1-CYCLOPROPYL-6-FLUORO-7-(8-METHOXYIMINO-2,6-DIAZA-SPIRO[3.4]OCT-6-YL)-4-OXO-1,4-DIHYDRO-[1,8]NAPHTHYRIDINE-3-CARBOXYLIC ACID ASPARTIC ACID SALT, PROCESS FOR THE PREPARATION THEREOF AND PHARMACEUTICAL COMPOSITION COMPRISING THE SAME FOR ANTIMICROBIAL

摘要

A 1-cyclopropyl-6-fluoro-7-(8-methoxyimino-2,6-diaza-spiro[3.4]oct-6-yl)-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid aspartic acid salt is provided to improve physicochemical properties including solubility and stability as compared to phosphate or hydrochloride thereof, and minimize toxicity, so that the compound is useful as antimicrobial agent in food and medicines. A 1-cyclopropyl-6-fluoro-7-(8-methoxyimino-2,6-diaza-spiro[3.4]oct-6-yl)-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid aspartic acid salt represented by the formula(1) is prepared by reacting 1-cyclopropyl-6-fluoro-7-(8-methoxyimino-2,6-diaza-spiro[3.4]oct-6-yl)-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid with aspartic acid in inert organic solvent selected from ethyl acetate, methanol, ethanol, isopropanol, acetone, acetonitrile, hexane, isopropyl ether and water. An antimicrobial pharmaceutical composition comprises 1-cyclopropyl-6-fluoro-7-(8-methoxyimino-2,6-diaza-spiro[3.4]oct-6-yl)-4-oxo-1,4-dihydro-[1,8]naphthyridine-3-carboxylic acid aspartic acid salt, and is formulated as injection. The aspartic acid salt is D-aspartic acid salt, L-aspartic acid salt or racemic mixture thereof.