反应详情

Under a nitrogen atmosphere, 4.50 g (13.96 mmol) of 4-[6-(2,5-Dimethyl-pyrrol-1-yl)-pyridin-2-yl]-6-ethyl-3-methoxyphenol (7) and 11.64 g (167.5 mmol) of hydroxylamine hydrochloride were combined in 84 mL of ethanol and 14 mL of water. The resultant mixture was allowed to reflux for 16 hours. The reaction mixture was then allowed to cool to ambient temperature and concentrated in vacuo. The resultant yellow residue was partitioned between ethyl acetate (200 mL) and dilute sodium bicarbonate (200 mL). The aqueous layer was extracted again with ethyl acetate (2×200 mL). The combined organic extracts were washed with brine (1×200 mL), dried over sodium sulfate, filtered and concentrated in vacuo to yield crude product as a brown solid. Chromatography of the crude product on 250 g of silica gel 60 (EM Science) using 4:1 ethyl acetate: hexane yielded 1.86 g (55%) of 4-(6-Amino-pyridin-2-yl)-2-ethyl-5-methoxyphenol (8) as a salmon colored solid.

1. temperatureto reflux for 16 hours
2. concentrationconcentrated in vacuo
3. customThe resultant yellow residue was partitioned between ethyl acetate (200 mL) and dilute sodium bicarbonate (200 mL)
4. extractionThe aqueous layer was extracted again with ethyl acetate (2×200 mL)
5. washThe combined organic extracts were washed with brine (1×200 mL)
6. dry with materialdried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customto yield crude product as a brown solid