3.2.5. Synthesis Method of Intermediate Phenylhydrazine

The purchased phenylhydrazine hydrochloride was dissolved in dichloromethane, and 3 M potassium hydroxide was added to carry out the reaction at room temperature, with attention to the whole process to avoid light, and the reaction lasted for about 1–3 h. The organic phase was extracted with dichlorohexane, and the solvent was removed on a rotary evaporator at low pressure. The temperature of solvent removal was not more than 40 ◦C. When the solvent was removed by rotary evaporation, the white solid product was phenylhydrazine.

#### 3.2.6. Synthesis Method of Target Compounds **A1–A10**

The Intermediate IV was dissolved in N, N-dimethylformamide (DMF), and then, the corresponding alcohol hydroxyl compounds were added, and the reaction was reflux at 110 ◦C for 3 h. After the reaction was over, the organic phase was extracted with dichloromethane and, then, washed with salt water. After that, the organic phase was dried with anhydrous magnesium sulfate, and the solvent was removed at low pressure on the rotary evaporator. The crude product was first purified by silica gel column chromatography with the ratio of petroleum ether/ethyl acetate (2/1) eluent to remove other impurities, and then, it was purified with the ratio of dichloromethane/methanol (40/1). Finally, the target compound was obtained.

#### 8-chloro-5-methyl-11-phenoxy-5H-indolo[2,3-b]quinoline (**A1**)

Yield, 81%; brown solid, m.p. 195–196 ◦C (DMSO); 1H NMR (400 MHz, Chloroform*d*) *δ* 8.23–8.18 (m, 1H), 7.81 (d, *J* = 6.3 Hz, 2H), 7.66 (s, 1H), 7.43 (d, *J* = 8.1 Hz, 1H), 7.32 (d, *J* = 2.4 Hz, 1H), 7.24–7.17 (m, 1H), 7.12–7.07 (m, 1H), 7.01 (d, *J* = 1.3 Hz, 1H), 7.00–6.94 (m, 2H), 6.93–6.89 (m, 1H), 6.89–6.83 (m, 1H), 4.36 (s, 3H). 13C NMR (100 MHz, Chloroform-*d*) *δ* 161.65, 157.40, 156.01, 153.26, 150.68, 137.10, 133.47, 130.50, 129.16, 128.51, 123.61, 123.44, 122.30, 121.43, 119.47, 119.40, 118.76, 116.40, 116.25, 114.56, 114.50, 113.53, 32.46. MS-ESI *m*/*z*: calcd for C22H15ClN2O[M + H]+: 359.0873; found: 359.1959.
