Cationic Naphthyldiazo Dyes and Keratin Fibers-Coloring Agents Containing These Dyes

Cationic naphthyldiazo dyes of general formula (I)

• wherein
• R1 stands for a hydrogen atom, halogen atom, straight-chain or branched (C1-C4)-alkyl group, straight-chain or branched (C1-C4)-alkoxy group, phenyl group or (C2-C4)-hydroxyalkyl group;
• R2 and R3 can be equal or different and independently of each other stand for a hydrogen atom, hydroxyl group, amino group, acetylamino group, (C1-C6)-alkoxy group, (C2-C4)-hydroxyalkoxy group, (C3-C6)-di- or polyhydroxyalkoxy group, —COOR group, —NRR′ group or —CONRR′ group, wherein R and R′ can be equal or different and stand for a hydrogen atom, a straight-chain or branched (C1-C6)-alkyl group or a hydroxyethyl group, or R and R′ together with the nitrogen atom to which they are attached form a heterocycle with at least four ring members optionally containing other heteroatoms and R and R′ and the afore-described heterocycle possibly being substituted with an alkyl group, alkoxy group, hydroxyalkyl group or aminoalkyl group;
• G stands for a nitrogen atom or a methine group (CH);
• Y stands for an oxygen atom, or an N—(C1-C4)-alkyl group;
• L represents a bridging group and stands for a straight-chain or branched (C1-C14)-alkylene group which optionally can be interrupted by one or more heteroatoms, the bridging group optionally being substituted with one or more hydroxyl groups, monohydroxy-(C2-C6)-alkyl groups, polyhydroxy-(C2-C6)-alkyl groups or (C1-C6)-alkoxy groups;
• Q+ stands for a saturated cationic group of formula (II) or an unsaturated cationic group of formulas (III) to (V)
• wherein
• R4 to R6 can be equal or different and independently of each other denote a straight-chain or branched (C1-C6)-alkyl group, (C2-C4)-hydroxyalkyl group, (C3-C6)-dihydroxyalkyl group, (C3-C6)-polyhydroxyalkyl group or (C1-C6)-alkoxy-(C1-C4)-alkyl group, wherein two of the R4 ro R6 groups together with the nitrogen atom to which they are attached form a five-membered or six-membered heterocycle optionally interrupted by one or more heteroatoms such as an oxygen atom, sulfur atom or nitrogen atom and optionally bearing other substituents, for example a halogen atom, hydroxyl group, amino group, straight-chain or branched (C1-C6)-alkyl group, (C1-C6)-alkoxy group, (C1-C6)-alkoxy-(C1-C4)-alkyl group or hydroxyethyl group;
• R7 stands for a straight-chain or branched (C1-C8)-alkyl group, allyl group, vinyl group, hydroxyethyl group or benzyl group;
• R8 stands for a hydrogen atom, straight-chain or branched (C1-C8)-alkyl group, amino group, di-(C1-C6)-alkylamino group or pyrrolidino group;
• R9 stands for a straight-chain or branched (C1-C8)-alkyl group, allyl group, vinyl group, hydroxyethyl group, dihydroxypropyl group or benzyl group, and
• X− stands for an anion.