Ammonium Chloride → 5-bromo-1H-indole-2-carboxamide

Participants

Reaction Steps

To a solution of 5-bromo-1H-indole-2-carboxylic acid (4 g, 16.7 mmol) in DMF (50 ml) at room temperature was added diisopropylethylamine (DIPEA) (5.71 ml, 32.8 mmol), PyBOP (13 g, 25.0 mmol) and HOBT (3.39 g, 25.0 mmol). After stirring the mixture for 30 minutes, NH4Cl (1.75 g, 32.8 mmol) was added and the resulting yellow suspension was stirred at room temperature for 6 hours. The reaction was quenched by addition of H2O. The yellow foamy precipitate was discarded and the mother liquor was extracted with EtOAc. The organic layers were combined, washed with NaOH (1M) and brine, dried over Na2SO4, filtered and concentrated. The residue was then dissolved in EtOAc and washed with HCl (1 M) and brine, dried over Na2SO4, filtered and concentrated. The oily residue was triturated with DCM affording, after filtration, 5-Bromo-1H-indole-2-carboxylic acid amideC as a light yellow solid (2.12 g, 53% yield).

Provenance & Evidence