Brominated Diamino Dihydroxyanthraquinones. Blue Dyes for Synthetic-polymer Fibres

The synthesis of all the isomeric mono-, di-, tri and tetrabromo derivatives of 1,8-diamino-4,5-dihydroxyanthraquinone and of 1,5-diamino-4,8-dihydroxyanthra-quinones is described. The effect of the number and orientation of bromine atoms on the dyeing and fastness properties of these dyes on polyester fibres is reported. Synergistic effects pertinent to the dyeing and fastness properties of mixtures of unbrominated and brominated derivatives are also noted.