2-, 3- and 4-Pivaloylamino derivatives of dibenzofuran [compounds (5), (4) and (6), respectively] and analogous 3-, 2- and 1-substituted derivatives of 9-methylcarbazole [compounds (8), (7) and (9), respectively] were subjected to lithiation at 0 degreesC and subsequent reaction with dimethylformamide. Aldehyde formation took place at positions alpha to delta to the heteroatom as follows: alpha for (4) and (7); delta for (5); delta and beta (3 : 1) for (8); and alpha' for (6). No formylation occurred with (9).
2-, 3- and 4-Pivaloylamino derivatives of dibenzofuran [compounds (5), (4) and (6), respectively] and analogous 3-, 2- and 1-substituted derivatives of 9-methylcarbazole [compounds (8), (7) and (9), respectively] were subjected to lithiation at 0 degreesC and subsequent reaction with dimethylformamide. Aldehyde formation took place at positions alpha to delta to the heteroatom as follows: alpha for (4) and (7); delta for (5); delta and beta (3 : 1) for (8); and alpha' for (6). No formylation occurred with (9).
Despite the utility of 9-silafluorenes as functional materials and as building blocks, methods for efficient functionalization of their backbone are rare, probably because of the presence of easily cleavable C–Si bonds. Although controlling the regioselectivity of iridium-catalyzed direct borylation of C–H bonds is difficult, we found that bromination and nitration of 2-methoxy-9-silafluorene under
Disclosed is a method for producing an aminocarbazole by catalytically reducing a nitrocarbazole, wherein as a catalyst is used an active nickel-based catalyst prepared by contacting a nickel-based catalyst with an alkali and an iron compound under a hydrogen gas or inert gas atmosphere in an inert solvent, and according to the method of the present inventions decrease in reaction speed, decrease in yield of a product or the like depending upon the lot of the starting nitrocarbazoles can be prevented, and aminocarbazoles can be produced in a good yield constantly.
A New Method of Nitration of Carbazoles Using Ceric Ammonium Nitrate (CAN)
作者:Manas Chakrabarty、Archana Batabyal
DOI:10.1080/00397919408012618
日期:1994.1
Abstract A convenient procedure for the mononitration of carbazole and 9-alkylcarbazoles using CAN in CH3CN in presence of SiO2 is reported. The results with 9-acetyl, 9-benzoyl and 9-benzenesulphonylcarbazoles are also discussed.
Disclosed is a method for producing an aminocarbazole by catalytically reducing a nitrocarbazole, wherein as a catalyst is used an active nickel-based catalyst prepared by contacting a nickel-based catalyst with an alkali and an iron compound under a hydrogen gas or inert gas atmosphere in an inert solvent, and according to the method of the present invention, decrease in reaction speed, decrease in yield of a product or the like depending upon the lot of the starting nitrocarbazoles can be prevented, and aminocarbazoles can be produced in a good yield constantly.