| abstract |
Use of at least one compound of the formula (I) where Ak is C1- to C4-alkylene or C1- to C4-monohydroxyalkylene, R1 is a branched or unbranched C1- to C4-alkyl group, a branched or unbranched, perfluorinated C1 to C4-alkyl group, a branched or unbranched C1-C4-hydroxyalkyl group or an optionally substituted benzyl group, R2, R3 and R4 are each, independently of one another, hydrogen, a nitro group or a branched or unbranched C1- to C4-alkyl group, R5 and R6 are each, independently of one another, hydrogen, a branched or unbranched C1- to C4-alkyl group, a methoxy or ethoxy group, a group RIRIIN-, in which RI and RII, independently of one another, are a hydrogen atom, a C1-C4-alkyl group, a C1-C4-hydroxyalkyl group or a C2-C4-dihydroxyalkyl group, or an amide radical, and R7 and R8 are each, independently of one another, hydrogen, halogen or a branched or unbranched C1- to C4-alkyl group, for colouring keratin fibres, in particular human hair, and a method of colouring keratin fibres by applying corresponding compounds to the fibre to be coloured, and also a specific compound of the formula (I). |