| 摘要 |
The disclosure relates to a process for preparing a (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid substance of formula (I), comprising: (a) reacting Compound 3 with a first aqueous base followed by neutralizing to obtain a primary (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid hydrate; (b) dehydrating the primary (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid hydrate from step (a) and reacting the dehydrated product with a second aqueous base followed by neutralizing to obtain a secondary (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid hydrate; and (c) dehydrating the secondary (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid hydrate obtained in step (b) to obtain the (+)-1,4-dihydro-7-[(3S,4S)-3-methoxy-4-(methylamino)-1-pyrrolidinyl]-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acid substance, wherein the first and second aqueous bases are selected from potassium hydroxide, sodium hydroxide, and lithium hydroxide, and the neutralizations of steps (a) and (b) are accomplished with acetic acid, and the dehydration of steps (b) and (c) are accomplished with ethanol. |
