Reagents and instrumentation
All reagents and instrumentation were shown in Supporting information.
Synthetic procedure
Synthesis and Characterization of Compound 2. Compound 129 (557.2 mg, 2.99 mmol) and 4-hydroxy-3,5-dimethoxybenzaldehyde (546.3 mg, 3.00 mmol) were dissolved in ethanol (20 mL). Piperidine (5 drops) was then added to the above solution, and the resulting mixture was refluxed for 6 h then filtrated. The filtrate was discarded and compound 2 (934.1 mg, 89.2%) as an orange solid was collected. 1H NMR (400 MHz, DMSO-d6): δ = 8.96 (s, 1H), 7.30 (d, J = 16.0 Hz, 1H), 7.23 (d, J = 16.4 Hz, 1H), 7.04 (s, 2H), 6.83 (s, 1H), 3.82 (s, 6H), 2.61 (s, 2H), 2.54 (s, 2H), 1.02 (s, 6H) ppm. 13C NMR (100 MHz, DMSO-d6): δ = 170.7, 157.2, 148.6 (2C), 139.6, 138.5, 127.2, 126.9, 121.8, 114.6, 113.9, 106.3 (2C), 75.2, 56.5 (2C), 42.8, 38.8, 32.1, 27.9 (2C) ppm. ESI-MS: m/z 351.2 [M+H]+.
Synthesis and Characterization of SWJT-5. Compound 2 (80.8 mg, 230.6 μmol) and triethylamine (49 μL) were dissolved in dichloromethane (5.0 mL). The reaction mixture was stirred for 10 min at 0 ℃. Acryloyl chloride (43 μL) was then added to the above mixture, and the resulting solution was stirred for 30 min at room temperature. The mixture was extracted with dichloromethane (3 × 30 mL) and washed with water (3 × 30 mL) and brine (3 × 30 mL). The organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. and The resulting residue was purified by flash column chromatography (petroleum ether : ethyl acetate = 5 : 1) on silica gel to afford SWJT-5 (72.7 mg, 77.4%) as a yellow solid. 1H NMR (400 MHz, DMSO-d6): δ = 7.48 (d, J = 16.0 Hz, 1H), 7.29 (d, J = 16.0 Hz, 1H), 7.15 (s, 2H), 6.91 (s, 1H), 6.52 (d, J = 17.2 Hz, 1H), 6.42 (dd, J = 17.2, 10.0 Hz, 1H), 6.15 (d, J = 10.0 Hz, 1H), 3.82 (s, 6H), 2.61 (s, 2H), 2.56 (s, 2H), 1.04 (s, 6H) ppm. 13C NMR (100 MHz, DMSO-d6): δ = 170.8, 163.5, 156.2, 152.5 (2C), 137.9, 135.0, 134.3, 130.3, 129.2, 127.6, 123.3, 114.3, 113.6, 105.2 (2C), 77.0, 56.6 (2C), 42.8, 38.8, 32.2, 27.9 (2C) ppm. ESI-MS: m/z 405.2 [M+H]+.