Patent GB-580175-A (GB)
Title: Manufacture of new dyestuffs
IPC: C09B43/16
Filed: 1943-04-02
Abstract: Polyazo dyes of the general formula <FORM:0580175/IV/1> wherein R1 represents a residue of the benzene series carrying an o-hydroxycarboxylic acid grouping, R2 and R3 represent benzene or naphthalene residues of middle components, two x's each represent H and one x represents a residue <FORM:0580175/IV/2> containing a residue of the benzene series carrying an o-hydrocycarboxylic acid grouping, the NH being connected to such residue through a CO group or a carbon atom of a <FORM:0580175/IV/3> grouping of a 6-membered heterocyclic ring containing 3 or 4 carbon atoms and 3 or 2 nitrogen atoms and containing the grouping <FORM:0580175/IV/4> at least twice, and through a bridge containing at least 1 nitrogen atom (including a bridge containing an azo group), are obtained by (a) coupling a diazotised aminodisazo compound of the formula R1-N=N-R2-N=N-R3-NH2, containing at least one sulphonic acid group, with the appropriate aminonaphtholsulphonic acid derivative, or (b) coupling such a diazotised aminodisazo compound with a corresponding aminonaphtholsulphonic acid derivative in which two x's each represent H and one x represents a primary amino group or an amino group containing as a substituent the residue of a carboxylic acid containing an aromaticallybound primary amino group, e.g. an amino group acylated by an aminoaroyl or arylcarbamic acid group and linking the product by means of a compound carrying 2 replaceable halogen atoms with an amine containing a residue of the benzene series carrying an o-hydroxycarboxylic acid grouping.  Specified first components R1-NH2 are 1-amino-4-hydroxybenzene-3-carboxylic acid and its 5-methyl and 5-sulphonic acid derivatives and the 5-chloro, 5-nitro and 5-sulphonic acid derivatives of 1-amino-2-hydroxybenzene-3-carboxylic acid.  Specified middle components providing the residues R2 and R3 (which may be used in some cases in the form of their -methanesulphonic acids) are 1-aminonaphthalene and its 2 - ethoxy derivative, 1 - aminonaphthalene - 6 - and 7-sulphonic acids and their 2-methoxy or 2-ethoxy derivatives, aniline and its 3-methyl, 2 : 5-dimethyl, 2- or 3-methoxy, 2 : 5-dimethoxy or diethoxy, 2-methoxy- or ethoxy-5-methyl, 3-acetylamino and 2-methoxy- or ethoxy-5-acetylamino derivatives.  Specified compounds providing the CO and heterocyclic linkages by condensation with amino compounds are phosgene, terephthaloyl chloride, cyanuryl chloride or bromide, 2 : 4-dichloroquinazoline, 2 : 4 : 6-tribromopyrimidine, 2 : 4 - dichloro - 6 - methyl - pyrimidine and 1 : 3 - dichloro - 5 - phenyl - or methyl - 2 : 4 : 6 - triazine.  The products dye natural or artificial fibres of cellulose grey shades of which the fastness to light and to wet treatments is improved by treatment with metal (e.g. copper) salts, during or after the dyeing operation.  Numerous examples are given.  2-Methoxy- and 2-ethoxy-5-acetylaminoanilines are obtainable by nitrating 4-methoxy- or 4-ethoxy-aniline in concentrated sulphuric acid, acetylating the product and reducing the nitro-group.  The Specification as open to inspection under Sect. 91 comprises also a reference to a dye-stuff in which the residue A of the grouping <FORM:0580175/IV/5> is separated from the -NH- group by a link <FORM:0580175/IV/6> This subject-matter does not appear in the Specification as accepted.