Phenyltrimethylammonium bromide dibromide → HCID 22473879, Verbindung

Phenyltrimethylammonium tribromide (1.47 g) was added in portions under nitrogen at 0° C. over 10 minutes to a stirred solution of 1-(4-methylbenzo[b]thiophen-2-yl)propan-1-one (0.53 g) in tetrahydrofuran (15 ml), then the mixture was stirred at 0° C. for 3 hours and at ambient temperature for 16 hours. Further phenyltrimethylammonium tribromide (0.49 g) was added, then the mixture was stirred at ambient temperature for 26 hours and filtered. The solvent was removed in vacuo and the residue was purified by flash chromatography over silica using a 4:1 mixture of petroleum ether (b.p. 60-80° C.) and dichloromethane as eluant. Appropriate fractions were combined and the solvents removed in vacuo to give 2-bromo-1-(4-methylbenzo[b]thiophen-2-yl)propan-1-one (0.3 g) as a yellow solid which was used without further purification.