3.2.11. (Z)-3-(2-Bromo-1-phenylethylidene)-1-methylindolin-2-one (**6**)

To a stirred solution of 3-methyleneoxindole **5a** (40.4 mg, 0.162 mmol) were added NBS (34.6 mg, 0.194 mmol, 1.2 equiv.) and AIBN (16 μL, 8.1 μmol, 5 mol%) in anhydrous 1,2 dichloroethane(DCE) (6 mL). The reaction mixture was refluxed under argon atmosphere for 10 h, then cooled to rt and diluted with EtOAc (50 mL) and water (50 mL). The organic layer was separated, dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude residue was purified by column chromatography to afford **6** (38.1 mg, 72% yield) as a yellow solid (mp = 161.5–163.1 ◦C). *R*<sup>f</sup> = 0.53 (silica gel, hexane:EtOAc = 3:1); 1H NMR (500 MHz, CDCl3): *δ* 7.51 (dt, *J* = 4.8, 2.5 Hz, 3H), 7.40–7.35 (m, 2H), 7.18 (td, *J* = 7.7, 1.1 Hz, 1H), 6.75 (d, *J* = 7.8 Hz, 1H), 6.64 (td, *J* = 7.7, 0.9 Hz, 1H), 6.11 (d, *J* = 7.7 Hz, 1H), 5.20 (s, 2H), 3.27 (s, 3H) ppm; 13C NMR (125 MHz, CDCl3) *δ* 167.2, 149.5, 143.4, 139.1, 129.9, 129.4, 129.3, 129.2, 127.8, 123.9, 122.0, 121.9, 108.0, 31.8, 26.0 ppm; HRMS (EI): calcd for C17H14BrNO [M+] : 327.0259, found 327.0254.
