2-Amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine → 3-Amino-2-benzyl-8-methoxybenzo[f]quinoxaline

Participants

Reaction Conditions

Reaction Steps

Under an argon atmosphere, to a solution of Hoveyda-Grubbs second generation catalyst (84.5 mg, 135 μmol) in 1,2-dichloroethane (100 mL) was added 2-amino-3-benzyl-5-(4-methoxy-2-vinylphenyl)-6-vinylpyrazine (9) (585 mg, 1.70 mmol) at room temperature. The mixture was then heated to 90° C. and stirred overnight (17 hours). After cooling to room temperature, the mixture was concentrated under reduced pressure. The residue was purified by silica gel flash column chromatography (n-hexane/ethyl acetate=3/1→2/1) to give 3-amino-2-benzyl-8-methoxybenzo[f]quinoxaline (12) as a white solid (136 mg, 431 μmol, 25.3%). TLC Rf=0.64 (n-hexane/ethyl acetate=1/1); NMR (500 MHz, CDCl3) δ 3.98 (s, 3H), 4.39 (s, 2H), 4.63 (s, 2H), 7.21-7.38 (m, 7H), 7.63 (d, 1H, J=9.0 Hz), 7.85 (d, 1H, J=9.0 Hz), 9.00 (d, 1H, J=9.0 Hz); 13C NMR (126 MHz, CDCl3) δ 41.8, 55.4, 107.5, 118.1, 124.9, 125.5, 125.8, 127.2, 128.7 (2C), 129.1 (2C), 130.1, 132.7, 134.6, 136.6, 138.9, 143.1, 151.2, 158.5.

Provenance & Evidence