Reaction Steps
To a solution in which the 2-hydroxy-4-(isopropyl(prop-2-ynyl)amino)benzaldehyde (1.8 g, 8.28 mmol) compound of Chemical Formula 4 was dissolved in ethanol (15 mL), ethyl 2-(benzo[d]thiazol-2-yl)acetate (1.83 g, 8.28 mmol) and piperidine (1.63 mL, 16.56 mmol) were added consecutively at room temperature. The reaction mixture was heated under reflux for 2 hours, cooled to room temperature, and 3-(benzo[d]thiazol-2-yl)-7-(isopropyl(prop-2-ynyl)amino)-2H-chromen-2-one (1.54 g, 50%) was obtained by filtering the precipitated solid. 1H NMR (500 MHz, CDCl3) d 8.94 (s, 1H), 8.02 (d, 1H, J=8.2 Hz), 7.94 (d, 1H, J=7.8 Hz), 7.54 (d, 1H, J=8.7 Hz), 7.47-7.50 (m, 1H), 7.35-7.38 (m, 1H), 6.88 (dd, 1H, J=2.3, 8.7 Hz), 6.80 (d, 1H, J=2.3 Hz), 4.21-4.26 (m, 1H), 4.04 (d, 2H, J=2.3 Hz), 2.26 (t, 1H, J=2.2 Hz), 1.34 (d, 6H, J=6.4 Hz); 13C NMR (125 MHz, CDCl3) d 161.5, 161.0, 156.7, 152.6, 152.4, 142.0, 136.4, 130.6, 126.2, 124.7, 122.3, 121.7, 113.9, 111.0, 109.8, 98.8, 80.0, 72.3, 49.5, 33.5, 20.2 (2).
