Process for the synthesis of nitrite ion-containing 1:1 complexes of cobalt and metallizable monoazo or azomethine compounds and such complexes

摘要

By metallization of metallizable monoazo or azomethine dyes with cobalt-donating compounds in the presence of a nitrite, especially NaNO. sub.2, 1:1 cobalt complexes containing a nitrite ion are obtained in a high degree of metallization which can be reacted with metallizable monoazo or azomethine dyes to give very homogeneous 2:1 cobalt complexes in a high degree of purity. This is particularly advantageous when asymmetrical 2:1 cobalt complexes are to be prepared. The process is particularly useful for the preparation of nitrite ion-containing 1:1 complexes of cobalt and a monoazo compound of the formula ##STR1## wherein X is --OH or --NHR,PPwherein R is hydrogen or a substituted or unsubstituted alkyl, cycloalkyl, phenyl or naphthyl group, PPRing A is further unsubstituted or further substituted by at least one halo, nitro or optionally substituted alkyl, alkoxy or sulfamoyl substituent, andPPTHE NAPHTHALENE RING IS FURTHER UNSUBSTITUTED OR FURTHER SUBSTITUTED BY AT LEAST ONE HYDROXY, SULFAMOYL OR ACYLAMINO SUBSTITUENT.