VERFAHREN ZUR HERSTELLUNG KATIONISCHER ANTHRACHINON-FARBSTOFFE

Cationic anthraquinone dyestuffs of the formula (I) wherein R1 denotes hydrogen, alkyl or cycloalkyl, R2 denotes hydrogen, alkyl or bromine, R3 denotes alkylene, R4 and R5 denote alkyl, aryl or aralkyl, R6 denotes alkyl or aralkyl and X(-) denotes an anion, and the substituents mentioned can in turn be substituted by non-ionic radicals, are prepared by reacting anthraquinones of the formula (II) with amines of the formula (III) in the presence of a proton acceptor and of copper salts as a catalyst, in a solvent mixture consisting of 50 to 90% of one or more aprotic, non-polar or slightly polar solvents and 10 to 50% of one or more protic or aprotic, polar solvents, trapping the acid formed during the reaction by bases which do not precipitate the catalyst and then quaternizing the product, without intermediate isolation.