[Synthesis]
General procedure for the synthesis of 1-(4-bromophenyl)-2-methylpropan-1-one from 1-(4-bromophenyl)-2-methylpropan-1-ol: To a dichloromethane ( at 0 °C) containing 1-(4-bromophenyl)-2-methylpropan-1-ol (13.6 g, 60 mmol), ammonium acetate (13.8 g, 178 mmol) and 4?molecular sieves (30 g) ( 500 mL) suspension was added pyridinium chlorochromate (PCC, 19.2 g, 89 mmol) in batches. The reaction mixture was gradually warmed to room temperature and stirred continuously for 14 hours. Upon completion of the reaction, the mixture was filtered through a diatomaceous earth pad and washed with dichloromethane. The volatiles in the filtrate were removed under reduced pressure, and the resulting crude product was purified by silica gel column chromatography to afford 1-(4-bromophenyl)-2-methylpropan-1-one (12.7 g, 94% yield) as a light yellow oil, using dichloromethane as eluent. The product characterization data were as follows: mass spectra (GC-MS) m/z = 226 (100%, [M]+, C10H11BrO), 228 (100%, [M+2]+, C10H11BrO). 1H NMR (400 MHz, CDCl3) δ 7.81 (2H, d, J = 8.6Hz), 7.59 (2H, d, J = 8.6Hz ), 3.49 (1H, sept, J = 6.8Hz), 1.20 (6H, d, J = 6.8Hz).13C NMR (100MHz, CDCl3) δ 203.3, 135.0, 142.7, 132.0, 129.9, 127.9, 35.5, 19.1. |