GB288291A - Process for the manufacture of new vat dyestuffs of the anthanthrone series - Google Patents

Abstract

288,291. I. G. Farbenindustrie Akt. Ges. April 9, 1927, [Convention date]. Anthanthrone derivatives.-The dyes obtained by treating halogenanthanthrones or their derivatives with aminoanthraquinones or their derivatives (Specification 286,669) are converted into new vat dyes by further treatment with a condensing agent. The products may, if desired, be subjected to the action of an oxidizing agent. As condensing agents, concentrated sulphuric acid, chlorsulphonic acid, aluminium chloride, alone or mixed with sodium chloride, and alkali hydroxides are specified. In examples (1) 2: 7- dibromanthanthrone is condensed with 1-benzoylamino-4-methoxy-5-aminoanthraquinone (2 molecules) by the process of Specification 286,669, and the product, which dyes cotton a powerful greenish-grey, is treated with concentrated sulphuric acid; on stirring the solution into water to which sodium nitrite, chromic acid or other oxidizing agent has been added, a dyestuff separates, which dyes cotton from the vat in violet-brown shades, (2) the dyestuff obtained according to Example 4 of Specification 286,669 by condensing 2 : 7-dibromanthanthrone with 1- benzoylamino-5-aminoanthraquinone, is treated with chlorsulphonic acid to yield a product which dyes cotton a fast khaki shade from a wine-red vat, (3) the dyestuff from 2 : 7-dibromanthanthrone and alpha-aminoanthraquinone is treated with sodium aluminium chloride or with a mixture of aluminium chloride and pyridine; the product dyes cotton a fast slate-grey shade, and (4) the dyestuff from 2 : 7-dibromanthanthrone and aaminoanthraquinone is heated with potassium hydroxide and methyl alcohol and the product separated by dilution with water and blowing air through or by oxidation with chlorine water or the like; it dyes cotton from the vat a powerful green shade.