反应详情

To a stirred solution of methyl 5-chloro-3-methyl-1H-indole-7-carboxylate (1.4 g, 4.5 mmol) from Step B above in DMF (10 ml) was added sodium hydride (313 mg, 7.8 mmol) in portions. The mixture was stirred at room temperature for 1 h, then potassium iodide (60 mg, 0.4 mmol) and 2-bromo-1,1-dimethoxyethane (2.1 ml, 17.9 mmol) were added. The mixture was heated to 80° C. for 15 h. After cooling to room temperature, the reaction was quenched with saturated aqueous ammonium chloride, extracted with ethyl acetate (3×), washed with brine, filtered, and dried over sodium sulfate. The filtrate was concentrated under reduced pressure and the residue purified by column chromatography (silica gel, 70:30 hexanes/ethyl acetate) to afford methyl 5-chloro-1-(2,2-dimethoxyethyl)-3-methyl-1H-indole-7-carboxylate (908 mg, 68%) as a semitransparent liquid: 1H NMR (500 MHz, CDCl3) δ 7.64 (d, J=1.0 Hz, 1H), 7.61 (d, J=1.0 Hz, 1H), 6.94 (s, 1H), 4.62 (t, J=5.0 Hz, 1H), 4.39 (d, J=5.0 Hz, 1H), 3.96 (s, 3H), 3.30 (s, 6H), 2.27 (s, 3H).

1. temperatureThe mixture was heated to 80° C. for 15 h
2. temperatureAfter cooling to room temperature
3. customthe reaction was quenched with saturated aqueous ammonium chloride
4. extractionextracted with ethyl acetate (3×)
5. washwashed with brine
6. filtrationfiltered
7. dry with materialdried over sodium sulfate
8. concentrationThe filtrate was concentrated under reduced pressure
9. customthe residue purified by column chromatography (silica gel, 70:30 hexanes/ethyl acetate)