反应详情

The product of Example 18A (0.98 g, 2.53 mmol) was treated with trifluoroacetic acid and dichloromethane (1:1 v/v, 20 mL) for 2 hours at room temperature. The solvent was removed by rotary evaporation and the resulting oil was chased with benzene/dichloromethane (3 times) to give a waxy solid. The salt was dissolved in anhydrous methanol (20 mL) and stirred with Amberlite IRA-400(OH), resin (10 g) for 2 hrs. The resin was removed by vacuum filtration and thoroughly washed with dry methanol. The filtrate was concentrated by rotary evaporation to give the title compound (0.415 g, 88%). MS (DCI/NH3) M/z 187/189 (M+H)+; 1H NMR (300 MHz, DMSO-d6) δ 3.73 (s, 2H), 8.02 (t, J=2.02 Hz, 1H), 8.50 (d, J=1.47 Hz, 1H), 8.53 (d, J=2.21 Hz, 1H).

1. customThe solvent was removed by rotary evaporation
2. customto give a waxy solid
3. customThe resin was removed by vacuum filtration
4. washthoroughly washed with dry methanol
5. concentrationThe filtrate was concentrated by rotary evaporation