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961.
M. D. Stanescu C. Popescu A. Rus C. Guran 《Journal of Thermal Analysis and Calorimetry》2008,94(2):535-538
A number of dibenzobicyclo[2.2.2]octane derivatives have been studied due to the interest of such compounds as ligands for
coordination compounds with potential biological activity. Their thermal behaviour has been analyzed in order to find out
more information about their fragmentation. A connection between the bridge substituents and the fragmentation process has
been observed. 相似文献
962.
963.
An efficient synthesis of new dioxygenated isoquinolines is reported. The novelty of this approach derives from its use of tricyclic-nitril (3) as a building block in a synthetic sequence of seven steps for the preparation of the tetracyclic isoquinoline (14) and its derivatives. The isoquinoline 16 was 10-fold more active against leukemia L1210 than the corresponding tetrahydroisoquinoline 14. 相似文献
964.
Ali Elriati Jutta Loose Roswitha Mayrhofer Hans-Joachim Bergmann Hans-Hartwig Otto 《Monatshefte für Chemie / Chemical Monthly》2008,139(7):835-846
Different modifications of the imine – acyl chloride reaction were used for the synthesis of 3-mono- and 3,3-dihalogenated
1,4-diaryl substituted β-lactams. Furthermore, these β-lactams were modified by halogen substitution either at the aryl at
position 1 or at the aryl substituent at position 4, or at both positions. The influence of the halogen atoms on the reactivity
of the β-lactam ring, visible by the carbonyl frequence in their IR spectra, was studied. A selection of compounds was tested
as inhibitors of the serin protease porcine pancreatic elastase. No simple correlation between IR frequence and biological
activity was found. Finally, the base induced rearrangement of N-benzyl β-lactams was used for the synthesis of 4,5-diaryl substituted pyrrolidinones.
Correspondence: Hans-Hartwig Otto, Department of Pharmaceutical/Medicinal Chemistry (PMC), Institute of Pharmacy, Ernst-Moritz-Arndt-University,
17487 Greifswald, Germany. 相似文献
965.
AlCl3-mediated tandem Friedel-Crafts reaction of vinylidenecyclopropanes with acyl chlorides produced the corresponding 1-[2-(2,2-diarylvinyl)-1-phenyl-3H-inden-5-yl]ethanone derivatives in moderate to good yields under mild conditions within short reaction time. 相似文献
966.
Multinuclear dynamic NMR spectroscopy of 5-trifluoromethylsulfonyl-1,3,5-dioxaazinane (4) revealed the existence of two close in energy chair conformers with differently oriented CF3 groups with respect to the ring. Of the two alternative routes for their interconversion, the ring inversion path with intermediate formation of the corresponding 2,5-twist-conformer is preferred, with the energy barrier of 11.2 kcal/mol in excellent agreement with the experimental value (11.7 kcal/mol). The Perlin effect is studied experimentally and calculated theoretically for all CH2 groups and found to be subject to the nature of the adjacent heteroatoms O and N, respectively. 相似文献
967.
We synthesized a novel benzimidazole-based fluorescent receptor bearing imine linkages with two sets of sp2 nitrogens, and investigated its binding properties toward various metal ions. The receptor exhibited a shift in emission band upon binding with Fe3+ ions, and no such significant response was noticed in other metal ions. The receptor shows a property of selective ratiometric fluorescent probe of Fe3+ ions without interferences of the background metal ions. 相似文献
968.
Vakhid A. Mamedov Dina F. Saifina Aidar T. Gubaidullin Alina F. Saifina Il’dar Kh. Rizvanov 《Tetrahedron letters》2008,49(43):6231-6233
A highly efficient one-step and versatile method for the synthesis of 2-(indolizin-2-yl)benzimidazoles has been developed on the basis of the novel ring contraction of 3-arylchloromethyl- and alkylchloromethylquinoxalin-2-ones with α-picoline. 相似文献
969.
Forogh Adhami Masomeh Tabatabaee Mitra Gassemzadeh Bernhard Neumüller 《无机化学与普通化学杂志》2008,634(9):1466-1468
Reaction of 4‐amino‐6‐methyl‐1,2,4‐triazine‐3‐thione‐5‐on (AMTTO) as a bidentate ligand with silver nitrate and triphenyl phosphine as the co‐ligand make the centrosymmetric dimeric complex {[(AMTTO)Ag(PPh3)2]NO3}2·0.5CH3OH·0.5H2O ( 1 ). 1 was characterized by elemental analyses, IR‐ and NMR spectroscopy as well as X‐ray diffraction studies. The silver atom in 1 has distorted tetrahedral coordination. 1 crystallizes in triclinic space group . Crystal data for 1 at −80 °C: a = 1185.8(1), b = 1314.6(1), c = 1385.3(1) pm, α = 97.78(1)°, β = 111.38(1)°, γ = 92.41(1)°, Z = 2, R1 = 0.0377. 相似文献
970.
Crina Cisma? 《Tetrahedron letters》2008,49(8):1336-1339
An alternative route for the synthesis of a photoaffinity labelling (PAL) dCTP derivative is reported. This method involves the intermediacy of exo-N-[2-(4-azido-2,3,5,6-tetrafluorobenzamido)ethyl]-dC. The latter is prepared from the coupling of known N-(2-aminoethyl)-4-azido-2,3,5,6-tetrafluorobenzamide, prepared in an improved three-step sequence, with an activated 4-triazolyl derivative of dU, followed by deprotection. 19F NMR spectroscopy proved extremely useful in following the synthetic transformations, and enabled control of any adventitious reduction of the azides. 相似文献