N-bromobutanimide → Methyl 6-((4-bromophenyl)amino)-7-fluoro-1H-benzo[d]imidazole-5-carboxylate

Participants

Reaction Steps

7-Fluoro-6-phenylamino-3H-benzoimidazole-5-carboxylic acid methyl ester (4.99 g, 17.51 mmol) was dissolved in N,N-dimethylformamide (275 ml). N-bromosuccinimide (3.15 g, 17.70 mmol) was added as a solid and the reaction mixture was stirred at room temperature under N2. After 30 minutes, the reaction mixture was quenched by the addition of aqueous saturated sodium bisulfite solution. The reaction mixture was then poured into a separatory funnel, diluted with water and ethyl acetate and the layers separated. The aqueous layer was extracted with ethyl acetate. The combined organic extracts were washed three times with water, once with brine and then dried (Na2SO4) and concentrated under reduced pressure to yield 6.38 g (100%) of the pure desired product as a tan solid. MS ESI (+) m/z 364, 366 (M+Br pattern) detected.

Provenance & Evidence