Sumitomo Chemical Company, Limited

Makoto Hattori

Akira Takeshita

Akihiro Taguma

Satoshi Kajitani

Yasuyoshi Ueda

Toshihiko Morimitsu

Masao Nishikuri

Kaneo Yokoyama

Anthraquinone compounds of the formula, ##STR1## wherein R is hydrogen, alkyl or cycloalkyl, which are useful as intermediates for disperse dyes and as sublimable dyes for thermal transfer recording, are prepared by allowing the compound of the formula, ##STR2## wherein X is hydrogen or sulfonic acid group, to react with a cyanogenating agent in an aqueous medium in the presence of a compound, such as polyalkylene glycols.

Method for producing anthraquinone compounds

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.

Process for preparing 1,4-diaminoanthraquinone-2,3-disubstituted compound

1-Amino-2-phenoxy-4-hydroxyanthraquinones, which are useful as a red disperse dye for polyester fibers, and also useful as an intermediate for the production of other red disperse dyes, are produced in a high yield and purity by reacting a 1-amino-2-halogeno-4-hydroxyanthraquinone with a phenol compound in a sulfane solvent in the presence of an acid binding agent.

Method for producing 1-amino-2-phenoxy-4-hydroxyanthraquinones

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.

Process for producing 1,4-diaminoanthraquinone-2-sulfonic acid

In a process for producing an anthraquinone dye intermediate, 1,4-diamino-2,3-dicyanoanthraquinone, by reacting 1,4-diaminoanthraquinone-2-sulfonic acid, a salt thereof, 1,4-diaminoanthraquinone-2-cyanoanthraquinone, 1,4-diamino-2,3-disulfonic acid, or a salt thereof with a cyanogenating agent in an aqueous medium, the yield and quality of the product can be improved markedly by carrying out the reaction in the presence of a quaternary ammonium compound, and further, depending upon the starting material used, in the presence or absence of a dehydrogenating agent.

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Osaka, Japan

Makoto Hattori