反应详情

To a solution of 2-(6-chloro-2-pyridinyl)-1-(4-fluorophenyl)ethanone (74.9 g, 299.8 mmol) in methanol (900 mL) was added hydroxylamine hydrochloride (104 g, 1.49 mol) followed by sodium hydroxide (600 mL, 10% aqueous, 1.5 mol). The resultant suspension was heated to reflux for 2 hours and then cooled to room temperature. The mixture was concentrated in vacuo and the residue taken up in ether and water. The organic layer was washed with brine. The aqueous layer was extracted with ether and the combined organics were dried over magnesium sulfate. Filtration and concentration gave a solid residue which was purified by recrystallization from ethyl acetate-hexanes to provide 2-(6-chloro-2-pyridinyl)-1-(4-fluorophenyl)ethanone oxime (67.9 g, 86%) as a white solid. 1H NMR (CDCl3): δ 8.69 (s, 1 H), 7.71 (dd, 2 H), 7.53 (t, 1 H), 7.18–7.16 (m, 2 H), 7.03 (t, 2 H), 4.37 (s, 2 H); 19F NMR (CDCl3) δ −111.77; MS m/z 265 (M+1).

1. temperatureto reflux for 2 hours
2. concentrationThe mixture was concentrated in vacuo
3. washThe organic layer was washed with brine
4. extractionThe aqueous layer was extracted with ether
5. dry with materialthe combined organics were dried over magnesium sulfate
6. filtrationFiltration and concentration
7. customgave a solid residue which
8. customwas purified by recrystallization from ethyl acetate-hexanes