Otsuka Pharmaceutical Company, Limited

D. Western Therapeutics Institute, Inc.

Norio Fukuda

Takao Nishi

Minoru Okada

Hiroyoshi Hidaka

Yasuo Koga

Yoshihiro Inoue

Yoshito Kihara

Yukio Kimura

Kengo Kawasaki

Takayuki Ikeda

Takeshi Sekine

Shinji Nishitani

The invention provides an improved process for preparing rebamipide that is useful as a medicament, which makes it possible to prepare rebamipide with high purity and high yield. The invention is an improved process for preparing rebamipide of the formula (1), comprising subjecting a carbostyril amino acid compound of the formula (5) or a salt thereof containing a compound of the formula (11) as an impurity to a reduction treatment in the presence of hydrogen and a catalyst in a basic aqueous solution, thereby selectively reducing the impurity compound (11) to transform into the carbostyril amino acid compound (5); and then acylating the compound (5) in a basic aqueous solution to give rebamipide (1). 

Process for preparing rebamipide

The invention provides an improved process for preparing a carbostyril compound (1) or a salt thereof that is useful as a medicament, which makes it possible to prepare it more safely and efficiently. In more detail, the invention provides an improved process for preparing the carbostyril compound (1) by heating the compound (4) with a high boiling solvent in hydrochloric acid under reflux to give the compound (5) safely; and then acylating the compound (5). 

Process for production of carbostyril compound

Carbostyril derivatives

Growing community of inventors

Tokushima, Japan

Norio Fukuda