GB495672A - The manufacture of azo dyestuffs - Google Patents

Abstract

Azo dyes are made by combining diazo compounds containing a metallizable group in o-position to the diazo group with monoaminonaphthol derivatives, acylated in the amino group by succinic acid with the formation of an -NH.CO.CH2.CH2.COOH group, or by treating the corresponding azo dyes which contain the amino group unsubstituted in the aminonaphthol residue with succinic anhydride. They are particularly useful for dyeing wool and can be converted in substance or on the fibre into metal complex compounds, e.g. by copper or chromium salts. In examples the manufacture of the following dyes is described: (1) 4-nitro- or 4-chloro-2-aminophenol-6-sulphonic acid --> 2-succinylamino - 7 - naphthol; (2) 4 - chloro - 2 - aminophenol --> 2 - succinylamino - 8 - naphthol-6 - sulphonic acid and 6-nitro-4-methyl-2-aminophenol --> 2 - succinylamino - 8 - naphthol - 6 - sulphonic acid or 1-succinylamino-5 - naphthol - 7 - sulphonic acid; (3) 6-nitro-4 - methyl - 2 - aminophenol or 5 - nitro-2 - aminophenol --> 1 - succinylamino - 8-naphthol - 6 - sulphonic acid. Specification 295,944, [Class 2 (iii)], is referred to. Mono - succinylaminonaphthol derivatives may be prepared by treating the corresponding amino compounds with succinic anhydride in the presence of an acid binding agent. The Specification as open to inspection under Sect. 91 comprises the production of azo dyes containing a succinylamino group by (1) combining diazo components containing a succinylamino group with any coupling components; (2) combining any diazo components with coupling components containing a succinylamino group; (3) treating azo dyes containing a free amino group with succinic anhydride. It includes the following additional examples: (1) 1 - succinylamino - 3 - aminobenzene - 4-sulphonic acid (obtained by the action of succinic anhydride on an aqueous solution of 1.3 - phenylenediamine - 4 - sulphonic acid in the presence of sodium acetate) --> (acid) 2 - amino - 8 - naphthol - 6 - sulphonic acid, 2 - acetylamino - 8 - naphthol - 6 - sulphonic acid or 1-benzoylamino-5-naphthol-7-sulphonic acid; 1-succinylamino-4-aminobenzene-3-sulphonic acid is also specified as diazo component; (2) 4.41-diaminodiphenyl-cyclohexane \sQ 1- or 2-succinylamino-5-naphthol-7-sulphonic acid; (4) 4-chloro-2-aminophenol --> 1-succinylamino-7-naphthol-3-sulphonic acid; (6) 2.4-dimethyl-1-aminobenzene-6-sulphonic acid --> 2-amino-8-naphthol-6-sulphonic acid is treated with succinic anhydride in aqueous solution; (7) 1-nitro-2-amino-4-succinylamino-benzene (obtained by heating 2.4 - diamino - 1 - nitrobenzene with succinic anhydride) --> (alkaline) 2-amino-8-naphthol - 3.6 - disulphonic acid, 2-phenylamino- or 2-(41-methoxyphenylamino)-8-naphthol - 6 - sulphonic acid; if N.N-dimethylaniline is coupled in slightly acid medium the product dyes acetate artificial silk orange shades; (8) 1-succinylamino-4-aminobenzene --> p-cresol or 1-phenyl-3-methyl-5-pyrazolone dyes acetate artificial silk. In addition to wool and acetate artificial silk the products are stated to be capable of dyeing silk, cotton, artificial silk and mixed fabrics. This subject-matter does not appear in the Specification as accepted.