Hochrainer, A. & Wessely, F. (1966). Monatsh. Chem. 97, 1–9. Junek, H. & Sterk, H. (1968). Tetrahedron Lett. 9, 4309–4310. Kuhn, S. J. & Rae, I. D. (1971). Can. J. Chem. 49, 157–160. Kunz, F. J. & Polansky, O. (1969). Monatsh. Chem. 100, 95–105. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Melting points were uncorrected. NMR spectra were acquired with a Bruker Ultra Shield ( 1 H : 300 MHz) (University of AL-al-Bayt,Jordan). The chemical shifts were referenced to tetra methyl silane (TMS) as an internal standard. The elemental analysis were performed by using Euro Vector EA3000A (University of AL-al- Bayt,Jordan).
1994), as luminescent sensors (Duarte et al., 2011; Qin et al., 2015), solid-state lasers (Samuel & Turnbull, 2007), organic light-emitting diodes (Muller et al., 2003), organic field-effect transistors (Suponitsky et al., 2006; Oliveira et al., 2018) and many more. The spectroscopic properties of pull–push mol- ecules are related to the donor and acceptor strength in these molecules and to the length of the -bridge. Many such compounds have been studied, but not all of their crystal structures have been reported. Such compounds are important for their NLO properties (Andreu et al., 2003; Raimundo et al., 2002). Herein, we report on the crystal structures, syntheses and spectroscopic and electrochemical properties of the title donor–-bridge–acceptor structures, ID and ID. The structures of three polymorphs of ID have been reported previously; the -polymorph (Magomedova & Zvonkova, 1978), the -polymorph (Magomedova & Zvonkova, 1980) and the -polymorph (Magomedova, Neigauz et al., 1980). We have repeated the structural study of ID in order to establish exactly which polymorph we obtained. It was then characterized by spectroscopic and electrochemical measure- ments.
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The measure of angle strain is 5.65° which is comparable with calculated crystal structure data value of 6.5°. The title compound 2-hydroxy-2-(2-oxocycloheptyl)-2,3-dihydro-1H-indene-1,3-dione crystallizes in orthorhombic space group Pbca. The five-membered ring adopts twist conformation on C8—C9 with Q = 0.1502 Å and φ = 302.24°. In the crystal structure, molecules are linked by intermolecular O—H···O and C—H···O hydrogen bonds. The symmetry related six-membered spiro rings show π-π interactions with distance of 3.7373 (8) Å (Fig. 2).
8.4 Hz, C 4 —H), 4.73 (1H, d, J = 12.8 Hz, C 3 —H), 5.85 (1H, s, OH), 6.10 (1H, d, J = 8.4 Hz, ArH), 6.75 (1H, t, J = 7.2 Hz, ArH), 6.98 (1H, d, J = 7.6 Hz, ArH), 7.14–7.24 (4H, m, ArH), 7.29–7.38 (5H, m, ArH), 7.46 (1H, t, J = 7.2 Hz, ArH), 7.53 (2H, d, J = 8.0 Hz, ArH), 7.67 (1H, d, J = 7.2 Hz, ArH). Single crystals suitable for X-ray diffraction were obtained by slow evaporation of a petroleum ether/acetone solution (5:1 v/v).
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In the title molecule, the cyclopentane ring (C1±C5) is the new ring formed by the dimerization of 2-(4-bromobenzal)-1- tetralone, induced by a low-valent titanium reagent. This ring adopts an envelope conformation; atoms C2, C3, C4 and C5 are coplanar, while atom C1 deviates from this plane by 0.720 (2) AÊ. There are two cyclohexane rings in the molecule; one (C5/C14±C16/C21/C22) adopts a boat conformation, with atoms C15 and C22 deviating from the plane de®ned by C5/ C14/C16/C21 by 0.628 (2) and 0.479 (3) AÊ, respectively, and the other (C3/C4/C13/C8/C7/C6) adopts a screw-boat confor- mation, with C3 and C6 deviating from the plane de®ned by C7/C8/C13/C4 by 0.463 (2) and 0.920 (3) AÊ, respectively. The dihedral angle between the two p-bromophenyl rings is 78.9 (2) . In the crystal structure, there are two hydrogen
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The molecule of (3) is shown in Fig. 1. The relative configurations of the various asymmetric centres are estab- lished as given in the title. The central six-membered ring is almost planar (mean deviation 0.06 A ˚ ) but is slightly folded, by 12.9 (1) , about the axis C2 C6; the five-membered ring is
plane of the fused-ring system. A weak C—H O interaction organizes the molecules into a helical chain along the b axis. In addition, there is a – stacking interaction between the five- membered rings of adjacent fused-ring systems, with a centroid–centroid distance of 3.666 (1) A ˚ .
Fig. 4b. It is worth noting that the interaction seen in Fig. 4b is not observed in the asymmetric unit, but in the extended packing of the crystal. These interactions are listed in Table 3. A second interaction, which contributes to the crystal packing, is a – interaction between arms 4 and 5, as seen in Fig. 5a. A third interaction, which contributes to the crystal packing, is a – interaction between arms 1 and 2, as seen in Fig. 5b. These interactions are listed in Table 3.
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The title compound crystallizes with three crystallographically independent molecules (A, B and C, containing atoms N10, N32 and N54, respectively) in the unit cell (Fig. 1). These independent molecules adopt very similar geometries and differ only in the conformations of the two methoxy substi- tuents at the benzene ring. In two of the three independent molecules, both methoxy groups are almost coplanar to the benzene ring [the C—C—O—Me torsion angles are 10.8 (2) and 12.3 (2) in molecule A and 9.1 (2) and 13.6 (3) in B],
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A 1,4-dioxane solution (20 ml) of imidazole (1.420 g, 20.8 mmol) was added to a suspension of oil-free sodium hydride (0.500 g, 20.8 mmol) in 1,4-dioxane (20 ml) and stirred for 1 h at 90°C. A 1,4-dioxane (20 ml) solution of benzyl bromide (3.240 g, 19 mmol) was then added dropwise to the above solution. The mixture was stirred for 22 h at 90°C, and a brown solution was obtained. The solvent was removed with a rotary evaporator and H 2 O (50 ml) was added to the
Dried and finely powdered whole plant of Azorella compacta (3,0 kg) were extracted with petroleum ether at room temperature. After filtration, the solvent was evaporated in vacuum yielding a gum (220 g). The concentrated petrol ether extract was adsorbed on silica gel (300 g) and slurried onto the top of a column containing silica gel (2.0 kg) in petroleum ether, and eluted with a petroleum ether/ethyl acetate gradient with increasing amounts of ethyl acetate to produce six fractions. Fraction 2 (100 g) eluted with petroleum ether/ethyl acetate(18:2) was further separated and purified by silica gel column chromatography(petroleum ether/ethyl acetate), 19:1) to give 600 mg of the title compound. The structure were elucidated by analysis of their spectroscopic data. Recrystallization from hexane-ethyl acetate (7:3) at room temperature afforded colourless crystals suitable for X-ray diffraction analysis.
To a solution of ninhydrin (1 equiv) and proline (1.4 equiv) in dry toluene, α,β-unsaturated sugar lactone was added under a nitrogen atmosphere. The solution was refluxed for 15 h under Dean-Stark reaction conditions to give a cycloadduct. After completion of the reaction indicated by TLC, the solvent was evaporated under reduced pressure. The residual mass was extracted with dichloromethane and water. The organic layer was dried with anhydrous sodium sulfate and
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Further, with a view to examine the effect of the polarity of the solvent on the manner of the phototransformations of all the four 2-aryl-2-bromo-1H-indene-1,3(2H)-diones (2), their photochemistry was also investigated in dry acetone under similar conditions as employed for anhydrous ethanol. The usual chromatographic work up of the photolysates yielded the corresponding 2-aryl-1H-indene-1,3(2H)-diones (1) as white leaflets in excellent yields. Mechanistically, the phototransformation 2 → 1 may be invisaged to occur through an initial homolytic cleavage of C 2 –Br bond yielding the resonance stabilized radical (3) which then abstracts a hydrogen radical from acetone to
The title compound, (I), represents the most stable dimer of indene obtained by the cationic dimerization through the reaction of the 2,3-dihydro-1H-inden-1-yl carbenium ion with 1H-indene at position 2. Compound (I) was described in the literature by Moglioni et al. (1998) and Noland et al. (1979), but a crystal structure has not been reported previously. It is the constituent of many pyrolysis oils and its characterization is important for environmental analysis. It also represents a useful model substance for MS and NMR analysis, and structural data are important for the understanding of some ®ne details of MS and NMR spectra.
Amouri et al., 1994) and, in our hands, this route does have promise for providing higher yields for many of the compounds. However, in the case of indene, there was no indication that an indenyl iridium complex had been prepared. Instead, a yellow–brown intractable solid was formed. Several attempts to dissolve the solid and to separate products through fractional crystallization all failed. During the course of this work-up, one of the solvents used was acetonitrile. At some point, the product mixture was allowed to stand in solution, and after about 24 hours several very nicely shaped
C19 and C10 are coplanar, while atoms C11 and C12 deviate from the plane by 0.233 (1) and ÿ0.490 (2) AÊ, respectively. Molecules show a dimer structure formed by an inter- molecular N1ÐH1A N2(1 ÿ x, ÿy, 1 ÿ z) hydrogen bond between the amino and cyano groups (Table 2 and Fig. 2).
Photo-induced electron-transfer (PET) reactions of cyano- arenes with alkenes have attracted much research interest in recent years (Mella et al., 1998; Zhang et al., 2006). 1,2,4,5- Tetracyanobenzene (TCNB) is the strongest electron acceptor of all cyanoarenes (Mattes & Farid, 1982). In our ongoing research work on PET reactions, we have found that the PET reaction between TCNB and an excess amount of 1-phenyl- 1,2,3,4-tetrahydronaphthalene in a polar solvent (acetonitrile) afforded the title compound, (I), as one of the products. As a part of this study, we have undertaken an X-ray crystal- lographic analysis of (I) in order to elucidate its conformation and configuration.
The feed rate of the mixture is adjusted so that the temperature rise does not exceed 1 - 2˚C. The reaction mixture is stirred until the temperature rises. The catalyst is then decomposed by the 1% - 3% solution of NaOH. The reaction mass is washed with a mixture of water-isopropyl alcohol to neutral medium, filtered, the solvent and light fractions are distilled off under vacuum. After that, the yield of the co-oligomers, their kinematic viscosity and molecular weight are determined.
Erogorgiane is a highly lipophilic diterpene isolated from the West Indian gorgonian octocoral Pseudoterogorgia elisabethae. Erogorgiane and its 7-hydroxy analogue have showed potent anti- tuberculosis activity. Interestingly, erogorgiane was also isolated from the root bark extract of Leucophyllum frutescens by Waksman (Universidad Autónoma de Nuevo Leon). We proposed a synthetic strategy for the synthesis of erogorgiane where the stereochemistry of C-1 and C-11 could be controlled by Michael addition of a methylcuprate nucleophile to an α , β -unsaturated sulfur-based imide chiral auxiliary (Scheme 7). In collaboration with Benemérita Universidad Autónoma de Puebla, we reported that addition of methylcuprates, generated in situ using an excess of a 1:2 mixture of CuI-DMS and the Grignard reagent to N-enoyl oxazolidinethione 18 in the presence of excess TMSI gave preferentially the anti-diastereomer 19. This Michael addition took place when the conformation of the substrate was syn-s-cis.
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