A solution of methyl [4-(4-bromomethyl-3-isopropyl-phenylethynyl)-phenyl]-acetate (Intermediate 156, 72.0 mg, 0.19 mmol) and 1-acetylimidazole (22.0 mg, 0.20 mmol) in 5 mL CH3CN was heated at 65° C. for 8 h and then at 55° C. for 16 hours. The solution was cooled to room temperature, diluted with H2O and made basic by addition of Na2CO3, and extracted with EtOAc. The combined organic layers were washed with H2O and saturated aqueous NaCl, dried (MgSO4), and concentrated under reduced pressure. Column chromatography (0.5% Et3N in 5% MeOH-EtOAc) afforded 40.0 mg (58%) of the title compound as a colorless solid.
