A mixture of (1-bromo-naphthalen-2-yloxy)-acetic acid tert-butyl ester (Intermediate 217; 500 mg; 1.48 mmol), 1-ethynyl-3-(propane-1-sulfonyl)-benzene (618 mg; 2.97 mmol) and PPh3 (39 mg; 0.15 mmol) in water (4.40 ml) and Acetone (5.6 ml) was treated with palladium(II) chloride (13 mg; 0.07 mmol) and piperidine (295 μl; 2.97 mmol) and heated at 60° C. for 2 days. The reaction mixture was extracted with EtOAc, the organic phase was dried over MgSO4 and concentrated under reduced pressure. The resulting residue was purified by flash column chromatography (silica), eluting with cyclohexane containing increasing amounts of EtOAc to give the title compound as a yellow sticky solid.
