Process for the preparation of cyanoazo compounds by reacting halogenoazo compounds with CuCN in an aqueous media in the presence of a nitrogen base
AssigneeBayer Aktiengesellschaft
InventorsAlois Gottschlich, Klaus Leverenz, Karl-Ludwig Moritz
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Abstract
Preparation of azo dyestuffs which possess at least one nitrile group in the ortho-position to the azo bridge, by reacting the corresponding ortho-halogenoazo compounds with CuCN or systems which for CuCN, in the presence of nitrogen bases and optionally of surface-active agents, in an aqueous medium, with replacement of at least one halogen substituent, which is in the orthoposition to the azo bridge, by a nitrile group. Preferably the reaction is carried out as one-pot-process. The dyestuffs prepared by the process, a substantial number of which are known, are useful in dyeing natural and synthetic fiber materials.
Claims12
In the cyano exchange process for preparing an azo compound having at least one cyano group ortho to the azo bridge by replacing an ortho halogen substituent with a cyano substituent;
- the improvement which comprises conducting the cyano exchange reaction at a temperature of 10.degree.C to 110.degree.C in an aqueous medium containing a nitrogen base and, CuCN or means for generating CuCN is situ;
- said nitrogen base being present in an amount of 0.05 to 5 moles per mole of CuCN;
- and said aqueous medium comprising water and up to 50 percent by weight of a non-basic, water-miscible organic solvent.
Process of claim in which CuCN is used.
Dependencies are inferred from the claim text.