Hydrogen Bromide → 2-Bromo-6-fluoro-1,3-benzothiazole
反応式
N[C:2]1[S:3][C:4]2[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:5]=2[N:6]=1.N([O-])=O.[Na+].[BrH:16]>O.[Cu]Br>[Br:16][C:2]1[S:3][C:4]2[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:5]=2[N:6]=1N[C:2]1[S:3][C:4]2[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:5]=2[N:6]=1.N([O-])=O.[Na+].[BrH:16]>O.[Cu]Br>[Br:16][C:2]1[S:3][C:4]2[CH:10]=[C:9]([F:11])[CH:8]=[CH:7][C:5]=2[N:6]=1Slurry 2-amino-6-fluorobenzothiazole (0.255mol) in water (325mL), heat to reflux and add 48% hydrobromic acid (130mL). Maintain at reflux for 20 minutes, cool to 0° C. and add a solution of sodium nitrite (17.56g, 0.255mol) in water (90mL), maintaining a temperature of 0° C. Stir at 0° C. for 15 minutes and add by dropwise addition (while keeping cold) to a rapidly stirring mixture of copper (I) bromide (42.03g,0.293mol) in 48% hydrobromic acid (86mL) and water (225mL). Stir at room temperature for 20 minutes. Allow to stand overnight, extract into methylene chloride and dry (MgSO4). Evaporate the solvent in vacuo and purify by chromatography to give 2-bromo-6-fluorobenzothiazole.
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