1‐Amino‐4‐hydroxyanthraquinone‐β‐ethers and thioethers: Red dyes for synthetic‐polymer fibres

Condensation of 1‐amino‐2‐bromo‐4‐hydroxyanthraquinone and of 1‐amino‐3‐bromo‐4‐hydroxyanthraquinone with alcohols, phenols and thiols yields the corresponding β‐ethers and thioethers. These compounds colour polyester in deep rose‐red to violet‐red hues of excellent build‐up and good fastness to light and sublimation. The colour of the dyes is discussed with respect to the nature and orientation of the β‐substituents.