反应详情

A solution of 0.90 g of 7-methyl-3,4-dihydro-1,8-naphthyridin-2(1H)-one in 150 mL of dioxane was heated under reflux while dividedly adding 25.7 g of selenium dioxide, and the mixture was stirred for 10 days. The insoluble substance was filtered off with celite, and the solvent was distilled off under reduced pressure. To the resultant residue, 2-propanol was added, and the solid was filtered off. The solid thus obtained was purified by silica gel column chromatography using an eluent of chloroform:methanol=20:1, and ethyl acetate was added thereto, and the solid was filtered off to obtain 0.48 g of 7-oxo-7,8-dihydro-1,8-naphthyridine-2-carbaldehyde as a light orange solid.

1. temperatureunder reflux
2. filtrationThe insoluble substance was filtered off with celite
3. distillationthe solvent was distilled off under reduced pressure
4. additionTo the resultant residue, 2-propanol was added
5. filtrationthe solid was filtered off
6. customThe solid thus obtained
7. customwas purified by silica gel column chromatography
8. additionmethanol=20:1, and ethyl acetate was added
9. filtrationthe solid was filtered off