2-Acetylbenzothiophene → 1-(1-Benzothiophen-2-yl)-2-bromoethan-1-one

Participants

Reaction Steps

Phenyltrimethylammonium tribromide (32.04 g) was added in portions under nitrogen at 0° C. over 10 minutes to a stirred solution of 1-(benzo[b]thiophen-2-yl]ethan-1-one (15.0 g) in tetrahydrofuran (400 ml), the mixture was stirred at ambient temperature for 5 hours, then it was filtered and the solvent was removed in vacuo. The residue was triturated with a 9:1 mixture of petroleum ether (b.p. 60-80° C.) and ethyl acetate (50 ml) and the resulting solid was collected by filtration and dried in vacuo to give 1-(benzo[b]thiophen-2-yl)-2-bromoethan-1-one (24.40 g) as a brown solid which was used without further purification.

Provenance & Evidence