Diethyl Ether → 1-(Pyridin-2-yl)butan-1-one

Participants

Reaction Steps

A solution of 2-cyanopyridine (2.20 g, 21.13 mmol) in Et2O (35 mL) added over 10 min to a rapidly stirring solution of freshly prepared n-PrMgBr (from n-PrBr (2.71 g, 22.03 mmol) and Mg (0.62 g) in Et2O (35 mL). Once addition was completed, the reaction was heated to reflux in a warm water bath for 2.5 hours. The reaction was cooled to RT then placed in ice, quenched with 5 mL H2O followed by 60 mL 5N H2SO4. The ether phase was separated. The aqueous phase was heated in warm water for 15 minutes, then cooled in ice, basified with sat. K2CO3. The mixture was extracted with CHCl3 and dried over K2CO3. The solution was filtered, concentrated and purified on Biotage Horizon (10-100% A=Hex, B=2:1 Hex:EtOAc) to afford 1.16 g of 1-(pyridin-2-yl)butan-1-one as an oil: 1H NMR (400 MHz, CDCl3) δ ppm 8.67 (ddd, J=4.74, 1.71, 0.88 Hz, 1H), 8.03 (dt, J=7.83, 1.01 Hz, 1H), 7.82 (td, J=7.71, 1.77 Hz, 1H), 7.45 (ddd, J=7.52, 4.74, 1.14 Hz, 1H), 3.15-3.21 (m, 2H), 1.71-1.80 (m, J=7.43, 7.43, 7.43, 7.43, 7.43 Hz, 2H), 1.00 (t, J=7.33 Hz, 3H).

Provenance & Evidence