Ciba-Geigy Corporation

Roland Ronco

Willy Stingelin

Pierre Pessonneaux

Ernst Hanggi

Ermanno Ciapponi

The invention relates to a continuous process for the preparation of cationic azo or hydrazone dyes from heterocyclic diazo components and coupling components. The diazo component is diazotised in water and an acid, the diazo solution is coupled with the coupling component and continuously alkylated, preferably using sufficient acid that, after the alkylation, a two-phase system forms, consisting of an aqueous solution which is substantially free from dye and a highly concentrated oil phase or solid dye.

Preparation of cationic azo or hydrazone dyes in which the alkylation

A process for the preparation of 2,4,6-tris(aminophenylamino)triazines by condensing s-trichlorotriazine with 3 equivalents of a partially protected phenylenediamine and subsequently removing the protective groups, which process comprises carrying out the condensation in an anhydrous or water-containing aliphatic C.sub.2 -C.sub.4 alcohol, in the presence of an acid acceptor. 2,4,6-Tris(aminophenylamino)triazines are important intermediates in dyestuff chemistry and are used, inter alia, for synthesizing textile, leather and paper dyes as well as pigments.

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Pfeffingen, Switzerland

Roland Ronco