1,4-Dioxane → 1-(5-Ethylpyridin-2-yl)ethanone

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-(5-bromopyridin-2-yl)ethanone (6.30 g, 31.5 mmol; Supplier=Kalexsyn; Lot=90) and [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (560 mg, 0.76 mmol) in dioxane (120 ml) was degassed by sparging with N2 for 10 minutes. Added a solution (15% w/w) of diethyl zinc in hexane (50 ml) slowly, dropwise and heated to 50° C. The orange mixture turned dark, ultimately generating a dark orange with yellow solids as it stirred at 50° C. for 30 minutes. Allowed to cool to room temperature. The reaction mixture was partitioned between EtOAc (200 ml) and water (200 ml), and the aqueous phase was extracted 2× with EtOAc. The combined organic phases were washed with brine (500 ml), dried (Na2SO4), filtered and evaporated in vacuo to give 4.14 g brown oil. Distilled under high vac using short-path distillation apparatus. BP=55° C. @ 0.32 torr to give 2.249 g of slightly tinted oil. 1H-NMR (CDCl3): δ 8.50 (d, J=1.9 Hz, 1H), 7.96 (d, J=7.9 Hz, 1H), 7.63 (dd, J=8.0, 2.2 Hz, 1H), 2.71 (m, 2H), 2.69 (s, 3H), 1.27 (t, J=7.6 Hz, 3H). HPLC: 2.011 min., 57 area % @ 210 nm; 2.012 min., 75 area % @ 254 nm. LCMS: MS (ESI—) for C10H12O m/z 150.1 (M+H)+.

Provenance & Evidence