2-Bromopyridine → (3R)-3-methyl-1-pyridin-2-ylpiperazine

Participants

Reaction Conditions

Reaction Steps

(R)-(−)-2-Methylpiperazine (0.50 g, 0.005 mol, Aldrich) and 2-bromopyridine (5 mL, 0.05 mol) were combined and heated at 120° C. for 14 hours. The reaction mixture was allowed to cool to 23° C. and partitioned between a large volume of ethyl acetate and water. The layers were separated, and then additional water was added to the ethyl acetate solution. Drops of 1 N HCl solution were added to the water/ethyl acetate mixture with vigorous mixing. The layers were separated, and the combined aqueous phases were basified to pH ˜11 with a solution of saturated sodium bicarbonate and solid sodium carbonate. Sodium chloride was added, and the saturated aqueous solution was extracted with chloroform containing a few drops of isopropyl alcohol (5×). The combined organic extracts were dried over Na2SO4, filtered, and the filtrate concentrated under reduced pressure to afford 0.79 g (89% yield) of the title compound. 1H NMR (400 MHz, DMSO-d6) δ 1.02 (d, J=6.0 Hz, 3H), 2.27 (dd, J=10, 12 Hz, 1), 2.67 (m, 3H), 2.92 (m, 1H), 4.07 (m, 2H), 6.58 (dd, J=6, 8 Hz, 1H), 6.77 (d, J=8 Hz, 1H), 7.49 (m, 1H), 8.08 (m, 1H); MS (ESI) m/e 178 (M+H)+.

Provenance & Evidence