Imperial Chemical Industries Limited

John H Moore

Peter M Quan

John R Lawson

James S Hunter

Process for disperse azo dyes having a cyano radical ortho to the azo group by reacting the corresponding halogeno dye with a covalent non-metallic nitrile in the presence of a copper catalyst and an acid acceptor. Previous processes have used a metal cyanide as the cyanide source. The present process does, however, contemplate the use of a non-metallic nitrile, even in small amounts, in combination with a metal cyanide for which advantages are to be gained in terms of reduced copper usage. The non-metallic nitrile is preferably a cyanohydrin which may be prepared in situ by reacting an aldehyde or ketone with a metal cyanide. The metal cyanide may itself provide the copper catalyst.

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Manchester, United Kingdom

John H Moore