A mixture of 2-bromo-1-(4-methylsulfonylphenyl)-propan-1-one (prepared using the methodology of WO 9500501, Ex. 9 Step 1) (8.7 g) and phenyl acetic acid (5 g) in 150 mL of CH3CN was treated with 8.5 mL of Et3N. The reaction mixture was stirred overnight at r.t. and then 12 mL of DBU was added dropwise over 2 min. After stirring for 1 h at r.t. O2 was bulbed into the mixture until it became colorless (in 45 min.). The reaction mixture was then poured into a solution of 80 mL 1N HCl and 100 mL of brine, and extracted with 500 mL of 1:1 EtOAc/hexane. The extract was dried over MgSO4, filtered and concentrated. The crude product was swished from 1:4 EtOAc/hexane (200 mL) to give 7.2 g of the title product as a white solid.
