Phenyl-azo-indole compounds

Monoazo dyestuffs which in the form of the free acid correspond to the general formula WHEREIN R1 is hydrogen or alkyl; R2 is hydrogen, halogen, alkyl, alkoxy, nitro, nitrile, carbonamide or carboxylic acid ester; R3 is hydrogen, halogen, alkyl or alkoxy; R4 is alkyl or aryl; R5 is hydrogen or alkyl, R6 is hydrogen, halogen or alkyl; R7 is hydrogen, halogen, alkyl, alkoxy or nitrile; X is C2-C4-alkylene, aralkylene or phenylene; Y is SO3H or, if X is phenylene, SO3H or a radical -SO2-NH-SO2-R8; and R8 is alkyl, aryl or dialkylamine. These dyestuffs are used for the dyeing of natural and synthetic fibre materials, especially for dyeing polyamide fibres. They yield level yellow to orange dyeings with very good fastness to light. Dyestuffs are absorbed well on polyamide fibres even in a neutral to weakly acid dyebath. The dyestuffs are employed in the form of the free acid or in the form of its salts, especially the alkali salts, such as the sodium or potassium salts or the ammonium salts.