Process for producing disperse dyes
AssigneeCiba-Geigy Corporation
InventorHansrudolf Schwander
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Abstract
A process for producing disperse dyes starting with anthraquinone compounds of the formula I ##STR1## in which one X is bromine and the other X is methylamine, or with mixtures thereof, which process comprises reacting these compounds with sulfuric acid, optionally containing SO.sub.3, in the presence of boric acid, at a temperature of between 100.degree. and 150.degree. C., to give compounds of the formula II ##STR2## in which one Y is hydroxyl and the other Y is methylamine, and n is 0.5 to 2.0, or mixtures thereof.
Claims7
A process for producing a disperse dye or their mixtures thereof of the formula (I) ##STR5## wherein one Y is hydroxyl and the other Y is methylamine, n is 0.5 to 2.0, which comprises the steps of:
- subjecting 1,5-dinitro-anthraquinone or 1,8-dinitroanthraquinone or their mixtures thereof or mixtures of nitration residues of 1-nitro-anthraquinone, 1,5-dinitro-anthraquinone, 1,6-dinitro-anthraquinone, 1,7-dinitro-anthraquinone and 1,8-dinitro-anthraquinone to aminolysis with methylamine to give 1,5-dimethylaminoanthraquinone or 1,8-dimethylaminoanthraquinone or their mixtures or corresponding mixtures of dimethylamino residues;
- brominating said 1,5-dimethylamino anthraquinone or
- 1. 8-dimethylamino anthraquinone or their mixtures or mixtures of dimethylamino residue, to give the corresponding bromo compound of the formula III or their mixtures thereof ##STR6## wherein one X is bromine and the other X is methylamine;
- and hydrolysing said bromo compound or their mixtures thereof with sulfuric acid, optionally containing SO.sub.3, in the presence of boric acid, at a temperature between 100.degree. and 150.degree. C., to give said disperse dye or their mixtures thereof.
Dependencies are inferred from the claim text.