conditions, in a domestic microwave oven. The product obtained was characterized by spectroscipic techniques and finally confirmed by X-ray diffraction studies. The title compound C₁₇H₁₈N₂O₅ crystallizes in the monoclinic system in the space group P2_1/c with cell parameters a  =  12.860(2) ?, b  =  7.4950(6) ?, c  =  16.734(3) ?, β = 94.436(3)°, Z = 4 and V = 1608.1(4) ?³. The 1,4-dihydropyridine ring in the structure is in a flattened boat conformation. The molecule possesses a chiral center at C(4). The 3-nitrophenyl ring is nearly orthogonal to the 1,4-dihydropyridine ring. The carbonyl groups at C(3) and C(5) are oriented in −antiperiplanar and +synperiplanar conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O and C–H···O.

Crystal structure of 3-pheny1-5-chloro-7-bromoisoxazolo[4,5-d]pyrimidine

The crystal and molecular structure of 3-phenyl-5-chloro-7-bromoisoxazolo-[4,5-d] pyrimidine, C₁₁H₅BrClN₃O, has been determined by X-ray techniques, and refined by Fourier and least-squares methods toR = 0·102 for 689 observed reflexions. The compound crystallizes in the orthorombic system:a = 15·72(4),b = 10·65(3),c = 6·72(3) Å,Z = 4, space groupPnam. The molecules lie on mirror planes, and all interatomic distances and angles within the molecule have reasonable values.Close molecular packing exists in layers (corresponding to crystallographic mirror planes) stacked normal toc.     

Crystal and molecular structure of 1-chlorobenz[a]phenazine-7N-oxide

Crystals of 1-chlorobenz[a]phenazine-7N-oxide, C₁₆H₉N₂OCl, are orthorhombic,a =15·04,b = 3·91,c = 20·50 Å,Z = 4, space groupPna2₁. The crystal structure has been determined from two- and three-dimensional X-ray photographic data and refined by Fourier and least-squares methods toR = 0·095 for 715 observed reflexions. The molecule is slightly non-planar. Bond lengths and angles compare well with those of other molecules. Close molecular packing is given by layers of molecules parallel to (001) plane.We are grateful to Professor V. Riganti for assistance with the data collection.     

Structure of 4,6-dimethylisothiazolo[5,4-b]pyridin-3(2H)-one and its 2-[4-(2-methylphenyl) piperazin-1-ylmethyl] derivative

The crystal and molecular structures of 4,6-dimethylisothiazolo[5,4-b]pyridin-3(2H)-one, C₈H₈N₂OS, 1, and its 2-[4-(2-methylphenyl)piperazin-1-ylmethyl] derivative, C₂₀H₂₄N₄OS, 2c, are described. These compounds crystallize in the monoclinic system in the space group P2 ₁/c. The cell constants for compound 1 are a = 5.049(1), b = 14.897(1), c = 11.330(1) Å, = 98.07(1)°, Z = 4, T = 293 K, and D _cal = 1.419 g cm^–3, and for compound 2c are a = 15.525(1), b = 12.021(1), c = 10.911(1) Å, = 106.42(1)°, Z = 4, T = 293 K, and D _cal = 1.253 g cm^–3 The structures were solved by direct methods and refined to R values of 0.0411 and 0.0380 for 1640 and 3504 reflections for 1 and 2c, respectively. The analysis of the geometry and difference electron density map reveal that the dimethylisothiazolopyridine 1 exists in the amino tautomeric form in the crystalline state. The conformation of the o-methylphenylpiperazine part of the molecule 2c strongly depends on the substituents effect in the phenyl ring and is very similar to those observed in crystals for other investigated arylopiperazine derivatives of the isothiazolopyridine.     

Crystal and molecular structure of 5-ethoxy-4-methylene-exo-10-oxatricyclo[5.2.1.02,6]-deca-8-ene-3-ol,C12H16O3

The structure of the title compound, C₁₂H₁₆O₃, was determined by X-rays.M _r =208.26, triclinic, space groupP¯1,a=7.802(2),b=8.449(2),c=9.069(1) Å,=90.79(1)°,=105.57(1)°, =106.07(1)°,Z=2,D _x =1.26 Mg m^–3; MoK radiation (graphite crystal monochromator, =0.71069 Å),(MoK)=0.96 cm^–1,T=290 K. Final conventionalR-factor=0.046,R _w =0.067 for 3009 observed reflections and 184 variables. The structure was solved using Patterson methods andDirdif, and the resulting all cis-endo configuration of the alcohol group on C(3) and the ethoxy group on C(5) shows that the stereochemistry of the metal-mediated addition reaction involved is solely determined by steric factors.