Reagents and Apparatus
All chemicals were obtained from commercial suppliers and directly used without further purification. 7-(diethylamino)coumarin-3-carbohydrazide was prepared according to the literature method [16]. Analytical grade acetonitrile and deionized water were used as solvents for spectral measurements. 1H NMR and 13C NMR spectra were recorded on a Bruker Av400 NMR spectrometer. HRMS spectra were performed on a Shimadzu LCMS-IT-TOF apparatus. Fluorescence spectra were taken on a Hitachi F-7000 fluorescence spectrometer. The X-ray diffraction data was collected on an Agilent Gemini A Ultra diffractometer (MoKα, λ = 0.71073 Å). Images of cells were obtained using a Nikon A1 confocal laser scanning microscope.
General Procedure for the Synthesis of Target Compounds
As shown in Scheme 1, 7-(diethylamino)coumarin-3-carbohydrazide (550.6 mg, 2.0 mmol) and one of the aromatic aldehydes (2.0 mmol) were dissolved in absolute ethanol (6 mL). the mixture was stirred at 70 °C for 5 h. In the meanwhile, massive amounts of solid product precipitated out, which was collected by filtration and then washed several times with a small amount of ethanol to afford the target compounds (CFH-1, 2, 3 and 4) respectively. All the structures of them were characterized by NMR and HRMS (Fig. S1–S12).
(E)-7-(diethylamino)-N'-(4-(dimethylamino)benzylidene)coumarin-3-carbohydrazide (CFH-1): orange powder, yield: 84.0 %, 1H NMR (400 MHz, CDCl3) δ 11.70 (s, 1H), 8.85 (s, 1H), 8.09 (s, 1H), 7.70 (d, 2H, J = 8.4 Hz), 7.47 (d, 1H, J = 9.0 Hz), 6.73–6.66 (m, 3H), 6.52 (s, 1H), 3.47 (q, 4H, J = 6.8 Hz), 3.03 (s, 3H), 1.25 (t, 6H, J = 6.8 Hz). 13C NMR (101 MHz, CDCl3) δ 162.8, 159.3, 157.7, 152.7, 151.9, 149.4, 148.7, 131.3, 129.4, 111.7, 110.1, 109.5, 108.6, 100.0, 96.6, 45.2, 40.2, 12.4. HRMS m/z calculated for [M+H]+ 407.2083, found 407.2009.
(E)-7-(diethylamino)-N'-(4-(diphenylamino)benzylidene)coumarin-3-carbohydrazide (CFH-2): green-yellow powder, yield: 84.0 %, 1H NMR (400 MHz, DMSO-d6) δ 11.63 (s, 1H), 8.74 (s, 1H), 8.33 (s, 1H), 7.72 (d, 1H, J = 9.2 Hz), 7.61 (d, 2H, J = 8.4 Hz), 7.35 (t, 4H, J = 7.6 Hz), 7.14–7.08 (m, 6H), 7.95 (d, 2H, J = 8.4 Hz), 6.83 (d, 1H, J = 9.2 Hz), 3.49 (q, 4H, J = 6.8 Hz), 1.15 (t, 6H, J = 6.8 Hz). 13C NMR (101 MHz, DMSO-d6) δ 162.1, 159.2, 157.8, 153.2, 149.5, 148.8, 148.5, 147.0, 132.2, 130.2, 129.0, 127.9, 125.5, 124.5, 121.8, 110.8, 109.1, 108.4, 96.4, 44.9, 12.8. HRMS m/z calculated for [M+H]+ 531.2396, found 531.2307.
(E)-7-(diethylamino)-N'-((6-methoxynaphthalen-2-yl)methylene)coumarin-3-carbohydrazide (CFH-3): yellow powder, yield: 82.4 %, 1H NMR (400 MHz, CDCl3 ) δ 11.90 (s, 1H), 8.88 (s, 1H), 8.32 (s, 1H), 8.08 (dd, 1H, J1 = 8.4 Hz, J2 = 1.6 Hz), 8.01 (s, 1H), 7.78 (d, 1H, J = 8.4 Hz), 7.75 (d, 1H, J = 8.4 Hz), 7.51 (d, 1H, J = 8.9 Hz), 7.18–7.15 (m, 2H), 6.74 (dd, 1H, J1 = 8.4 Hz, J2 = 2.4 Hz), 6.60 (d, 1H, J = 2.4 Hz), 3.49 (s, 3H), 3.48 (q, 4H, J = 7.0 Hz), 1.26 (t, 6H, J = 7.0 Hz). 13C NMR (101 MHz, CDCl3) δ 162.8, 159.7, 158.8, 157.8, 149.1, 149.0, 136.0, 131.5, 130.1, 129.6, 129.1, 128.6, 127.4, 124.6, 119.3, 110.7, 109.7(4), 109.7(0), 109.2, 106.2, 97.3, 55.5, 45.6, 12.4. HRMS m/z calculated for [M+H]+ 444.1923, found 444.1844.
(E)-7-(diethylamino)-N'-(quinolin-2-ylmethylene)coumarin-3-carbohydrazide (CFH-4): yellow powder, yield: 80.5 %, 1H NMR (400 MHz, CDCl3 ) δ 11.99 (s, 1H), 8.78 (s, 1H), 8.57 (s, 1H), 8.43 (d, 1H, J = 8.6 Hz), 8.12 (d, 1H, J = 8.6 Hz), 8.05 (d, 1H, J = 8.2 Hz), 8.02 (d, 1H, J = 8.2 Hz), 7.81 (t, 1H, J = 7.0 Hz), 7.75 (d, 1H, J = 9.0 Hz), 7.65 (t, 1H, J = 7.0 Hz), 6.85 (dd, 1H, J1 = 9.0 Hz, J2 = 2.0 Hz), 6.67 (d, 1H, J = 2.0 Hz), 3.51 (q, 4H, J = 7.0 Hz), 1.16 (t, 6H, J = 7.0 Hz). 13C NMR (101 MHz, DMSO-d6) δ 160.8, 159.3, 157.2, 153.7, 152.4, 148.7, 148.1, 146.5, 136.7, 131.9, 130.1, 128.9, 128.0, 127.9, 126.5, 116.7, 111.7, 168.5, 107.9, 97.2, 44.9, 13.6. HRMS m/z calculated for [M+H]+ 415.1770, found 445.1701.