Nippon Steel Corporation

Nippon Steel Chemical Co., Ltd.

Syntex Pharmaceuticals International Limited

Shuichi Mitamura

Koichi Fujishiro

Yasuhisa Tsutsumi

Yoshimi Kata

Yasuhisa Asano

Tamejiro Hiyama

Atsushi Kawada

Hiroharu Inoue

Naoya Okabayashi

Koji Kitajima

Hiroshi Kajiro

Gen-Ichi Tsuchihashi

Process for preparing indan derivatives

The process of this invention for preparing 2,6-naphthalene-dicarboxylic acid comprises a reaction step (Step A) wherein 2,6-naphthalene-dicarboxylic acid potassium salts consisting of 2,6-naphthalene-dicarboxylic acid dipotassium salt and/or 2,6-naphthalene-dicarboxylic acid monopotassium salt are allowed to react with benzene-carboxylic acids in the presence of water to yield 2,6-naphthalene-dicarboxylic acid and benzene-carboxylic acid potassium salts and a separation step (Step B) wherein the crystallized 2,6-naphthalene-dicarboxylic acid is separated from the benzene-carboxylic acid potassium salts dissolved in the aqueous solution and provides 2,6-naphthalene-dicarboxylic acid, useful as raw material for polymers, at low cost on a commerical scale with recycle of potassium.

Process for preparing 2,6-naphthalene-dicarboxylic acid

A process for the preparation of aromatic carboxylic acids or their salts comprises heating carboxyl-free aromatic compounds and aromatic carboxylic acid salts whose basic structures differ from those of the aromatic compounds, or heating polycyclic aromatic compounds with three or more rings and monocyclic or bicyclic aromatic carboxylic acid salts, under carbon dioxide pressure in the presence of one or more metal compounds selected from group (a) of compounds of zinc, cadmium, and thallium and one or more compounds selected from group (b) of compounds of cesium, Group II metals, And Group IIIa metals to effect the intermolecular transfer of the carboxyl groups.

Process for the preparation of aromatic carboxylic acids

Disclosed is a process for the preparation of a naphthalene-2,6-dicarboxylic acid dialkali metal salt which comprises heating an alkali metal salt of naphthoic acid and/or a dialkali metal salt of naphthalene-dicarboxylic acid under pressure with carbon dioxide gas in the presence of a catalyst, wherein an aprotic polycyclic aromatic compound having 2 or 3 rings is used as a reaction medium. Naphthalene-2,6-dicarboxylic acid dialkali metal salt can be obtained in high yield and selectivity with a good reproducibility of the reaction.

Process for preparation of naphthalene-2,6-dicarboxylic acid dialkali

A manufacturing method is described for the preparation of optically active 1-aromatic-group-substituted-1-alkanones characterized in that an optically active alkane acid halide is allowed to react with an aromatic compound in the presence of a Lewis acid. The optically active 1-aromatic-group-substituted-1-alkanones are useful intermediates in the preparation of optically active alpha-arylalkanoic acids, which are useful as pharmaceutical, e.g. anti-inflammatory, analgesic and anti-pyretic, agents and as insecticidal agents.

Optically active 1-aromatic-group-substituted-1-alkanones and methods

Growing community of inventors

Kanagawa, Japan

Shuichi Mitamura