1,2-Dibromoethane → 1h-Indole-1-carboxylic acid,7-bromo-2,3-dihydro-5-methoxy-,1,1-dimethylethyl ester

Participants

Reaction Conditions

Reaction Steps

To 1-(tert-Butoxycarbonyl)-5-methoxyindoline (2.0 g) and TMEDA (1.57 mL, 1.3 eq.) in ether (40 mL) at −78° C. was added sec-BuLi (7.4 mL, 1.2 eq.). The reaction was warmed to −40° C. for 2 hours and then cooled to −78° C. 1,2-dibromoethane (2.07 mL, 3 eq.) was added and the reaction stirred for 45 minutes at −78° C. The bath was then removed and the reaction was stirred for 1 hour. The reaction was quenched with water and extracted with ether. The ether was washed with brine, dried over MgSO4, and concentrated. The crude product was chromatographed on silica gel, using hexane/ethyl acetate (19:1) as eluent, affording 1-(tert-butoxycarbonyl)-7-bromo-5-methoxyindoline (1.16 g).

Provenance & Evidence