N-bromobutanimide → 3-bromo-1-(4-fluorophenyl)-2-methyl-5-[4-(methylsulfonyl)phenyl]-1H-pyrrole

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(4-fluorophenyl)-2-methyl-5-[4-(methylsulfonyl)phenyl]-1H-pyrrole (Example 1) (3.3 g, 10 mmol) in THF (80 ml) at -70° C., N-bromosuccinimide (1.78 g, 10 mmol) was added over 10 minutes. The reaction was warmed to 20° C. over 3 hours and stirred for 18 hours. After dilution with aqueous sodium bicarbonate, the mixture was extracted with ethyl acetate. The organic fractions were washed with water, dried (MgSO4), filtered and concentrated. The crude yellowish liquid (4.52 g) was purified by chromatography (silica gel, hexane/ethyl acetate, 7/3) to give 3-bromo-1-(4-fluorophenyl)-2-methyl-5-[4-(methylsulfonyl)phenyl]-1H-pyrrole (3.6 g, 88%): mp (DSC) 153° C. Anal Calc'd. for C18H15NSBrFO2 : C, 52.95; H, 3.70; N, 3.43; S, 19.53. Found: C, 53.01; H, 3.93; N, 3.39; S, 19.06.

Provenance & Evidence