Process for the preparation of metallisable azo dyes
AssigneeCiba-Geigy Corporation
InventorsHans P. Joswig, Werner Huber
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Abstract
A process for the preparation of azo dyes of formula ##STR1## wherein K is the radical of a coupling component of the benzene or naphthalene series or of the heterocyclic series, and the hydroxy group is attached to K adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion or an ammonium ion, which process comprises coupling a diazo component of formula ##STR2## in the presence of a zinc salt and in an inert gas atmosphere, to a coupling component of formula ##STR3## in which formula (2) and (3) above K and X are as defined for formula (1). The process makes it possible to obtain the azo dyes in high yield.
Claims15
A process for the preparation of an azo dye of formula ##STR8## wherein K is the radical of a coupling component of the benzene or naphthalene series or of the heterocyclic series, and the hydroxy group is attached to K adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion or an ammonium ion, which process comprises coupling a diazo component of formula ##STR9## in the presence of a zinc salt and in the substantial absence of surface active agents in an inert gas atmosphere, and at a temperature from 30.degree. to 35.degree. C. to a coupling component of formula ##STR10## in which formulae (2) and (3) above K and X are as defined for formula (1).
Dependencies are inferred from the claim text.