反应详情

A mixture of the product of Step A (0.2 g; 1.41 mmol), HCl×H2NOH (0.36 g; 5.2 mmol), and Na2CO3 (0.26 g; 2.44 mmol) in H2O (8 ml) and EtOH (2 ml) was gently stirred for 10 min, then refluxed overnight under N2. After cooling most of the ethanol was removed under reduced pressure and the product was extracted with EtOAc (20 ml). The organic phase was separated, dried over anhydrous MgSO4 and filtered. The filtrate was evaporated to dryness under reduced pressure to give the title compound (0.23 g; 92%), as a creamy foam. 1H-NMR (CDCl3+CD3OD) 1.71 (broad s, H2O); 4.93* (broad s, 0.5H); 6.55 (d, 1H, J=3 Hz); 7.21 (d, 1H, J=3 Hz); 7.28-7.42 (m, 2H); 7.87 (d, 1H, J=1 Hz); 8.63* (broad s, 0.3H).

1. temperaturerefluxed overnight under N2
2. customwas removed under reduced pressure
3. extractionthe product was extracted with EtOAc (20 ml)
4. customThe organic phase was separated
5. dry with materialdried over anhydrous MgSO4
6. filtrationfiltered
7. customThe filtrate was evaporated to dryness under reduced pressure