The present invention refers to dyestuffs of the formula I wherein R is an optionally substituted alkyl group; each of R1, R2 and R3, independently, is H or an optionally substituted alkyl group; each of X1 and X2, independently, is a labile atom or group; and each of A1 and A2, independently, is a chromophoric residue, processes for their preparation and their use for dyeing and printing hydroxy- and/or carboxamido-containing fiber materials.