Synthesis
General procedure: 4-methylstyrene (1 mmol) was dissolved in a solvent mixture of acetone (3 mL) and water (0.1 mL) at room temperature. Subsequently, dibromo-p-toluenesulfonamide (TsNBr2, 2.2 mmol) was slowly added to this solution. After the reaction was complete, sodium thiosulfate (~200 mg) was added to quench the reaction and stirring was continued for 10 minutes. The reaction mixture was extracted with ethyl acetate and the organic phase was dried over anhydrous sodium sulfate (Na2SO4) and subsequently concentrated under reduced pressure to remove the solvent. The crude product was purified by column chromatography on silica gel (230-400 mesh), the eluent being a mixed petroleum ether-ethyl acetate solvent, to give the final pure 2-bromo-4'-methylacetophenone.
References
[1] Tetrahedron Letters, 2015, vol. 56, # 2, p. 356 - 358
[2] Organic and Biomolecular Chemistry, 2016, vol. 14, # 48, p. 11389 - 11395
[3] Green Chemistry, 2013, vol. 15, # 8, p. 2175 - 2179
[4] Synlett, 2010, # 15, p. 2335 - 2339
[5] Organic Letters, 2015, vol. 17, # 11, p. 2704 - 2707
