反应详情

2-(3,5-Dichloro-pyridin-4-yl)-1-(2,3-dihydroxy-4-methoxy-phenyl)-ethanone (450 mg, 1.4 mmol) from preparation 3 was dissolved in dry DMF (10 mL). K2CO3 (566 mg, 4.1 mmol) was added followed by Ethyl iodide (442 μL, 5.5 mmol). The reaction mixture was stirred at rt overnight. Water (10 mL) was added and the organic products were extracted with EtOAc (2×25 mL). The combined organic phases were washed with water (10 mL) and brine (10 mL) and then dried over MgSO4. The solvent was removed in vacuo and the pure product obtained be standard silica gel chromatography to provide 2-(3,5-Dichloro-pyridin-4-yl)-1-(2,3-diethoxy-4-methoxy-phenyl)-ethanone as a white solid. Yield 220 mg (42%). The compound was redissolved in DCM (1 mL) under argon. BCl3 (0.97 mL of a 1M solution in DCM) was added slowly at room temperature. EtOH (2 mL) was added slowly after 2 hours. The solvent were removed in vacuo and the pure product obtained be standard silica gel chromatography to provide 2-(3,5-Dichloro-pyridin-4-yl)-1-(3-ethoxy-2-hydroxy-4-methoxyphenyl)-ethanone was obtained as a white solid. 1H NMR (DMSO-d6) δ=11.36 (1H, s), 8.67 (2H, s), 7.88 (1H, d), 6.77 (1H, d), 4.80 (2H, s), 3.96 (2H, q), 3.91 (3H, s), 1.26 (3H, t). Yield 100 mg (49%)

1. extractionthe organic products were extracted with EtOAc (2×25 mL)
2. washThe combined organic phases were washed with water (10 mL) and brine (10 mL)
3. dry with materialdried over MgSO4
4. customThe solvent was removed in vacuo
5. customthe pure product obtained