GB355657A - Manufacture of anthraquinone derivatives - Google Patents

Abstract

Aminoanthraquinones; cellulose esters, dyeing.-Hydroxy groups are replaced by amino, alkylamino or aralkylamino groups by heating with ammonia or a primary aliphatic or araliphatic amine, in presence of water, a leuco derivative of an o-oxyanthraquinone- or a -oxyaminoanthraquinone-sulphonic acid in which a sulpho group is in d -position to an a -oxy group; the said sulpho group being eliminated by the reaction. Instead of the leuco derivative, the corresponding anthraquinone may be employed, the reduction of the leuco derivative and condensation of the latter being combined in one operation. If desired, the products may be oxidized. In examples (1) sodium-1 : 5 - dioxy - 4 : 8 - diaminoanthraquinone - 2 : 6 - disulphonate is heated with sodium hydrosulphite and aqueous ammonia solution; (2) sodium 1 : 8-dioxy-4 : 5-diaminoanthraquinone-2 : 7-disulphonate is heated with sodium hydrosulphite, water and methylamine; (3) sodium 1 : 5-dioxy-4 : 8-diaminoanthraquinone-2 : 6-disulphonate is heated with sodium hydrosulphite, water and methylamine, the product is probably 1 : 5-diamino-4-oxy-8-methylaminoanthraquinone; instead of methylamine, a homologue or substitution product thereof, such as b -oxyethylamine, ethylenediamine or benzylamine may be used, and the disulphonic acid may be replaced by mixtures of disulphonic acids or by monosulphonic acids; (4) 1 : 4-dioxyanthraquinone-2-sulphonic acid is heated with sodium hydrosulphite and aqueous methylamine solution, 1 : 4 - dimethyldiaminoanthraquinone is obtained, and (5) the technical mixture of leuco 1 : 5 - dioxy-4 : 8-diaminoanthraquinone-2-sulphonic acid and leuco 1 : 8-dioxy-4 : 5-diaminoanthraquinone-2-sulphonic acid (made by reduction with zinc dust or hydrosulphite in aqueous caustic soda solution, followed by precipitation with hydrochloric acid) is heated with methylamine and water. The products dye cellulose acetate silk in blue shades when applied in suitable suspensions, for example in sulphite cellulose lye. Specifications 15355/08, [Class 2, Acids and salts, Organic &c.], and 263,579, [Class 2 (iii), Dyes &c.], are referred to.