Preparation of chloroanthraquinones from nitroanthraquinones
AssigneeBayer Aktiengesellschaft
InventorKarl-Julius Reubke
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Abstract
The nitro group of an .alpha.-nitroanthraquinone is replaced by chlorine by reaction with an ionic chloride in a solvent in the presence of an acid or of a compound which eliminates an acid. The ionic chloride may be an alkali metal, alkaline earth metal, ammonium or quaternary ammonium chloride. A molten tertiary amine hydrochloride can function as the ionic chloride, the acid and the solvent. The process permits one or more nitro groups of a poly-.alpha.-nitroanthraquinone to be selectively replaced.
Claims10
In the preparation of an .alpha.-chloroanthraquinone by reacting the corresponding .alpha.-nitro compound with a chlorinating agent in a solvent, the improvement which comprises employing an ionic chloride as said chlorinating agent and effecting the chlorination in the presence of an acid or of a compound which eliminates an acid under the reaction conditions, the ionic chloride being selected from the group consisting of inorganic chlorides soluble in the solvent under the reaction conditions, hydrochlorides of tertiary amines, quaternary ammonium chlorides and anion exchangers in the chloride form, and the acid being selected from the group consisting of a mineral acid and a Lewis acid.
Dependencies are inferred from the claim text.