反应详情

The product from Example 10B (110 mg, 0.2 mmol) and hydroxylamine hydrochloride (0.69 g, 10 mmol) were dissolved in methanol (6 ml) and heated at reflux for 18 hours. The mixture was allowed to cool to room temperature and the methanol was removed under reduced pressure. The residue was taken up in water, extracted with 10% methanol in methylene chloride, the aqueous layer was brought to pH 7 with aqueous sodium bicarbonate, and extracted again with ethyl acetate. All the organic layers were combined, dried with magnesium sulfate, filtered, and the filtrate concentrated under reduced pressure. The residue was purified by flash chromatography eluting with 5% methanol in methylene chloride, followed by preparative thin-layer chromatography eluting with 10% methanol in methylene chloride to provide the title compound (20 mg, 18% yield) and the bis(oxime) (28 mg, 24% yield). 1H NMR (CD3OD) δ 9.37 (d, 1H, J=7 Hz), 8.73 (d, 1H, J=2 Hz), 8.61 (d, 1H, J=2 Hz), 8.41 (d, 1H), J=7 Hz), 8.08 (dd, 1H, J1=7 Hz, J2=2 Hz), 7.96 (dd, 1H, J1=7 Hz, J2=2 Hz), 7.00-6.95 (m, 2H), 6.63 (narrow m, 2H), 8.10-8.05 (m, 2H), 7.98-7.94 (m, 2H); MS (ESI+) 566 (M+H)+.

1. temperatureheated
2. temperatureat reflux for 18 hours
3. customthe methanol was removed under reduced pressure
4. extractionextracted with 10% methanol in methylene chloride
5. extractionextracted again with ethyl acetate
6. dry with materialdried with magnesium sulfate
7. filtrationfiltered
8. concentrationthe filtrate concentrated under reduced pressure
9. customThe residue was purified by flash chromatography
10. washeluting with 5% methanol in methylene chloride
11. washeluting with 10% methanol in methylene chloride