反应详情

A mixture ethyl 6-ethoxy-4-(4-methoxyanilino)-7-methyl-1,8-naphthyridine-3-carboxylate (6.38 g), water (40 ml), sodium hydroxide solution (120 ml, 0.6M) was boiled and stirred under reflux for 2 hours and then allowed to cool. The mixture was acidified with 5M hydrochloric acid (100 ml) and filtered. The filtrate was extracted with dichloromethane to give a residue which was washed with 5M hydrochloric acid and filtered to give 6-ethoxy-4-(4-methoxyanilino)-7-methyl-1,8-naphthyridine-3-carboxylic acid, m.p. 259°-263° C.

1. temperatureunder reflux for 2 hours
2. temperatureto cool
3. filtrationfiltered
4. extractionThe filtrate was extracted with dichloromethane
5. customto give a residue which
6. washwas washed with 5M hydrochloric acid
7. filtrationfiltered