Tetrahydrofuran → 1-(6-Bromo-2-methylpyridin-3-yl)-2-oxopyrrolidin-3-yl acetate

関与物質

反応条件

反応手順

A 500 mL round-bottom flask was charged with crude 3-bromo-1-(6-bromo-2-methylpyridin-3-yl)pyrrolidin-2-one from step A (18.5 g), THF (50 mL), 18-Crown-6 (576 mg, 2.18 mmol) and KOAc (12.84 g, 131 mmol). The mixture was heated at 70° C. under argon overnight. After cooling the reaction mixture to room temperature, ethyl acetate (50 mL) was added. The organic layer was separated and washed with water (50 mL), brine (50 mL), dried over MgSO4, filtered and concentrated to a dark solid, which was purified by flash chromatography (silica gel, 20-100% ethyl acetate/hexane) to give 1-(6-bromo-2-methylpyridin-3-yl)-2-oxopyrrolidin-3-yl acetate (8.9 g, 65% yield for two steps) as white solid. 1H NMR (400 MHz, CHLOROFORM-d) δ 7.38 (q, J=8.3 Hz, 3H), 5.43 (t, J=8.2 Hz, 1H), 3.47-4.03 (m, 3H), 2.62-2.90 (m, 1H), 2.38-2.56 (m, 4H), 2.06-2.32 (m, 5H); MS (ESI) 314 (M+H).

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