Water → N-(3-Benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazin-2-yl)acetamide

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere, to a solution of 2-amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine (9) (100 mg, 292 μmol) in anhydrous pyridine (20 mL) were successively added 4-(dimethylamino)pyridine (DMAP)(3.0 mg, 25 μmol) and acetyl chloride (65.0 μL, 911 μmol) at room temperature. The mixture was heated at 60° C. and stirred for an hour. After cooling to room temperature, to the mixture was added water and the product was extracted with ethyl acetate (×3). The combined organic extract was washed successively with water (×1) and brine (×1), followed by drying over anhydrous sodium sulfate. After filtration and concentration under reduced pressure, the residue was purified by silica gel flash column chromatography (n-hexane/ethyl acetate=3/1) to give N-(3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazin-2-yl)acetamide (10) (89.5 mg, 232 μmol, 79.7%) as a yellow solid. TLC Rf=0.17 (n-hexane/ethyl acetate=3/1); 1H NMR (400 MHz, CDCl3) δ 2.33 (s, 3H), 3.89 (s, 3H), 4.28 (s, 2H), 5.19 (dd, 1H, J=1.0, 10.8 Hz), 5.39 (dd, 1H, J=2.0, 10.8 Hz), 5.66 (dd, 1H, J=1.0, 17.2 Hz), 6.30 (dd, 1H, J=2.0, 17.2 Hz), 6.45 (dd, 1H, J=10.8, 17.2 Hz), 6.52 (dd, 1H, J=10.8, 17.2 Hz), 6.94 (dd, 1H, J=2.6, 8.4 Hz), 7.19-7.24 (m, 5H), 7.27-7.32 (m, 2H).

Provenance & Evidence