GB815840A - New sulphur dyestuffs of the dioxazine series - Google Patents

Abstract

The invention comprises sulphur dyestuffs of the dioxazine series and a process for making them by transforming a dioxazine compound of the general formula <FORM:0815840/IV (c)/1> (wherein R is an iso- or heterocyclic residue which may be substituted and X is is halogen) or a sulphonic acid thereof into a corresponding sulphochloride and treating it with an acidic reducing agent. The sulphochlorides are made by treating a dioxazine of the above formula with chlorosulphonic acid at up to 150 DEG C. or by treating a sulphonic acid thereof with phosphorus pentachloride or chlorosulphonic acid. Acid reducing agents specified are mixtures of water and hydrochloric acid with iron powder, zinc dust or stannous chloride. In examples, the dioxazines derived from chloranil and (1) aniline; (2) 1-amino-2-methoxy-5-methyl-benzene; (3) dehydrothiotoluidine followed by ring closure with organic acid halides, phosphorus halides or ferric chloride in nitrobenzene, and the corresponding dioxazine containing no methyl substituents, (4) a - and b -naphthylamine; (5) 2-aminodiphenylene oxide or 2-amino-3-methoxydiphenylene oxide; (6) p-aminodiphenyl; (7) o-aminodiphenyl ether; (8) 3-aminocarbazole and 3-amino-N-ethyl-carbazole; (9) 3-aminopyrene; (10) 2-amino-chrysene; and (11) 2-aminoflourene followed by ring closure by boiling in nitrobenzene, are treated with chlorosulphonic acid and reduced. The dyestuffs dye vegetable fibres such as cotton red, purple, violet and blue shades from a sodium sulphide vat followed by air or potassium dichromate oxidation. The shades may be brightened and fastness improved by an aftertreatment with perborates, percarbonates or potassium dichromate-acetic acid-copper sulphate. Specifications 886/1912 [Class 2 (Iii)], and 416,887 are referred to.