Abstract: An anthraquinone dye of sparing aqueous solubility of the formula ##STR1## WHEREIN X represents oxygen or NH, Y represents alkylene having 1 to 4 carbon atoms which is optionally interrupted by oxygen, nitrogen or sulphur, Z represents oxygen or -NR.sub.1, in which R.sub.1 represents an alkyl having 1 to 4 carbon atoms or hydrogen, Ac represents the acyl radical of a carboxylic acid having up to 8 carbon atoms, a sulphuric acid having up to 7 carbon atoms or a carbamic acid having up to 8 carbon atoms, and B represents chlorine, bromine or hydrogen. The new dyestuffs dye polyester fibres in very fast blue shades.