| 摘要 |
The invention relates to the preparation of storage-stable, concentrated solutions of urea compounds of the formula F1-HN-CO-NH-F2 wherein F1 and F2 denote radicals of dyestuffs or dyestuff intermediates containing acid groups by reacting 2 equivalents of amines of the formula F1,2-NH2 with one equivalent of a compound of the formula Cl-CO-X wherein X is chlorine or an aryloxy radical in the presence of alkaline earth metal ions in the pH range of 4.0 to 8.0, separating off the sparingly soluble alkaline earth metal salt of the resulting urea compounds, adding - for example - a salt of lithium of which the anion forms a salt, which is sparingly soluble in the reaction medium, with the alkaline earth metal cation of the urea compound to the suspension of these urea compounds and separating off the alkaline earth metal salt which has precipitated.
|
