3.2.3. (E)-1-Methyl-3-(1-phenylethylidene)indolin-2-one (**(***E***)-5a**) [19]

13% Yield; yellow solid; mp = 140.4–142.2 ◦C (lit. [19] 142.7-144.1 ◦C); *R*<sup>f</sup> = 0.55 (silica gel, hexane:EtOAc = 4:1); 1H NMR (500 MHz, CDCl3): *δ* 7.51–7.41 (m, 3H), 7.28 (dt, *J* = 3.6, 2.0 Hz, 2H), 7.14 (dd, *J* = 11.2, 4.2 Hz, 1H), 6.76 (d, *J* = 7.8 Hz, 1H), 6.64 (td, *J* = 7.7, 0.8 Hz, 1H), 6.14 (d, *J* = 7.7 Hz, 1H), 3.28 (s, 3H), 2.81 (s, 3H) ppm; 13C NMR (125 MHz, CDCl3) *δ* 168.3, 155.0, 143.1, 142.4, 129.3, 128.4, 128.2, 126.6, 123.5, 122.9, 122.8, 121.5, 107.6, 29.8, 25.9, 23.0 ppm.
