Ethyl 1H-indole-3-acetate → tert-butyl 2-bromo-3-(2-ethoxy-2-oxoethyl)-1H-indole-1-carboxylate

Participants

Reaction Steps

To a solution of ethyl 2-(1H-indol-3-yl)acetate (5 g, 24.6 mmol) in 25 ml of DCM was added N-bromosuccinimide (4.38 g, 24.6 mmol) in small portions at 0° C. The mixture was warmed to room temperature and stirred for 6 hours. Di-tert-butyl pyrocarbonate (10.74 g, 49.2 mmol), DIPEA (8.6 ml, 49.5 mmol) and DMAP (cat) was added to the mixture. The reaction was stirred overnight. The mixture was diluted with DCM (100 ml) and washed with HCl (0.5 N, 2×50 ml). The organic layer was dried with Na2SO4, filtered and concentrated. The crude product was introduced to a silica gel loading column and purified by column chromatography on silica (5-20 EtOAc/hexanes) to get 6.3 g (16.5 mmol) of product. MS (m/z) 382 [M+H]+.

Provenance & Evidence