反应详情

A suspension of (E)-tert-butyl 3-(7-oxo-7,8-dihydro-1,8-naphthyridin-3-yl)acrylate (500 mg, 1.84 mmol) in CH2Cl2 (7 mL) was treated with trifluoroacetic acid (7 mL). The mixture became homogeneous and it was stirred at room temperature for 1 h. The solution was concentrated to dryness and treated with 4M HCl in dioxane (5 mL). The suspension was sonicated for 20 min, diluted with Et2O (50 mL) and sonicated for an additional 20 min. The solid was filtered and dried under reduced pressure overnight. Yield: 450 mg (96.8%) 1H-NMR (300 MHz, DMSO-d6) δ 12.4 (br s, 1H), 8.82 (s, 1H), 8.52 (s, 1H), 7.91 (d, 1H, J=9.0 Hz), 7.67 (d, 1H, J=15.0 Hz), 6.67 (d, 1H, J=15.0 Hz), 6.61 (m, 1H); ESI MS m/z 217 [C11H8N2O3+]+

1. concentrationThe solution was concentrated to dryness
2. additiontreated with 4M HCl in dioxane (5 mL)
3. customThe suspension was sonicated for 20 min
4. additiondiluted with Et2O (50 mL)
5. customsonicated for an additional 20 min
6. filtrationThe solid was filtered
7. customdried under reduced pressure overnight