AGENT FOR DYEING KERATIN CONTAINING FIBERS
The invention relates to an agent for dyeing keratin containing fibers, especially human hair, comprising at least one cyclopentaquinoxalinium derivative of the formula (I), wherein R<1>, R<2>, R<3> independently represent a hydrogen atom or a C1-C4 alkyl group, and R<1> and R<2> together may form a ring, X<1> and X<2> represent an oxygen or sulfur atom or together a 1,2-arylenediimino group that in turn can be substituted in the aromatic group by halogen atoms, C1-C4 alkyl, C1-C4 alkoxy, nitro, amino, C1-C4 alkyl, C1-C4 alkylamino, hydroxy, carboxy, or sulfo groups or an additional condensed aromatic ring and is quaternated on one of the nitrogen atoms by a C1-C6 alkyl, aralkyl, aryl, C2-C4 alkenyl, or C1-C6 hydroxyalkyl, or carboxyalkyl group, and wherein the additional condensed aromatic ring may be substituted by halogen atoms, in halogen atoms, C1-C4 alkyl, C1-C4 alkoxy, nitro, amino, C1-C4 alkyl, C1-C4 alkylamino, hydroxy, carboxy, or sulfo groups. The invention further relates to the tautomeric forms or the physiologically acceptable salts of the inventive derivative.