N-bromobutanimide → 2-bromo-1-(1H-pyrrol-2-yl)ethanone

Temperature

0 °C

Crude 2-[1 -(trimethyl-silanyloxy)-vinyl]-1H-pyrrole was diluted with CH2Cl2 (10 ml), cooled to 0° C., and treated with N-bromosuccinimide (1.94 mmol, 0.35 g). The resulting mixture was put in a −20° C. freezer overnight. After warming to room temperature, the mixture was diluted with ethyl acetate (75 ml), washed with saturated aqueous sodium bicarbonate (2×20 ml), brine (2×20 ml), and the organics concentrated under reduced pressure. Purification of the residue by silica gel chromatography provided 0.29 g (80%) of 2-bromo-1-(1H-pyrrol-2-yl)-ethanone. 1H NMR (CDCl3) δ7.12 (1H, dt, J=2.7, 1.3), 7.02 (1H, ddd, J=3.8, 2.4, 1.3), 6.36-6.31 (1H, m), 4.27 (2H, s).

1. temperatureAfter warming to room temperature
2. washwashed with saturated aqueous sodium bicarbonate (2×20 ml), brine (2×20 ml)
3. concentrationthe organics concentrated under reduced pressure
4. customPurification of the residue by silica gel chromatography

ORD record

ord-a1f7e3ecd762467a9cbfd07ba26dce86

Source dataset

uspto-grants-2003_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06610730B2