Crystal Structures of Four Solvates of Lorazepam*: with EthanoI (A), Acetone (B), Dioxane (C), and Cyclohexanone (D)

X-ray structure analysis of four solvates of lorazepam with ethanol (A), acetone (B), dioxane (C) and cyclohexanone (D) is d~cribed. All four crystallize in the triclinic system, space group Pl, and with the lorazepam molecules of essentially the same conformation. As common in other benzodiazepines, the sevenmembered rings adopt a boat conformation. The four solvates have different kinds of hydrogen bonding. While in (A), (B) and (D) lorazepam molecules are interconnected either by N-H ... O (282 to 292 pm) or O-H .. ,O hydrogen bonds (289 pm) in (C) such bonding does not exist. The solvent molecules filI cavities in the crystal structures and are linked to the lorazepam molecules either by van der Waals interactions as in (A), (B) and (C) or by hydrogen bond of the O-H.,. O type of 281 pm in (D). The investigated structures are compared with other lorazepam derivatives and solvates previously described in the literature

Crystal Structures of Four Solvates of Lorazepam*: with EthanoI (A), Acetone (B), Dioxane (C), and Cyclohexanone (D)

X-ray structure analysis of four solvates of lorazepam with ethanol (A), acetone (B), dioxane (C) and cyclohexanone (D) is d~cribed. All four crystallize in the triclinic system, space group Pl, and with the lorazepam molecules of essentially the same conformation. As common in other benzodiazepines, the sevenmembered rings adopt a boat conformation. The four solvates have different kinds of hydrogen bonding. While in (A), (B) and (D) lorazepam molecules are interconnected either by N-H ... O (282 to 292 pm) or O-H .. ,O hydrogen bonds (289 pm) in (C) such bonding does not exist. The solvent molecules filI cavities in the crystal structures and are linked to the lorazepam molecules either by van der Waals interactions as in (A), (B) and (C) or by hydrogen bond of the O-H.,. O type of 281 pm in (D). The investigated structures are compared with other lorazepam derivatives and solvates previously described in the literature

A Folded Conformation of 1,4,8,11-Tetrathiacyclotetradecane in its Mercury Compound: l,4,8,11-Tetrathiacyclotetradecanedipicratomercury( II) Heminitromethane, [Hg(C10H20S4)· (C6H2N307)2] · 1/2CH3N02

The crystals of 1,4,8,11-tetrathiacyclotetradecanedipicratomercury( II) heminitromethane, [Hg(C10H20S4) · (CsH2Ns01h] · 1/2CHsN02, are triclinic, spcrce group Pl with a = 1.2794(6), b = 1.3108(5), c = = 1.0090(3) nm, a= 92.85(3) 0 , fJ = 107.67(3)0 , y = 94.54(4) 0 , V = 1.60236 nm3, and Z = 2. The structure was solved by the heavy atom method and refined by the least-squares method to R = 0.030 for the 7321 unique reflections. It consists of discrete, well separated molecules. Coordination of the mercury atom is a distorted octahedron with four sulfur atoms (Hg-S distances are 245.8(1), 251.9(1), 262 .. 9(2), and 305.0(2) pm) from the macrocycle and two oxygen moms (Hg-0 distances are 253.1(3) and 255.8(3) pm) from the two picrates. The macrocycle is folded so that three sulfur atoms with short Hg-S bonds are in an equatorial and the fourth in an apical position. The conformation of the coordinated macrocycle is compared to the conformation of cyclotetradecane at 116 K and to the conformation of the free crysta-lline macrocycle

Benzylidene-bis-(4-Hydroxycoumarin) and Benzopyrano- Coumarin Derivatives: Synthesis, 1H/13C-NMR Conformational and X-ray Crystal Structure Studies and In Vitro Antiviral Activity Evaluations

We report on the synthesis of 4-hydroxycoumarin dimers 1-15 bearing an aryl substituent on the central linker and fused benzopyranocoumarin derivatives 16-20 and on their in vitro broad anti-DNA and RNA virus activity evaluations. The chemical identities and structure of compounds 1-20 were deduced from their homo- and heteronuclear NMR measurements whereas the conformational properties of 5, 14 and 20 were assessed by the use of 1D difference NOE enhancements. Unequivocal proof of the stereostructure of compounds 7, 9, 16 and 18 was obtained by single crystal X-ray diffraction method. The X-ray crystal structure analysis revealed that two 4-hydroxycoumarin moieties in the 4-trifluoromethylphenyl- and 2-nitrophenyl derivatives (compounds 7 and 9, respectively) are intramolecularly hydrogen-bonded between hydroxyl and carbonyl oxygen atoms. Consequently, the compounds 7 and 9 adopt conformations in which two 4-hydroxycoumarin moieties are anti-disposed. Antiviral activity evaluation results indicated that the 4-bromobenzylidene derivative of bis-(4-hydroxycoumarin) (compound 3) possesses inhibitory activity against HSV-1 (KOS), HSV-2 (G), vaccinia virus and HSV-1 TK- KOS (ACVr) at a concentration of 9-12 mM and at a minimum cytotoxic concentration (MCC) greater than 20 M. Compounds 4-6, 8, and 20 were active against feline herpes virus (50% effective concentration, EC50 = 5-8.1 M), that is at a 4-7-fold lower concentration than the MCC

Complexes of Azithromycin with Some Divalent Metal Ions

The formation of 2 : 1 complexes of azithromycin with copperdl), zincdl), cobaltdl), nickel(II), magnesiumdl) and calciumdl) ions was examined. These compounds (2-7) showed the same in vitro biological potency as azithromycin (1). The complexes (3-7) are isostructural and different when compared with azithromycin-Cu(II)- complex. Copper(II)-complex (2) was most stable and selected for structure determination by X-ray crystallography. Some physical characteristics and analyses of the complexes are also presented

Merocyanine Isomers of Spiro[indolino-indolopyrans]: 1H and 13C NMRand X-ray Crystal Structure Study

The synthesis of stable merocyanine isomers 4 and 5 of the corresponding spiro[indolino-indolopyrans] is described. The structure of 4 and 5 was deduced on the basis of their lH and 13C NMR spectra. Geometrical data from X-ray structure analysis show that indolo and indolino rings in 4 are coplanar with the central diene bridge. The bond length shortening of the central single bond and the heterocyclic moieties indicate an electron delocalization over the whole molecule

New Acyclic Purine Nucleoside Analogues Containing Exocyclic Pyrrolo Moiety: Synthetic, NMR and X-ray Crystal Structure Studies

The synthesis of novel 6-(N-pyrrolyl)purine nucleoside analogues containing acyclic side chains attached to the purine ring at N-9 is described. The structures were determined by 1H and 13CNMR on the basis of chemical shifts, substituent induced shifts, C-H coupling constants and connectivity in the COSY,NOESY and HETCOR spectra. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the two 6-(N-pyrrolyl) purine rings involved in the skeleton of 6 are anti-disposed but not centrosymmetric with respect to the central aliphatic bridge

Crystal and Molecular Structure of 9-deoxo-9a-ethyl-9a-aza-9a-homoerythronolide A

The title compound is the 15-membered aglycone ring of the N-ethyl derivative of the new semisynthetic macrolide antibiotic 9-deoxo-9a-aza-9a- homoerythromycin A. Its molecular and crystal structure has been determined from the diffractometer X-ray intesity data and refined by the least-squares method to the reliability index R= 0.064. The crystals are orthorhombic, space group P2i2i2i, with cell parameters a = 17.784 (5), b = 22.009 (5), c = 13.675 (3) A. Although the molecular structure is similar to the analogous N-methyl derivative, as well as to other compounds with such 15-membered aglycone rings, the packing of molecules in the crystal structure is significantly different In the present structure, all hydroxyl-hydrogen atoms of the aglycones take part in the hydrogen bondings between neighbouring molecules forming helices around each screw diad axis. The helices are interconnected by an additional hydrogen bond

Merocyanine Isomers of Spiro[indolino-indolopyrans]: 1H and 13C NMRand X-ray Crystal Structure Study

The synthesis of stable merocyanine isomers 4 and 5 of the corresponding spiro[indolino-indolopyrans] is described. The structure of 4 and 5 was deduced on the basis of their lH and 13C NMR spectra. Geometrical data from X-ray structure analysis show that indolo and indolino rings in 4 are coplanar with the central diene bridge. The bond length shortening of the central single bond and the heterocyclic moieties indicate an electron delocalization over the whole molecule

New Acyclic Purine Nucleoside Analogues Containing Exocyclic Pyrrolo Moiety: Synthetic, NMR and X-ray Crystal Structure Studies

The synthesis of novel 6-(N-pyrrolyl)purine nucleoside analogues containing acyclic side chains attached to the purine ring at N-9 is described. The structures were determined by 1H and 13CNMR on the basis of chemical shifts, substituent induced shifts, C-H coupling constants and connectivity in the COSY,NOESY and HETCOR spectra. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the two 6-(N-pyrrolyl) purine rings involved in the skeleton of 6 are anti-disposed but not centrosymmetric with respect to the central aliphatic bridge