6311-19-9Relevant academic research and scientific papers
Synthesis and evaluation of novel pyrimido-acridone, -phenoxadine, and -carbazole as topoisomerase II inhibitors
Kamata, Junichi,Okada, Toshimi,Kotake, Yoshihiko,Niijima, Jun,Nakamura, Katsuji,Uenaka, Toshimitsu,Yamaguchi, Atsumi,Tsukahara, Kappei,Nagasu, Takeshi,Koyanagi, Nozomu,Kitoh, Kyosuke,Yoshimatsu, Kentaro,Yoshino, Hiroshi,Sugumi, Hiroyuki
, p. 1071 - 1081 (2007/10/03)
As part of a series of studies to discover new topoisomerase II inhibitors, novel pyrimidoacridones, pyrimidophenoxadines, and pyrimidocarbazoles were synthesized, and in vitro and in vivo antitumor activities and DNA-protein and/or DNA-topoisomerase II c
Microbial transformation of selected carbazole derivatives
Chakraborty,Chowdhury
, p. 617 - 620 (2007/10/03)
A strain of Pseudomonas aeruginosa and another of Aspergillus fumigatus are found to have the ability to degrade carbazole derivatives. These strains show different specificities for growth on 1- and 3-methylcarbazoles and accumulate forraylcarbazoles as end products in low yields. Pseudomonas species degrade 1- and 3-formylcarbazoles to the corresponding carboxylic acid derivatives which in turn are decarboxylated to carbazole in high yields. This strain also biotransforms the N-acetylcarbazoles (8, 9 and 10) and the respective deacetyl-derivatives (7,2 and 11) are obtained in good yields. This study provides an evidence in favour of the suggested biotransfonnation of 3-methylcarbazole to carbazole via 3-formylcarbazole and carbazole-3-carboxylic acid in the plants.
Improved Syntheses of Substituted Carbazoles and Benzocarbazoles via Lithiation of the (Dialkylamino)methyl (Aminal)Derivatives
Katritzky, Alan R.,Rewcastle, Gordon W.,Vazquez de Miguel, Luis M.
, p. 794 - 799 (2007/10/02)
The lithiation of N-carbazoles occurs readily and exclusively at the protonated carbon adjacent to the nitrogen atom.Reaction with a variety of electrophiles produces good to excellent yields of monosubstituted derivatives.Removal of the lithio-directing and nitrogen-protecting function is readily achieved by mild acid-catalyzed hydrolysis during workup of the reaction.Thus, carbazole undergoes lithiation at the 1-position, dibenzocarbazole at the analogous 6-position, and benzocarbazole at both the 6-and 8-positions, with the former predominating. 1,2,3,4-Tetrahydrocarbazole undergoes lithiation at the 8-position, but with 2,3-dimethylindole reaction occurs at the 2-methyl group.Benzocarbazole fails to form an aminal derivative, but on direct lithiation in ether it can be substituted exclusively at the 1-position of the fused benzene ring.
PALLADIUM-CATALYSED CYCLISATION OF 2-SUBSTITUTED HALOGENOARENES BY DEHYDROHALOGENATION
Ames, D.E.,Opalko, A.
, p. 1919 - 1926 (2007/10/02)
Cyclodehydrohalogenation mediated by various palladium catalysts and solvents with different bases (the most generally satisfactory system being palladium(II) acetate in NN-dimethylacetamide (DMA) with sodium carbonate as base) has been examined as a route to some heterocyclic systems.Whereas dehydrogenative cyclisation processes require stoichiometric amounts of palladium(II) reagent, the present procedure involves only catalytic amounts (0.1 molar proportion, or less), of palladium compound.The preparation of dibenzofuran, carbazole, fluorenone, 6H-dibenzothiazine-5,5-dioxide, 6H-dibenzopyran and benzofuranopyridine derivatives is described.The cyclisation of 3-benzamido-2-chloropyridine to 6-hydroxybenzonaphthiridine illustrates the regiospecificity of the process.
One-electron photooxidation of carbazole in the presence of carbon tetrachloride. Part I. Carbon tetrachloride and ethanol used as reaction media
Zelent, Bogumil,Durocher, Gilles
, p. 945 - 956 (2007/10/02)
The photochemical reaction products of carbazole with carbon tetrachloride in ethanol have been isolated and identified along with photoproducts in the irradiated solution of carbazole in pure CCl4 using water and ethanol added after the irradiation.This allowed us to discuss the complex mechanism of secondary photochemical changes in the carbazole-CCl4 system.We propose that the electron transfer from carbazole to CCl4 molecule in the excited CT complex, , is the primary photochemical reaction followed by a heterolytic dissociation of C-Cl bond which gives rise to the primary photoproducts in the solvent cage .Secondary photochemical reactions initiate transformation of the radical cation of carbazole in the solvent cage giving rise to the following intermediate species: .The probability of formation and further transformations of these transient products: α, β, and γi, depends strongly on the nature of the reaction media.Thermodinamically stable products are formed depending on the reaction media; (carboethoxy)carbazoles, (carbo-N-carbazyl)carbazoles, and carbazole - carboxylic acids can serve as a proof for the formation of the above listed intermediates.All the results reported on the secondary photochemical reactions strongly support the electron-transfer primary mechanism used to explain the fluorescence quenching of carbazole by CCl4.The results also explain the changes observed in the fluorescence spectrum of carbazole when the ethanol solution of carbazole in the presence of CCl4 is irradiated.
