A mixture of 4-(5-bromo-2-hydroxy-phenylethynyl)-piperidine-1-carboxylic acid tert-butyl ester (70 mg), copper iodide (9 mg), N,N-dimethylformamide (1 mL), triethylamine (100 μL), and Pd(PPh3)2Cl2 (7 mg) is heated under an argon atmosphere to 55° C. for 0.5 h. The reaction mixture is diluted with ice water after cooling to room temperature and extracted with ethyl acetate. The combined extracts are dried over MgSO4 and concentrated in vacuo. The residue is chromatographed on silica gel (cyclohexane/ethyl acetate 80:20→50:50) to give the title compound. LC (method 2): tR=1.49 min; Mass spectrum (ESI+): m/z=380, 382 [M+H]+.
