67 research outputs found
A new route towards dithienoquinazoline and benzo[f]thieno[3,2-h]quinazoline systems using Pd-catalyzed intramolecular cyclization under microwave irradiation
Nitration of 5,11-dihydroindolo[3,2-b]carbazoles and synthetic applications of their nitro-substituted derivatives
A new general approach to double nitration of 6,12-di(hetero)aryl-substituted and 6,12-unsubstituted 5,11-dialkyl-5,11-dihydroindolo[3,2-b]carbazoles by acetyl nitrate has been developed to obtain their 2,8-dinitro and 6,12-dinitro derivatives, respectively. A formation of mono-nitro derivatives (at C-2 or C-6) from the same indolo[3,2-b]carbazoles has also been observed in several cases. Reduction of 2-nitro and 2,8-dinitro derivatives with zinc powder and hydrochloric acid has afforded 2-amino- and 2,8-diamino-substituted indolo[3,2-b]carbazoles, while reduction of 6,12-dinitro derivatives under similar reaction conditions has been accompanied by denitrohydrogenation of the latter compounds into 6,12-unsubstituted indolo[3,2-b]carbazoles. Formylation of 6,12-dinitro derivatives has proved to occur only at C-2, while bromination of these compounds has taken place at both C-2 and C-8 of indolo[3,2-b]carbazole scaffold. Moreover, 6,12-dinitro-substituted indolo[3,2-b]carbazoles have been modified by the reactions with S- and N-nucleophiles. Notably, the treatment of 6,12-dinitro compounds with potassium thiolates has resulted in the displacement of both nitro groups, unlike potassium salts of indole or carbazole, which have caused substitution of only one nitro group
A new and convenient synthetic way to 2-substituted thieno[2,3-b]indoles
Abstract A short and robust approach for the synthesis of 2-(hetero)aryl substituted thieno [2,3-b]indoles from easily available 1-alkylisatins and acetylated (hetero)arenes has been advanced. The two-step procedure includes the "aldol-crotonic" type of condensation of the starting materials, followed by treatment of the intermediate 3-(2-oxo-2-(hetero)arylethylidene)indolin-2-ones with Lawesson's reagent. The latter process involves two sequential reactions, namely reduction of the C=C ethylidene double bond of the intermediate indolin-2-ones followed by the Paal-Knorr cyclization, thus affording tricyclic thieno [2,3-b]indoles. 100
Synthesis of 7-cycloalkylimino substituted 3-amino-6-fluoro-2-methyl-3H-quinazolin-4-ones
Transition metal-free oxidative and deoxygenative C-H/C-Li cross-couplings of 2H-imidazole 1-oxides with carboranyl lithium as an efficient synthetic approach to azaheterocyclic carboranes
New "turn-off" fluorescence sensors to detect vapors of nitro-explosives on the basis of 4,6-bis[5-(heteroaryl)thiophen-2-yl] substituted 5-(4-tertbutylphenyl)pyrimidines
Microwave-assisted palladium-catalyzed C–C coupling versus nucleophilic aromatic substitution of hydrogen (S N H ) in 5-bromopyrimidine by action of bithiophene and its analogues
A facile, metal-free, oxidative coupling of new 6-(hetero) aryl-[1,2,5]-oxadiazolo[3,4-b] pyrazines with pyrroles, indoles and carbazoles
Synthesis and fluorescent properties of 2-styryl-6,7-difluoro-8-hydroxyquinoline and its Zn(II) complex
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