Triethylamine → 5-Bromo-1-(ethylsulfonyl)indoline

Participants

Reaction Steps

5-Bromoindoline (1.98 g, 10 mmol) was dissolved in methylene chloride (100 mL) and triethylamine (4.3 mL, 30 mmol) was added. The mixture was treated with ethanesulfonyl chloride (1.41 mL, 15 mmol) and stirred for 2 hours. The mixture was diluted with methylene chloride, washed with water, 2N HCl, brine, dried over anhydrous magnesium sulfate, and concentrated. Purification via Isco chromatography (the Redisep® column, silica, 1% ethyl acetate in methylene chloride) afforded 5-bromo-1-(ethylsulfonyl)indoline (2.1 g) as a white solid. MS (EI) m/z 286.9; HPLC purity 100.0% at 210-370 nm, 10.2 min.; the Xterra® RP18 column, 3.5μ, 150×4.6 mm column, 1.2 mL/min, 85/15-5/95 (Ammonium formate buffer pH=3.5μ acetonitrile+MeOH) for 10 minutes, hold 4 minutes.

Provenance & Evidence