New disazo dyestuffs containing a di(cyanoethyl) group and their application to the dyeing of synthetic fibres

摘要

The invention comprises disazo dyestuffs of the formula wherein X is H, Cl, CH3 or OCH3; Ar is a benzene or naphthalene residue and the nuclei A and Ar may be substituted by halogen atoms, CH3, OCH3 or OC2H5. They may be obtained by coupling a diazotized aminobenzene, which may be substituted, with the N-methyl omega sulpho derivative of another aminobenzene or of an alpha-aminonaphthalene, which may be substituted, as coupling component saponifying the monoazo derivative, diazotizing the resulting aminoazo compound and coupling in acid medium with a dicyanoethyl derivative of the formula Examples are given for the production of the dyes. They may be used for dyeing synthetic fibres such as polyester and cellulose triacetate fibres yellow-orange to red-orange or brownish red colours.