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US 5,132,437 AGranted
Synthesis of 1-aminoanthraquinone
AssigneeHoechst Celanese Corporation
InventorsMohammad Aslam, Daniel A. Aguilar
Life of this patent
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Abstract
1-Aminoanthraquinone (1-AAQ) is synthesized by the reaction of 2-chlorobenzyl chloride and xylene in the presence of a solid acid catalyst to yield 2-chloro dimethyldiphenylmethane, subsequent oxidation of the methyl groups, ring closure to form a 1-chloroanthraquinone carboxylic acid, replacement of the 1-chloro group with ammonia, and decarboxylation.
Claims30
A process for producing a compound of the formula ##STR4## comprising reacting a benzyl compound having the structural formula:
- ##STR5## wherein X and Y may be the same or different and are selected from the group consisting of halogen, hydroxy, alkoxy, thioalkyl, nitro, and sulfonyl, with xylene in the presence of a solid acid catalyst consisting of a member of the group consisting of alumina, silica-alumina, aluminophosphates, aluminosilicates, and silicalites.
A process for preparing 1-aminoanthraquinones from a 2-substituted benzyl compound having the structural formula:
- ##STR6## wherein X and Y may be the same or different and are selected from the group consisting of halogen, hydroxy, alkoxy, nitro and sulfonyl, which comprises the steps of (i) reacting said 2-substituted benzyl compound with xylene in the presence of a solid acid catalyst consisting of a member of the group consisting of alumina, silica-alumina, aluminophosphates, aluminosilicates, and silicalites for a period of time sufficient to obtain a 2-substituted dimethyldiphenylmethane, (ii) oxidizing said 2-substituted dimethyldiphenylmethane for a period of time sufficient to obtain a 2-substituted benzophenonedicarboxylic acid;
- (iii) contacting said benzophenonedicarboxylic acid with an acid for a period of time sufficient to obtain a 1-substituted anthraquinonecarboxylic acid;
- and (iv) contacting said anthraquinonecarboxylic acid with ammonia or an amine of the formula RNH.sub.2 wherein R is alkyl, cycloalkyl, or aryl for a period of time sufficient to obtain a 1-aminoanthraquinone-carboxylic acid.
Dependencies are inferred from the claim text.