1-Methylpiperidine-2,3-dione → 3-Ethynyl-3-hydroxy-1-methylpiperidin-2-one

Participants

Reaction Steps

To a solution of ethynylmagnesium bromide (0.5M in tetrahydrofuran, 4 mL, 2 mmol) maintained under nitrogen at −20° C. was added a solution of 1-methylpiperidine-2,3-dione (220 mg, 0.87 mmol) in tetrahydrofuran (3 mL) dropwise with stirring within 1 min. The reaction mixture was stirred for 2 hr at room temperature and then quenched by the addition of saturated ammonium chloride solution (1 mL). The mixture was diluted with DCM (50 mL), dried over anhydrous sodium sulfate and concentrated under vacuum. The crude residue was purified on a silica gel column, elution with ethyl acetate/petroleum ether (0:1-1:0) afforded the title compound (40 mg, 30%) as a brown oil: 1H NMR (400 MHz, CDCl3) delta 4.23 (s, 1H), 3.35-3.30 (m, 2H), 2.95 (s, 3H), 2.47 (s, 1H), 2.35-2.16 (m, 2H), 1.97-1.90 (m, 2H). LC-MS m/z=+154 [M+H]+.

Provenance & Evidence