Patent GB-677204-A (GB)
Title: Manufacture of new azo-dyestuffs
IPC: C09B29/30
Filed: 1950-08-24
Abstract: Naphthalene - amino - phenylbenzthiazoles of the formula <FORM:0677204/IV (b)/1> where R is a 2-phenylbenzthiazole residue attached via the phenyl residue and the NHR group is attached in a b -position of the naphthalene ring, are obtained by reacting aminophenyl-benzthiazoles with aminonaphtholsulphonic acids or dihydroxy - naphthalenesulphonic acids in the presence of sulphites. Examples show the production of 2-[41-(511-oxynaphthyl - 211 - aminophenyl)] - 6 - methylbenzthiazole - X : 711 - disulphonic acid, 2-[41 - (811 - oxynaphthyl - 211 - aminophenyl)]-6 - methylbenzthiazole - X : 611 - disulphonic acid and 2 - [41 - (811 - oxynaphthyl - 211-aminophenyl)] - 6 - methylbenzthiazole - 611-sulphonic acid, X indicating that the position of attachment to the phenylbenzthiazole nucleus is uncertain.  Other products are listed; the phenyl residue may carry a methyl substituent.  The starting materials are obtained by acylating 2-amino-thiophenol with nitrobenzoyl chloride, ring-closing with hydrochloric acid, sulphonating, reducing the nitro group to an amino group and again sulphonating if desired.ALSO:The invention comprises azo dyestuffs of the formula <FORM:0677204/IV (c)/1> where R1 is the residue of a diazo component, R is a 2-phenylbenzthiazole residue attached via the phenyl group and -NHR is in one of the b -positions in the naphthalene ring. R1 preferably contains an o-metallizable group, e.g. hydroxy, methoxy or carboxy, together with an o-hydroxy-carboxylic group if desired.  R1 may be of the benzene or naphthalene series and may contain a further arylazo group.  The phenylbenzthiazole residue may be substituted, e.g. by methyl or sulphonic acid groups.  When R1 contains an amino group (or acylamino converted thereto by hydrolysis), two mols. of the dyestuff or one mol. of this and one mol. of another aminoazo dyestuff may be linked together with phosgene or a halogen substituted heterocyclic compound, e.g. cyanuric chloride or dichloroquinazoline.  Similarly, when R1 contains a nitrogroup, two mols. may be linked by reducing the nitro groups to azo or azoxy, or alternatively the nitrogroups may be reduced to amino and reacted as above.  The products dye cellulosic fibres such as linen, cotton, artificial silk or staple fibre from regenerated cellulose.  They may be metallised (especially coppered) in substance, in the dyebath or on the fibre, e.g. by the process of Specification 455,274 or 644,883.  In the examples: (1) the dyestuff 2-aminophenol-4-sulphonamide --> 2-[41-(511-oxynaphthyl-211-aminophenyl)] - 6 - methylbenzthiazole disulphonic acid is prepared and coppered; (2) 5-amino-salicylic acid is diazotized and coupled with the same component; (3) tetrazotized benzidine is coupled with one mol. of salicylic acid and one mol. of 2-[31- or 41-(811-oxynaphthyl - 211-aminophenyl)] - 6 - methylbenzthiazole disulphonic acid; (4) 4-amino-41-hydroxyazobenzene-31-carboxylic acid is diazotized and coupled with the components of (3); (5) 4 - amino - 41 - hydroxyazobenzene - 3 : 31-dicarboxylic acid is diazotized and coupled with 2 - [41 - (811 - oxynaphthyl - 211 - aminophenyl - 6 - methylbenzthiazole - 611 - sulphonic acid; (6) 5-nitro-anthranilic acid is diazotized and coupled with the 41-component of (3); the product is reduced with glucose and alkali, and may be coppered if desired; (7) the nitro-dyestuff of (6) is reduced with sodium sulphide and reacted with one mol. of phosgene together with one mol. of 4-amino-41-hydroxyazobenzene-31-carboxylic acid; (8) as in (6) using as diazo component 5-nitro-2-aminoanisole; coppering may precede reduction; (9) the dyestuff 8-(p-chlorobenzenesulphonyloxy) - 1 - naphthylamine-3 : 6-disulphonic acid --> 4-methoxy-m-toluidine is diazotized and coupled with the component of (1) or (6) and the sulphonic ester group then hydrolysed; (10) cotton is dyed with the product of example (3)-41-isomer-and after-coppered in one of three ways.  Various other substituted anilines, naphthylamines and p-aminoazobenzenes are specified as diazo components, including the dyestuffs 2-naphthylamine-4 : 8-disulphonic acid --> and 1-amino-8 - naphthol - 3 : 6 - disulphonic acid --> 4-methoxy-m-toluidine.  Other coupling components are mentioned.