Alkali metal salts of quinolinecarboxylic acid derivatives and process for purifying quinoline-carboxylic acid derivatives by using the salts

摘要

A process for purifying quinolinecarboxylic acid derivatives of general formula (I) (wherein R is halogeno or methyl), characterized by reacting a quinolinecarboxylic acid derivative of general formula (I) with an alkali metal compound to form an alkali metal salt of the derivative, isolating the salt, and treating the resulting salt with an acid; alkali metal salts of quinolinecarboxylic acid derivatives (I); and antimicrobial agents containing the salts as the active ingredient. The process makes it possible to purify quinolinecarboxylic acid derivatives (I) in a short time at a sufficiently high purity and a high recovery, thus being industrially useful as a simple and efficient purification process for the derivatives (I). Further, the alkali metal salts of the derivatives (I) are useful as intermediates for the purification and as antimicrobial agents.