反应详情

A mixture of ethyl 6-ethoxy-4-hydroxy-7-methyl-1,8-naphthyridine-3-carboxylate (10.0 g), 5M sodium hydroxide solution (200 ml), IMS (64 ml) and water (64 ml) was boiled under reflux for 2 hours. The mixture was cooled to ambient temperature and then filtered. The residue was dissolved in water, acidified to pH 5 with glacial acetic acid and filtered. The residue was triturated with hot IMS, cooled and filtered to give 6-ethoxy-4-hydroxy-7-methyl-1,8-naphthyridine-3-carboxylic acid, m.p. 259°-261° C.

1. temperatureunder reflux for 2 hours
2. filtrationfiltered
3. dissolutionThe residue was dissolved in water
4. filtrationfiltered
5. customThe residue was triturated with hot IMS
6. temperaturecooled
7. filtrationfiltered