N-(8-chloro-5-methyl-5H-indolo[2,3-b]quinolin-11-yl)-4-methoxybenzamide (**C8**)

Yield, 52%; brown solid, m.p. 310–312 ◦C (DMSO); 1H NMR (400 MHz, DMSO-*d*6) *δ* 11.76 (s, 1H), 8.55 (d, *J* = 8.5 Hz, 1H), 8.45 (d, *J* = 8.8 Hz, 1H), 8.28 (d, *J* = 8.4 Hz, 2H), 7.99–7.84 (m, 1H), 7.83 (s, 1H), 7.69 (d, *J* = 8.5 Hz, 1H), 7.49 (d, *J* = 9.3 Hz, 1H), 7.22

(d, *J* = 8.4 Hz, 3H), 4.56 (s, 3H), 3.92 (s, 3H). 13C NMR (100 MHz, DMSO-*d*6) *δ* 164.13, 159.40, 141.21, 137.57, 134.20, 134.09, 133.57, 131.17 (2C), 128.24, 126.53, 126.38, 124.10, 122.41, 121.53, 119.93, 117.15, 114.62 (2C), 113.74, 105.36, 99.87, 56.15, 37.66. MS-ESI *m*/*z*: calcd for C24H18ClN3O2[M + H]+: 416.1063; found: 416.1347.

#### N-(8-chloro-5-methyl-5H-indolo[2,3-b]quinolin-11-yl)hexanamide (**C9**)

Yield, 73%; white solid, m.p. 284–286 ◦C (DMSO); 1H NMR (400 MHz, DMSO-*d*6) *δ* 11.64 (s, 1H), 8.54 (d, *J* = 8.4 Hz, 1H), 8.40 (d, *J* = 9.0 Hz, 1H), 8.16 (t, *J* = 8.1 Hz, 1H), 7.92–7.70 (m, 3H), 7.51 (d, *J* = 8.6 Hz, 1H), 4.53 (s, 3H), 2.83 (t, *J* = 8.0 Hz, 2H), 1.77 (m, 2H), 1.40 (m, 4H), 0.94 (t, *J* = 7.0 Hz, 3H). 13C NMR (100 MHz, DMSO-*d*6) *δ* 172.28, 155.32, 141.07, 137.62, 135.13, 130.64, 129.75, 127.92, 126.73, 126.48, 125.11, 123.61, 120.74, 117.65, 113.30, 102.48, 36.16, 31.52, 24.93, 22.40, 14.42. MS-ESI *m*/*z*: calcd for C22H22ClN3O[M + H]+: 380.1451; found: 380.1520.

#### N-(8-chloro-5-methyl-5H-indolo[2,3-b]quinolin-11-yl)-3-methylbutanamide (**C10**)

Yield, 81%; white solid, m.p. > 400 ◦C (DMSO); 1H NMR (400 MHz, DMSO-*d*6) *δ* 11.56 (s, 1H), 8.49 (d, *J* = 8.3 Hz, 1H), 8.41 (d, *J* = 8.9 Hz, 1H), 8.17 (t, *J* = 8.0 Hz, 1H), 7.88 (m, 2H), 7.80 (s, 1H), 7.52 (d, *J* = 8.4 Hz, 1H), 4.51 (s, 3H), 2.82–2.61 (m, 2H), 2.33–2.17 (m, 1H), 1.08 (d, *J* = 6.7 Hz, 6H). 13C NMR (100 MHz, DMSO-*d*6) *δ* 171.64, 156.39, 142.78, 137.24, 134.07, 131.54, 129.15, 128.32, 126.71, 126.48, 124.85, 123.35, 120.63, 119.24, 117.69, 100.58, 45.12, 34.61, 25.83, 22.93 (2C). MS-ESI *m*/*z*: calcd for C21H20ClN3O[M + H]+: 366.1295; found: 366.1364.

#### N-(8-chloro-5-methyl-5H-indolo[2,3-b]quinolin-11-yl)-2-fluorobenzenesulfonamide (**D1**)

Yield, 73%; yellow solid, m.p. 302–305 ◦C (DMSO); 1H NMR (400 MHz, DMSO-*d*6) *δ* 12.82 (s, 1H), 8.85 (d, *J* = 8.3 Hz, 1H), 8.12 (d, *J* = 8.3 Hz, 1H), 8.01 (d, *J* = 8.8 Hz, 1H), 7.96 (t, *J* = 5.2 Hz, 1H), 7.89 (t, *J* = 7.6 Hz, 1H), 7.59 (t, *J* = 7.3 Hz, 1H), 7.56–7.50 (m, 1H), 7.50 (s, 1H), 7.32 (m, 2H), 7.13 (d, *J* = 8.4 Hz, 1H), 4.16 (s, 3H). 13C NMR (100 MHz, DMSO-*d*6) *δ* 162.75, 159.84, 157.34, 155.04, 148.19, 138.47, 138.30, 133.46 (d, *J* = 8.0 Hz), 132.61, 129.91, 129.63, 128.09, 124.54 (d, *J* = 3.5 Hz), 123.88, 123.20, 121.82 (d, *J* = 5.0 Hz), 117.30, 117.09, 116.32, 111.58, 107.23, 35.20. MS-ESI *m*/*z*: calcd for C22H15ClFN3O2S[M + H]+: 440.0547; found: 440.1713.
