Azo dyes

A compound of formula (1)

• wherein
• R1, R2, independently of each other, represent hydrogen, substituted or unsubstituted alkoxyl, substituted or unsubstituted aryl, substituted or unsubstituted phenyl, amino, sulfonic, carboxyl, hydroxyl, or halogen groups;
• and
• one or both of R1 and R2 is a sulfonic group;
• C, D, independently of each other, represent
• R3 and R5, independently of each other, represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxyl, substituted or unsubstituted aryl, substituted or unsubstituted phenyl, amino, nitro, sulfonic, carboxyl, hydroxyl, or halogen groups;
• R8, R11 and X are as defined below;
• R4, R6, independently of each other, represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxyl, substituted or unsubstituted aryl, substituted or unsubstituted phenyl, amino, sulfonic, carboxyl, hydroxyl, or halogen groups;
• m, n, r, independently of each other, are 0 or 1, and
• s is 1
• A, B independently of each other, represent
• wherein R1, R2 and C are as defined above,
• R7 to R11 represent, independently of each other, hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted phenyl, sulfonic, carboxyl, amino, nitro, hydroxyl, or halogen groups;
• and
• X represents O, S, NH, SO2, CH═CH, NHCO, NH—CO—NH, N═N, or N═N(O).