Potassium Carbonate → 1-(5-Ethynylpyridin-2-yl)-4-methylpiperazine

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Reaction Steps

Potassium carbonate (1M aq., 1.5 mL, 1.5 mmol) was added in a drop-wise manner to a solution of 1-methyl-4-(5-((trimethylsilyl)ethynyl)pyridin-2-yl)piperazine (325 mg, 1.19 mmol) in MeOH (5.0 mL) at room temperature, and the resulting mixture was stirred for 2 h. After removal of the solvent in vacuo, water (5 mL) and brine (10 mL) were added and the product was extracted with DCM (150 mL, then 3×10 mL). The combined organic layers were washed with brine (15 mL), dried over Na2SO4 and filtered. Evaporation of the solvent gave 1-(5-ethynylpyridin-2-yl)-4-methylpiperazine (239 mg, quantitative yield), which was used in the next step without purification. 1H NMR (400 MHz, CDCl3) δ ppm 8.32 (s, 1H), 7.55 (dd, J=8.9, 2.1 Hz, 1H), 6.58 (d, J=8.8 Hz, 1H), 3.54-3.67 (m, 4H), 3.08 (s, 1H), 2.46-2.58 (m, 4H), 2.35 (s, 3H); MS ESI [M+H]+ 201.9, calcd for [C12H15N3+H]+ 202.1.

Provenance & Evidence