Preparation of hydroxyanthraquinones
AssigneeAmerican Color & Chemical Corporation
InventorWilliam A. Michalowicz
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Abstract
A process for preparing hydroxyanthraquinones from the corresponding nitroanthraquinones is provided. A nitroanthraquinone is reacted with a metal salt selected from sodium formate, potassium formate, sodium carbonate and potassium carbonate, in a specific reaction medium at a reaction temperature and for a time sufficient to convert the nitroanthraquinone to the corresponding hydroxyanthraquinone.
Claims8
A process for preparing a dihydroxyanthraquinone comprising reacting a dinitroanthraquinone with a metal salt selected from the group consisting of sodium formate and potassium formate at a molar ratio of metal salt to dinitroanthraquinone of at least 1.1 and in a reaction medium selected from the group consisting of dimethylformamide;
- dimethylacetamide;
- tetramethylurea;
- N-methylpyrrolidone;
- dimethylsulfoxide;
- tetramethylene sulfone;
- dimethylsulfone;
- N,N-dimethylmethylcarbamate and pyridine at a temperature of from 80.degree. C. to 150.degree. C. and separating the dihydroxyanthraquinone from the reaction system.
Dependencies are inferred from the claim text.