反应详情

温度

60 °C

To a three-necked flask equipped with a magnetic stir bar was added 4′-iodo-2-nitrobiphenyl (1.63 g, 5.0 mmol, 1.0 equiv), benzo[d]oxazole (0.72 g, 6.0 mmol, 1.2 equiv), Ag2CO3 (2.76 g, 10.0 mmol, 2.0 eq), Pd(dppf)Cl2.CH2Cl2 (0.20 g, 0.25 mmol, 0.05 eq) and PPh3 (0.13 g, 0.5 mmol, 0.1 eq). The tube was evacuated and back-filled with nitrogen and this evacuation/back-fill procedure was repeated twice. Then solvent CH3CN (25 mL) was added under the protection of nitrogen. The mixture was stirred in an oil bath at a temperature of 55-65° C. for 4 days and then cooled. The solid was filtered off through a pad of celite and washed with ethyl acetate. The filtrate was concentrated under reduced pressure and the residue was purified through column chromatography on silica gel using hexane and ethyl acetate (10:1-5:1) as an eluent to afford the desired product 2-(2′-nitrobiphenyl-4-yl)benzo[d]oxazole (0.85 g in 54% yield). 1H NMR (DMSO-d6, 400 MHz): δ 7.43-7.49 (m, 2H), 7.61-7.63 (m, 2H), 7.66 (d, J=7.6 Hz, 1H), 7.69-7.73 (m, 1H), 7.83-7.87 (m, 3H), 8.08 (d, J=8.8 Hz, 1H), 8.30 (dd, J=8.0, 1.2 Hz, 2H).

1. customTo a three-necked flask equipped with a magnetic stir bar
2. customThe tube was evacuated
3. additionback-filled with nitrogen
4. additionThen solvent CH3CN (25 mL) was added under the protection of nitrogen
5. temperaturecooled
6. filtrationThe solid was filtered off through a pad of celite
7. washwashed with ethyl acetate
8. concentrationThe filtrate was concentrated under reduced pressure
9. customthe residue was purified through column chromatography on silica gel