The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1976
Filed:
Mar. 19, 1975
Mitsui Toatsu Chemicals, Incorporated, Tokyo, JA;
Abstract
1-Aminoanthraquinone of high purity is obtained either by catalytically hydrogenating 5-nitro-1,4,4a,9a-tetrahydroanthraquinone dissolved in a polar organic solvent such as methyl cellosolve (i.e., .beta.-hydroxyethyl methyl ether) in the presence of a hydrogenation catalyst such as palladium on carbon or Raney nickel and then treating the resultant hydrogenated product with a base such as sodium hydroxide or pyridine, or by catalytically hydrogenating the 5-nitro-1,4,4a,9a-tetrahydroanthraquinone in the presence of both the hydrogenation catalyst and the base. By the action of the base, the 5-nitro-1,4,4a,9a-tetrahydroanthraquinone nucleus releases hydrogen atoms and is converted to the anthraquinone nucleus, and the released hydrogen serves to reduce the nitro group. Where an excess of hydrogen is introduced into the reaction system for hydrogenation, 1-aminoanthraquinone is further reduced into a leuco type compound thereof which can easily be returned to 1-aminoanthraquinone by oxidation.