反应详情

2-Butyl-5-hydroxy-6-isopropyl-4-(7-methoxy-1, 1-dioxo-1,2-dihydro-1λ6-benzo[1,2,4]thiadiazin-3-yl)-2H-pyridazin-3-one (5e) (56 mg) was dissolved in 3 mL of methylene chloride. BBr3 (466 μL, 1.0 M in methylene chloride) was added and the mixture was stirred at room temperature for 1.5 hours. LC-MS result showed the incompletion of the reaction. BBr3 (0.5 mL, 1.0 M) was added and the reaction mixture was continued to shake at room temperature overnight. LC-MS confirmed that the reaction was close to completion. The reaction mixture was poured onto ice (10 mL), extracted with CHCl3 (20 mL×3). The organic layer was dried over MgSO4, filtered, concentrated under reduced pressure and further purified by flash chromatography on silica gel to give the desired product (5f) (42.2 mg) in 78.0% yield. 1H NMR (400 MHz, CDCl3): δ 7.46 (d, 1H, J=2.8 Hz), 7.16-7.26 (m, 2 H), 4.20 (t, 2H, J=7.2 Hz), 3.34 (m, J=6.8 Hz, 1H), 1.81 (m, 2H), 1.41 (m, 2H), 1.29 (d, 6H, J=6.8 Hz), 1.00 (t, 3H, J=7.4 Hz); LC-MS (ESI+): m/e=407.1 [M+1]+ (exact MS: 406.13).

1. customLC-MS result
2. customthe incompletion of the reaction
3. waitto shake at room temperature overnight
4. customwas close to completion
5. additionThe reaction mixture was poured onto ice (10 mL)
6. extractionextracted with CHCl3 (20 mL×3)
7. dry with materialThe organic layer was dried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customfurther purified by flash chromatography on silica gel