The invention relates to a process for the manufacture of 1:1 metal complexes of azines of the formula ##STR1## wherein R.sub.1 is a hydrogen atom, an alkyl or aryl group, R.sub.2 is an isocyclic or heterocyclic radical containing a hydroxyl or mercapto group adjacent to the azomethine group, Y is the radical of a compound which contains active methylene groups, or of an aryl or heteroaryl amine, and the ring A can contain substituents that do not confer solubility in water, which process comprises reacting a compound of the formula ##STR2## wherein R.sub.3 is a hydrogen atom or an alkyl radical, R.sub.4 is an alkyl, aryl or heteroaryl radical or the radical of the formula ##STR3## or R.sub.3 and R.sub.4, together with the nitrogen atom to which they are attached, form a 5- or 6-membered heterocyclic ring, and Y has the given meaning, with a hydrazone of the formula ##STR4## in the presence of a transition metal donor and in a polar organic solvent, at temperatures above 100.degree. C.Compared with pigments obtained by the prior art methods, the pigments of this invention have greater purity and better fastness properties, especially better fastness to migration, overspraying, light, atmospheric influences and heat.