Fiber-reactive azo dyes and dye mixtures, preparation thereof and use thereof

An azo dye of the formula (1)

• in which
• Y is —CH═CH2 or —CH2CH2Z, in which
• Z is an alkali-detachable group;
• R is a radical —COOR1, —CN or —CONR2R3, in which
• R1 is M or (C1-C4)-alkyl;
• R2 and R3 independently of one another are hydrogen or (C1-C4)-alkyl;
• and
• M is hydrogen, ammonium, an alkali metal, or the equivalent of an alkaline earth metal.