Sulfuric Acid → 2-Bromo-12H-chromeno[2,3-b]quinolin-12-one
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([NH:12][C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1)=[C:6]([CH:19]=O)[C:5]2=[O:21].OS(O)(=O)=O>>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]1=[N:12][C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=3[CH:19]=[C:6]1[C:5]2=[O:21]Participants
3
Procedure
To the product of Step A (1 g; 2.92 mmol) concentrated H2SO4 (1 ml) was gently added with stirring. The mixture was kept in sealed vial for 24 h, at room temperature, than poured onto ice water and extracted with CH2Cl2 (50 ml). The organic layer was washed with NaHCO3 solution, H2O, dried over MgSO4 and filtered. The filtrate was distilled off and the residue was crystallized from CH3CN to give the title compound (0.73 g, 77%), as green yellow solid. 1H-NMR (CDCl3) 9.28 (s, 1H); 8.44 (d, 1H, J=2.1 Hz); 8.1-8.06 (m, 2H); 7.94-7.84 (m, 2H); 7.63 (t, 1H, J=7.88 Hz); 7.51 (d, 1H, J=8.83 Hz).
Workup
- custom