N-bromobutanimide → 5-bromo-7-fluoro-2,3-dihydro-1H-indole

Temperature

0 °C

7-Fluoroindoline (1.1 g, 8.0 mmol) was dissolved in acetonitrile (80 mL), cooled to 0° C., and N-bromosuccinimide (1.43 g, 8.0 mmol) was added. The mixture was warmed to 25° C. and stirred for 3 hours. The mixture was concentrated to 10 mL and diluted with ethyl acetate and washed with NaHCO3, water, brine, dried over anhydrous magnesium sulfate, and concentrated. Purification via Isco chromatography (the Redisep® column, silica, gradient 5%-15% ethyl acetate in hexane) afforded 5-bromo-7-fluoroindoline (1.05 g). MS (ES) m/z 215.8; HPLC purity 97.6% at 210-370 nm, 10.5 min.; the Xterra® RP18 column, 3.5μ, 150×4.6 mm column, 1.2 mL/min, 85/15-5/95 (Ammonium formate buffer pH=3.5 acetonitrile+MeOH) for 10 minutes, hold 4 minutes.

1. temperatureThe mixture was warmed to 25° C.
2. concentrationThe mixture was concentrated to 10 mL
3. additiondiluted with ethyl acetate
4. washwashed with NaHCO3, water, brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. customPurification via Isco chromatography (the Redisep® column, silica, gradient 5%-15% ethyl acetate in hexane)

ORD record

ord-a05fd7e085104285a8551e12552e941c

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07750038B2