反应详情

In 250 ml of 1N hydrochloric acid and 100 ml of dioxane was dissolved 32.2 g of 2-amino-3,4-diethoxycarbonyl-6-(4-methoxyethoxymethoxyphenyl)pyridine, whereto a solution of 6.9 g (1.3 eq.) of sodium nitrite dissolved in 30 ml of water was added dropwise under ice-cooling. The mixture was stirred for 1 hour and left standing in a refrigerator overnight. The mixture was neutralized with sodium hydrogencarbonate, and dioxane was distilled off, followed by extraction with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium chloride and dried. Then, the solvent was distilled off. The residue was purified by silica gel column chromatography (eluent:dichloromethane→ethyl acetate).

1. additionwas added dropwise under ice-
2. temperaturecooling
3. waitleft
4. customstanding in a refrigerator overnight
5. distillationwas distilled off
6. extractionfollowed by extraction with ethyl acetate
7. washThe organic layer was washed with a saturated aqueous solution of sodium chloride
8. customdried
9. distillationThen, the solvent was distilled off
10. customThe residue was purified by silica gel column chromatography (eluent:dichloromethane→ethyl acetate)