摘要 |
Dyestuffs of the formula <IMAGE> in which D is the radical of an aromatic or heterocyclic diazo component and K is the radical of an aromatic or heterocyclic coupling component, or is the radical of an active methylene compound, are obtained in an ecologically advantageous manner by reacting an aromatic or heterocyclic diazo components of the formula D-NH2and a coupling component of the formula H-Kwith a nitrite, for example NaNO2, in the presence of CO2 at a pressure of 5-100 at. The process is suitable in particular for the preparation of concentrated dye-stuff solutions, because expensive operations, such as, for example, pressure permeation and reverse osmosis, can be omitted.
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