Sodium Carbonate → 7-Bromo-5-chloro-1H-benzimidazole

Participants

Reaction Conditions

Reaction Steps

A mixture of 109b (4.3 g, 19.5 mmol) in formic acid (10 mL) was heated at 80° C. for 1 h. After cooled to room temperature, the reaction mixture was poured into aqueous Na2CO3 (30 mL) and the mixture was extracted with ethyl acetate (30 mL×3). The combined organic phase was dried over anhydrous Na2SO4, filtered, and evaporated under reduced pressure to afford 109c as a brown solid (3.5 g, 77%). LCMS: [M+H]+ 233. 1H NMR (500 MHz, CDCl3) δ 10.05 (bs, 1H), 8.18 (s, 1H), 7.64 (bs, 1H), 7.50 (s, 1H).

Provenance & Evidence