反应详情

A mixture containing 7-chloro-1-ethyl-6-fluoro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid (1.0 g), pyrrolidine (1.31 g), and acetonitrile (80 ml) was heated under reflux for 2 hours. The reaction mixture was concentrated to dryness under reduced pressure. The residue was mixed with 5% hydrochloric acid (25 ml) and the mixture was heated on a steam-bath for several minutes and then cooled. The resulting precipitate was collected, washed with water, and recrystallized from chloroform-ethyl acetate to give 1.0 g of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-pyrrolidinyl)-1,8-naphthyridine-3-carboxylic acid, m.p. 299°-300° C.

1. temperaturewas heated
2. temperatureunder reflux for 2 hours
3. concentrationThe reaction mixture was concentrated to dryness under reduced pressure
4. additionThe residue was mixed with 5% hydrochloric acid (25 ml)
5. temperaturethe mixture was heated on a steam-bath for several minutes
6. temperaturecooled
7. customThe resulting precipitate was collected
8. washwashed with water
9. customrecrystallized from chloroform-ethyl acetate