A stirred, cooled (ice bath) solution of [4-(5-tert-butyl-3-hydroxymethyl-4-isopropoxy-2-methyl-phenylethynyl)-phenyl]-acetic acid methyl ester (Intermediate 147, 0.15 g, 0.37 mmol) and triphenylphosphine (0.125 g, 0.48 mmol) in anhydrous dichloromethane (5 mL) was treated with N-bromo succinimide (0.085 g, 0.48 mmol) under argon and the resulting reaction mixture was allowed to warm to ambient temperature and stirred overnight. The reaction mixture was quenched with dilute, aqueous sodium bicarbonate solution and extracted with diethyl ether. The organic phase was washed with water (×1) and brine (×1), dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo to a residue that on flash column chromatography over silica gel (230–400 mesh) using 4–5% ethyl acetate in hexane as the eluent afforded the title compound (0.12 g, 69%) as a colorless oil. It was used as such for the next step.
