- Synthesis, crystal structure, cytotoxicity and evaluation of the 6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-5-carbaldehydes for inhibitory effect against protein kinases (VEGFR-2 and EGFR) and cyclooxygenase-2 (COX-2) activities
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The 2-aryl-8-bromo-6-oxo-6H-pyrrolo[3,2,1-ij]quinoline-5-carbaldehydes 2a–e were prepared and their structure characterised using a combination of NMR (1H- & 13C-), infrared and mass spectroscopic techniques. Their structure and geometry were also confirmed in the solid state by means of single crystal X-ray diffraction method. The compounds were evaluated for cytotoxicity in vitro against the human MCF-7 and MDA-MB-231 breast cancer cell lines as well for toxicity against the human embryonic kidney derived Hek293-T cell line. Preliminary apoptotic assay using DNA laddering assay revealed that these compounds have potential to induce apoptosis in the MCF-7 cell line. Compounds 2c and 2d were also found to exhibit increased inhibitory activity against vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase and significant interruption of cyclooxygenase-2 (COX-2) activity.
- Choong, Yee Siew,Lerooibaaki, Sharon T.,Maluleka, Marole M.,Mphahlele, Malose J.
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- Iminium Salts in Quantitative Gas/Solid and Solid/Solid Reactions
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Iminium salts that are highly susceptible to hydrolysis are quantitatively prepared and reacted in the solid state without solvents or liquid phases. Atomic force microscopy AFM helps in elucidating the mechanism of these still unusual gas-solid and solid-solid syntheses by recording surface topographies of reacting crystals of L-histidine (10) and triphenylverdazyl (15). Various imines add gaseous HCl or HBr to form stable iminium halides (1, 3, 4, 5, 11) even if frozen liquids of very weak heterocyclic bases are treated at low temperatures. Another way for quantitative yields of iminium salt hydrates (6) starts with solid primary ammonium halides and gaseous acetone. o-Phenylenediamines (7) give quantitatively 1,5-benzodiazepines (9) by solid state cyclization of bis-iminium salt intermediates (8). Crystalline nitroxyls (12) and triphenylverdazyl (15) undergo stoichiometric one-electron transfer with gaseous NO2 or XeF2 to give nitrosonium (14) and azonium salts (17). The solid state chlorination of tetramethylthiuramdisulfide (18) or dimethylthiocarbamoylchloride (20) yields phosgene dimethyliminiumchloride (Viehe salt 21) in quantitative yield. Solid Viehe salt is quantitatively treated with gaseous Cl2 to give the trichloride 19 and solid SbCl5 or PCl5 to produce the hexachloroantimoniates (22), -phosphates (23). Solid brenzcatechol (24), mercaptobenzimidazole (27), p-nitroaniline (30), N-methylbenzothiazolone-2-hydrazone (34) and acetophenone (41) are treated with 21 to give the corresponding chloroiminium salts (25, 28, 31, 35, 43). p-Toluenesulfonamide (37) and 22 give the chloroiminium salt 38.These quantitative solid-solid reactions are most easily run in ball mills with cooling device. The "waste-free" techniques achieve exclusion of moisture in an elegant way. The preparative use of the versatile products with nucleophiles is indicated. The three-step solid-state mechanisms are discussed.
- Kaupp, Gerd,Boy, Juergen,Schmeyers, Jens
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p. 346 - 355
(2007/10/03)
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- A Convenient Laboratory Preparation of N,N-Dimethyldichloro-methylene-iminium Chloride (Phosgene-iminium Chloride)
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A method of preparation of the title compound 1a avoiding the use of gaseous chlorine is described.Tetramethylthiuram disulfide 4 is oxidized with sulfuryl chloride to dimethylthiocarbamoyl chloride 5, which is converted to 1a by means of phosphorus pentachloride.
- Vilkas, Michel,Qasmi, Driss
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p. 2769 - 2773
(2007/10/02)
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- CHLORINATING CHARACTERISTICS OF THE COMPLEX OF N,N-DIMETHYLDICHLOROMETHYLENEIMINIUM CHLORIDE WITH CHLORINE
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The chlorinating characteristics of the complex (I) of N,N-dimethyldichloromethyleneiminium chloride with chlorine were studied for the case of its reactions with olefins (1-hexene, cyclohexene, tetrachloroethylene), unsaturated alcohols (allyl alcohol), and phenols (phenol, p-cresol).It was found that the ionic chlorination of the olefins by the complex takes place at high rates and with a high degree of selectivity.With the hydroxy compounds there are parallel reactions, in which the chlorinating characteristics of the complex (I) and the reactivity of the N,N-dimethyldichloromethyleneiminium chloride appear.Chlorination of the phenols by the complex (I) takes place at the ortho position, and this leads to the formation of di(o-chloroacyl) carbonates (with the complex and the phenol in a ratio of 1:2) or o-chloroaryl dimethylcarbamates (with the reagents in a ratio of 1:1).
- Mironova, D. F.,Stetsyuk, G. A.,Kukhar', V. P.
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p. 2319 - 2323
(2007/10/02)
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- ADDITION AT THE C=N BOND IN KETENE IMINES. REACTION OF DIPHENYLKETENE N-(p-TOLYL)IMINE WITH N,N-DIMETHYLDICHLOROMETHYLENEAMMONIUM CHLORIDE
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Electrophilic addition to arylketene imines at the C=N bond is described for the reaction of diphenylketene N-(p-tolyl)imine with N,N-dimethyldichloromethyleneammonium chloride.Chlorinating characteristics were found in the complex of N,N-dimethyldichloromethyleneammonium chloride with chlorine.
- Mironova, D. F.,Vykhrestyuk, N. I.,Kukhar', V. P.
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p. 242 - 245
(2007/10/02)
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