- NUCLEOPHILIC SUBSTITUTION OF HYDROGEN IN AROMATIC SYSTEMS. II. MECHANISM OF AMINATION IN ANTHRAISOXAZOL-6-ONES
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The nucleophilic substitution of the C5-H hydrogen atom in anthraisoxazol-6-ones by amines in acetonitrile in the absence of Cu2+, Ag+, Co2+, or Ni2+ cations takes place with the formation of strong hydrogen bond in the sixmembered chelate ring of the product from 1,4-addition of the amine to the isoxazolone at the C5 and =O atoms.The structure of the reaction product is determined by the character of the amine, and (with the absence of readily eliminated groups) substitution of C5-H is suppressed by the competing amination of C3-H and reduction of the heterocycle.The substitution of C5-Hlg by amines under analogous conditions leads to trivial reaction products.In nitromethane C3-H or C3-Hlg is mainly substituted, and C5-H or C5-Hlg is partly substituted, leading to products with trivial structures.In the presence of Cu2+, Ag+, Co2+, Ni2+ cations in acetonitrile only C3-H or C3-Hlg is substituted through the formation of mixed complex of amine and isoxazolone on the cation.
- Galushko, A. M.,Dokunikhin, N. S.
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p. 1347 - 1357
(2007/10/02)
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- Process for the manufacture of 1,2-diaminoanthraquinone
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A process for the manufacture of 1,2-diaminoanthraquinone, which comprises reacting 1-nitro-2-acetylaminoanthraquinone with hydrazine or hydroxylamine, or with derivatives thereof, in protic solvents.
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- Preparation of aminoanthraquinones from nitroanthraquinones
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In the reaction of a nitroanthraquinone with ammonia in a solvent at elevated temperature to produce the corresponding aminoanthraquinone, the improvement which comprises effecting the reaction in the presence of an ammonium halide. Advantageously, the nitroanthraquinone is an α-nitroanthraquinone, the ammonium halide is at least one of ammonium chloride and ammonium bromide, and the solvent comprises at least one member selected from the group consisting of water, nitrobenzene, a glycol, an acid amide and sulfolane.
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- Process for preparing aminoanthraquinones
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A process for preparing aminoanthraquinones of high purity, which comprises catalytically hydrogenating nitroanthraquinones in the suspended state in an aqueous medium in the presence of a hydrogenating catalyst. In a preferred embodiment, the catalytic hydrogenation may be carried out in the presence of an organic or inorganic base, followed, if desired, by oxidizing the hydrogenation product.
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