Dimethyl Sulfoxide → 4-Bromo-3'-methoxybenzophenone

To a solution of DMSO (8.13 mL, 114.7 mmol) in CH2Cl2 (80 mL) at −78 was added solution of trifluoroacetic acid (TFAA) (12.12 mL, 86.0 mmol) in CH2Cl2 (50 mL) over 5 min. The mixture was stirred for 20 min and a solution of (4-bromo-phenyl)-(3-methoxy-phenyl)-methanol (16.8 g, 57.4 mmol) in CH2Cl2 (50 mL) was added dropwise over 5 min. The reaction mixture was stirred at −78° C. for 30 min and Et3N (24.0 mL, 172 mmo) was added. The mixture was stirred at −78° C. for an additional 30 min and at room temperature for 1 h. The CH2Cl2 layer was washed with brine (3×30 mL), dried over Na2SO4 and concentrated. Purification with hexanes/EtOAc (10:1) afforded 16.0 9 of (4-Bromo-phenyl)-(3-methoxy-phenyl)-methanone. 1HNMR (400 MHz, CDCl3) δ 7.67-7.66 (comp, 2H), 7.64-7.60 (comp, 2H), 7.37 (m, 1H), 7.34-7.27 (comp, 2H), 7.14-7.11 (m, 1H), 3.84 (s, 3H).