Kabushiki Kaisha Ueno Seiyaku Oyo Kenkyujo

Kabushiki Kaisha Ueno Seiyaku Oyo Kenkujo

Kabushiki Kaisha Veno Seiyaku Oyo Kenkyujo

Yoshiro Uchiyama

Ryuzo Ueno

Masaya Kitayama

Shigeji Mori

Kuniyo Yanagawase

Syungo Nara

The present invention provides a process for separating and purifying alkali metal salts of hydroxynaphthalenecarboxylic acids, in which alkali metal salt(s) of hydroxynaphthalenecarboxylic acid(s) are separated and purified from a mixture of alkali metal salts of hydroxynaphthalenecarboxylic acids by treating it with a nonionic porous synthetic adsorbent using water or water and water-soluble organic solvent(s).

Process for separating and purifying alkali metal salts of hydroxynaphthalenecarboxylic acids

The present invention relates to a process for preparing 2-hydroxynaphthalene-3,6-dicarboxylic acid which comprises reacting potassium 2-naphtholate and carbon dioxide at a temperature 290.degree. C. or higher under a pressure 30 kg/cm.sup.2 (G) or higher. According to this process, 2-hydroxynaphthalene-3,6-dicarboxylic acid can be obtained in high yield.

Process for producing 2-hydroxynaphthalene-3,6-dicarboxylic acid

Method for separating and purifying hydroxynaphtalenecarboxylic acids

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Sanda, Japan

Yoshiro Uchiyama