| abstract |
Treating compounds of the formula ##STR1## in which the nuclei marked "A" and "B" can be substituted by halogen, lower alkyl, lower alkoxy or phenyl, with acid binding agents at elevated temperatures in polar organic solvents yields compounds of the formula ##STR2## in which A and B have the same meaning. The products are dyestuffs of high brillancy, pure shades, high fluorescence, excellent tinctorial strength and good fastness to light. |