The present invention relates to azo dyes of formula wherein R1 denotes hydrogen or C1-C12alkyl which is unsubstituted or substituted by one or more C1-C12alkoxy groups, C1-C12alkylcarbonyl groups, C7-C25arylcarbonyl groups, hydroxyl groups, amino groups, cyano groups or halogen atoms and which may be interrupted one or more times by the radical —O—, —S—, —NR4—, —COO— or —OOC—, R4 is hydrogen or C1-C12alkyl; X is hydrogen or halogen; and R2 and R3 are each independently of the other hydrogen; C1-C12alkyl which is unsubstituted or substituted by cyano, carboxy, hydroxy, C1-C6alkoxy or C2-C8alkoxyalkoxy; or are C7-C25aralkyl which is unsubstituted or substituted by cyano, carboxy, hydroxy, C1-C6alkoxy or C2-C8alkoxyalkoxy, to mixtures containing said dyes and to the use thereof in dyeing or printing semi-synthetic and especially synthetic hydrophobic fibre materials, more especially textile materials.