VERFAHREN ZUR HERSTELLUNG VON 1-AMINO-4-HYDROXY-2-(6'-HYDROXYHEXOXY)-ANTHRACHINON.

摘要

The patent describes an improved method for the synthesis of 1-amino-4-hydroxy- 2-(6'-hydroxy-hexyloxy)-anthraquinone (I). In III R = phenoxy, in (IV) R = Cl or Br, from 1-amino-4-hydroxy-2-halog-anthraquinone (IV), or 1-amino-4-hydroxy -2-phenoxy-anthraquinone (III), and 1,6-hexanediol with an alkali, in a polyethylene glycol or alcohol-ethylene-oxide adduct. If a halogeno-anthraquinone deriv. is used as starting material, a phenol must be added to the reaction-mixture so as to form the phenoxy-anthraquinone in situ. The method is improved by producing less of a by-product (II) previously found to have been problematic in use, because this by-product causes the dyestuff (I) to be weaker in colour, less heat fixable, less light-stable and causes the polyester in which it is the dye to be less ductile. By the method here described, the quality of by-product (II) in the final product can be reduced to 2% by wt. or below, by heating first to 125-135 deg. C then subsequently to 140-150 deg. C for 4-16 hrs.