Patent ID: 6997961

Claim:
An agent for oxidative dyeing of keratin fibers, said agent containing at least one developer and at least one coupler, wherein said at least one coupler is at least one N-heteroarylmethyl-m-phenylenediamine derivative of formula (I), or a salt thereof with an organic or inorganic acid, wherein X5 denotes sulfur, nitrogen, oxygen, C—R6 or N—R5; X6 denotes sulfur, nitrogen, oxygen, C—R7 or N—R5; X7 denotes sulfur, nitrogen, oxygen, C—R8 or N—R5; R1 denotes hydrogen, a C 1 –C 4 -alkyl group, a C 1 –C 4 -hydroxyalkoxy group or a C 1 –C 4 -hydroxyalkyl group; R2 and R3 can be equal or different and independently of each other denote hydrogen or a C 1 –C 6 -alkyl group; R4, R6, R7, R8 can be equal or different and independently of each other denote hydrogen, a halogen atom, a cyano group, a C 1 –C 4 -alkoxy group, a C 1 –C 6 -alkyl group, a C 1 –C 4 -alkyl thioether group, a mercapto group, a nitro group, an amino group, a C 1 –C 4 -alkylamino group, a di(C 1 –C 4 )-alkylamino group, a di(C 1 –C 4 -hydroxyalkyl)amino group, a C 1 –C 4 -hydroxyalkylamino group, a trifluoromethyl group, a —C(O)CH 3 — group, a —C(O)CF 3 group, an —Si(CH 3 ) 3 group, a C 1 –C 4 -hydroxyalkyl group or a C 3 –C 4 dihydroxyalkyl group; and R5 denotes hydrogen, a C 1 –C 6 -alkyl group, a C 2 –C 4 -hydroxyalkyl group, a phenyl group or an acetyl group; and wherein at least one and at the most two of the X5 to X7 groups denote respectively C—R6 or C—R7 or C—R8 and at the most one of the X5 to X7 groups denote sulfur, oxygen or N—R5.