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AssigneeCiba-Geigy Corporation
InventorsHorst Langfeld, Claudio Puebla, Gunter Sereinig
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Process for the preparation of azo dyes of the formula ##STR1## in which K is the radical of a coupling component of the benzene or naphthalene series or of the heterocyclic series in which the hydroxyl group is attached to K in a position adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion or ammonium ion, which comprises coupling a diazo component of the formula ##STR2## in the presence of an alkali metal chloride and ammonium chloride with a coupling component of the formula (3) ##STR3## K and X in the formulae (2) and (3) being as defined under formula (1). The present invention allows the preparation of the said azodyes in high yields.
A process for the preparation of azo dyes of the formula ##STR40## in which K is benzene, naphthalene or heterocyclic radical in which the hydroxyl group is attached to K in a position adjacent to the azo group, X is hydrogen or nitro and M is an alkali metal ion or ammonium ion consisting essentially of coupling a diazo component of the formula ##STR41## in the presence of 5-molar to 15-molar amount of an alkali metal chloride and ammonium chloride, relative to the molar amount of the diazo component of the formula (2), with a coupling component of the formula (3) ##STR42## K and X in the formulae (2) and (3) being as defined under formula (1).
Dependencies are inferred from the claim text.