1-Bromo-2-methylpropane → 7-iodo-3-isobutyl-3H-benzoimidazole-5-carboxylic acid methyl ester

Participants

Reaction Steps

To a solution of 7-iodo-3H-benzoimidazole-5-carboxylic acid methyl ester (783 mg, 2.59 mmol) in DMF (50 mL) was added Cs2CO3 (1.69 g, 5.18 mmol), followed by isobutyl bromide ((0.338 mL, 3.11 mmol). The reaction mixture was stirred room temperature overnight, then partitioned between water and ethyl acetate. The organic layer was separated, dried over MgSO4, filtered and concentrated under reduced pressure. Purification of the residue by column chromatography gave 805 mg (87%) of 7-iodo-3-isobutyl-3H-benzoimidazole-5-carboxylic acid methyl ester (the regioisomer 7-iodo-1-isobutyl-1H-benzoimidazole-5-carboxylic acid methyl ester (100 mg, 11%) was recovered as separate fraction).

Provenance & Evidence