6-Nitro-1H-indole → 3-Bromo-6-nitro-1H-indole

Participants

Reaction Steps

Add N-bromosuccinamide (NBS) to 6-nitroindole 1 (22.72 g, 140.12 mmol) dissolved in tetrahydrofuran (600 mL) and allow the resulting mixture to stir for 18 hours. Quench the reaction mixture with saturated aqueous sodium thiosulfate solution (600 mL), dilute with ethyl acetate (EtOAc) (600 mL), and separate the layers. Sequentially, wash the organic layer with saturated aqueous sodium bisulfate (100 mL), saturated aqueous sodium bicarbonate (100 mL), water (100 mL), and brine (100 mL). Dry the resulting organic layer over Na2SO4 and filter. Concentrate the filtrate to give a yellow solid. Recrystallize the solid from dichloromethane and hexane to give 29.21 g of the title compound (86%). LRMS (API ES+)=263.0 (M+Na).

Provenance & Evidence