7-Nitro-2,1,3-benzoxadiazole derivatives and 7-nitro-2,1,3-benzthiadiazole derivatives and dyes, which contain these compounds and which are used for dying keratin fibers

4-Nitro-2,1,3-benzoxadiazole derivatives and 4-nitro-2,1,3-benzthiadiazole derivatives of the general Formula

• 4
• in which
• X is oxygen or sulfur
• Y1 and Y2 may be the same of different and, independently of one another, represent a nitrogen atom or a nitrogen monoxide group (NO),
• R1 and R2 may be the same of different and, independently of one another, may be hydrogen, a halogen atom, a (C1-C4) alkyl group, (C1-C4) alkyl group substituted with a halogen atom, a (C1-C4) alkoxy group, a nitro group or an NRaRb group, the Ra and Rb being the same or different and, independently of one another, representing hydrogen, a (C1-C4) alkyl group, an optionally substituted, aromatic carbocyclic group or a (C1-C4) alkane carbonyl group, or Ra and Rb, together with the nitrogen atom, form a heterocyclic (C3-C6) group, V represents hydrogen, an aliphatic group, an aromatic isocyclic group, an aromatic heterocyclic group, a cyano group or a carbonyl function (CO)—R3, wherein R3 represents hydrogen, a hydroxy group, a (C1-C4) alkoxy group, an amino group, a (C1-C4) alkylamino group, a (C1-C6) alkyl group or an aryl group,
• W represents a cyano group or a carbonyl function (CO)—R4, R4 representing hydrogen, a hydroxy group, a (C1-C4) alkoxy group, an amino group, a (C1-C4) alkylamino group, a (C1-C6) alkyl group or an aryl group;
• alternatively, V and W can also jointly form an aliphatic or aromatic isocyclic or heterocyclic ring system;
• and
• Kat+ represents an alkali cation, an alkaline earth cation, a quaternary ammonium group, a quaternary phosphonium group or a sulfonium group.