To a solution of 5c (0.78 g, 3 mmol) in dry tetrahydrofuran (60 ml) were added activated zinc powder (0.26 g, 3.9 mmol), hydroquinone (6 mg), and ethyl 2-(bromomethyl)acrylate (0.78 g, 4 mmol). The mixture was refluxed under nitrogen atmosphere for 6 h (monitored by TLC). After cooling, it was poured into an ice-cold 5% HCl solution (300 ml), neutralized with 1.0N NaHCO3, and extracted with CH2Cl2 (75 ml×3). The dichloromethane extracts were combined and washed with water, dried over Na2SO4, and then evaporated to give a residual oil which was purified by column chromatography on silica gel using CH2Cl2 as the eluent to afford the title compound (0.59 g, 60%). UV λmax (log ε): 258 (4.70) (0.1N HCl in MeOH), 246 (4.69) (MeOH), 261 (4.59) (0.1N NaOH in MeOH); 1H-NMR (CDCl3): δ1.61 (s, 3H, 2'-CH3), 2.78 (dt, 1H, 3'-H), 3.17 (dt, 1H, 3'-H), 4.50 (s, 2H, OCH2), 5.65 (t, 1H, vinylic H), 6.29 (t, 1H, vinylic H), 6.91 (d, 1H, 3-H), 7.18-7.41 (m, 3H, Ar--H), 8.02 (d, 1H, 4-H). Anal Calcd for C16H15NO4 : C, 67.36; H, 5.30; N, 4.91. Found: C, 67.38; H, 5.32; N, 5.00.
