GENERAL STEPS: Aniline (0.465 g, 5.0 mmol) and benzaldehyde (0.53 g, 5.0 mmol) were dissolved in ethanol (10 mL) and stirred at room temperature for 5 minutes. Subsequently, 8-hydroxyquinaldine (0.795 g, 5.0 mmol) and a catalytic amount of pyridine (2 drops) were added to the reaction system, and the mixture was heated to 100 °C for 24 h at reflux. The reaction process was monitored by thin layer chromatography (TLC, unfolding agent ratio acetonitrile:water = 3:2) and liquid chromatography-mass spectrometry (LC-MS). After completion of the reaction, the solvent ethanol was removed by rotary evaporator to obtain the crude product. The crude product was purified by fast column chromatography with the eluent being hexane solution containing 2% ethyl acetate. The fraction containing the target compound was collected and allowed to stand overnight in a fume hood to afford the needle-like crystal product 2-methyl-7-(phenyl(phenylamino)methyl)quinolin-8-ol (0.92 g, 54% yield). The structure of the product was confirmed by 1H NMR, 13C NMR, high resolution mass spectrometry (HRMS-ESI) and elemental analysis.1H NMR (500 MHz, CDCl3, δ): 7.97 (d, J = 8.4 Hz, 1H), 7.51 (d, J = 8.5 Hz, 1H), 7.48 (m, 2H), 7.31 (m, 2H), 7.24 (m, 3H), 7.10 (m, 3H), 7.10 (m, 3H), 7.11 (m, 3H), 7.11 (m, 3H). 3H), 7.10 (m, 2H), 6.67 (m, 1H), 6.63 (m, 2H), 6.12 (d, J = 3.4 Hz, 1H), 4.49 (s, 1H), 2.69 (s, 3H); 13C NMR (125 MHz, CDCl3, δ): 157.3, 148.6, 147.7, 142.8, 137.8 , 136.2, 129.3, 128.8, 127.6, 127.4, 125.8, 125.7, 124.2, 122.7, 117.86, 117.78, 113.8, 57.0, 25.1; HRMS-ESI (m/z): [M-C6H6N]+ calcd for C23H20N2O 248.10754, found 248.10762. Elemental analysis calcd (%) for C23H20N2O: C, 81.15; H, 5.92; N, 8.23; found: C, 80.88; H, 5.89; N, 8.17. HPLC (Method-B) Rt = 2.770 min (>95%). 2.770 min (>95%).
