3.6.5. (E)-3-((E)-1,3-Bis(4-methoxyphenyl)allylidene)-1-methylindolin-2-one (**3dd**)

91% yield; yellow solid; mp = 131.7 ◦C; *R*<sup>f</sup> = 0.21 (silica gel, hexane:EtOAc = 5:1); 1H NMR (500 MHz, CDCl3): *δ* 9.23 (d, *J* = 15.9 Hz, 1H), 7.49 (d, *J* = 8.8 Hz, 2H), 7.19 (dt, *J* = 13.9, 2.3 Hz, 2H), 7.09 (td, *J* = 7.7, 0.8 Hz, 1H), 7.06 (dt, *J* = 14.0, 2.4 Hz, 2H), 6.85 (d, *J* = 8.8 Hz, 2H), 6.74 (d, *J* = 7.7 Hz, 1H), 6.63 (td, *J* = 7.7, 0.8 Hz, 1H), 6.48 (d, *J* = 15.9 Hz, 1H), 5.89 (d, *J* = 7.7 Hz, 1H), 3.9 (s, 3H), 3.82 (s, 3H), 3.30 (s, 3H) ppm; 13C NMR (125 MHz, CDCl3): *δ* 168.2, 160.6, 159.8, 151.8, 142.6, 141.3, 130.1, 130.0, 129.6, 127.9, 126.2, 123.8, 123.4, 121.8, 121.5, 114.6, 114.3, 107.5, 55.49, 55.46, 25.8 ppm; HRMS (EI): calcd for C26H23NO3 [M+]: 397.1678, found 397.1677.
