- Synthesis method 1 -aminoanthraquinone
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The invention belongs to the technical field of dye intermediate synthesis, and particularly relates 1 - hydroxyaminoanthraquinone synthesis method which comprises dissolving 1 -nitroanthraquinone in a mixed solution N, N - dimethyl formamide and water, and then reducing the sodium borohydride to obtain the target product 1 - hydroxyanthraquinone. The volume ratio of N, N -dimethylformamide to water in the mixed solution was 0.5: 1 - 3:1. A mixture solution of N, N - dimethyl formamide and water and a mass ratio 1 - nitroanthraquinone of 100:1 - 600:1. The molar ratio of sodium borohydride to 1 -nitroanthraquinone 0.5: 1 - 10:1. Reaction temperature is 10 - 90 °C. The reaction time is 5 - 60 min. The method is mild in reaction condition, short in reaction time and high in 1 - hydroxyl amino anthraquinone product yield, and has the characteristics of greenness, safety and high efficiency.
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Paragraph 0023-0039
(2021/10/27)
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- PHOTOCHEMICAL HYDROXYLATION OF ANTHRAQUINONE IN SULFURIC ACID
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The photolysis of anthraquinone in sulfuric acid leads to hydroxylation of its ring with the preferential formation of 2-hydroxyanthraquinone in concentrated and 1-hydroxyanthraquinone in dilute sulfuric acid.The second hydroxy group only enters photochemically at position 4 of 1-hydroxyanthraquinone if the latter is activated by complex formation with boric acid.During photolysis in deaerated sulfuric acid the nitroanthraquinones are reduced photochemically to (hydroxyamino)anthraquinones; here 1-(hydroxyamino)anthraquinones with an unoccupied para position in the same condensed benzene ring undergo rearrangement under the reaction conditions to 1-amino-4-hydroxyanthraquinones.The main photochemical stage of hydroxylation in concentrated sulfuric acid is nucleophilic substitution of hydrogen in the monoprotonated anthraquinone by the HSO4(-) ion, while in dilute sulfuric acid it is electron transfer from water to anthraquinone.
- Studzinskii, O.P.,El'tsov, A.V.
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p. 1666 - 1673
(2007/10/02)
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- Process for the preparation of 1-substituted anthraquinones
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A process for the preparation of 1-substituted anthraquinones represented by the general formula I EQU1 where, in the formula, R1 and R2 represent individually a hydrogen atom or methyl group and X represents a hydroxylamino or amino group, Which comprises treating in a liquid medium a 5-nitro-1,4,4a,9a-tetrahydroanthraquinone represented by the general formula II EQU2 where, in the general formula, R1 and R2 represent individually a hydrogen atom or methyl group, In the presence of a basic compound with or without a reducing agent.
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