Dyestuffs of the formula ##STR1## wherein D represents the radical of an aromatic carbocyclic or heterocyclic diazo component,K represents the radical of a carbocyclic or heterocyclic coupling component,A and B represent a direct bond or a bridge member,R.sub.1 represents hydrogen, C.sub.1 -C.sub.4 -alkyl, optionally substituted phenyl or naphthyl, carbo-C.sub.1 -C.sub.4 -alkoxy, cyano or optionally substituted carboxamide,R.sub.2 represents C.sub.1 -C.sub.4 -alkyl or optionally substituted phenyl or naphthyl andm and n represent 0, 1 or 2, and the sum of m and n denotes 1 or 2,Are suitable for the dyeing of natural and synthetic fibre materials, particularly polyamide materials in level, violet to blue-green shades in good color yield and with good fastness properties.