Boron tribromide → 4-Chloro-1-(2,2,2-trifluoroethyl)-2-(trifluoromethyl)-1H-benzimidazol-5-ol
Reaction equation
[Cl:1][C:2]1[C:10]2[N:9]=[C:8]([C:11]([F:14])([F:13])[F:12])[N:7]([CH2:15][C:16]([F:19])([F:18])[F:17])[C:6]=2[CH:5]=[CH:4][C:3]=1[O:20]C.B(Br)(Br)Br>C(Cl)Cl>[Cl:1][C:2]1[C:10]2[N:9]=[C:8]([C:11]([F:14])([F:12])[F:13])[N:7]([CH2:15][C:16]([F:17])([F:18])[F:19])[C:6]=2[CH:5]=[CH:4][C:3]=1[OH:20]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A CH2Cl2 (15 mL) solution of 4-chloro-5-(methyloxy)-1-(2,2,2-trifluoroethyl)-2-(trifluoromethyl)-1H-benzimidazole (0.14 g, 0.422 mmol) at rt was treated dropwise with BBr3 (1M CH2Cl2, 1.055 ml, 1.055 mmol) and stirred for 2 h. The mixture was quenched with saturated aqueous NaHCO3, adjusted to a pH of 7, and extracted with CH2Cl2. The combined organic portions were washed combined with brine, dried over Na2SO4, filtered, and concentrated in vacuo. Purification (SiO2; EtOAc/hexanes) afforded the title compound (0.103 g): MS (ESI) m/z 319 (M+1).