反应详情

2-(3-Methoxy-2-nitrophenyl)-4-oxo-4H-[1]benzopyran (1.73 g, 5.8 mmol) in methanol (50 mL) and THF (50 mL) is hydrogenated under pressure with RaNi (0.5 g). The solution is concentrated under reduced pressure and recrystallized from toluene to yield 2-(2-amino-3-methoxyphenyl)-4-oxo-4H-[1]benzopyran (900 mg, 58%) as a solid. 1H NMR (DMSO): δ8.07 (1H, d, J=8.0 Hz), 7.83 (1H, t, J=6.9 Hz), 7.70 (1H, d, J=7.7 Hz), 7.51 (1H, t, J=7.0 Hz), 7.09 (1H, d, J=8.0 Hz), 7.00 (1H, d, J=7.0 Hz), 6.71 (1H, t, J=8.0 Hz), 6.56 (1H, s), 5.30 (2H, s), 3.85 (3H, s).

1. concentrationThe solution is concentrated under reduced pressure
2. customrecrystallized from toluene