Process for preparing 1,4-diaminoanthraquinone-2,3-disubstituted compound
AssigneeSumitomo Chemical Company, Limited
InventorsMakoto Hattori, Satoshi Kajitani
Life of this patent
Estimating the term…
Abstract
1,4-Diaminoanthraquinone-2,3-disulfonic acid or salt thereof and 1,4-diaminoanthraquinone-2,3-dinitrile which are intermediate of anthraquinone dyes are economically prepared by allowing 1,4-diamino-2,3-dihalogenoanthraquinone to react with alkalimetal sulfite in aqueous solution in the presence of quaternary ammonium or phosphonium compound, while water is being removed, to obtain 1,4-diaminoanthraquinone-2,3-disulfonic acid or salt thereof and, if necessary, cyanogenating the reaction mixture above without removing the disulfonic acid or salt thereof produced above to obtain 1,4-diaminoanthraquinone-2,3-dinitrile. The quaternary ammonium or phosphonium compound is recovered from and re-used for the reactions above.
Claims23
A process for producing 1,4-diaminoanthraquinone-2,3-disulfonic acid, which comprises reacting 1,4-diamino-2,3-dihalogenoanthraquinone in water with a sulfonating agent in the presence of at least one quaternary compound selected from quaternary ammonium compounds and quaternary phosphonium compounds, while removing water out of the reaction system.
A process for producing 1,4-diaminoanthraquinone-2,3-dinitrile, which comprises subjecting 1,4-diamino-2,3-dihalogenoanthraquinone in water with a sulfonating agent in the presence of at least one quaternary compound selected from quaternary ammonium compounds and quaternary phosphonium compounds, while removing water out of the reaction system, and subjecting the reaction mixture containing 1,4-diaminoanthraquinone-2,3-disulfonic acid and the quaternary compound to cyanogenation reaction with a cyanogenating agent.
Dependencies are inferred from the claim text.