GB472652A - Process for the manufacture of acid wool dyestuffs of the anthraquinone series - Google Patents

Abstract

Dyes are made by reacting salts of sulphurous acid, particularly sodium sulphite, with halogen alkylaminoanthraquinones wherein the alkyl group has more than one carbon atom. The products are alkylaminoanthraquinones containing an SO3H group attached to the alkyl, and are used as acid wool dyestuffs, or, if they contain easily replaceable substituents such as halogen atoms or amino groups, as intermediates. The reaction is preferably carried out in an aqueous medium at an elevated temperature of, for instance, 100--130 DEG C. and under raised pressure. Organic solvents such as alcohol may be added. The starting materials are prepared by reacting aminoanthraquinones with compounds containing an ethylene oxide group and a halogen atom or from hydroxyalkylaminoanthraquinones by replacement of the hydrory group. In example, (1) 1-b -chloro-ethylaminoanthraquinone is reacted with sodium sulphite; the product dyes wool red shades and can be converted to other dyestuffs by introducing a bromine atom and replacing the latter by an amino group; (2) 1-b -hydroxy-g -chloropropylamino - 4 - hexahydroanilidoanthraquinone or the corresponding 4-anilido compound is heated with sodium sulphite (blue or greenish-blue shades respectively). 1 - b - Hydroxy - g - chloropropylamino - 4 - anilidoanthraquinone and the corresponding 4-hexahydroanilido compound are obtained by reacting epicplorhydrin with 1-amino-4-anilidoanthraquinone and 1-amino-4-hexahydroanilidoanthraquinone respectively. 1 - b - Chloroethylaminoanthraquinone is prepared from 1 - b - hydroxyethylaminoanthraquinone by reaction with phosphorus pentachloride. The Specification as open to inspection under Sect. 91, describes also the bromination of 1 - b - sulphoethylaminoanthraquinone to the 4-brom compound and its acetylation with acetic anhydride to give 1-(b -sulphoethylacetyl) - amino - 4 - bromanthraquinone. The latter, when heated with caustic soda in methyl alcohol, gives a 1.9-anthrapyridone, the bromine of which is exchanged by reaction with hexahydroaniline. 1 - (b - sulphoethylamino) - 4 - bromanthraquinone is also reacted with p-aminoacetanilide. This subject-matter does not appear in the Specification as accepted.