GB692465A - Metallisable disazo dyestuffs - Google Patents

Abstract

The invention comprises disazo dyestuffs from diazotized anthranilic acid or sulphoanthranilic acid (2 mols. same or mixed in any proportion) and stilbene-bis-pyrazolones of the formula <FORM:0692465/IV (c)/1> (A = hydrogen, methyl, chlorine or bromine); also complex metal derivatives. The dyestuffs are made (1) from 4-amino-41-nitrostilbene-2 : 21-disulphonic acid by condensation with Hal-CO-CH=CA-CO-Hal to give the dinitro-diamide, conversion into the diamino, dihydrazino and dipyrazolone compounds in known manner and coupling with the diazo component; or (2) from the dyestuff <FORM:0692465/IV (c)/2> (or sulphonic acid derivative thereof or mixtures of the two) by condensation with Hal-CO-CH=CA-CO-Hal. The products give yellow dyeings on cotton and regenerated cellulose. They can be metallized on the fibre, in substance or at the stage of the intermediate of method (2). In the examples: (1) 2 mols. of anthranilic acid --> bispyrazolone (A = H); (2) the aminoazo compound of the above formula is treated with fumaric chloride; (3) the sulphonated aminoazo compound (sulpho group pto azo) is treated with fumaric chloride and the product coppered; (4) as in (3) but coppering first; (5) 2 mols. of 5-sulphoanthranilic acid --> bispyrazolone (A = H) and the product coppered; (6) mixtures of anthranilic acid and 5-sulphoanthranilic acid (e.g. 1 : 1, 0.4 : 1.6, 1.6 : 0.4) --> bispyrazolone (A = H) and the products coppered; (7) the two dyestuffs of (6) are prepared separately, mixed and coppered; (8) the aminoazo compounds of (2) and (3) are mixed and treated with fumaric chloride; the product is then coppered; (9) as in (8) the mixed amines being diazotized and coupled with the stilbene pyrazolone. 4-Sulphoanthranilic acid is also specified as a component, together with the dichlorides and dibromides of fumaric, maleic, mesaconic, citraconic, chlorofumaric and bromofumaric acids.