反应详情

To a suspension of XXIV (235 mg, 0.62 mmol) in MeOH (3 mL) and ethyl acetate (3 mL) was added 10% Pd—C (47 mg) under nitrogen atmosphere. The resulting mixture was hydrogenated at rt overnight. The catalyst was removed by filtration under nitrogen and washed with methanol, the filtrate was concentrated under reduced pressure to give a white solid. MS (ES, Pos.): m/z 260 [MH+]. The hydrogenation product was suspended in trimethyl orthoformate (5 mL), and p-toluenesulfonic acid monohydrate (12 mg, 0.062 mmol) was added. The resulting mixture was stirred at rt overnight. The white solid was collected by filtration. MS (ES, Pos.): m/z 270 [MH+]. 1H NMR (CD3OD, 400 MHz): δ=3.99 (s, 3H), 7.00 (d, J=8.8 Hz, 2H), 7.59 (d, J=8.8 Hz, 2H), 8.71 (d, J=1.8 Hz, 1H), 8.72 (s, 1H), 9.05 (d, J=1.8 Hz, 1H).

1. customThe catalyst was removed by filtration under nitrogen
2. washwashed with methanol
3. concentrationthe filtrate was concentrated under reduced pressure
4. customto give a white solid
5. filtrationThe white solid was collected by filtration