GB633480A - Manufacture of a dyestuff of the anthraquinone series - Google Patents

Abstract

The leuco - sulphuric ester of 1 : 4 - di - (p-methane - sulphonylbenzoyl - amino) - anthraquinone and the salts thereof is made by a process comprising treating a metal salt of the corresponding leuco compound or a complex compound comprising the metal salt of the corresponding leuco compound, in the presence of an organic amide derived from a secondary amine, with sulphur trioxide, or with an addition compound of sulphur trioxide and an organic amide or tertiary base or with any substance known to be capable of forming sulphuric esters from vat dyestuffs in the presence of metals, or from leuco compounds, or metal salts thereof, or complex compounds comprising the metal salts thereof. Amides specified are dimethylformamide, diethylformamide, dimethylacetamide, N : N-diethyl-p-toluenesulphonamide, tetramethylurea. Diluents specified are acetone and nitrobenzene. The metal salt is made by reacting the dye with, e.g. zinc, in presence of the amide and preferably a catalyst such as potassium methyl sulphate. The product dyes textiles pink shades. In examples: 1 : 4-di-(p-methanesulphonylbenzoylamino)-anthraquinone is (1) heated with zinc dust, potassium methyl sulphate and dimethylformamide, followed by treatment with a solution of sulphur trioxide or methyl chlorosulphonate in dimethylformamide; (2) heated with zinc dust, sodium b -naphthalene sulphonate and N-formylmorpholide, followed by treatment with sulphur trioxide and N-formylmorpholide addition compound. Specifications 274,156, [Class 2 (iii)], and 633,481 are referred to.