反应详情

温度

60 °C

A mixture of 10 g of ethyl 4-hydroxy-7-methyl-1,8-naphthyridine-3-carboxylate and 50 ml of phosphorus oxychloride was heated at 60°C with stirring for 1 hour. The excess phosphorus oxychloride was removed under reduced pressure and the product was poured into ice-water. The insoluble matter was filtered off, the filtrate was adjusted to pH 8 by the addition of aqueous ammonia under cooling and extracted with ether. The extracts were dried over anhydrous magnesium sulfate. Then 0.5 g of activated carbon was added to the ether extracts for decoloration. The ether extracts were filtered, concentrated to a small volume and cooled. The precipitate was filtered to provide 8.6 g of ethyl 4-chloro-7-methyl-1,8-naphthyridine-3-carboxylate as yellow needles, m.p. 99°-100°C (decomp.).

1. customThe excess phosphorus oxychloride was removed under reduced pressure
2. additionthe product was poured into ice-water
3. filtrationThe insoluble matter was filtered off
4. additionthe filtrate was adjusted to pH 8 by the addition of aqueous ammonia
5. temperatureunder cooling
6. extractionextracted with ether
7. dry with materialThe extracts were dried over anhydrous magnesium sulfate
8. additionThen 0.5 g of activated carbon was added to the ether
9. filtrationThe ether extracts were filtered
10. concentrationconcentrated to a small volume
11. temperaturecooled
12. filtrationThe precipitate was filtered