Sumitomo Chemical Company, Limited

Akihiro Taguma

Akira Takeshita

Makoto Hattori

Yutaka Kayane

Narutoshi Hayashi

Toshihiko Morimitsu

An azo-compound, free acid form of which is represented by the following formula (I):

Azo-compounds and dye polarizing films containing them

A process for producing 1,4-diaminoanthraquinone-2,3-disulfonic acid or a salt thereof which comprises reacting a 1,4-diamino-2,3-dihalogenoanthraquinone with a sulfonating agent in an aqueous medium in the presence of at least one of a quaternary ammonium compound and a quaternary phosphonium compound and optionally, in the presence of an inert organic solvent is disclosed. A process for producing 1,4-diamino-2,3-dicyanoanthraquinone which comprises further reacting the thus obtained 1,4-diaminoanthraquinone-2,3-disulfonic acid or salt thereof with a cyanogenation agent is also disclosed.

Process for producing anthraquinone compounds

A process for the production of 1,4-diaminoanthraquinone-2-sulfonic acid or a salt thereof is disclosed, comprising reacting 1-amino-4-bromoanthraquinone-2-sulfonic acid or its salt with liquid ammonia in the presence of a copper catalyst wherein the reaction is carried out in the presence of an inert organic solvent, e.g., n-heptane and cyclohexane. In this process, crystals of the desired product do not substantially deposit on reactor walls, and distillation recovery of ammonia can be performed easily without causing deterioration of the desired product. 1,4-Diaminoanthraquinone-2-sulfonic acid or salt thereof is a useful intermediate for the preparation of, e.g., anthraquinone dyes.

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Hyogo, Japan

Akihiro Taguma