Chloro- or bromo-anthraquinone prepn - by halogen reaction with melt of nitro-anthraquinone and halo-anthraquinone diluent

摘要

or Br-anthraquinone prepn. by treatment of the corresponding nitro-anthraquinones in bulk with Cl2 or Br2 takes place by (a) preparing the melt of a mixt. of a nitro-anthraquinone or a nitro-anthraquinone or a Cl- or Br- >10 wt.% Cl- or Br-anthraquinone or a Cl- or Br-anthraquinone mixt., and (b) allowing the halogen to act on melt at 180-300(240-280) degrees C. Products are starting materials for prepn. of vat dispersion dyes, by alkylation, acylation, reaction with glycols or thioalcohols. Process yields products in better yields and purity, is more easily worked up than soln. processes and cheaper. Diluent addn. shortens reaction times, reduces energy consumption, minimises ventilation problems, facilitates handling and allows process to be carried out continuously.