- Preparation method for 3,5,-dichloro-2,4,-difluoroaniline
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The invention relates to the field of organic synthesis, specifically to a preparation method for 3,5,-dichloro-2,4,-difluoroaniline and application thereof. The preparation method for 3,5,-dichloro-2,4,-difluoroaniline provided by the invention comprises the following steps: 1) nitration reaction; 2) reduction reaction; 3) diazotization reaction; 4) nitration reaction; 5) fluorination reaction; and 6) reduction reaction. The preparation method for 3,5,-dichloro-2,4,-difluoroaniline provided by the invention has the following beneficial effects: 1) the method has mild reaction conditions, is stable and controllable, has less active sites, is insusceptible to side reaction, and has good yield and quality in the whole line; and 2) raw materials are cheap and easily available, so cost can be effectively reduced, and energy is saved; meanwhile, the use of chlorine gas is avoided, so the method is environment-friendly.
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- A new class of heterogeneous platinum catalysts for the chemoselective hydrogenation of nitroarenes
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A new series of nanostructured platinum catalysts able to catalyze the selective reduction of nitroarenes has been developed. The materials, made of organosilica physically doped with nanostructured platinum(0), are stable and efficient. Reactions in general proceed with high yield and often go to completion, while the catalysts can be reused in further reaction runs. This establishes a new class of relevant solid catalysts for synthetic organic chemistry named SiliaCat Platinum-Hydrogel.
- Pandarus, Valerica,Ciriminna, Rosaria,Beland, Francois,Pagliaro, Mario
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scheme or table
p. 1306 - 1316
(2011/06/25)
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- Hydrolysis and Fe2+-induced Reduction of N-Aryl -O-pivaloylhydroxylamines: Aqueous Solution Chemistry of Model Carcinogens.
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The N-aryl-O-pivaloylhydroxylamines, 1a-d, which serve as models for the carcinogenic metabolites of aromatic amines, decompose in aqueous media by heterolysis of the N-O bond.Substituent effects on rates of reaction and products of the decomposition of 1a-c are entirely consistent with the intermediacy of a singlet nitrenium ion.The least reactive compound in the series N-(4-nitrophenyl)-O-pivaloylhydroxylamine (1d) yields 4-nitroaniline (2d) as its major decomposition product.This material may be formed through H radical abstraction by a triplet ion, but a nitrene reaction appears to be more likely.In the presence of Fe2+ 1a-d undergo rapid reduction to the corresponding anilines 2a-d.This reaction requires complexation of the ester with Fe2+ and proceeds with heterolysis of the N-O bond since nearly quantitative yields of pivalic acid are isolated.The radical cations 25a-d appear to be the most likely precursors to the reduction products.
- Novak, Michael,Lagerman, Robert K.
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p. 4762 - 4769
(2007/10/02)
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- Process for the preparation of 2,4,6-trichloroaniline
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2,4,6-Trichloroaniline is prepared by reaction of aniline, which is optionally substituted by halogen, with a chlorinating agent in the presence of inert organic solvents and/or diluents at elevated temperatures.
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