N-bromobutanimide → 4-Bromo-2-(4-fluorophenyl)-3-(pyridin-4-yl)-1-triisopropylsilyl-1H-pyrrole

Participants

Reaction Steps

A suspension of 8.61 g (47.4 mmol) of N-bromosuccinimide in 100 ml of tetrahydrofuran was added to a solution of 18.70 g (47.4 mmol) of 2-(4-fluorophenyl)-3-(pyridin-4-yl)-1-triisopropylsilyl-1H-pyrrole [prepared as described in step 7(ii) above] in 300 ml of tetrahydrofuran at −78° C., after which the resulting mixture was stirred at the same temperature for 6 hours. After removal of the cooling bath, the mixture was then stirred at room temperature for a further 1 hour. At the end of this time, 400 ml of hexane was added to the reaction mixture and the insoluble material was removed by filtration. The resulting filtrate was concentrated by evaporation under reduced pressure and the residue thus obtained was purified by chromatography on a silica gel column using a 2:1 by volume mixture of hexane and ethyl acetate as the eluant to give 9.57 g (yield 43%) of the title compound as pale yellow prismatic crystals.

Provenance & Evidence