- Preparation of aminoanthraquinones from nitroanthraquinones
-
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.
- -
-
-
- Use of alpha-di(lower alkoxy) anthraquinones in the synthesis of Alizarin Saphirols
-
Alpha-dihydroxyanthraquinones used as intermediates in the synthesis of many dyestuffs, such as the Alizarin Saphirols (e.g. Color Constitution No. 63000, 63005, 63010, 63011, 63315 and 63610) can be replaced on an equimolar basis by alpha-di(lower alkoxy)anthraquinones. The alpha-di(lower alkoxy) anthraquinones can be converted in a single step, by treatment with oleum, to the corresponding alpha-dihydroxyanthraquinone-beta-disulfonic acids in almost quantitative yield. The corresponding diamine is obtained by dinitrating followed by reduction of the nitro groups. The known intermediate, leuco 1,4,5,8-tetrahydroxyanthraquinone (see C.I. No. 62500) can be obtained either by reduction of the diamine or by reduction of the dinitro compound. In one embodiment, the alpha-di(lower alkoxy)anthraquinone is obtained from dinitroanthraquinone by treatment thereof with methanol and KOH.
- -
-
-
- Process for the nitration of anthraquinones
-
The invention relates to a process for the manufacture of anthraquinones which are mononitrated in the α-position, especially 1-nitroanthraquinone, wherein an anthraquinone which possesses at least 1 free α-position and is optionally substituted in the other α-position with halogen, preferably chlorine, or with hydroxyl groups, but especially the unsubstituted anthraquinone, is nitrated with concentrated nitric acid without further additives adiabatically, or at temperature above 40°C isothermically, and optionally under pressure.
- -
-
-
- Process for the production of dinitro-anthraquinones
-
Dinitro-anthraquinones are produced by nitrating an anthraquinone in the presence of an indifferent organic solvent. As inert organic solvents there is suggested an aliphatic or alicyclic hydrocarbon having up to 12 carbon atoms and substituted once or several times by halogen or by the nitro group.
- -
-
-
- Nitroanthraquinones
-
Process for dyeing and printing synthetic fiber materials using compounds of the formula SPC1 In which R represents an optionally substituted phenyl radical, as well as special new dyestuffs within the above formula.
- -
-
-